TWI861019B - Semiconductor device manufacturing method - Google Patents

Abstract

The subject of the present invention is to provide a method for manufacturing a semiconductor device, which protects the bump neck of a semiconductor wafer having bumps by forming a protective film containing a curable resin layer, while achieving both thinning of the semiconductor wafer and suppression of warping of the semiconductor wafer. Moreover, the manufacturing method of the semiconductor device includes the following steps (A) to (E) in sequence: (A) forming a hardening resin layer on the bump forming surface of a semiconductor wafer having bumps, (B) hardening the hardening resin layer to form a protective film, (C) attaching a back grinding tape to the protective film forming surface of the semiconductor wafer having bumps, (D) grinding the opposite surface of the bump forming surface of the semiconductor wafer having bumps while the back grinding tape is attached, (E) peeling off the back grinding tape from the semiconductor wafer having bumps after grinding.

Description

Semiconductor device manufacturing method

The present invention relates to a method for manufacturing a semiconductor device.

In recent years, the manufacture of semiconductor devices using a mounting method called a flip-chip method has been carried out. In the flip-chip method, a semiconductor chip (hereinafter simply referred to as a "chip") having a bump on the circuit surface and a substrate for mounting the chip are stacked in such a way that the circuit surface of the chip and the substrate face each other, and the chip is mounted on the substrate. Furthermore, the chip is usually obtained by singulating a semiconductor wafer having bumps on the circuit surface. In the following description, a semiconductor wafer is also simply referred to as a "wafer". In addition, a semiconductor wafer having bumps on the circuit surface is also referred to as a "wafer with bumps". In addition, the circuit surface of the wafer with bumps is also referred to as a "bump forming surface".

In addition, a protective film is provided on a wafer with bumps for the purpose of protecting the joint between the bump and the wafer (hereinafter also referred to as the "bump neck"). For example, in Patent Document 1, a laminate formed by sequentially laminating a supporting substrate, an adhesive layer, and a thermosetting resin layer is pressed onto the bump-forming surface of a wafer with bumps using the thermosetting resin layer as a bonding surface, and then the thermosetting resin layer is heated to harden and form a protective film. Prior Art Documents Patent Documents

Patent document 1: Japanese Patent Application Publication No. 2015-092594

Invent the problem you want to solve

In recent years, with the improvement of the performance of electronic devices and the expansion of the IoT (Internet of Things) market, there is a demand for high-density chip mounting. As one of the countermeasures to this demand, the thinning of the chip can be cited. As one of the methods for thinning the chip, a method for thinning the wafer with bumps by grinding the back side of the wafer with bumps can be cited. In Patent Document 1, it is described that the back side of the wafer with bumps is ground while the aforementioned laminate is attached to the bump forming surface of the wafer with bumps, and the supporting substrate and adhesive layer of the aforementioned laminate are peeled off from the thermosetting resin layer, and then the thermosetting resin layer is heated to harden it. In this specification, the so-called "back side of the wafer with bumps" means the side opposite to the bump-formed side of the wafer with bumps.

However, in recent years, the diameter of wafers used in semiconductor manufacturing processes has been increased from the perspective of improving batch processing efficiency. In addition, from the perspective of making chips lighter and thinner, there is a tendency for wafers to be thinned. Therefore, in the technology described in Patent Document 1, if a step of heating a thermosetting resin layer to harden the back of a wafer with bumps is performed after grinding the back side, warping is likely to occur in the wafer with bumps as the thermosetting resin layer shrinks. If warping occurs in a wafer with bumps, poor storage of the wafer with bumps is likely to occur in wafer carriers, wafer cassettes, wafer boats, etc., which becomes a major factor in damage to the wafer with bumps. Furthermore, during the transportation of the wafer with bumps, and more particularly during the transportation of the chips after the wafer with bumps is singulated into chips, a defect may easily occur during the adsorption of the wafer or the chips, or transportation failure may easily occur.

Furthermore, the above-mentioned problem may occur not only when the protective film is formed by heating the thermosetting resin layer and hardening it, but also when the protective film is formed from the entire curable resin layer that can shrink during curing.

The present invention is made in view of such a problem, and aims to provide a method for manufacturing a semiconductor device , which protects the bump neck of a semiconductor wafer having bumps by forming a protective film containing a curable resin layer, while achieving both thinning of the semiconductor wafer and suppression of warping of the semiconductor wafer.

The inventors of the present invention have made intensive research and found that a method for manufacturing a semiconductor device comprising the following steps (A) to (E) in sequence can solve the above-mentioned problems. That is, the present invention relates to the following [1] to [7]. [1] A method for manufacturing a semiconductor device, comprising the following steps (A) to (E) in sequence: (A) forming a hardening resin layer on a bump-forming surface of a semiconductor wafer having bumps, (B) hardening the hardening resin layer to form a protective film, (C) attaching a back grinding tape to the protective film-forming surface of the semiconductor wafer having bumps, (D) grinding the surface opposite to the bump-forming surface of the semiconductor wafer having bumps while the back grinding tape is attached, and (E) peeling off the back grinding tape from the ground semiconductor wafer having bumps. [2] A method for manufacturing a semiconductor device as described in [1] above, wherein the step (A) comprises the following steps (A1) and (A2) in sequence: (A1) a step of attaching a protective film forming laminate having a laminated structure consisting of a laminated support sheet and a curable resin layer to the bump forming surface of a semiconductor wafer having the bump, wherein the curable resin layer is used as the attachment surface; (A2) a step of peeling off the support sheet from the protective film forming laminate and forming the curable resin layer on the bump forming surface of the semiconductor wafer having the bump. [3] A method for manufacturing a semiconductor device as described in [1] or [2] above, wherein the curable resin layer is a thermosetting resin layer. [4] A method for manufacturing a semiconductor device as described in any one of [1] to [3] above, wherein the thickness of the semiconductor wafer used in the step (A) is 300 μm or more. [5] A method for manufacturing a semiconductor device as described in any one of [1] to [4] above, wherein a starting point for singulating the semiconductor wafer having the bumps is formed before the step (A), between the step (A) and the step (B), between the step (B) and the step (C), and between the step (C) and the step (D). [6] A method for manufacturing a semiconductor device as described in any one of the above [1] to [5], wherein between the above step (B) and the above step (C) and in any one of the above step (E), an exposure treatment is performed to remove the above-mentioned protective film covering the top of the above-mentioned bump or a portion of the above-mentioned protective film attached to the top of the above-mentioned bump to expose the top of the above-mentioned bump. [7] A method for manufacturing a semiconductor device as described in the above [6], wherein the above-mentioned exposure treatment is a plasma etching treatment. Effect of the invention

According to the method for manufacturing a semiconductor device of the present invention, the protective film formed by the curable resin layer can protect the bump neck of a semiconductor wafer having bumps while achieving both thinning of the semiconductor wafer and suppression of warping of the semiconductor wafer.

Embodiments of the invention [Method for manufacturing a semiconductor device of the invention]

The manufacturing method of the semiconductor device of the present invention comprises the following steps (A) to (E) in sequence: (A) forming a hardening resin layer on the bump forming surface of a semiconductor wafer having bumps, (B) hardening the hardening resin layer to form a protective film, (C) attaching a back grinding tape to the protective film forming surface of the semiconductor wafer, (D) grinding the opposite surface of the bump forming surface of the semiconductor wafer with the back grinding tape attached, (E) peeling off the back grinding tape from the semiconductor wafer after the grinding.

Below, after describing in detail the semiconductor wafer with bumps used in the method for manufacturing the semiconductor device of the present invention, each step of the method for manufacturing the semiconductor device of the present invention is described in detail.

Also, in this manual, "protective film" and "protective layer" can be referred to interchangeably.

<Semiconductor wafer with bumps>

FIG. 1 shows an example of a semiconductor wafer with bumps used in the method for manufacturing a semiconductor device of the present invention. The semiconductor wafer 10 with bumps has bumps 12 on the electrical path 11a of the semiconductor wafer 11. The bumps 12 are usually provided in plural.

In addition, similar to the definition of the above abbreviations, in the following description, "a semiconductor wafer with bumps" is also referred to as a "wafer with bumps". "Semiconductor wafer" is also referred to as a "wafer". "Electroconductive surface" is also referred to as a "bump forming surface".

The shape of the bump 12 is not particularly limited, and can be any shape as long as it can contact the electrode on the substrate for chip mounting and be fixed. For example, in FIG. 1 , the bump 12 is set to be spherical, but the bump 12 can also be a rotation ellipse. The rotation ellipse can be, for example, a rotation ellipse extending in a vertical direction with respect to the bump forming surface 11a of the wafer 11, or a rotation ellipse extending in a horizontal direction with respect to the bump forming surface 11a of the wafer 11.

There is no particular limit to the height of the bump 12, for example, 30μm~300μm, preferably 60μm~250μm, and more preferably 80μm~200μm.

Furthermore, the so-called "height of the bump 12" refers to the height of the highest position from the bump forming surface 11a when focusing on one bump.

Wafer 11 is, for example, a semiconductor wafer with circuits such as wiring, capacitors, diodes, and transistors formed on the surface. The material of the wafer is not particularly limited, and examples thereof include silicon wafers, silicon carbide wafers, compound semiconductor wafers, and sapphire wafers.

From the perspective of improving batch processing efficiency, the size of the wafer 11 is usually 8 inches (200 mm in diameter) or larger, preferably 12 inches (300 mm in diameter) or larger. In addition, the shape of the wafer is not limited to a circle, and may be a square or rectangular shape. For square wafers, from the perspective of improving batch processing efficiency, the length of the longest side of the wafer 11 is preferably larger than the above size (diameter).

The thickness of the wafer 11 is, for example, 300 μm or more, preferably 400 μm or more, more preferably 500 μm or more, and particularly preferably 600 μm or more, from the perspective of suppressing the warping of the wafer 11 accompanying the hardening of the curable resin layer in the above step (B). In addition, the wafer 11 is preferably not thinned by back grinding.

The ratio of the size (diameter: unit mm) to the thickness (unit μm) of the wafer 11 [wafer size (diameter)/wafer thickness] is preferably 1000 or less, more preferably 700 or less, particularly preferably 500 or less, particularly preferably 400 or less, and still more preferably 300 or less. Furthermore, the ratio of the size (diameter: unit mm) to the thickness (unit μm) of the wafer 11 [wafer size (diameter)/wafer thickness] is usually 100 or more, preferably 200 or more.

<Step (A)> In step (A), as shown in FIG. 2(A), a hardening resin layer 20 is formed on the bump forming surface 11a of the wafer 10 with bumps. The method for forming the hardening resin layer 20 is not particularly limited, and for example, a method of applying a hardening resin composition described later on the bump forming surface 11a of the wafer 10 with bumps and then drying the hardening resin layer 20 can be cited.

Here, in one aspect of the present invention, the formation of the curable resin layer 20 is preferably performed using a protective film forming laminate having a laminated structure formed of a laminated support sheet and a curable resin layer. Specifically, step (A) preferably includes the following steps (A1) and (A2) in sequence. (A1) A step of attaching a protective film forming laminate having a laminated structure consisting of a laminated support sheet and a curable resin layer to the aforementioned bump forming surface of a semiconductor wafer having the aforementioned bump, wherein the aforementioned curable resin layer is used as the attaching surface, (A2) A step of peeling off the aforementioned support sheet from the aforementioned protective film forming laminate and forming the aforementioned curable resin layer on the aforementioned bump forming surface of the semiconductor wafer having the aforementioned bump. The following describes step (A1) and step (A2) in detail.

(Step (A1)) In step (A1), the supporting sheet constituting the laminate for forming the protective film is not particularly limited as long as it is a sheet-like member that can support the curable resin layer. For example, the supporting sheet may be a supporting substrate, a release film with a release treatment applied to one surface of the supporting substrate, or a laminate having a supporting substrate and an adhesive layer. When the supporting sheet is a release film, the curable resin layer is formed on the release-treated surface of the supporting substrate. Furthermore, when the supporting sheet is a laminate of a supporting substrate and an adhesive layer, the curable resin layer is bonded to the adhesive layer of the supporting sheet.

