JP2007165740A - Manufacturing method of semiconductor device - Google Patents

Abstract

A die is fixed to a substrate without contaminating an electrode on the upper surface of the die with an adhesive.
In a method of manufacturing a semiconductor device, a semiconductor wafer is attached to a dicing tape via a die attach film, then the die is formed by cutting the semiconductor wafer and the die attach film, and then the die is fixed to the substrate. A semi-cured portion is formed in a frame shape by irradiation with ultraviolet light around the entire periphery of the substrate. When fixing the die to the substrate, the die is placed on the substrate via the die attach film, and then the die attach film is temporarily heated in a state where the die is pressed against the substrate. The die attach film inside the frame-shaped semi-cured part is a fluid adhesive, but the semi-cured part itself flows slightly to the outside of the die because the periphery is suppressed by the semi-cured part. Even if there is, the entire adhesive material will not flow out greatly and the adhesive material will not crawl up to the top surface of the die and contaminate the electrode.
[Selection] Figure 1

Description

  The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a technique effective when applied to a technique for connecting a thin die (semiconductor chip) to a substrate using a die attach film.

  In a method of manufacturing a semiconductor device, when a die (also referred to as a semiconductor element or a semiconductor chip) is fixed to a substrate, a die attach film is pasted on the bonding surface side of the die, and the die is used as a substrate by using this die attach film. There is known a technique for fixing to a substrate (for example, Patent Document 1). That is, when fixing the semiconductor chip to the substrate, the semiconductor chip is stacked on the substrate via the die attach film, and then the die attach film is temporarily heated to cure the die attach film to fix the semiconductor chip to the substrate. To do.

  In this method of using a die attach film, in order to make the wet shape of the die bond material uniform when, for example, dies (semiconductor chips) are stacked, a die attach film as a die bond material is pasted on the adhesive surface of the semiconductor chip in advance. deep. For this reason, when forming a semiconductor chip with a die attach film, the die attach film is bonded to the entire surface of the semiconductor wafer in which the semiconductor chips are aligned in the vertical and horizontal directions, and then the semiconductor wafer is diced in the vertical and horizontal directions together with the die attach film. A semiconductor chip (die) with a touch film is formed. Thereafter, the semiconductor chip with the die bond material attached thereto is pressurized and heated on a substrate such as a package substrate, thereby causing the fluidity and adhesiveness of the die bond material component to appear and mounting the semiconductor chip on the substrate.

  On the other hand, as a method of dividing a semiconductor wafer to form a semiconductor chip, after attaching the semiconductor wafer to a dicing tape, the laser beam is focused on the center of the wafer thickness and scanned along the dividing line. A so-called stealth dicing method is known in which a modified layer is formed, and then the dicing tape is expanded, and the wafer is divided into the modified layers by the stress during expansion (for example, Patent Document 2).

Japanese Patent Laid-Open No. 2005-116739 JP-A-2005-203803

  A conventional method for manufacturing a semiconductor device using a die attach film has, for example, steps shown in FIGS. 17 (a) to 17 (f). First, as shown in FIG. 17A, a semiconductor wafer 1 is prepared. Although not shown, the semiconductor wafer 1 is provided with dividing lines in the vertical and horizontal directions on the first surface 1a of the semiconductor wafer 1, and a circuit having electrodes on the surface is formed in a rectangular region surrounded by the dividing lines. . The semiconductor wafer 1 is finally divided vertically and horizontally along the dividing line 2, and each square area becomes a die (semiconductor chip).

  Next, as shown in FIG. 17B, a die attach film 5 made of an epoxy resin or the like is attached to the entire area of the second surface 1b opposite to the first surface 1a of the semiconductor wafer 1.

  Next, as shown in FIG. 17C, the semiconductor wafer 1 is affixed to the dicing tape 6 via the die attach film 5.

  Next, as shown in FIG. 17D, the semiconductor wafer 1 is provided with grooves 7 vertically and horizontally on the first surface 1a. Since the groove 7 is formed by a dicing blade (not shown) and the cutting depth of the dicing blade is adjusted, the groove bottom 7a becomes the intermediate depth of the dicing tape 6 as shown in FIG. A rectangular region surrounded by the groove 7 becomes a die (semiconductor chip) 8 having a circuit.

  Next, as shown in FIG. 17 (e), the die 8 is held by the collet 10 which is a vacuum suction tool, and the die 8 is peeled from the dicing tape 6. At this time, since the adhesive force between the die 8 and the die attach film 5 is large between the die attach film 5 and the dicing tape 6, the die attach film 5 is peeled off from the dicing tape 6 while being attached to the die 8. Is done.

  Next, the collet 10 carries the die 8 on the substrate 11 located at another station of semiconductor device manufacture, and places the die 8 on the substrate 11 [see FIG. 17 (e)]. The die attach film 5 on the lower surface side of the die 8 is temporarily heated from the heated substrate 11 or the like, and the die 8 is temporarily loaded. As a result, as shown in FIG. 17 (f), the die attach film 5 exhibits fluidity and undergoes a curing reaction, thereby fixing the die 8 on the substrate 11.