Here, in one aspect of the present invention, as shown in FIG3(A1), the support sheet 30a preferably has a laminated structure in which a first support substrate 31, a first buffer layer 32, and a first adhesive layer 33 are laminated in sequence. Furthermore, the protective film forming laminate 30 preferably has a laminated structure in which a first support substrate 31, a first buffer layer 32, a first adhesive layer 33, and a curable resin layer 20 are laminated in sequence. When the protective film forming laminate 30 is press-bonded to the bump forming surface 11a of the wafer 10 with bumps using the curable resin layer 20 as a bonding surface, the curable resin layer 20, the first adhesive layer 33, and the first buffer layer 32 of the protective film forming laminate 30 are pressed by the bump 12. Therefore, in the initial stage of press-bonding, the curable resin layer 20, the first adhesive layer 33, and the first buffer layer 32 are deformed into a concave shape following the shape of the bump 12. Furthermore, if the pressure from the bump 12 continues, the top of the bump 12 finally penetrates the hardening resin layer 20 and contacts the supporting sheet 30a. At this time, the pressure applied to the bump 12 is dispersed by the first adhesive layer 33 and the first buffer layer 32 of the supporting sheet 30a, thereby suppressing damage to the bump 12. However, the bump 12 may not necessarily protrude from the side of the supporting sheet 30a, but may be buried inside the hardening resin layer 20. Even in such a state, the top of the bump 12 may be exposed from the protective film 40 by the exposure treatment described later.

Here, the support sheet constituting the protective film forming laminate used in step (A1) requires good embedding property for the bump and easy peeling property of the support sheet from the protective film forming laminate in step (A2). In one embodiment of the present invention, the first buffer layer 32 of the support sheet 30a is preferably 100 to 500 μm thick, more preferably 150 to 450 μm thick, and particularly preferably 200 to 400 μm thick from the viewpoint of easily ensuring good embedding property for the bump. Based on the same viewpoint, the thickness of the first adhesive layer 33 of the supporting sheet 30a is preferably 5 to 50 μm, more preferably 5 to 30 μm, and even more preferably 5 to 15 μm.

Furthermore, in one embodiment of the present invention, the first buffer layer 32 of the support sheet 30a preferably has a shear storage modulus G'(23°C) of 200 MPa or less, more preferably 180 MPa or less, and particularly preferably 150 MPa or less at room temperature (23°C) from the viewpoint of easily ensuring the easy peelability of the support sheet from the protective film forming laminate in step (A2). Furthermore, the shear storage modulus G'(23°C) of the first buffer layer 32 is usually 80 MPa or more from the viewpoint of fully ensuring the room temperature retention of the hardening resin layer 20 caused by the first support substrate 31. In addition, in this specification, the shear storage elastic modulus G'(23°C) at room temperature (23°C) is a value measured by a torsional shear method using a viscoelasticity measuring device (manufactured by Anton Paar, device name "MCR300"), with a test start temperature of -20°C, a test end temperature of 150°C, a heating rate of 3°C/min, and a frequency of 1 Hz, using a test sample of 8 mm in diameter x 3 mm in thickness formed by the same composition as the composition forming the first buffer layer 32.

Furthermore, the support sheet constituting the protective film forming laminate used in step (A1) is required to have good embedding properties for the bumps as described above and to be easily releasable from the protective film forming laminate in step (A2). On the other hand, it is required to have fixing performance to the attached object with respect to the temperature rise during back grinding as required for the back grinding tape (in other words, the adhesive layer's adhesive force should be maintained with respect to the temperature rise during back grinding). Furthermore, the design of the buffer layer is not required to take into account the depression suppression during back grinding. Therefore, in one embodiment of the present invention, the first buffer layer 32 of the supporting sheet 30a is formed by taking into account the good embedding property of the bump and the easy peeling property of the supporting sheet from the protective film forming laminate in step (A2). Therefore, compared with the general back grinding tape, it has the advantage of improving the design freedom of the first buffer layer 32.

(Step (A2)) In step (A2), the support sheet is peeled off from the protective film forming laminate body, and a hardening resin layer is formed on the bump forming surface of the wafer with bumps. For example, as shown in FIG. 3 (A2), the support sheet 30a having a laminate structure in which a first support substrate 31, a first buffer layer 32, and a first adhesive layer 33 are sequentially laminated is peeled off from the hardening resin layer 20 and separated from the protective film forming laminate body 30. In this way, a hardening resin layer 20 is formed on the bump forming surface 11a of the wafer 10 with bumps. The surface of the curable resin layer 20 opposite to the bump forming surface 11a is exposed. In one embodiment of the present invention, as described above, by making the shear storage modulus G' (23°C) of the first buffer layer 32 of the supporting sheet 30a at room temperature (23°C) less than 200 MPa, the supporting sheet 30a can be easily peeled off from the protective film forming laminate 30 at room temperature. However, the method of peeling the supporting sheet 30a from the protective film forming laminate 30 is not limited to this method. For example, when the first adhesive layer 33 is an adhesive layer formed of an energy ray curing adhesive, a heat foaming adhesive, or a water swelling adhesive, the supporting sheet 30a can be peeled off from the protective film forming laminate 30 by energy ray curing, heat foaming, or water swelling.

Through the above step (A), the wafer 10 with bumps having the curable resin layer 20 formed on the bump forming surface 11a is supplied to the next step (B).

<Step (B)> In step (B), the curable resin layer formed on the bump forming surface of the wafer with bumps is cured to form a protective film. For example, as shown in FIG. 2(B), by curing the curable resin layer 20 and forming a protective film 40, the bump forming surface 11a and the bump neck of the wafer 10 with bumps can be protected. The protective film formed by curing the curable resin layer is stronger than the curable resin layer at room temperature. Therefore, by forming the protective film, the bump neck is well protected.

The curing of the curable resin layer can be performed by either heat curing or curing by irradiation with energy rays, depending on the type of curable component contained in the curable resin layer. In addition, in this specification, the so-called "energy ray" means an electromagnetic wave or a charged particle ray having energy quanta, and examples thereof include ultraviolet rays, electron rays, etc., preferably ultraviolet rays. As conditions for heat curing, the curing temperature is preferably 90°C to 200°C, and the curing time is preferably 1 hour to 3 hours. The conditions for curing by energy ray irradiation can be appropriately set according to the type of energy ray used. For example, when ultraviolet rays are used, the illuminance is preferably 170mw/ ^cm2 to 250mw/ ^cm2 , and the light quantity is preferably 600mJ/ ^cm2 to 1500mJ/ ^cm2 . The details of the curable resin layer for forming the protective film are described later.

Here, in one aspect of the present invention, in the process of hardening the hardening resin layer and forming the protective film, the hardening resin layer is preferably a thermosetting resin layer from the viewpoint of improving the flatness of the protective film by causing the hardening resin layer to flow by heating during thermal curing. Furthermore, when the hardening resin layer is a thermosetting resin layer, in step (A), even if the bump does not completely penetrate the hardening resin layer but is formed in a state of being buried inside, the hardening resin can flow by heating during thermal curing, so that the top of the bump is exposed from the protective film 40. Based on such a viewpoint, the hardening resin layer is preferably a thermosetting resin layer.

The wafers constituting the wafers with bumps in step (B) are enlarged in diameter from the viewpoint of improving the efficiency of batch processing, and on the other hand, sufficient thickness is ensured as described above. In one aspect of the present invention, the thickness of the semiconductor wafer is set to be 300 μm or more. Therefore, the warping of the wafer accompanied by the shrinkage caused by the hardening of the curable resin layer can be suppressed. Therefore, in the subsequent steps, the disadvantages caused by the warping of the wafer can be suppressed. Specifically, the poor storage of the wafers with bumps in the wafer carrier, wafer cassette and wafer boat can be suppressed, and the damage of the wafers with bumps can be suppressed. In addition, the poor handling of the wafers with bumps can be suppressed, and the poor handling of the wafers after the wafers with bumps are singulated into chips can be suppressed. Furthermore, since the warping of the wafer is suppressed, the backside grinding in step (D) can be performed with high precision.

By the above step (B), the curable resin layer 20 is cured, and the wafer 10 with bumps having a protective film 40 formed on the bump forming surface 11a is supplied to the next step (C). In addition, in the method for manufacturing a semiconductor device of the present invention, when the curable resin layer is a thermosetting resin layer, the support sheet or back grinding tape constituting the laminate for forming the protective film is not exposed to heat during the heat treatment for curing the thermosetting resin layer. Therefore, heat resistance to heat during the curing of the thermosetting resin layer is not required for the support sheet or back grinding tape, so there is an advantage that the design freedom of the support sheet or back grinding tape is greatly increased.

<Step (C)> In step (C), a back grinding tape is attached to the surface of the protective film. The back grinding tape used in step (C) is not particularly limited, and a general back grinding tape used when grinding the back side of a wafer with bumps formed on a protective film can be used. Here, in one embodiment of the present invention, the back grinding tape is, for example, a back grinding tape 50 as shown in FIG. 2 (C), preferably having a laminated structure in which a second supporting substrate 51, a second buffer layer 52, and a second adhesive layer 53 are laminated in sequence. When the back grinding tape 50 is pressed onto the surface of the protective film 40 formed on the wafer 10 with bumps, the second adhesive layer 53 and the second buffer layer 52 of the back grinding tape 50 are pressed by the bumps 12. Therefore, the second adhesive layer 53 and the second buffer layer 52 are deformed into a concave shape following the shape of the bumps 12, and the bumps 12 are buried and protected. Thereby, the wafer 10 with bumps formed with the protective film 40 is fixed by the back grinding tape 50, and the back grinding can be well performed.

Here, the back grinding tape attached to the surface of the protective film in step (C) requires good embedding performance for the bumps and fixing performance of the wafer with bumps formed with the protective film during back grinding. In one embodiment of the present invention, the second buffer layer 52 of the back grinding tape 50 is preferably 50 to 450 μm thick, more preferably 100 to 400 μm, and particularly preferably 150 to 350 μm from the viewpoint of easily ensuring good embedding performance for the bumps. Based on the same viewpoint, the second adhesive layer 53 of the back grinding tape 50 is preferably 5 to 50 μm thick, more preferably 5 to 30 μm, and particularly preferably 5 to 15 μm thick.

Furthermore, in one embodiment of the present invention, the peak value of tan δ of the second buffer layer 52 of the back grinding tape 50 is preferably greater than 1.2, more preferably greater than 1.3, and particularly preferably greater than 1.4. Furthermore, the peak value of tan δ is usually less than 5.0, preferably less than 4.0. Since the peak value of tan δ of the second buffer layer 52 is within the above range, even when the flexibility of the protective film 40 increases due to the heat generated during back grinding, the movement of the wafer 10 with the bumps can be suppressed. If the wafer 10 with the bumps moves during back grinding, bumps and depressions are likely to occur on the ground surface, and if a recess (depression) occurs at a location corresponding to the location where the bumps are formed, there is a risk of cracks starting from the recess. Since the peak value of tan δ of the second buffer layer 52 is within the above range, the occurrence of depressions can be suppressed, thereby suppressing the occurrence of cracks starting from depressions. In addition, in this specification, the peak value of tan δ is a value measured by a torsional shear method using a viscoelasticity measuring device (manufactured by Anton Paar, device name "MCR300"), under the conditions of test start temperature: -20°C, test end temperature: 150°C, heating rate: 3°C/min, and frequency: 1Hz, using a test sample with a diameter of 8mm×thickness of 3mm formed of the same composition as the composition forming the second buffer layer 52.

Here, in one aspect of the present invention, it is preferred that the attachment direction of the back grinding tape 50 to the wafer 10 with bumps formed with the protective film 40 is different from the attachment direction of the protective film forming laminate 30 to the wafer 10 with bumps in step (A1). Specifically, relative to the attachment direction of the protective film forming laminate 30 to the wafer 10 with bumps in step (A1), it is preferred that the attachment direction of the back grinding tape 50 to the wafer 10 with bumps formed with the protective film 40 is staggered by 30° to 90°, more preferably by 45° to 90°, particularly preferably by 60° to 90°, and particularly preferably by 90°. In this way, by changing the attachment direction of the back grinding tape 50 to the wafer 10 with bumps formed with the protective film 40 relative to the attachment direction of the protective film forming laminate 30 to the wafer 10 with bumps in step (A1), the force applied when the back grinding tape 50 is pressed against the wafer 10 with bumps can be used to offset the slight warp of the wafer 10 with bumps caused by the force applied when the protective film forming laminate 30 is pressed against the wafer 10 with bumps, thereby further suppressing the warp of the wafer 10 with bumps.

<Step (D)> In step (D), the surface opposite to the bump-forming surface of the wafer with bumps is ground while the back grinding tape is attached. That is, the wafer 10 with bumps is ground on the back to thin the wafer 11. The back grinding of the wafer 10 with bumps is performed, for example, by fixing the surface side of the wafer 10 with bumps attached with dicing tape on a fixed table such as a suction table, and grinding the back side 11b of the wafer 11 by a grinder or the like. In the present invention, the thickness of the wafer 10 with bumps after grinding can be set to 250μm or less. In this way, in the present invention, even when the thickness of the wafer 11 is reduced, the warping of the wafer 11 can be suppressed. Therefore, it is possible to suppress poor storage of the bumped wafer 10 in a wafer carrier, a wafer cassette, a wafer boat, etc., and suppress damage to the bumped wafer 10. It is also possible to suppress poor handling of the bumped wafer 10, and further suppress poor handling of the wafer after the bumped wafer is singulated into chips.

<Step (E)> In step (E), the back grinding tape 50 is peeled off from the semiconductor wafer after the grinding. The back grinding tape 50 can be peeled off at room temperature, but in one embodiment of the present invention, the back grinding tape 50 can be peeled off by heating the back grinding tape 50 to increase the fluidity of the second adhesive layer 53 of the back grinding tape 50 and reduce the adhesive force. However, the method for peeling the back grinding tape 50 is not limited to these methods. For example, when the second adhesive layer 53 is formed of an energy ray curing adhesive, a heat foaming adhesive, or a water swelling adhesive, the back grinding tape 50 can be peeled off by energy ray curing, heat foaming, or water swelling.

<Formation of the division starting point> In one aspect of the present invention, it is preferred that a step of forming a division starting point for singulating the semiconductor wafer with bumps is provided before the aforementioned step (A), between the aforementioned step (A) and the aforementioned step (B), between the aforementioned step (B) and the aforementioned step (C), and between the aforementioned step (C) and the aforementioned step (D). As a method of forming a division starting point for singulating the semiconductor wafer with bumps, for example, a pre-cutting method and an invisible cutting (registered trademark) method can be cited. Furthermore, for a semiconductor wafer with bumps formed thereon as a starting point for singulation, a method for manufacturing a semiconductor device according to one aspect of the present invention can be adopted, and in this case, the step of forming the starting point for singulation can be omitted.

(Pre-cut method) The pre-cut method is, for example, as shown in FIG. 4, a method of forming a groove 61 in the bump forming surface 11a of the wafer 10 with bumps along a predetermined dividing line, grinding the back surface 11b of the wafer 10 with bumps until at least reaching the groove 61, thinning the wafer 10 with bumps, and singulating the wafer 10 with bumps into a single chip body CP. In the pre-cut method, the starting point for singulating the wafer 10 with bumps is the groove 61. Here, in one embodiment of the present invention, the formation of the groove 61 is preferably performed after step (B), that is, after forming the protective film 40 on the bump forming surface 11a of the wafer 10 with bumps. At this time, the groove 61 is preferably formed from the surface of the protective film 40 to the inside of the wafer 11 of the wafer 10 with bumps, as shown in FIG. 4. Thus, the wafer 10 with bumps formed with the protective film 40 can be easily singulated with the protective film attached. In addition, after the groove 61 is formed from the bump forming surface 11a of the wafer 10 with bumps to the inside of the wafer 11, in the case where the protective film 40 is formed on the bump forming surface 11a of the wafer 10 with bumps, the wafer 10 with bumps formed with the protective film 40 can also be singulated with the protective film 40 attached. That is, after grinding the back side 11b of the wafer 10 with bumps until at least reaching the groove 61, the wafer 10 with bumps is thinned, and then an external force such as pressure is applied to cut the protective film 40 together with the wafer 10 with bumps using the groove 61 as a starting point for division. The wafer 10 with bumps formed with the protective film 40 can be singulated in a state with the protective film 40 attached.

(Invisible dicing method) The so-called invisible dicing method is a method of singulating the wafer with bumps by forming a modified region inside the wafer of the wafer with bumps by laser light, and using the modified region as the starting point for division. Specifically, as shown in FIG. 5, for the wafer 11 of the wafer with bumps 10, the focal point is aligned with the inside of the wafer, and laser light is irradiated to form a modified region 71 caused by multiphoton absorption as the starting point for division. Then, along the predetermined division line of the wafer with bumps 10, a cutting starting point region is formed inside the specified distance from the aforementioned laser light incident surface. Then, after the wafer 10 with bumps is thinned by back grinding, it is cut by processing pressure of a grinding stone, etc., and divided into individual chips and singulated. When the modified area 71 is formed before step (A), the laser light incident surface can be the bump forming surface of the wafer with bumps or the back surface, but from the perspective of suppressing the influence on the circuit formed on the bump forming surface of the wafer with bumps, the laser light incident surface is preferably the back surface of the wafer with bumps. In addition, after step (A), a protective film 40 is formed on the bump forming surface 11a of the wafer 10 with bumps. In addition, there is also a method of attaching a back grinding tape 50 or the like to the surface of the protective film 40. Therefore, even when the modified region 71 is formed after step (A), the laser light incident surface is preferably the back surface of the wafer with bumps.

<Exposure treatment> In one aspect of the present invention, it is preferred that, between the aforementioned step (B) and the aforementioned step (C) and after the aforementioned step (E), an exposure treatment is performed to remove the aforementioned protective film covering the top of the aforementioned bump or a portion of the aforementioned protective film attached to the top of the aforementioned bump to expose the top of the aforementioned bump. As the exposure treatment for exposing the top of the bump, for example, an etching treatment such as a wet etching treatment or a dry etching treatment can be cited. Here, as the dry etching treatment, for example, a plasma etching treatment can be cited. Plasma etching treatment may also be performed under high temperature conditions. However, when plasma etching treatment is performed under high temperature conditions between the aforementioned step (B) and the aforementioned step (C) and in any of the aforementioned steps (E), the hardening resin layer has already hardened to form a protective film, so the hardening and shrinkage of the hardening resin layer does not occur due to the high temperature conditions of the plasma etching treatment, and thus the wafer warping accompanying the hardening and shrinkage of the hardening resin layer does not occur. In addition, the exposure treatment is performed in the case where the surface of the protective film is not exposed at the top of the bump, with the purpose of making the protective film retreat to the top of the bump to be exposed.

Next, the details of the components constituting the protective film forming multilayer body and the back grinding tape used in the method for manufacturing a semiconductor device of the present invention are described.

[Hardenable resin layer] In a method for manufacturing a semiconductor device according to one aspect of the present invention, a protective film forming laminate is used. The protective film forming laminate has a curable resin layer. The curable resin layer may be a thermosetting resin layer that undergoes a curing reaction by heat treatment, or an energy ray curing resin layer that undergoes a curing reaction by energy ray irradiation. The thermosetting resin layer and the energy ray curing resin layer are not particularly limited, and well-known thermosetting resin layers and energy ray curing resin layers may be appropriately used.

Here, as described above, from the viewpoint of improving the flatness of the protective film by causing the curable resin layer to flow by heat treatment during curing, in one embodiment of the present invention, the curable resin layer is preferably a thermosetting resin layer. The thermosetting resin layer used in one embodiment of the present invention is described in detail below.

<Thermosetting resin layer> The thermosetting resin layer used in one embodiment of the present invention is formed, for example, from a thermosetting resin layer-forming composition (hereinafter also simply referred to as "resin layer-forming composition (X)") containing a polymer component (XA) and a thermosetting component (XB).

(Polymer component (XA)) The polymer component (XA) is a polymer compound used to impart film-forming properties or visibility to the thermosetting resin layer, and is a component formed by a polymerization reaction of a polymerizable compound. In addition, in this specification, the polymerization reaction also includes a polycondensation reaction. The polymer component (XA) contained in the resin layer-forming composition (X) and the thermosetting resin layer may be only one kind or two or more kinds. When there are two or more kinds, their combination and ratio can be arbitrarily selected.

As the polymer component (XA), for example, polyvinyl acetal, acrylic resin, polyester, urethane resin, acrylic urethane resin, silicone resin, polyolefin resin (such as rubber resin, etc.), phenoxy resin, thermoplastic polyimide, etc. can be cited. Furthermore, since it is easy to adjust the shear viscosity in the temperature range of 90°C to 200°C during the thermal curing process, and the effect of suppressing the repulsion of the surface of the semiconductor wafer becomes higher when the thermosetting resin layer is attached to the bump forming surface of the wafer with bumps and thermally cured, it is easy to suppress the poor formation of the protective film caused by repulsion. Among these, polyvinyl acetal and acrylic resin are preferred. Hereinafter, polyvinyl acetal and acrylic resin are described as preferred examples of the polymer component (XA).

Furthermore, in this specification, "the shear viscosity at 90°C to 200°C is easy to adjust" means that the minimum shear viscosity of the thermosetting resin layer before curing at 90°C to 200°C (preferably 90°C to 130°C) when the temperature is increased at 10°C/min can be preferably adjusted to 500 Pa·s or more, more preferably to 1,000 Pa·s or more, and even more preferably to 2,000Pa・s or more. By adjusting the minimum shear viscosity at 90℃～200℃ (preferably 90℃～130℃) to the above range, it is easy to suppress the poor formation of the protective film caused by repulsion. In addition, in this specification, the minimum shear viscosity of the curable resin layer at 90℃～200℃ (preferably 90℃～130℃) is measured by the method described in the embodiment.

(Polyvinyl acetal) The polyvinyl acetal used as the polymer component (XA) is not particularly limited, and for example, well-known polyvinyl acetals can be used. Among the polyvinyl acetals, for example, polyvinyl formaldehyde, polyvinyl butyral, etc. can be cited, and polyvinyl butyral is preferred. As polyvinyl butyral, those having the constituent units shown by the following formulas (i-1), (i-2) and (i-3) are preferred from the viewpoints that the shear viscosity can be easily adjusted in the temperature range of 90°C to 200°C during the thermal curing process, and the thermosetting resin layer is attached to the bump forming surface of the wafer with bumps, so that the effect of suppressing the repulsion of the surface of the semiconductor wafer during the thermal curing is higher.

In the above formulae (i-1), (i-2) and (i-3), p, q and r are the content ratios (mol %) of the respective constituent units.

The weight average molecular weight (Mw) of polyvinyl acetal is preferably 5,000 to 200,000, more preferably 8,000 to 100,000, particularly preferably 9,000 to 80,000, and particularly preferably 10,000 to 50,000. Since the weight average molecular weight of polyvinyl acetal is in such a range, the shear viscosity at 90°C to 200°C can be adjusted more easily, and the effect of suppressing the repulsion of the surface of the semiconductor wafer when the thermosetting resin layer is attached to the bump forming surface of the wafer with bumps and thermally cured becomes higher. In addition, the effect of suppressing the residual thermosetting resin layer on the upper part of the bump (the top of the bump and its vicinity) becomes higher. In this specification, the weight average molecular weight of a polymer (resin) can be measured as a standard polystyrene conversion value by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

The content ratio p (butyralization degree) of the constituent units of the butyraldehyde group represented by the above formula (i-1) is preferably 40 to 90 mol %, more preferably 50 to 85 mol %, and particularly preferably 60 to 76 mol %, based on all the constituent units of the polymer component (XA).

The content ratio q of the constituent unit having an acetyl group represented by the above formula (i-2) is preferably 0.1 to 9 mol %, more preferably 0.5 to 8 mol %, and particularly preferably 1 to 7 mol %, based on all the constituent units of the polymer component (XA).

The content ratio r of the constituent unit having a hydroxyl group represented by the above formula (i-3) is preferably 10 to 60 mol %, more preferably 10 to 50 mol %, and particularly preferably 20 to 40 mol %, based on all the constituent units of the polymer component (XA).

The glass transition temperature (Tg) of polyvinyl acetal is preferably 40 to 80°C, more preferably 50 to 70°C. Since the Tg of polyvinyl acetal is in such a range, when the thermosetting resin layer is attached to the bump forming surface of the wafer with bumps, the effect of suppressing the residual thermosetting resin layer on the upper part of the bump becomes higher, and the hardness of the protective film formed by thermally curing the thermosetting resin layer can be made sufficient. In addition, in this specification, the glass transition temperature (Tg) of the polymer (resin) is a value measured by the method described in the embodiment described later.

The content ratio of the above three constituent units constituting polyvinyl butyral can be arbitrarily adjusted according to the desired physical properties. In addition, polyvinyl butyral may also have constituent units other than the above three constituent units, but the content of the above three constituent units is based on the total amount of polyvinyl butyral, preferably 80 to 100 mol%, more preferably 90 to 100 mol%, and even more preferably 100 mol%.

(Acrylic resin) The acrylic resin in the polymer component (XA) is not particularly limited, and for example, a well-known acrylic polymer can be used. The weight average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000. Since the weight average molecular weight of the acrylic resin is within this range, it is easier to adjust the shear viscosity at 90°C to 200°C, and the effect of suppressing the repulsion of the surface of the semiconductor wafer when the thermosetting resin layer is attached to the bump forming surface of the wafer with bumps and heat-curing it becomes higher. In addition, the shape stability is excellent, and the thermosetting resin layer can easily follow the uneven surface of the adherend, and the occurrence of gaps between the adherend and the thermosetting resin layer is further suppressed.