  In die bonding using such a die attach film, when the die 8 is thick, for example, about 200 to 300 μm or more, as shown in FIG. There is little possibility that the adhesive 5a creeps up to the upper surface side of the die 8. When the adhesive 5a does not crawl up to the upper surface side of the die 8, as shown in FIG. 18, the electrode 4 provided on the upper surface of the die 8 is not covered by the adhesive 5a, and a wire is connected to the electrode 4. In this case, the wire bonding failure due to the interposition of the insulating adhesive material 5a does not occur.

  However, when the die 8 is thinned to, for example, 150 to 80 μm or less, the adhesive material 5a having fluidity crawls up to the upper surface of the die 8, or the thin die 8 is deformed and the wetting shape by the adhesive material 5a is not uniform. Thus, the fixing of the die 8 to the substrate 11 becomes unstable.

  For example, as shown in FIG. 19 (f), when the adhesive 5 a crawls up to the upper surface side of the die 8, the scooped adhesive 5 a may cover the electrode 4 as shown in FIG. 20. As described above, covering the surface of the electrode 4 with all or part of the insulating adhesive 5a results in insufficient electrical connection (wire bonding failure) when a wire is connected on the electrode 4, and the semiconductor device. This leads to a decrease in reliability and generation of defective products.

  19A to 19F are views showing a method of manufacturing a semiconductor device when the die 8 is thin, and are process sectional views corresponding to FIGS. 17A to 17F. Therefore, the description is omitted. When the die 8 is thick, as shown in FIG. 17E, it is held by a collet 10 having a pyramidal depression on the lower surface. However, when the die 8 is thin, it is difficult to hold the collet 10 having a pyramid depression. Therefore, when the die 8 is thinned, as shown in FIG. 19 (e), the collet 10 having a flat tip surface is used to hold the entire surface of the die 8 by vacuum suction.

  An object of the present invention is to provide a technique for stably fixing a die to a substrate in a method of manufacturing a semiconductor device in which a die is fixed to a substrate using a die attach film.

  Another object of the present invention is to provide a technique for fixing a die to a substrate without contaminating the upper surface of the die in a method of manufacturing a semiconductor device in which a die is fixed to a substrate using a die attach film.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  The following is a brief description of an outline of typical inventions disclosed in the present application.

(1) A manufacturing method of a semiconductor device of the present invention includes:
(A) preparing a semiconductor wafer in which a circuit having an electrode on a surface thereof is formed in a rectangular region surrounded by a dividing line provided vertically and horizontally on a first surface;
(B) a step of attaching a die attach film to a second surface opposite to the first surface of the semiconductor wafer;
(C) attaching the semiconductor wafer to a dicing tape through the die attach film;
(D) forming a groove on the first surface of the semiconductor wafer, the groove bottom reaching the dicing tape along the dividing line, and separating the circuits to form a die;
(E) peeling from the dicing tape in a state where the die attach film is attached to each die, and bonding the die onto a substrate having a wire connection portion via the die attach film;
(F) temporarily heating and curing the die attach film, and fixing the die to the substrate;
(G) connecting the electrode of the die and the wire connecting portion with a conductive wire;
After forming the groove in the step (d),
(H) The method includes the step of semi-curing the die attach film portion exposed to the groove by irradiating the entire first surface of the semiconductor wafer with ultraviolet light.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  According to the means (1), (a) a semiconductor wafer is attached to a dicing tape via a die attach film attached to the second surface of the semiconductor wafer, and then a groove is formed on the first surface of the semiconductor wafer. A plurality of quadrangular dies are formed by forming a groove whose bottom reaches the dicing tape along the dividing line. Thereafter, the die attach film portion exposed to the groove is semi-cured by irradiating the entire first surface of the semiconductor wafer with ultraviolet light. By this ultraviolet light irradiation, a semi-cured portion is formed in a frame shape over the entire circumference of the square die. Therefore, when a die is placed on a substrate via a die attach film and then the die attach film is heated, the die attach film becomes a fluid adhesive, but the fluid adhesive is a frame-shaped adhesive. The outflow is limited by the semi-cured part of the. As a result, even if the semi-cured portion itself has fluidity, the protrusion of the adhesive to the outside of the die is limited, and it does not reach the upper surface of the die, and a good meniscus is formed. This prevents the electrodes on the top surface of the die from being contaminated by the adhesive.

  (B) By mounting the die on the substrate under pressure and heating, fluidity and adhesiveness appear in the adhesive material, and the die is fixed. By adjusting the fluidity by the semi-curing treatment as described above, Further, it is possible to eliminate the creeping of the adhesive material on the die surface and to control the shape of the meniscus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment of the invention, and the repetitive description thereof is omitted.

  1 to 6 are diagrams relating to a method of manufacturing a semiconductor device which is Embodiment 1 of the present invention. FIG. 1 is a process sectional view showing a method for manufacturing a semiconductor device. Referring to FIG. 1, in the method of manufacturing a semiconductor device according to the first embodiment, a die with a die attach film is manufactured from a semiconductor wafer, the die is fixed to the substrate, and the die electrodes and the wiring of the substrate are connected with wires. A process until connection is described.