The glass transition temperature (Tg) of the acrylic resin is preferably -50 to 70°C, more preferably -30 to 50°C. When the Tg of the acrylic resin is above the lower limit, the adhesion between the thermosetting resin layer and the supporting sheet is suppressed, and the peeling property of the supporting sheet is improved. When the Tg of the acrylic resin is below the upper limit, the adhesion between the thermosetting resin layer and the adherend is improved.

Examples of acrylic resins include polymers of one or more (meth)acrylates; copolymers obtained by copolymerizing one or more monomers selected from (meth)acrylates, iaconic acid, vinyl acetate, acrylonitrile, styrene, and N-hydroxymethylacrylamide, etc. In addition, in this specification, the term "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid". The same is true for (meth)acrylic acid and similar terms, for example, the term "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate", and the term "(meth)acryl" is a concept that includes both "acryl" and "methacryl".

Examples of the (meth)acrylate ester constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecanyl (meth)acrylate, octadecyl (meth)acrylate (octadecyl (meth)acrylate), (Meth) acrylate alkyl esters whose alkyl group constituting the alkyl ester is a chain structure with a carbon number of 1 to 18; (Meth) acrylate cycloalkyl esters such as isoborneol (meth) acrylate and dicyclopentyl (meth) acrylate; (Meth) acrylate aryl alkyl esters such as benzyl (meth) acrylate; (Meth) acrylate cycloalkyl esters such as dicyclopentenyl (meth) acrylate; (Meth) acrylate cycloalkyl esters such as dicyclopentenyl (meth) acrylate; (Meth) acrylate cycloalkyl oxyalkyl esters such as dicyclopentenyloxyethyl (meth) acrylate; (Meth) acrylate imide; (Meth) (Meth)acrylates containing a glycidyl group such as glycidyl methacrylate; (Meth)acrylates containing a hydroxyl group such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate; (Meth)acrylates containing a substituted amino group such as N-methylaminoethyl (meth)acrylate. Here, the so-called "substituted amino group" means a group in which one or two hydrogen atoms of the amino group are replaced by a group other than a hydrogen atom.

The monomers constituting the acrylic resin may be only one kind or two or more kinds. When there are two or more kinds, the combination and ratio of the monomers may be arbitrarily selected.

Acrylic resins may also have functional groups such as vinyl, (meth)acryl, amino, hydroxyl, carboxyl, isocyanate, etc. that can bond with other compounds. The aforementioned functional groups of acrylic resins may bond with other compounds via a crosslinking agent (XF) described below, or may bond directly with other compounds without a crosslinking agent (XF). Since acrylic resins bond with other compounds via the aforementioned functional groups, there is a tendency to improve the reliability of a package having a protective film formed using a protective film-forming laminate.

In one aspect of the present invention, for example, as the polymer component (XA), a thermoplastic resin other than polyvinyl acetal and acrylic resin (hereinafter also simply referred to as "thermoplastic resin") may be used alone, and polyvinyl acetal and acrylic resin may be used instead of, or in combination with, polyvinyl acetal or acrylic resin. Due to the aforementioned thermoplastic resin, the peeling property of the thermosetting resin layer from the supporting sheet is improved, and the thermosetting resin layer becomes easier to follow the uneven surface of the attached object, and the occurrence of gaps between the attached object and the thermosetting resin layer can be further suppressed.

The weight average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, more preferably 3,000 to 80,000.

The glass transition temperature (Tg) of the thermoplastic resin is preferably -30 to 150°C, more preferably -20 to 120°C.

Examples of the thermoplastic resin include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

The thermoplastic resin contained in the resin layer-forming composition (X) and the thermosetting resin layer may be only one kind or two or more kinds. When there are two or more kinds, the combination and ratio of the thermoplastic resins may be arbitrarily selected.

In the resin layer forming composition (X), the ratio of the content of the polymer component (XA) to the total content of all components other than the solvent (i.e., the content of the polymer component (XA) in the thermosetting resin layer) is preferably 5 to 85% by mass, more preferably 5 to 80% by mass, regardless of the type of the polymer component (XA), and may be any of 5 to 70% by mass, 5 to 60% by mass, 5 to 50% by mass, 5 to 40% by mass, and 5 to 30% by mass. However, these contents in the resin layer forming composition (X) are merely examples.

Here, the polymer component (XA) may also be equivalent to the thermosetting component (XB). In one aspect of the present invention, when the resin layer forming composition (X) contains components equivalent to both the polymer component (XA) and the thermosetting component (XB), the resin layer forming composition (X) is regarded as containing the polymer component (XA) and the thermosetting component (XB).

(Thermosetting component (XB)) Thermosetting component (XB) is a component used to form a hard protective film by curing the thermosetting resin layer by heat treatment. The thermosetting component (XB) contained in the resin layer forming composition (X) and the thermosetting resin layer may be only one kind or two or more kinds. When there are two or more kinds, their combination and ratio can be arbitrarily selected.

Examples of the thermosetting component (XB) include epoxy-based thermosetting resins, thermosetting polyimide, polyurethane, unsaturated polyester, and silicone resins. Among these, epoxy-based thermosetting resins are preferred.

(Epoxy-based thermosetting resin) The epoxy-based thermosetting resin includes an epoxy resin (XB1) and a thermosetting agent (XB2). The epoxy-based thermosetting resin contained in the resin layer-forming composition and the thermosetting resin layer may be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

The epoxy resin (XB1) is not particularly limited, and for example, well-known epoxy resins can be used. For example, polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated product, o-cresol novolac epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, and other epoxy compounds having two or more functionalities can be mentioned.

As the epoxy resin (XB1), an epoxy resin having an unsaturated hydrocarbon group can be used. An epoxy resin having an unsaturated hydrocarbon group has higher compatibility with an acrylic resin than an epoxy resin having no unsaturated hydrocarbon group. Therefore, by using an epoxy resin having an unsaturated hydrocarbon group, the reliability of a package having a protective film formed using a protective film forming laminate is improved.

Examples of epoxy resins having unsaturated hydrocarbon groups include compounds obtained by converting a portion of epoxy groups of a multifunctional epoxy resin into groups having unsaturated hydrocarbon groups. Such compounds can be obtained, for example, by subjecting (meth)acrylic acid or its derivatives to an addition reaction of epoxy groups. In addition, examples of epoxy resins having unsaturated hydrocarbon groups include compounds obtained by directly bonding groups having unsaturated hydrocarbon groups to aromatic rings constituting epoxy resins. The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include vinyl (vinyl), 2-propenyl (allyl), (meth)acrylyl, (meth)acrylamide, etc., and preferably, an acryl group.

The weight average molecular weight of the epoxy resin (XB1) is preferably 15,000 or less, more preferably 10,000 or less, and particularly preferably 5,000 or less. Since the weight average molecular weight of the epoxy resin (XB1) is below the upper limit value, the shear viscosity at 90°C to 200°C can be adjusted more easily, and the effect of suppressing the repulsion of the surface of the semiconductor wafer when the thermosetting resin layer is attached to the bump-forming surface of the wafer with bumps and thermally cured becomes higher. In addition, the effect of suppressing the residue of the protective film in the top of the bump becomes higher.

The lower limit of the weight average molecular weight of the epoxy resin (XB1) is not particularly limited. However, the weight average molecular weight of the epoxy resin (XB1) is preferably 300 or more, more preferably 500 or more, in order to further improve the curability of the thermosetting resin layer and the strength and heat resistance of the protective film.

The weight average molecular weight of the epoxy resin (XB1) can be arbitrarily combined with the above-mentioned preferred lower limit and upper limit to be appropriately adjusted within the set range. For example, in one embodiment of the present invention, the weight average molecular weight of the epoxy resin (XB1) is preferably 300 to 15,000, more preferably 300 to 10,000, and particularly preferably 300 to 3,000. In addition, in one embodiment, the weight average molecular weight of the epoxy resin (XB1) is preferably 500 to 15,000, more preferably 500 to 10,000, and particularly preferably 500 to 3,000. However, these are examples of preferred weight average molecular weights of the epoxy resin (XB1).

The epoxy equivalent of the epoxy resin (XB1) is preferably 100 to 1,000 g/eq, more preferably 130 to 800 g/eq. In addition, in this specification, "epoxy equivalent" means the number of grams (g/eq) of an epoxy compound containing 1 gram equivalent of epoxy groups, which is a value measured in accordance with JIS K 7236:2009.

The epoxy resin (XB1) is preferably liquid at room temperature (also referred to simply as "liquid epoxy resin (XB1)" in this manual). If a liquid epoxy resin is used at room temperature, it is easy to adjust the shear viscosity. In addition, the thermosetting resin layer becomes easier to follow the uneven surface of the attached object, and the occurrence of gaps between the attached object and the thermosetting resin layer is further suppressed. Furthermore, the "liquid at room temperature" mentioned here means "liquid at 25°C", and the same applies to the subsequent descriptions.

The epoxy resin (XB1) may be used alone or in combination of two or more. When two or more types are used in combination, their combination and ratio may be arbitrarily selected.

The proportion of the epoxy resin (XB1) in the resin layer forming composition (X) and the thermosetting resin layer is preferably 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 55% by mass or more at room temperature, and may be any one of 60% by mass or more, 70% by mass or more, 80% by mass or more, and 90% by mass or more. Since the above-mentioned proportion is above the above-mentioned lower limit, when the temperature of the thermosetting resin film before curing is increased at 10°C/min, the minimum shear viscosity at 90°C to 200°C can be easily adjusted to 500 Pa·s or more, and the thermosetting resin layer is attached to the bump forming surface of the wafer with bumps, and the effect of suppressing the repulsion of the surface of the semiconductor wafer during thermal curing becomes higher. In addition, the effect of suppressing the residual of the protective film residue in the top of the bump becomes higher. The upper limit of the above ratio is not particularly limited, and the above ratio can be less than 100 mass %.

Thermosetting agent (XB2) functions as a hardener for epoxy resin (XB1). As the thermosetting agent (XB2), for example, a compound having two or more functional groups that can react with epoxy groups in one molecule can be cited. As the aforementioned functional group, for example, phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, acid groups anhydrided groups, etc. can be cited, preferably phenolic hydroxyl groups, amino groups or acid groups anhydrided groups, and more preferably phenolic hydroxyl groups or amino groups.

Among the thermosetting agents (XB2), examples of phenolic curing agents having a phenolic hydroxyl group include multifunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Among the thermosetting agents (XB2), examples of amine-based curing agents having an amine group include dicyandiamide.

Thermosetting agent (XB2) may also have an unsaturated hydrocarbon group. Examples of thermosetting agent (XB2) having an unsaturated hydrocarbon group include compounds in which a portion of the hydroxyl groups of a phenolic resin is replaced by a group having an unsaturated hydrocarbon group, compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of a phenolic resin, and the like. The unsaturated hydrocarbon group in thermosetting agent (XB2) is the same as the unsaturated hydrocarbon group in the above-mentioned epoxy resin having an unsaturated hydrocarbon group.

When a phenolic hardener is used as the thermosetting agent (XB2), the thermosetting agent (XB2) preferably has a high softening point or glass transition temperature from the viewpoint of improving the peeling property of the thermosetting resin layer from the supporting sheet.

In the thermosetting agent (XB2), the number average molecular weight of the resin components such as multifunctional phenol resin, novolac phenol resin, dicyclopentadiene phenol resin, aralkyl phenol resin, etc. is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. In the thermosetting agent (XB2), the molecular weight of the non-resin components such as biphenol and dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

The thermosetting agent (XB2) may be used alone or in combination of two or more. When two or more types are used in combination, their combination and ratio may be arbitrarily selected.

In the resin film-forming composition (X) and the thermosetting resin layer, the content of the thermosetting agent (XB2) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, and can be any of 1 to 150 parts by mass, 1 to 100 parts by mass, 1 to 75 parts by mass, 1 to 50 parts by mass, and 1 to 30 parts by mass, relative to 100 parts by mass of the content of the epoxy resin (XB1). Since the aforementioned content of the thermosetting agent (XB2) is above the aforementioned lower limit, the thermosetting resin layer is more easily cured. Furthermore, since the aforementioned content of the thermosetting agent (XB2) is below the aforementioned upper limit value, the moisture absorption rate of the thermosetting resin layer is reduced, and the reliability of the package having a protective film formed using the protective film forming laminate is further improved.

In the resin film-forming composition (X) and the thermosetting resin layer, the content of the thermosetting component (XB) (e.g., the total content of the epoxy resin (XB1) and the thermosetting agent (XB2)) is preferably 50 to 1,000 parts by mass, more preferably 60 to 950 parts by mass, and particularly preferably 70 to 900 parts by mass relative to 100 parts by mass of the polymer component (XA). Since the aforementioned content of the thermosetting component (XB) is within such a range, the adhesion between the thermosetting resin layer and the supporting sheet is suppressed, and the peeling property of the supporting sheet is improved.

(Hardening accelerator (XC)) The resin layer forming composition (X) and the thermosetting resin layer may contain a hardening accelerator (XC). The hardening accelerator (XC) is a component for adjusting the hardening speed of the thermosetting resin layer. Preferred curing accelerators (XC) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which one or more hydrogen atoms are replaced by groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines (phosphines in which one or more hydrogen atoms are replaced by organic groups) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylborates such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

The resin layer-forming composition (X) and the curing accelerator (XC) contained in the thermosetting resin layer may be only one kind or two or more kinds. When there are two or more kinds, their combination and ratio can be arbitrarily selected.

When a curing accelerator (XC) is used, the content of the curing accelerator (XC) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the content of the thermosetting component (XB) in the resin layer-forming composition (X) and the thermosetting resin layer. Since the above-mentioned content of the curing accelerator (XC) is not less than the above-mentioned lower limit, the effect of using the curing accelerator (XC) is more significantly obtained. Furthermore, since the content of the curing accelerator (XC) is below the aforementioned upper limit, the effect of suppressing the migration of the highly polar curing accelerator (XC) to the bonding interface side with the attached body and segregation in the thermosetting resin layer under high temperature and high humidity conditions is enhanced, and the reliability of the package having a protective film formed using the protective film forming laminate is further improved.

(Filler (XD)) The resin layer forming composition (X) and the thermosetting resin layer may contain a filler (XD). Since the thermosetting resin layer contains a filler (XD), it is easier to adjust the thermal expansion coefficient of the protective film obtained by curing the thermosetting resin layer. Moreover, since this thermal expansion coefficient is optimized for the object of forming the protective film, the reliability of the package with the protective film formed using the protective film forming laminate is further improved. In addition, since the thermosetting resin layer contains a filler (XD), it is also possible to reduce the moisture absorption rate of the protective film or improve the heat dissipation.

The filler (XD) may be any of an organic filler and an inorganic filler, but preferably an inorganic filler. As preferred inorganic fillers, for example, powders of silica, alumina, talc, calcium carbonate, titanium dioxide, red iron, silicon carbide, boron nitride, etc.; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, etc. Among these, the inorganic filler is preferably silica or alumina.

The resin layer forming composition (X) and the filler (XD) contained in the thermosetting resin layer may be only one kind or two or more kinds. When there are two or more kinds, the combination and ratio of the fillers may be arbitrarily selected.

The average particle size of the filler (XD) is preferably 1 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.1 μm or less. Since the average particle size of the filler (XD) is below the aforementioned upper limit, the shear viscosity at 90°C to 200°C can be adjusted more easily, and the effect of suppressing the surface repulsion of the semiconductor wafer when the thermosetting resin layer is attached to the bump forming surface of the wafer with the bump and thermally cured becomes higher. In addition, the effect of suppressing the residue of the protective film in the top of the bump becomes higher. Furthermore, the "average particle size" in this specification, unless otherwise specified in advance, means the value of the particle size ( _D50 ) of the cumulative value 50% in the particle size distribution curve obtained by the laser diffraction scattering method.

The lower limit of the average particle size of the filler (XD) is not particularly limited. For example, in order to make it easier to obtain the filler (XD), the average particle size of the filler (XD) is preferably 0.01 μm or more.

When a filler (XD) is used, the ratio of the content of the filler (XD) to the total content of all components (hereinafter also referred to as "effective components") other than the solvent in the resin layer forming composition (X) (i.e., the content of the filler (XD) in the thermosetting resin layer) is preferably 3 to 60% by mass, and more preferably 3 to 55% by mass. Since the content of the filler (XD) is in such a range, the shear viscosity at 90°C to 200°C can be adjusted more easily, and when the thermosetting resin layer is attached to the bump forming surface of the wafer with bumps and is thermally cured, the repulsion of the surface of the semiconductor wafer can be suppressed. In addition, the effect of suppressing the residual of the protective film residue in the top of the bump becomes higher, and the adjustment of the above-mentioned thermal expansion coefficient becomes easier.

(Coupling agent (XE)) The resin layer forming composition (X) and the thermosetting resin layer may contain a coupling agent (XE). By using a coupling agent (XE) having a functional group that can react with an inorganic compound or an organic compound, the adhesion and tightness of the thermosetting resin layer to the attached body can be improved. In addition, by using a coupling agent (XE), the protective film obtained by curing the thermosetting resin layer does not impair the heat resistance, and the water resistance is improved.

The coupling agent (XE) is a compound having a functional group that can react with the functional group of the polymer component (XA), the thermosetting component (XB), etc., and is preferably a silane coupling agent. As preferred silane coupling agents, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane can be cited. , 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-butylpropyltrimethoxysilane, 3-butylpropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane, etc.

The coupling agent (XE) contained in the resin layer-forming composition (X) and the thermosetting resin layer may be one kind or two or more kinds. When there are two or more kinds, the combination and ratio of the coupling agents may be arbitrarily selected.

When a coupling agent (XE) is used, the content of the coupling agent (XE) is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total content of the polymer component (XA) and the thermosetting component (XB) in the resin layer-forming composition (X) and the thermosetting resin layer. Since the aforementioned content of the coupling agent (XE) is above the aforementioned lower limit, the effects of using the coupling agent (XE), such as the improvement of the dispersibility of the filler (XD) in the resin or the improvement of the adhesion between the thermosetting resin layer and the attached body, are more significantly obtained. In addition, since the aforementioned content of the coupling agent (XE) is below the aforementioned upper limit, the occurrence of outgassing is further suppressed.

(Crosslinking agent (XF)) When the above-mentioned acrylic resin or the like having a functional group such as a vinyl group, a (meth)acryl group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, etc. that can bond with other compounds is used as the polymer component (XA), the resin layer forming composition (X) and the thermosetting resin layer may contain a crosslinking agent (XF). The crosslinking agent (XF) is a component used to crosslink the above-mentioned functional groups in the polymer component (XA) with other compounds. By crosslinking, the initial adhesion and cohesion of the thermosetting resin layer can be adjusted.

Examples of the crosslinking agent (XF) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridine group).

Examples of the organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, and alicyclic polyvalent isocyanate compounds (hereinafter, these compounds are collectively referred to as "aromatic polyvalent isocyanate compounds, etc."); trimers, isocyanurates, and adducts of the aromatic polyvalent isocyanate compounds, etc.; terminal isocyanate urethane prepolymers obtained by reacting the aromatic polyvalent isocyanate compounds, etc. with polyol compounds, etc. The "adducts" are reaction products of the aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, or alicyclic polyvalent isocyanate compounds with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trihydroxymethylpropane, or castor oil. Examples of the adduct include the trihydroxymethylpropane-xylylene diisocyanate adduct described below.

More specifically, the organic polyvalent isocyanate compound includes 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 1,3-phenylenediisocyanate; 1,4-xylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate. Diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; a compound in which one or more of toluene diisocyanate, hexamethylene diisocyanate and xylylene diisocyanate are added to all or part of the hydroxyl groups of a polyol such as dicyclohexylmethane-2,4'-diisocyanate or trihydroxymethylpropane; lysine diisocyanate, etc.

Examples of the organic polyvalent imine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trihydroxymethylpropane-tri-β-aziridine propionate, tetrahydroxymethylmethane-tri-β-aziridine propionate, and N,N'-toluene-2,4-bis(1-aziridinecarboxamide) triethylmelamine.

When an organic polyvalent isocyanate compound is used as the crosslinking agent (XF), it is preferred to use a hydroxyl group-containing polymer as the polymer component (XA). When the crosslinking agent (XF) has an isocyanate group and the polymer component (XA) has a hydroxyl group, a crosslinking structure can be easily introduced into the thermosetting resin layer by the reaction between the crosslinking agent (XF) and the polymer component (XA).

The resin layer-forming composition (X) and the crosslinking agent (XF) contained in the thermosetting resin layer may be only one kind or two or more kinds. When there are two or more kinds, the combination and ratio of the crosslinking agents may be arbitrarily selected.

When a crosslinking agent (XF) is used, the content of the crosslinking agent (XF) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the polymer component (XA) in the resin layer-forming composition (X). Since the above-mentioned content of the crosslinking agent (XF) is above the above-mentioned lower limit, the effect of using the crosslinking agent (XF) is more significantly obtained. In addition, since the above-mentioned content of the crosslinking agent (XF) is below the above-mentioned upper limit, excessive use of the crosslinking agent (XF) is suppressed.

(Other components) Within the scope of not impairing the effect of the present invention, the resin layer forming composition (X) and the thermosetting resin layer may contain other components other than the above-mentioned polymer component (XA), thermosetting component (XB), curing accelerator (XC), filler (XD), coupling agent (XE) and crosslinking agent (XF). As the aforementioned other components, for example, energy ray curing resin, photopolymerization initiator, colorant, general additive, etc. can be cited. The aforementioned general additive is well known and can be arbitrarily selected according to the purpose without special limitation, but as preferred ones, for example, plasticizer, antistatic agent, antioxidant, colorant (dye, pigment), getter, etc. can be cited.

The aforementioned other components contained in the resin layer forming composition (X) and the thermosetting resin layer may be only one or two or more. When there are two or more, their combination and ratio can be arbitrarily selected. The content of the aforementioned other components in the resin layer forming composition (X) and the thermosetting resin layer is not particularly limited and can be arbitrarily selected according to the purpose.

The resin layer-forming composition (X) and the thermosetting resin layer preferably contain a polymer component (XA) and a thermosetting component (XB), contain polyvinyl acetal as the polymer component (XA), and contain an epoxy resin (XB1) that is liquid at room temperature. In addition to these components, it is more preferable to further contain a curing accelerator (XC) and a filler (XD). Moreover, the filler (XD) at that time is preferably one having the above-mentioned average particle size. Due to the use of such a resin layer-forming composition (X) and a thermosetting resin layer, the shear viscosity at 90°C to 200°C can be adjusted more easily, and the thermosetting resin layer is attached to the surface of the bump-forming surface of the wafer with bumps, and when it is thermally cured, the repulsion of the surface of the semiconductor wafer can be suppressed. Furthermore, the effect of suppressing the residual of the protective film residue becomes higher in the top part of the bump.

(Solvent) The resin layer forming composition (X) preferably further contains a solvent. The resin layer forming composition (X) containing a solvent has good operability. The aforementioned solvent is not particularly limited, and preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone, etc. The solvent contained in the resin layer forming composition (X) may be only one kind or two or more kinds. When there are two or more kinds, the combination and ratio of the solvents may be arbitrarily selected.

The solvent contained in the resin layer forming composition (X) is preferably methyl ethyl ketone or the like from the viewpoint of being able to more uniformly mix the components contained in the resin layer forming composition (X).

The content of the solvent in the resin layer forming composition (X) is not particularly limited and may be appropriately selected according to the types of components other than the solvent, for example.

[Substrate] The first support substrate used in the support sheet of the protective film forming laminate used in the manufacturing method of the semiconductor device of one aspect of the present invention is in the form of a thin sheet or a film, and various resins can be cited as its constituent material. In addition, the second support substrate used in the back grinding tape used in the manufacturing method of the semiconductor device of one aspect of the present invention is also in the form of a thin sheet or a film, and various resins can be cited as its constituent material. Examples of the resin include polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resins; ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylate copolymers, and ethylene-norbornene copolymers (copolymers obtained using ethylene as a monomer); and vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers. (resin obtained by using vinyl chloride as a monomer); polystyrene; polycycloolefin; polyethylene terephthalate, polyethylene naphthalate, polyethylene terephthalate, polyethylene isophthalate, polyethylene 2,6-naphthalate, polyesters such as wholly aromatic polyesters having aromatic cyclic groups as all constituent units; copolymers of two or more of the aforementioned polyesters; poly(meth)acrylate; polyurethane; polyurethane acrylate; polyimide; polyamide; polycarbonate; fluororesin; polyacetal; modified polyphenylene ether; polyphenylene sulfide; polysulfone; polyether ketone, etc. In addition, as the aforementioned resin, for example, polymer blends such as mixtures of the aforementioned polyesters and other resins can also be cited. The polymer blend of the aforementioned polyester and other resins is preferably one in which the amount of the resin other than the polyester is relatively small. In addition, as the aforementioned resin, for example, there can be cited a crosslinked resin obtained by crosslinking one or more of the aforementioned resins exemplified so far; a modified resin using an ionic polymer of one or more of the aforementioned resins exemplified so far, etc.