  First, as shown in FIG. 1A, a semiconductor wafer 1 is prepared. As shown in FIG. 2, the semiconductor wafer 1 is provided with dividing lines 2 in the vertical and horizontal directions on the first surface 1 a of the semiconductor wafer 1, and has electrodes 4 on the surface of a rectangular region 3 surrounded by the dividing lines 2. A circuit is formed. FIG. 2 is a plan view showing a part of a semiconductor wafer 1 used in the method for manufacturing a semiconductor device. The dividing line 2 is shown hatched. Although it is called the dividing line 2, for example, since it is a cutting line cut by a dicing blade, it is a band-like region having a predetermined width. The semiconductor wafer 1 is finally divided vertically and horizontally along the dividing line 2 so that each rectangular region 3 becomes a die (semiconductor chip) 8 as shown in FIG. 4B. The semiconductor wafer 1 is as thin as 150 μm, for example. The semiconductor wafer 1 may be as thin as 80 μm. Use of the thin semiconductor wafer 1 can reduce the thickness of the semiconductor device.

  Next, as shown in FIG. 1A, an adhesive die attach film 5 is attached to the entire area of the second surface 1 b that is the opposite surface of the first surface 1 a of the semiconductor wafer 1. This die attach film 5 is made of, for example, an insulating epoxy resin having a thickness of about 25 μm, and is semi-cured when irradiated with ultraviolet light or laser light, and its fluidity is not irradiated even when heated. It becomes a low nature. As the die attach film 5, a film having a thickness of about 10 μm may be used. Use of the thin die attach film 5 can reduce the thickness of the semiconductor device.

  Next, as shown in FIG. 1B, an adhesive dicing tape 6 is attached to the second surface 1 b side of the semiconductor wafer 1. That is, the semiconductor wafer 1 is attached to the dicing tape 6 via the die attach film 5. Since the dicing tape 6 is a support tape that supports the semiconductor wafer 1 and needs a predetermined strength, for example, the thickness is about 100 μm.

  Next, as shown in FIGS. 1C and 3, grooves 7 are provided vertically and horizontally on the first surface 1 a of the semiconductor wafer 1. FIG. 3 is a plan view of a part of the semiconductor wafer 1 schematically showing the grooves 7. The groove 7 is formed along the dividing line 2 so as to coincide with the center of the dividing line 2 having a predetermined width by a dicing blade (not shown). Further, the cutting depth of the dicing blade is adjusted, and the groove bottom 7a is cut so as to become a halfway depth of the dicing tape 6 as shown in FIG. By this cutting, each rectangular region 3 of the semiconductor wafer 1 is cut into a die (semiconductor chip) 8. Each die 8 is supported by the dicing tape 6 while the semiconductor wafer 1 is disposed.

  Next, as shown in FIG. 1D, a semi-curing process is performed by irradiating the ultraviolet light 9 including the entire die 8 in an arrayed state on the semiconductor wafer, that is, the groove 7 region. Due to the irradiation with the ultraviolet light 9, the die attach film portion exposed to the groove 7 is changed into a semi-cured portion 15. The depth of the semi-cured portion 15, that is, the width in the direction perpendicular to the groove 7 varies depending on the irradiation time and irradiation energy of the ultraviolet light 9, but is about 100 to 500 μm, for example. As shown in FIGS. 3 and 4B, the semi-cured portion 15 is formed along the entire circumference of the square die 8 and becomes a frame. FIG. 4B is a schematic diagram showing the surface side of the die 8 to which the die attach film 5 is attached. FIG. 3 is a diagram schematically showing the groove 7 and also a diagram schematically showing the die attach film 5. In this figure, the portions indicated by thick black lines on both sides of the groove 7 are semi-cured portions 15. When the die attach film 5 is heated, the semi-cured portion 15 is a portion where the fluidity is lower than the fluidity of the portion that is not irradiated with the ultraviolet light 9 and is difficult to flow out.

  Next, as shown in FIG. 1 (e), the die 8 is held by a collet 10 which is a vacuum suction tool, and the die 8 is peeled from the dicing tape 6. At this time, since the adhesive force between the die 8 and the die attach film 5 is large between the die attach film 5 and the dicing tape 6, the die attach film 5 is peeled off from the dicing tape 6 while being attached to the die 8. Is done.

  Next, the collet 10 carries the die 8 on the substrate 11 located at another station of semiconductor device manufacture, and places the die 8 on the substrate 11. The die attach film 5 on the lower surface side of the die 8 is temporarily heated from the heated substrate 11 or the like, and the die 8 is temporarily loaded. As a result, as shown in FIG. 1 (f), the die attach film 5 exhibits fluidity and undergoes a curing reaction to fix the die 8 on the substrate 11. FIG. 4A is a schematic diagram showing the die 8 fixed on the substrate 11 by the adhesive 5a. As shown in FIGS. 1 (g) and 4 (a), the meniscus protruding from the periphery of the die 8 of the adhesive 5 a that fixes the die 8 to the substrate 11 is formed evenly except for the corners of the square die 8. In addition, it does not creep up to the upper surface side of the die 8 beyond the peripheral surface of the die 8.

  That is, the die 8 is picked up by the collet 10 and pressure-mounted on the heated substrate 11 or the like, whereby fluidity or adhesiveness appears in the adhesive 5a that is a die bond material, and the die 8 is fixed. The fluidity can be adjusted by selecting the width of the semi-cured portion 15 by the semi-curing treatment performed previously. As a result, it is possible to eliminate the creeping of the adhesive 5a on the surface of the die 8 having the electrode 4 and to control the shape of the meniscus so that stable die bonding can be performed.

  In addition, since the semi-cured portion 15 is not formed in the central portion of the die 8 or the like, even if the surface of the substrate 11 has irregularities, the adhesive 5a can fill the irregularities and ensure good adhesion.

  Next, as shown in FIG. 1E, the electrode 4 (not shown) of the die 8 and the wiring (wire bonding pad) (not shown) of the substrate 11 are electrically connected by a conductive wire 16.

  Thereafter, a sealing body made of an insulating resin is formed on the upper surface side of the wiring substrate 11 and, if necessary, external electrode terminals such as bump electrodes are formed on the electrodes on the lower surface of the wiring substrate 11 to manufacture a semiconductor device.

  FIG. 5 is a cross-sectional view of a semiconductor device manufactured by the method for manufacturing the semiconductor device of FIGS. 6 is an enlarged cross-sectional view of a part of FIG.

  As shown in FIG. 5, the semiconductor device 20 has a rectangular wiring board. This wiring board constitutes the board 11 shown in FIG. 1 and the like and is described in more detail in FIG.

  The wiring board 11 has, for example, a multilayer wiring structure made of glass / epoxy resin. The wiring board 11 has predetermined patterns of wirings 22, 23, and 24 on the upper surface, the lower surface, and the middle layer, respectively. At least a part of these wirings 22, 23, 24 are electrically connected by conductors 25 provided in the depth direction of the wiring board 11. Solder resists 27 and 28 are selectively provided on the upper and lower surfaces of the wiring board 11. The wirings 22, 23, and 24 are formed of, for example, a copper layer having a thickness of 20 μm, and the solder resists 27 and 28 have a thickness of about 30 to 40 μm.

  A bump electrode 29 made of a ball electrode is formed on the wiring 23 on the lower surface of the wiring substrate 11. The bump electrode 29 is formed of, for example, a ball electrode made of SnAgCu having a diameter of 0.3 mm, and the pitch is about 0.8 to 0.5 mm. In the embodiment, the bump electrodes 29 are arranged in two rows along each side of the rectangular wiring board 11.

  As shown in FIGS. 5 and 6, the first die 8a is fixed on the solder resist 27 at the center of the upper surface of the wiring substrate 11 by an adhesive 5a. A second die 8b is fixed on the first die 8a by an adhesive 5a. The second die 8b is smaller than the first die 8a, and when the second die 8b is fixed on the first die 8a so that the center of the second die 8b is aligned with the center of the first die 8a. The electrode 4 on the upper surface of the first die 8a is exposed to the outside of the second die 8b. Both the adhesive 5a for adhering the first die 8a to the wiring substrate 11 and the adhesive 5a for adhering the second die 8b on the first die 8a are semi-cured portions 15.

  The exposed electrode 4 of the first die 8 a and the predetermined wiring 22 are electrically connected by a conductive wire 16. Further, the electrode 4 of the second die 8 b and the predetermined wiring 22 are electrically connected by a conductive wire 16. As the wire 16, for example, a gold wire having a diameter of 18 to 25 μm is used.

  The upper surface side of the wiring board 11 is covered with a sealing body 30 made of an insulating resin having a certain height. The height of the sealing body 30 is about 0.6 mm, for example. The height (loop height) of the wire 16 connected to the electrode 4 of the second die 8b from the upper surface of the second die 8b is suppressed to about 100 to 120 μm. As a result, the thickness of the resin forming the sealing body 30 on the apex of the wire 16 connected to the second die 8b is as thick as 250 μm, and the moisture resistance of the semiconductor device 20 is good.

  The semiconductor device 20 has a structure in which dies are stacked in two stages. The die attach film 5 having a semi-cured portion 15 formed on the periphery thereof is used to form a die (first die) on each of the wiring substrate 11 and the first die 8a. In order to fix the second die 8a and 8b), the respective bonding materials 5a can be die-bonded without crawling up to the upper surfaces of the first and second dies 8a and 8b.

  Further, in the wiring substrate 11, the unevenness on the surface of the solder resist 27 becomes a maximum variation of 10 to 15 μm due to the variation in the thickness of the wiring, but because it is die bonding by the die attach film 5 having a thickness of 25 μm, Reliable bonding is possible without being affected by the variation. This is because the die attach film 5 affixed to the die has only a semi-cured portion 15 only at the peripheral portion thereof, and the adhesive 5a inside the semi-cured portion 15 extending in a frame shape becomes the semi-cured portion 15. Since the bonding is performed in a state of being surrounded by the periphery, the bonding with the adhesive 5a having a sufficient thickness (25 μm) is possible, and the reliable die bonding is possible.

  Next, a method for manufacturing such a semiconductor device 20 will be briefly described. In the manufacture of the semiconductor device 20, the wiring substrate 11 is first prepared.