The resins constituting the first supporting substrate and the second supporting substrate may be only one type or two or more types. When there are two or more types, their combination and ratio may be arbitrarily selected.

The first supporting substrate and the second supporting substrate may be only one layer (single layer) or may be a plurality of layers of two or more layers. In the case of a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited. Furthermore, in this specification, not limited to the first supporting substrate and the second supporting substrate, the so-called "plurality of layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same", and the so-called "plurality of layers may be different from each other" means "at least one of the constituent material and thickness of each layer is different from each other".

The thickness of the first supporting substrate and the second supporting substrate is preferably 5 to 1000 μm, more preferably 10 to 500 μm, particularly preferably 15 to 300 μm, and particularly preferably 20 to 150 μm. Here, the so-called "thickness of the first supporting substrate" and "thickness of the second supporting substrate" refer to the thickness of the entire first supporting substrate and the thickness of the entire second supporting substrate. For example, the so-called thickness of the first supporting substrate composed of multiple layers refers to the total thickness of all layers constituting the first supporting substrate. Similarly, the so-called thickness of the second supporting substrate composed of multiple layers refers to the total thickness of all layers constituting the second supporting substrate.

Here, the second support substrate used for the back grinding tape is preferably one with high thickness accuracy, that is, one with suppressed thickness variation regardless of the location, from the viewpoint of further improving the accuracy of back grinding. Among the above-mentioned constituent materials, materials that can be used to constitute such a second support substrate with high thickness accuracy include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, ethylene-vinyl acetate copolymer, and the like.

In addition, the second supporting substrate used in the back grinding tape preferably has a Young's modulus of 600 MPa or more, more preferably 800 MPa or more, and particularly preferably 1,000 MPa or more, from the viewpoint of improving the supporting performance of the wafer with bumps and further improving the accuracy of back grinding. In addition, in order to relieve the stress acting on the wafer with bumps or its monolithic product when peeling off the back grinding tape, the Young's modulus of the second supporting substrate is preferably 30,000 MPa or less, more preferably 20,000 MPa or less, and particularly preferably 10,000 MPa or less. On the other hand, for the first supporting substrate used in the supporting sheet of the laminate for forming the protective film, since there is no need to consider the improvement of the back grinding accuracy, the Young's modulus of the first supporting substrate can be set by considering the peeling property of the supporting sheet from the curing resin layer. Based on this viewpoint, the Young's modulus of the first supporting substrate is preferably 10,000 MPa or less, more preferably 5,000 MPa or less, particularly preferably less than 1,000 MPa, and more preferably less than 600 MPa. Furthermore, the Young's modulus of the first supporting substrate is usually 100 MPa or more, preferably 200 MPa or more. The Young's modulus of the substrate is a value measured in accordance with JIS K-7127 (1999).

The first supporting substrate and the second supporting substrate may contain various well-known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, softeners (plasticizers), etc. in addition to the main constituent materials such as the aforementioned resins.

The first supporting substrate and the second supporting substrate may be transparent or opaque, may be colored according to the purpose, and may be vapor-deposited with other layers. When the aforementioned thermosetting resin film is energy-ray-curable, the first supporting substrate and the second supporting substrate are preferably energy-ray-permeable.

The first supporting substrate and the second supporting substrate can be manufactured by a well-known method. For example, the first supporting substrate and the second supporting substrate containing a resin can be manufactured by molding a resin composition containing the above-mentioned resin.

[Buffer layer] The first buffer layer used in the support sheet of the protective film forming laminate used in the method for manufacturing a semiconductor device of one aspect of the present invention is not particularly limited as long as it is a buffer layer generally used for back grinding tape. However, from the perspective of easily ensuring good embedding of the bump and easy peeling of the support sheet from the protective film forming laminate in the above step (A2), as described above, the shear storage elastic modulus G' (23°C) of the first buffer layer at room temperature (23°C) is preferably 200 MPa or less, more preferably 180 MPa or less, and even more preferably 150 MPa or less. Furthermore, from the viewpoint of sufficiently ensuring the retention of the curable resin layer at room temperature by the first supporting substrate, the shear storage modulus G' (23°C) of the first buffer layer is usually 80 MPa or more.

Furthermore, the second buffer layer used in the back grinding tape used in the method for manufacturing a semiconductor device according to one aspect of the present invention is not particularly limited as long as it is a buffer layer generally used for back grinding tapes. However, from the perspective of easily ensuring good embedding properties for bumps and good fixing performance when fixing a wafer with bumps to back grinding, as described above, the peak value of tan δ of the second buffer layer is preferably 1.2 or more, more preferably 1.3 or more, and particularly preferably 1.4 or more. Furthermore, the peak value of tan δ is usually 5.0 or less, preferably 4.0 or less.

Furthermore, the thickness of the first buffer layer and the second buffer layer is as described above. Here, in a method for manufacturing a semiconductor device of one aspect of the present invention, a protective film-forming laminate and a back grinding tape are used respectively, and when the back grinding tape is used, the bump neck of the wafer with bumps is protected by the protective film. Therefore, the bump embedding performance of the back grinding tape can be lower than the bump embedding performance of the protective film-forming laminate. Therefore, the thickness of the second buffer layer can be thinner than the thickness of the first buffer layer. Specifically, the ratio of the thickness of the second buffer layer to the thickness of the first buffer layer [(thickness of the second buffer layer)/thickness of the first buffer layer] is preferably 0.9 or less, more preferably 0.8 or less, and particularly preferably 0.7 or less, and is usually 0.5 or more.

Here, in one aspect of the present invention, from the viewpoint of easily adjusting the shear storage elastic modulus (23°C) and tan δ to the above range, the first buffer layer and the second buffer layer are preferably formed of a resin composition containing urethane (meth) acrylate and a thiol group-containing compound. The following describes the details of each component contained in the resin composition for forming the first buffer layer and the second buffer layer (hereinafter also referred to as "resin composition for forming the buffer layer").

<Urethane (meth)acrylate> Urethane (meth)acrylate is a compound having at least a (meth)acryl group and a urethane bond, and has the property of being polymerized by energy ray irradiation. The number of (meth)acryl groups in urethane (meth)acrylate may be monofunctional, difunctional, or trifunctional or higher, but from the perspective of forming a buffer layer whose shear storage elastic modulus G'(23°C) or tan δ is adjusted to the above range, it is preferred to include a monofunctional urethane (meth)acrylate. If a monofunctional urethane (meth)acrylate is included in the film-forming composition, it is difficult to form a three-dimensional mesh structure because the monofunctional urethane (meth)acrylate does not participate in the formation of a three-dimensional mesh structure in the polymerization structure, and it is particularly easy to form a buffer layer whose shear storage elastic modulus G' (23°C) or tan δ is adjusted to the above range. The urethane (meth)acrylate used in the resin composition for forming the buffer layer can be obtained by, for example, reacting a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound with a polyvalent isocyanate compound with a (meth)acrylate having a hydroxyl group. Furthermore, the urethane (meth)acrylate can be used alone or in combination of two or more.

(Polyol compound) There are no particular restrictions on the polyol compound as long as it is a compound having two or more hydroxyl groups. Specific examples of polyol compounds include alkanediols, polyether polyols, polyester polyols, polycarbonate polyols, etc. Among these, polyether polyols are preferred. In addition, the polyol compound may be any of a difunctional diol, a trifunctional triol, or a polyol having four or more functions, but from the viewpoint of ease of acquisition, versatility, reactivity, etc., a difunctional diol is preferred, and a polyether diol is more preferred.

The polyether diol is preferably a compound represented by the following formula (1).

In the above formula (1), R is a divalent alkyl group, preferably an alkylene group, and more preferably an alkylene group having 1 to 6 carbon atoms. Among the alkylene groups having 1 to 6 carbon atoms, ethylene, propylene, and butylene are preferred, and propylene and butylene are more preferred. In addition, n is the number of repeating units of alkylene oxide, and is preferably 10 to 250, more preferably 25 to 205, and particularly preferably 40 to 185. If n is within the above range, the urethane bond concentration of the obtained urethane (meth) acrylate is appropriate, and the tan δ of the buffer layer can be easily adjusted to the above range. Among the compounds represented by the above formula (1), polyethylene glycol, polypropylene glycol, and polybutylene glycol are preferred, and polypropylene glycol and polybutylene glycol are more preferred. By reacting a polyether diol with a polyvalent isocyanate compound, an isocyanate-terminated urethane prepolymer having an ether bond [-(-RO-)n-] introduced therein is generated. By using such a polyether diol, the urethane (meth)acrylate contains a constituent unit derived from the polyether diol.

As the polyacid component used in the production of polyester polyol, compounds generally known as polyacid components of polyester can be used. As specific polyacid components, for example, dibasic acids such as adipic acid, maleic acid, succinic acid, oxalic acid, fumaric acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, and suberic acid; dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, and 2,6-naphthalene dicarboxylic acid, or aromatic polyacids such as polyacids such as trimellitic acid and pyromellitic acid, anhydrides corresponding to these or their derivatives, dimer acids, hydrogenated dimer acids, etc. Among these, aromatic polyacids are preferred from the viewpoint of forming a coating film with appropriate hardness. In the esterification reaction used to produce polyester polyol, various well-known catalysts can be used as needed. Examples of the catalyst include tin compounds such as dibutyltin oxide and stannous octoate, and titanium alkoxides such as tetrabutyl titanate and tetrapropyl titanate. There are no particular limitations on the polycarbonate type polyol, and examples include the reaction products of the aforementioned diols and alkyl carbonates.

The number average molecular weight calculated from the hydroxyl value of the polyol compound is preferably 1,000 to 10,000, more preferably 2,000 to 9,000, and particularly preferably 3,000 to 7,000. If the number average molecular weight is above 1,000, it is undesirable because it is difficult to control the shear storage elastic modulus of the buffer layer due to the formation of an excessive amount of urethane bonds. On the other hand, if the number average molecular weight is below 10,000, it is preferable because it can prevent the resulting buffer layer from being excessively softened. The number average molecular weight calculated from the hydroxyl value of the polyol compound is a value calculated by [number of polyol functional groups]×56.11×1,000/[hydroxyl value (unit: mgKOH/g)].

(Polyvalent isocyanate compounds) As polyvalent isocyanate compounds, there can be mentioned, for example, aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, etc.; isophorone diisocyanate, norbornane diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4 Alicyclic diisocyanates such as '-diisocyanate, ω,ω'-diisocyanate dimethylcyclohexane, etc.; aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, xylylene diisocyanate, toluidine diisocyanate, tetramethylene xylylene diisocyanate, naphthalene-1,5-diisocyanate, etc. Among them, from the perspective of operability, isophorone diisocyanate or hexamethylene diisocyanate, xylylene diisocyanate are preferred.

((Meth)acrylate having a hydroxyl group) The (meth)acrylate having a hydroxyl group is not particularly limited as long as it is a compound having a hydroxyl group and a (meth)acryl group in at least one molecule. Specific examples of (meth)acrylates having a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate, 5-hydroxycyclooctyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate, polyethylene glycol mono(meth)acrylate, and polypropylene glycol mono(meth)acrylate; (meth)acrylamide containing a hydroxyl group such as N-hydroxymethyl (meth)acrylamide; and reactants obtained by reacting diglycidyl esters of vinyl alcohol, vinyl phenol, and bisphenol A with (meth)acrylic acid. Among these, hydroxyalkyl (meth)acrylate is preferred, and 2-hydroxyethyl (meth)acrylate is more preferred. As conditions for reacting the terminal isocyanate urethane prepolymer and the (meth)acrylate having a hydroxyl group, it is preferred to react at 60 to 100°C for 1 to 4 hours in the presence of a solvent or catalyst added as needed.

The urethane (meth) acrylate used in the resin composition for forming the buffer layer thus obtained may be any of an oligomer, a high molecular weight body or a mixture thereof, but is preferably a urethane (meth) acrylate oligomer. The weight average molecular weight of the urethane (meth) acrylate is preferably 1,000 to 100,000, more preferably 3,000 to 80,000, and particularly preferably 5,000 to 65,000. If the weight average molecular weight is 1,000 or more, in the polymer of the urethane (meth) acrylate and the polymerizable monomer described later, appropriate hardness is imparted to the buffer layer due to the intermolecular force between the structures of the urethane (meth) acrylate, so it is preferred. The blending amount of urethane (meth) acrylate in the resin composition for forming the buffer layer is preferably 20 to 70 mass%, more preferably 25 to 60 mass%, particularly preferably 30 to 50 mass%, and particularly preferably 33 to 47 mass%. If the blending amount of urethane (meth) acrylate is within such a range, it is easier to adjust the shear storage elastic modulus (23°C) or tan δ of the buffer layer to the above range.