  Next, the 1st die | dye 8a is fixed using the die attach film 5 which has the semi-hardened part 15 in the periphery at the one surface side which has the wiring 22 of the wiring board 11. FIG.

  Next, the 2nd die | dye 8b is fixed using the die attach film 5 which has the semi-hardened part 15 in a periphery on the 1st die | dye 8a.

  Next, the electrode 4 of the first die 8 a and the predetermined wiring 22 of the wiring substrate 11 are connected by the wire 16, and the electrode 4 of the second die 8 b and the predetermined wiring 22 of the wiring substrate 11 are connected by the wire 16. To do.

  Next, a resin layer having a predetermined height is formed of an insulating resin on the surface side of the wiring board 11 on which the first and second dies 8a and 8b are mounted.

  Next, a ball electrode is attached on each wiring 23 of the wiring board 11 and the ball electrode is temporarily heated to form a bump electrode 29.

  Next, a plurality of semiconductor devices 20 are formed by cutting the wiring substrate 11 and the resin layer vertically and horizontally with a dicing blade.

  FIG. 7 is a modification of the first embodiment, and is another example in which the semi-cured portion 15 is formed along the periphery of the die 8. FIG. 7 shows a state where the die attach film 5 is attached to the second surface 1 b of the semiconductor wafer 1 and the die attach film 5 is attached to the dicing tape 6. For such a thing, the focus of the laser beam is tied inside the die attach film 5 by an optical system. That is, the laser light 36 emitted from a laser light source (not shown) of the optical system is converged by the convex lens 35 and the focal point 37 is connected to the inside of the die attach film 5. As a result, the die attach film portion to which the focal point 37 is connected becomes the semi-cured portion 15 by the heat of the laser beam. Therefore, the semi-cured portion 15 can be formed in a desired pattern by moving the optical system relative to the semiconductor wafer 1. For example, the semi-cured portion 15 is formed along the dividing line 2 of the semiconductor wafer 1 and wider than the groove width by the dicing blade formed on the dividing line 2, and after the dividing by the groove, the semi-cured portion is semi-cured around the periphery of the die 8. The portion 15 is left with a predetermined width.

  In FIG. 7, the laser beam 36 is irradiated from the first surface 1 a side of the semiconductor wafer 1 to focus the focal point 37 on the intermediate thickness portion of the die attach film 5, but the laser beam is irradiated from the dicing tape 6 surface side. 36 may be irradiated so that the focal point 37 is formed at the intermediate thickness portion of the die attach film 5.

The first embodiment has the following effects.
(1) After attaching the semiconductor wafer 1 to the dicing tape 6 via the die attach film 5 attached to the second surface 1b of the semiconductor wafer 1, the groove bottom 7a is formed on the first surface 1a of the semiconductor wafer 1. A plurality of rectangular dies 8 are formed by forming grooves 7 reaching the dicing tape 6 along the dividing line 2. Thereafter, the ultraviolet light 9 is applied to the entire first surface 1 a of the semiconductor wafer 1 to semi-cure the portion of the die attach film 5 exposed in the groove 7. By this ultraviolet light irradiation, a semi-cured portion 15 is formed in a frame shape over the entire periphery of the square die 8. Accordingly, when the die 8 is placed on the substrate 11 via the die attach film 5 and then the die attach film 5 is heated, the die attach film 5 becomes an adhesive 5a having a reduced elastic modulus and fluidity. However, the outflow is limited by the frame-shaped semi-cured portion 15. As a result, even if the semi-cured portion itself has fluidity, the protrusion of the adhesive 5a to the outside of the die 8 is limited and does not reach the upper surface of the die 8, and a good meniscus is formed. . Thereby, the electrode 4 on the upper surface of the die 8 is not contaminated by the adhesive 5a. In other words, in the manufacturing method of the semiconductor device 20 that fixes the die 8 to the substrate 11 using the die attach film 5, the die 8 can be fixed to the substrate 11 without contaminating the upper surface of the die 8. Therefore, according to the embodiment, the die 8 can be stably fixed to the substrate 11.

  (2) By mounting the die 8 on the substrate 11 under pressure and heat, fluidity and adhesiveness appear in the adhesive material 5a, and the die 8 is fixed. By adjusting, it is possible to eliminate the creeping of the adhesive 5a on the die surface, and the shape of the meniscus can be controlled.

  (3) Since the wet shape of the adhesive 5a (die bond material) can be controlled by the semi-curing process, the assembly failure of the semiconductor device 20 (package) using the thin die 8 is reduced and the package design is free. The degree increases.

  8 to 10 are diagrams relating to a method of manufacturing a semiconductor device which is Embodiment 2 of the present invention. FIG. 8 is an explanatory view showing a state in which the die attach film attached to the die is partially semi-cured, and FIG. 9 is an illustration showing a state in which the die attach film attached to the die is partially semi-cured. FIG. 10 and FIG. 10 are explanatory views showing the die fixed to the substrate.

  Example 2 is a method of locally irradiating the ultraviolet light 9 before or after forming the groove 7 on the first surface 1a of the semiconductor wafer 1 in the method of manufacturing the semiconductor device of Example 1. That is, the first surface 1a or the second surface 1b of the semiconductor wafer 1 is locally irradiated with the ultraviolet light 9 so that the die attach film 5 portion along the dividing line 2 is continuously or partially semi-cured. Thereby, the semi-cured portion 15 extending continuously or partially along the edge of the rectangular region 3 of the semiconductor wafer 1 can be formed. When the die 8 is mounted on the substrate 11 using the die attach film 5, the semi-cured portion 15 prevents the adhesive 5 a from creeping up on the upper surface of the die 8. The second embodiment is an example in which the ultraviolet light 9 is irradiated from the second surface 1b side of the semiconductor wafer 1.

  FIGS. 8A and 8B are examples in which the semi-cured portion 15 is provided on the center side of each of the four sides without providing the semi-cured portion 15 at the four corners of the square die 8. In order to form such a die 8, as shown in FIG. 9A, spot light 40 such as ultraviolet light 9 is irradiated from the surface of the dicing tape 6 side. Then, the spot light 40 is moved along the dividing line 2, in other words, along the groove 7, and the die attach film 5 in the portion near the center of each side of the die 8 along the groove 7 is made a semi-cured portion 15. Further, the spot light 40 (ultraviolet light 9) is not irradiated to the intersection of the dividing lines 2, in other words, the intersection of the grooves 7. As a result, as shown in FIG. 9B, the semi-cured portions 15 can be provided on the center side of each of the four sides without providing the semi-cured portions 15 at the four corners of the die 8. The spot light 40 can be accurately moved by using the dividing line 2 or the groove 7 as a guide.

  FIGS. 10A and 10B are a schematic plan view and a schematic cross-sectional view in which the die 8 is fixed to the substrate 11 by the adhesive 5a made of the die attach film 5. FIG. Since the die attach film 5 is not a semi-cured portion 15 at the four corners of the quadrilateral die 8, the die attach film 5 may spread on the upper surface of the substrate 11 and crawl up to the upper surface of the die 8 as shown in FIG. However, since there is no electrode 4 in the corresponding portion, there is no problem, and since the die attach film 5 is a semi-cured portion 15 on the center side of each side of the square die 8, Since the adhesive 5a near the center is prevented from flowing out of the die 8 by the semi-cured portion 15, a good meniscus is formed as shown in FIG. .

  According to the second embodiment, the semiconductor wafer 1 to which the die attach film 5 is pasted is diced, and a spot light 40 such as ultraviolet light 9 is irradiated from the back surface of the wafer with a dicing line (groove 7) as a reference. There is a feature that a semi-cured region can be freely formed so as to obtain a desired wet shape, such as semi-curing the die bond component (adhesive 5a) only at the center of the side of the part.

  FIG. 11 is an explanatory view showing a state in which the die attach film attached to the die is partially semi-cured in the semiconductor device manufacturing method according to the third embodiment of the present invention, and FIG. 12 shows the semiconductor device according to the third embodiment. It is explanatory drawing which shows the die | dye fixed to the board | substrate in the manufacturing method of.

  The method for manufacturing a semiconductor device according to Example 3 is an example in which a semi-cured portion having a desired pattern is formed by performing ultraviolet irradiation treatment a plurality of times. In the third embodiment, the ultraviolet light irradiation process is performed twice in the second embodiment, and in one of the two processes, the die 8 (in the state of the semiconductor wafer 1) as shown in FIG. Forms a semi-cured portion 15a over the entire periphery of the rectangular region 3). In another process, as shown in FIG. 11 (a), inside the semi-cured portion 15a and at the corner (corner) of the die 8 (rectangular region 3 in the state of the semiconductor wafer 1). ) (The center side of each side) is semi-cured to form a semi-cured portion 15b.

  12A and 12B show a schematic plan view and a schematic cross-sectional view in which the die 8 is fixed to the substrate 11 with an adhesive 5a made of a die attach film 5. FIG. At the four corners of the quadrilateral die 8, the die attach film 5 is only the semi-cured portion 15a, and the side portion outside the four corners is a wide portion where the semi-cured portion 15a and the semi-cured portion 15b are arranged. Thereby, in the four corners, the force by the semi-cured portion 15a that suppresses the protrusion of the adhesive material 5a is smaller than the force that suppresses the protrusion of the adhesive material 5a by the semi-cured portion 15a and the semi-cured portion 15b of the side portion. 5a can fix the die 8 in a state where a uniform and good meniscus is formed on the entire circumference of the die 8 without climbing up to the upper surface of the die 8.

  13 to 16 are diagrams relating to a method for manufacturing a semiconductor device according to a fourth embodiment of the present invention. FIG. 13 is a schematic view showing a state in which the altered layer is formed by focusing the laser beam inside the semiconductor wafer, and a state in which the semi-cured portion is formed by focusing the laser beam inside the die attach film. FIG. 14 is a schematic view showing a deteriorated layer portion formed on a semiconductor wafer, FIG. 15 is a plan view showing a state in which the dicing tape is expanded to divide the semiconductor wafer and the die attach film, and FIG. 16 is an expanded dicing tape. It is sectional drawing which shows the state which divides a semiconductor wafer and a die attach film.