<Thiol group-containing compound> There is no particular limitation on the thiol group-containing compound as long as it has at least one thiol group in the molecule, but from the viewpoint of easily forming a buffer layer whose tan δ is adjusted to the above range, a polyfunctional thiol group-containing compound is preferred, and a tetrafunctional thiol group-containing compound is more preferred. Specific thiol group-containing compounds include, for example, nonylmercaptan, 1-dodecanethiol, 1,2-ethanedithiol, 1,3-propanedithiol, trithiol, trithioldithiol, trithioltrithiol, 1,2,3-propanetrithiol, tetraethylene glycol-bis(3-butylpropionate), trihydroxymethylpropanetris(3-butylpropionate), pentaerythritoltetra(3-butylpropionate), quaternary Pentaerythritol tetra-glycolate, dipentaerythritol hexa(3-butylpropionate), tris[(3-butylpropenyloxy)-ethyl]-isocyanurate, 1,4-bis(3-butylbutyryloxy)butane, pentaerythritol tetra(3-butylbutyrate), 1,3,5-tris(3-butylbutoxyethyl)-1,3,5-tris(3-butylbutoxyethyl)-2,4,6-(1H,3H,5H)-trione, etc. In addition, these thiol group-containing compounds can be used alone or in combination of two or more.

The molecular weight of the thiol group-containing compound is preferably 200 to 3,000, more preferably 300 to 2,000. If the molecular weight is within the above range, the compatibility with the urethane (meth) acrylate becomes good, and the film-forming property can be made good. The blending amount of the thiol group-containing compound is preferably 1.0 to 4.9 parts by mass, more preferably 1.5 to 4.8 parts by mass, relative to 100 parts by mass of the total of the urethane (meth) acrylate and the polymerizable monomer described later. If the blending amount is 1.0 parts by mass or more, it is easy to form a buffer layer whose tan δ is adjusted to the above range. On the other hand, if the blending amount is 4.9 parts by mass or less, the bleeding of the buffer layer when it is wound into a roll shape can be suppressed.

(Polymerizable monomer) In the resin composition for the buffer layer used in the present invention, it is preferred to further include a polymerizable monomer from the viewpoint of improving film-forming properties. The polymerizable monomer is a polymerizable compound other than the above-mentioned urethane (meth)acrylate, a compound that can polymerize with other components by irradiation with energy rays, excluding the resin component, and preferably a compound having at least one (meth)acryloyl group. In addition, in this specification, the so-called "resin component" is an oligomer or a high molecular weight body having a repeated structure in the structure, and refers to a compound with a weight average molecular weight of 1,000 or more.

Examples of the polymerizable monomer include (meth)acrylates having an alkyl group having 1 to 30 carbon atoms, (meth)acrylates having a functional group such as a hydroxyl group, an amide group, an amino group, an epoxy group, etc., (meth)acrylates having an alicyclic structure, (meth)acrylates having an aromatic structure, (meth)acrylates having a heterocyclic structure, styrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, N-vinylformamide, N-vinylpyrrolidone, vinyl compounds such as N-vinylcaprolactam, and the like.

Examples of the (meth)acrylate having an alkyl group with 1 to 30 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, and the like.

Examples of the (meth)acrylate having a functional group include hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide; Amide group-containing compounds such as amine, N-hydroxymethylpropane (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, etc.; (meth)acrylates containing amino groups such as (meth)acrylates containing primary amino groups, (meth)acrylates containing secondary amino groups, (meth)acrylates containing tertiary amino groups, etc.; (meth)acrylates containing epoxy groups such as glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, allyl glycidyl ether, etc.

Examples of (meth)acrylates having an alicyclic structure include isoborneol (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentyloxy (meth)acrylate, cyclohexyl (meth)acrylate, and adamantyl (meth)acrylate. Examples of (meth)acrylates having an aromatic structure include phenylhydroxypropyl (meth)acrylate, benzyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate. Examples of (meth)acrylates having a heterocyclic structure include tetrahydrofurfuryl (meth)acrylate and morpholine (meth)acrylate.

Among these, from the viewpoint of compatibility with the above-mentioned urethane (meth)acrylate, those having a relatively large group are preferred, and more specifically, (meth)acrylate having an alicyclic structure, (meth)acrylate having an aromatic structure, (meth)acrylate having a heterocyclic structure are preferred, and (meth)acrylate having an alicyclic structure is more preferred. Furthermore, from the viewpoint of obtaining a buffer layer-forming resin composition that easily forms a buffer layer having tan δ adjusted to the above-mentioned range, as a polymerizable monomer, (meth)acrylate having a functional group and (meth)acrylate having an alicyclic structure are preferably included, and hydroxypropyl (meth)acrylate and isoborneol (meth)acrylate are more preferably included.

Based on the above viewpoints, the blending amount of the (meth)acrylate having an alicyclic structure in the resin composition for forming the buffer layer is preferably 32 to 53% by mass, more preferably 35 to 51% by mass, particularly preferably 37 to 48% by mass, and particularly preferably 40 to 47% by mass%. In addition, from the above viewpoints, the blending amount of the (meth)acrylate having an alicyclic structure relative to the total amount of the polymerizable monomer contained in the resin composition for forming the buffer layer is preferably 52 to 87% by mass, more preferably 55 to 85% by mass, particularly preferably 60 to 80% by mass, and particularly preferably 65 to 77% by mass. If the blending amount of the (meth)acrylate having an alicyclic structure is within such a range, it is easier to adjust the shear storage modulus (23° C.) of the buffer layer to the above range.

Furthermore, the blending amount of the polymerizable monomer in the resin composition for forming the buffer layer is preferably 30 to 80 mass%, more preferably 40 to 75 mass%, particularly preferably 50 to 70 mass%, and particularly preferably 53 to 67 mass%. If the blending amount of the polymerizable monomer is within such a range, the mobility of the polymerizable monomer polymerized portion in the buffer layer is high, and the buffer layer tends to become soft, making it easier to form a buffer layer whose tan δ is adjusted to the above range or to form a buffer layer whose shear storage modulus is adjusted to the above range. From the same viewpoint, the mass ratio of urethane (meth) acrylate to polymerizable monomer in the buffer layer-forming resin composition [urethane (meth) acrylate/polymerizable monomer] is preferably 20/80 to 60/40, more preferably 30/70 to 50/50, and even more preferably 35/65 to 45/55.

(Energy ray polymerization initiator) Using ultraviolet rays or the like as energy rays to harden a coating film formed by a resin composition for forming a buffer layer, when forming a buffer layer, it is preferable that an energy ray polymerization initiator is further included in the resin composition for forming a buffer layer. Since energy ray polymerization initiators are generally also referred to as "photopolymerization initiators", they are also referred to as "photopolymerization initiators" in this manual. As the photopolymerization initiator, for example, benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and the like, and photosensitizers such as amines or quinones, etc., can be cited. More specifically, for example, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, etc. can be cited. These photopolymerization initiators can be used alone or in combination of two or more. The amount of the photopolymerization initiator blended is preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.3 to 5 parts by mass, relative to 100 parts by mass of the total of the urethane (meth)acrylate and the polymerizable monomer.

(Other additives) The resin composition for forming the buffer layer may contain other additives within the range that does not impair the effect of the present invention. As other additives, for example, crosslinking agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, pigments, dyes, etc. can be cited. When these additives are blended, the blending amount of other additives is preferably 0.01 to 6 parts by mass, and more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the total of urethane (meth) acrylate and thiol group-containing compound. Furthermore, the resin composition for forming the buffer layer may contain resin components other than urethane (meth) acrylate within the scope that does not impair the effect of the present invention, but preferably contains only urethane (meth) acrylate as the resin component. The content of the resin component other than urethane (meth) acrylate contained in the resin composition for forming the buffer layer is preferably 5% by mass or less, more preferably 1% by mass or less, particularly preferably 0.1% by mass or less, and particularly preferably 0% by mass.

Furthermore, when the buffer layer is formed more easily with tan δ adjusted to the above range or with shear storage modulus adjusted to the above range, in addition to being formed with the above-mentioned buffer layer-forming resin composition, it can also be formed with a hardened material or ethylene-α-copolymer containing a hardening composition of a non-reactive urethane polymer or oligomer and a polymerizable monomer. The non-reactive urethane polymer or oligomer can be a well-known one, and as the polymerizable monomer, the same as the above-mentioned one can be used. Such a hardening composition can also contain the above-mentioned energy line polymerization initiator.

Ethylene-α-olefin copolymer is obtained by polymerizing ethylene and α-olefin monomers. Examples of the α-olefin monomer include propylene, 1-butene, 2-methyl-1-butene, 2-methyl-1-pentene, 1-hexene, 2,2-dimethyl-1-butene, 2-methyl-1-hexene, 4-methyl-1-pentene, 1-heptene, 3-methyl-1-hexene, 2,2-dimethyl-1-pentene, 3,3-dimethyl-1-pentene, 2,3-dimethyl-1-pentene, 3-ethyl-1-pentene, 2,2,3-trimethyl-1-butene, 1-octene, and 2,2,4-trimethyl-1-octene. These α-olefin monomers may be used alone or in combination of two or more. In addition to the above-mentioned monomers, other polymerizable monomers can be used in the ethylene-α-olefin copolymer. Examples of other polymerizable monomers include vinyl compounds such as vinyl acetate, styrene, acrylonitrile, methacrylonitrile, and vinyl ketone; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated carboxylic acid esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, methyl methacrylate, ethyl methacrylate, and n-propyl methacrylate; and unsaturated carboxylic acid amides such as acrylamide and methacrylamide. These polymerizable monomers can be used alone or in combination of two or more.

[Adhesive layer] The first adhesive layer used in the support sheet of the protective film forming laminate used in the method for manufacturing a semiconductor device of one aspect of the present invention can keep the hardening resin layer in the form of a support sheet before the above step (A2) is performed. There is no particular limitation as long as the support sheet can be peeled and separated from the hardening resin layer while the hardening resin layer is adhered to the bump-attached wafer in the above step (A2). Furthermore, the second adhesive layer used in the back grinding tape used in the method for manufacturing a semiconductor device according to one aspect of the present invention is not particularly limited as long as it can fix and protect the wafer with bumps formed on the protective film.

The adhesive forming the first adhesive layer and the second adhesive layer is not particularly limited, and various adhesives that can be used for back grinding tapes in the past can be used. Specifically, rubber-based, acrylic-based, silicone-based, polyvinyl ether-based adhesives can be used. In addition, energy-ray-hardening, heat-foaming, and water-swelling adhesives can also be used. In addition, the thickness of the first adhesive layer and the second adhesive layer is as described above. Furthermore, the adhesive layer can be further bonded with a peeling film and protected by the peeling film. The peeling film is not particularly limited, and can be used on a thin sheet such as a film or paper that is peeled with a peeling agent.

[Manufacturing method of a protective film-forming laminate] The manufacturing method of the protective film-forming laminate used in one embodiment of the present invention is not particularly limited and can be manufactured by a well-known method. Specifically, for example, a support sheet is manufactured by forming a first buffer layer on a first support substrate and then forming a first adhesive layer. Then, a resin film-forming composition (X) is applied to a release material to form a curable resin layer, and the first adhesive layer and the curable resin layer of the support sheet are bonded to manufacture a protective film-forming laminate. As a method for forming the first buffer layer on the first supporting substrate, there can be cited a method of coating a buffer layer-forming resin composition on one surface of the first supporting substrate to form a coating film, and then performing a curing treatment to form the first buffer layer, or a method of coating a buffer layer-forming resin composition on a release-treated surface of a release material to form a coating film, and then performing a semi-curing treatment to form a semi-cured layer on the release material, and then bonding the semi-cured layer to the first supporting substrate, and before or after removing the release material, completely curing the semi-cured layer to form the first buffer layer, etc. As a method for forming the first adhesive layer on the first buffer layer, there can be cited a method of coating an adhesive composition for forming the first adhesive layer on the first buffer layer, or a method of coating the adhesive composition on a peeling-treated surface of a peeling material to form the first adhesive layer on the peeling material, and bonding the first adhesive layer and the first buffer layer.

As a method for applying the buffer layer forming resin composition, adhesive composition or resin film forming composition (X) on the first supporting substrate or release material, for example, spin coating, spray coating, rod coating, doctor blade coating, roll coating, blade coating, die coating, gravure coating, etc. can be cited. Furthermore, when the buffer layer forming resin composition, adhesive composition or resin film forming composition (X) is in the form of a solution containing an organic solvent, it is preferably dried by heating at a temperature of 80 to 150°C for 30 seconds to 5 minutes after application. Note that the heat treatment of the resin film-forming composition (X) is not included in the hardening treatment of the hardening resin layer in the method for manufacturing a semiconductor device of the present invention.