  In Example 4, as shown in FIG. 1B of Example 1, the adhesive 5a is attached to the second surface 1b of the semiconductor wafer 1, and the dicing tape 6 is attached to the die attach film 5. prepare.

  Next, as shown in FIG. 13A, the laser beam 36 is irradiated from the first surface 1a side of the semiconductor wafer 1 by the convex lens 35 constituting the optical system, and the laser beam is irradiated into the semiconductor wafer 1 by the convex lens 35. The focal point 37 of the light 36 is formed. Further, the modified lens 45 is continuously or partially formed on the semiconductor wafer 1 by moving the convex lens 35 so as to coincide with a dividing line (not shown). In the embodiment, the altered layer 45 is formed as shown in FIG. FIG. 14 schematically shows the altered layer 45 formed on the semiconductor wafer 1. The altered layer 45 overlaps the dividing line 2. The altered layer 45 has a tensile strength that is lowered by laser light irradiation, and is divided by a predetermined tensile force.

  Next, as shown in FIG. 13B, laser light 36 is irradiated from the first surface 1a side of the semiconductor wafer 1 by the convex lens 35 constituting the optical system, and the die attach film 5 is irradiated by the convex lens 35. The focal point 37 of the laser beam 36 is formed. Further, the convex lens 35 is moved so as to coincide with a dividing line (not shown), and the die attach film 5 is semi-cured continuously or partially to form the semi-cured portion 15. The semi-cured portion 15b is formed so as to overlap the altered layer 45 shown in FIG. This semi-cured portion 15 may have a function of improving the breakability at the time of stretching by laser beam irradiation, but it may have a characteristic of being divided along the parting line of the die at the time of stretching regardless of the laser beam irradiation. good.

  Next, as shown in FIGS. 13C, 15 and 16, the dicing tape 6 is expanded as shown by the arrows. As a result, the semiconductor wafer 1 is divided at the altered layer 45 formed along the dividing line 2, and the die attach film 5 is divided at the semi-cured portion 15 formed along the dividing line 2. As shown in FIG. 13 (c), the die 8 is formed by this division, and the die attach film 5 attached to the die 8 is a semi-cured portion along the periphery of the die attach film 5. 15

  In the embodiment, the laser beam is irradiated from the first surface 1 a side of the semiconductor wafer 1, but the laser beam may be irradiated from the second surface 1 b side of the semiconductor wafer 1. In the embodiment, the laser beam irradiation is continuous, but partial irradiation may be performed.

  In the fourth embodiment, it is not necessary to form a groove as in the first embodiment. Instead, an altered layer 45 is formed inside the semiconductor wafer 1 by an optical system, and then the dicing tape 6 is expanded and the altered layer 45 is used as the semiconductor. A so-called stealth dicing method for dividing the wafer 1 is employed. And it is set as the method of forming the semi-hardened part 15 in the die attach film 5 using the optical system used with a stealth dicing method. As a result, it is possible to provide a stable die bonding method capable of reducing the number of man-hours required for apparatus setting.

  The invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Nor.

It is process sectional drawing which shows the manufacturing method of the semiconductor device which is Example 1 of this invention. 2 is a plan view showing a part of a semiconductor wafer used in Example 1. FIG. It is a schematic diagram of a part of a semiconductor wafer showing a state where grooves are formed in Example 1 and the die attach film is partially altered. It is a schematic diagram which shows the die | dye fixed on the board | substrate in Example 1, and the adhesion surface side of die | dye. 1 is a cross-sectional view of a semiconductor device manufactured according to Example 1. FIG. FIG. 6 is an enlarged sectional view of a part of FIG. 5. It is a schematic diagram which shows the state which focuses the laser beam inside the die attach film by the modification of Example 1. FIG. In the manufacturing method of the semiconductor device which is Example 2 of this invention, it is explanatory drawing which shows the state which made the die attach film affixed on die | dye partially the semi-hardened part. In the manufacturing method of the semiconductor device of Example 2, it is explanatory drawing which shows the state which makes the die attach film affixed on die | dye partially a semi-hardened part. In the manufacturing method of the semiconductor device of Example 2, it is explanatory drawing which shows the die fixed to the board | substrate. In the manufacturing method of the semiconductor device which is Example 3 of this invention, it is explanatory drawing which shows the state which made the die attach film affixed on die | dye partially the semi-hardened part. In the manufacturing method of the semiconductor device of Example 3, it is explanatory drawing which shows the die | dye fixed to the board | substrate. In the method of manufacturing a semiconductor device according to the fourth embodiment of the present invention, the state in which the deteriorated layer is formed by focusing the laser beam inside the semiconductor wafer, and the laser beam is focused inside the die attach film. It is a schematic diagram which shows the state etc. which form a semi-hardened part. In Example 4, it is a schematic diagram which shows the deteriorated layer part formed in the semiconductor wafer. In Example 4, it is a top view which shows the state which expands a dicing tape and divides | segments a semiconductor wafer and a die attach film. In Example 4, it is sectional drawing which shows the state which expands a dicing tape and divides | segments a semiconductor wafer and a die attach film. It is process sectional drawing explaining the manufacturing method of the semiconductor device which uses the conventional die attach film. In the manufacturing method of the semiconductor device using the conventional die attach film, it is a top view of the die formed and fixed with a favorable meniscus. It is process sectional drawing which shows the method of fixing a thin die | dye to a board | substrate with the manufacturing method of the semiconductor device which used the conventional die attach film. It is a top view which shows the inconvenient state at the time of fixing a thin die | dye to a board | substrate with the manufacturing method of the semiconductor device which used the conventional die attach film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Semiconductor wafer, 1a ... 1st surface, 1b ... 2nd surface, 2 ... Dividing line, 3 ... Square area, 4 ... Electrode, 5 ... Die attach film, 5a ... Adhesive material, 6 ... Dicing tape, 7 ... groove, 7a ... groove bottom, 8 ... die (semiconductor chip), 8a ... first die (semiconductor chip), 8b ... second die (semiconductor chip), 9 ... ultraviolet light, 10 ... collet, 11 ... substrate 15 ... semi-cured portion, 15a ... semi-cured portion, 15b ... semi-cured portion, 16 ... wire, 20 ... semiconductor device, 22, 23, 24 ... wiring, 25 ... conductor, 27, 28 ... solder resist, 29 ... bump Electrode, 30 ... sealed body, 35 ... convex lens, 36 ... laser light, 37 ... focus, 40 ... spot light, 45 ... altered layer.