As a hardening treatment after coating the resin composition for forming the buffer layer to form the coating film, it is preferable to irradiate the formed coating film with energy rays such as ultraviolet rays to polymerize and harden it. In addition, the hardening treatment may be performed once to completely harden it, or may be performed in multiple steps to harden it. As energy rays, for example, ultraviolet rays, electron rays, etc. can be cited, and ultraviolet rays are preferred. In addition, the irradiation amount of energy rays is appropriately changed according to the type of energy rays. For example, when ultraviolet rays are used, the irradiation intensity of the ultraviolet rays is preferably 50 to 500 mW/cm ² , more preferably 100 to 340 mW/cm ² , and the irradiation amount of the ultraviolet rays is preferably 100 to 2,500 mJ/cm ² , more preferably 150 to 2,000 mJ/cm ² .

[Manufacturing method of back grinding tape] The manufacturing method of the back grinding tape used as one aspect of the present invention is not particularly limited, and it can be manufactured by a well-known method. Specifically, for example, a method can be cited in which a second buffer layer is formed on a second supporting substrate by the same method as the manufacturing method of the supporting sheet constituting the laminate for forming the protective film, and then a second adhesive layer is formed.

The present invention is specifically described by the following embodiments, but the present invention is not limited to the following embodiments.

[Measurement methods of various physical property values] The physical property values in the following examples and comparative examples are measured by the following methods.

<Weight average molecular weight> Measured using a gel permeation chromatograph (manufactured by Tosoh Corporation, product name "HLC-8020") under the following conditions, using the value measured in terms of standard polystyrene. (Measurement conditions) ・Column: "TSK guard column HXL-L", "TSK-Gel G2500HXL", "TSK-Gel G2000HXL", "TSK-Gel G1000HXL" (all manufactured by Tosoh Corporation) connected in sequence ・Column temperature: 40°C ・Developing solvent: tetrahydrofuran ・Flow rate: 1.0 mL/min

<Measurement of thickness of each layer> Measurement was performed using a constant pressure thickness gauge manufactured by TECLOCK Co., Ltd. (model: "PG-02J", standard specification: in accordance with JIS K6783, Z1702, Z1709).

<Glass transition temperature> The glass transition temperature (Tg) of the polymer component (XA) described below was determined by measuring the temperature profile from -70°C to 150°C at a heating and cooling rate of 10°C/min using a differential scanning calorimeter (PYRIS Diamond DSC) manufactured by PerkinElmer, Inc., and identifying the inflection point.

<Epoxy equivalent> Measured in accordance with JIS K7236:2009.

<Average Particle Size> The particles to be measured were dispersed in water by ultrasound, and the particle size distribution was measured on a volume basis using a dynamic light scattering particle size distribution analyzer (LB-550 manufactured by Horiba, Ltd.). The median particle size (D ₅₀ ) was taken as the average particle size.

[Preparation of resin layer forming composition (X)] The resin layer forming composition (X) used in the production of the protective film forming laminate used in the following examples and comparative examples was prepared by the following method.

<Ingredients used for preparing the resin layer forming composition (X)> The following shows the ingredients used for preparing the resin layer forming composition (X).

(Polymer component (XA)) Polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., S-LEC (registered trademark) B BL-10, weight average molecular weight 25,000, glass transition temperature 59°C) having constituent units represented by the following formula (i-1), the following formula (i-2) and the following formula (i-3) was used. In the following formula, p is 68 to 74 mol%, q is 1 to 3 mol%, and r is about 28 mol%.

(Epoxy resin (XB1)) The following two types of epoxy resins were used. ・Epoxy resin (XB1-1): Liquid bisphenol A type epoxy resin (manufactured by DIC Corporation, EPICLON (registered trademark) EXA-4850-1000, epoxy equivalent 404 to 412 g/eq) ・Epoxy resin (XB1-2): Dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, EPICLON (registered trademark) HP-7200, epoxy equivalent 254 to 264 g/eq)

(Thermosetting agent (XB2)) Novolac type phenolic resin (Showa Denko Co., Ltd., Shonol (registered trademark) BRG-556) was used.

(Curing accelerator (XC)) 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemical Industries, Ltd., Curezol (registered trademark) 2PHZ) was used.

(Filler (XD)) Epoxy-modified spherical silica (Admanano (registered trademark) YA050C-MKK, manufactured by ADMATECHS Co., Ltd., average particle size 0.05 μm) was used.

<Preparation of resin layer forming composition (X)> The polymer component (XA), epoxy resin (XB1-1), epoxy resin (XB1-2), thermosetting agent (XB2), curing accelerator (XC) and filler (XD) are dissolved or dispersed in methyl ethyl ketone in the following contents based on the total amount (100% by mass) of the resin layer forming composition (X), and stirred at 23°C to prepare a resin layer forming composition (X) having an active ingredient (solid component) concentration of 55% by mass. ・Polymer component (XA): 9.9 mass% ・Epoxy resin (XB1-1): 37.9 mass% ・Epoxy resin (XB1-2): 24.7 mass% ・Thermosetting agent (XB2): 18.3 mass% ・Curing accelerator (XC): 0.2 mass% ・Filling material (XD): 9.0 mass%

[Manufacturing of a laminate for forming a protective film] The laminate for forming a protective film used in the following examples and comparative examples is manufactured by the following method. First, a resin layer forming composition (X) is applied on the aforementioned peeling treatment surface of a polyethylene terephthalate peeling material (SP-PET381031 manufactured by LINTEC Co., Ltd., thickness 38 μm) having a peeling treatment surface treated with polysilicone, and then dried by heating at 120°C for 2 minutes to manufacture a laminate formed by laminating a thermosetting resin layer and a peeling material. Next, a bonding tape (E-8510HR manufactured by LINTEC Co., Ltd.) in which a first base material (thickness: 100 μm), a first buffer layer (thickness: 400 μm) and a first adhesive layer (thickness: 10 μm) are sequentially laminated is used as a supporting sheet, and the first adhesive layer of the bonding tape is laminated to a thermosetting resin layer of a laminate of a thermosetting resin layer and a release material to manufacture a laminate for forming a protective film in which a supporting sheet, a thermosetting resin layer and a release material are sequentially laminated.

[Evaluation of the minimum shear viscosity of the thermosetting resin layer] From the laminated body formed by laminating the thermosetting resin layer and the peeling material, the peeling material is peeled off, and a thermosetting resin layer with a thickness of 500μm is formed by laminating a plurality of thermosetting resin layers. Thus, a cylindrical evaluation sample with a diameter of 25mm and a thickness of 500μm is prepared, and this sample is set in the shear viscosity measuring device. At this time, the above-mentioned sample is placed in the setting place of the measuring device, and the measuring fixture is pushed from the top of the sample to fix the sample in the above-mentioned setting place. Under the conditions of frequency: 1Hz, heating rate: 10℃/min, measure the shear viscosity from room temperature (23℃) to 150℃, and find the minimum shear viscosity between 90℃ and 130℃.

[Example 1] The peeling material is removed from the protective film forming laminate, and the surface (exposed surface) of the thermosetting resin layer thus exposed is pressed against the bump forming surface of an 8-inch φ wafer with bumps, and the protective film forming laminate is attached to the bump forming surface of the semiconductor wafer. At this time, the attachment of the protective film forming laminate is performed using an attachment device (roller laminating machine, "RAD-3510 F/12" manufactured by LINTEC Co., Ltd.) under the conditions of a stage temperature of 90°C, an attachment speed of 2 mm/sec, and an attachment pressure of 0.5 MPa, while heating the thermosetting resin layer. As an 8-inch wafer with bumps, a 0.4mm pich BGA semiconductor wafer (WLPTEG M2 manufactured by Walts, wafer thickness 700μm) with a bump height of 210μm, a bump width of 250μm, and a distance between adjacent bumps of 400μm was used. Through the above, a multilayer structure formed by attaching a protective film forming multilayer body to the bump forming surface of the semiconductor wafer was obtained. Next, after UV irradiation and peeling off the support sheet of the laminate for forming the protective film (RAD-2700 manufactured by LINTEC Co., Ltd.), the wafer with bumps attached to the thermosetting resin layer was heat treated in a pressurized oven (RAD-9100 manufactured by LINTEC Co., Ltd.) at a temperature of 130°C, a time of 2 hours, and an internal pressure of 0.5 MPa to thermally cure the thermosetting resin layer and form a protective film. Then, E-8510HR manufactured by LINTEC Co., Ltd. was attached as a back grinding tape on the protective film formation surface, and the back grinding was performed to make the wafer thickness 200μm, and then the back grinding tape was peeled off to visually confirm the warp of the wafer. As a result, the wafer warping was almost invisible. In addition, after the protective film was formed, the bump surface was scanned with a digital microscope. As a result, pinholes and other points exposed on the bump formation surface of the wafer were not detected, and it was obvious that no rejection occurred. In addition, the minimum shear viscosity of the thermosetting resin layer was 2,700 Pa·s.

10: Semiconductor wafer with bumps 11: Semiconductor wafer 11a: Bump forming surface 11b: Back surface 12: Bumps 20: Curable resin layer 30: Laminated body for forming protective film 30a: Support sheet 40: Protective film 50: Back grinding tape 61: Starting point for division (groove) 71: Starting point for division (modified area)

[FIG. 1] is a schematic cross-sectional view showing an example of a wafer with bumps. [FIG. 2] is a schematic view showing steps (A) to (E) of the method for manufacturing a semiconductor device of the present invention. [FIG. 3] is a schematic view showing steps (A1) and (A2) of the method for manufacturing a semiconductor device of one embodiment of the present invention. [FIG. 4] is a schematic view showing an example of a method for manufacturing a semiconductor device of one embodiment of the present invention in which a division starting point is formed and single-chip is performed. [FIG. 5] is a schematic view showing another example of a method for manufacturing a semiconductor device of one embodiment of the present invention in which a division starting point is formed and single-chip is performed.

10: Semiconductor wafer with bumps

11: Semiconductor wafers

11a: Bump forming surface

11b: Back

12: Bump

20: Hardened resin layer

40: Protective film

50: Back grinding tape

51: Second supporting substrate

52: Second buffer layer

53: Second adhesive layer

Claims (6)

A method for manufacturing a semiconductor device comprises the following steps (A) to (E) in sequence: (A) forming a hardening resin layer on a bump-forming surface of a semiconductor wafer having bumps, (B) hardening the hardening resin layer to form a protective film, (C) attaching a back grinding tape to the protective film-forming surface of the semiconductor wafer having bumps, (D) grinding the surface opposite to the bump-forming surface of the semiconductor wafer having bumps while the back grinding tape is attached, and (E) peeling off the back grinding tape from the ground semiconductor wafer having bumps. The step (A) comprises the following steps (A1) and (A2) in sequence: (A1) a step of attaching a protective film forming laminate having a laminated structure of a laminated support sheet and a curable resin layer to the bump forming surface of the semiconductor wafer having the bump, wherein the curable resin layer is laminated to the bump forming surface of the semiconductor wafer having the bump; As the attachment surface, (A2) the step of peeling the support sheet from the protective film forming laminate and forming the curable resin layer on the bump forming surface of the semiconductor wafer having the bump; the support sheet has a laminate structure in which a first support substrate, a first buffer layer and a first adhesive layer are laminated in sequence. A method for manufacturing a semiconductor device as claimed in claim 1, wherein the aforementioned hardening resin layer is a thermosetting resin layer. A method for manufacturing a semiconductor device as claimed in claim 1 or 2, wherein the thickness of the semiconductor wafer used in the aforementioned step (A) is greater than 300μm. A method for manufacturing a semiconductor device as claimed in claim 1 or 2, wherein a dividing starting point for singulating the semiconductor wafer having the bumps is formed before the aforementioned step (A), between the aforementioned step (A) and the aforementioned step (B), between the aforementioned step (B) and the aforementioned step (C), and between the aforementioned step (C) and the aforementioned step (D). A method for manufacturing a semiconductor device as claimed in claim 1 or 2, wherein between the aforementioned step (B) and the aforementioned step (C) and in any one of the steps after the aforementioned step (E), an exposure treatment is performed to remove the aforementioned protective film covering the top of the aforementioned bump or a portion of the aforementioned protective film attached to the top of the aforementioned bump to expose the top of the aforementioned bump. A method for manufacturing a semiconductor device as claimed in claim 5, wherein the exposure treatment is a plasma etching treatment.

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