Claims (5)

(A) preparing a semiconductor wafer in which a circuit having an electrode on a surface thereof is formed in a rectangular region surrounded by a dividing line provided vertically and horizontally on a first surface;
(B) a step of attaching a die attach film to a second surface opposite to the first surface of the semiconductor wafer;
(C) attaching the semiconductor wafer to a dicing tape through the die attach film;
(D) forming a groove on the first surface of the semiconductor wafer, the groove bottom reaching the dicing tape along the dividing line, and separating the circuits to form a die;
(E) peeling from the dicing tape in a state where the die attach film is attached to each die, and bonding the die onto a substrate having a wire connection portion via the die attach film;
(F) temporarily heating and curing the die attach film, and pressurizing and fixing the die to the substrate;
(G) connecting the electrode of the die and the wire connecting portion with a conductive wire;
After forming the groove in the step (d),
(H) A method of manufacturing a semiconductor device, comprising the step of semi-curing the die attach film portion exposed to the groove by irradiating the entire first surface of the semiconductor wafer with ultraviolet light. (A) preparing a semiconductor wafer in which a circuit having an electrode on a surface thereof is formed in a rectangular region surrounded by a dividing line provided vertically and horizontally on a first surface;
(B) a step of attaching a die attach film to a second surface opposite to the first surface of the semiconductor wafer;
(C) attaching the semiconductor wafer to a dicing tape through the die attach film;
(D) forming a groove on the first surface of the semiconductor wafer, the groove bottom reaching the dicing tape along the dividing line, and separating the circuits to form a die;
(E) peeling from the dicing tape in a state where the die attach film is attached to each die, and bonding the die onto a substrate having a wire connection portion via the die attach film;
(F) temporarily heating and curing the die attach film, and pressurizing and fixing the die to the substrate;
(G) connecting the electrode of the die and the wire connecting portion with a conductive wire;
Before or after the formation of the groove in the step (d),
(H) The first surface or the second surface of the semiconductor wafer is locally irradiated with ultraviolet light so that the die attach film portion along the dividing line is continuously or partially semi-cured, and the quadrangle A method of manufacturing a semiconductor device, comprising: forming a semi-cured portion that extends continuously or partially along an edge of a region. In the step (h), the ultraviolet light irradiation treatment is performed twice. In one of the two times, the semi-cured portion is formed over the entire edge of the rectangular region, and the other time 3. The method of manufacturing a semiconductor device according to claim 2, wherein in the processing, a portion inside the semi-cured portion and excluding a corner portion of the quadrangular region is semi-cured. (A) preparing a semiconductor wafer in which a circuit having an electrode on a surface thereof is formed in a rectangular region surrounded by a dividing line provided vertically and horizontally on a first surface;
(B) a step of attaching a die attach film to a second surface opposite to the first surface of the semiconductor wafer;
(C) attaching the semiconductor wafer to a dicing tape through the die attach film;
(D) forming a groove on the first surface of the semiconductor wafer, the groove bottom reaching the dicing tape along the dividing line, and separating the circuits to form a die;
(E) peeling from the dicing tape in a state where the die attach film is attached to each die, and bonding the die onto a substrate having a wire connection portion via the die attach film;
(F) temporarily heating and curing the die attach film, and pressurizing and fixing the die to the substrate;
(G) connecting the electrode of the die and the wire connecting portion with a conductive wire;
Before or after the formation of the groove in the step (d),
(H) Laser light is irradiated from the first surface or the second surface side of the semiconductor wafer by an optical system, the laser light is focused inside the die attach film by the optical system, and the optical system A method of manufacturing a semiconductor device, comprising the step of moving the die attach film so as to coincide with the dividing line and semi-curing the die attach film continuously or partially. (A) preparing a semiconductor wafer in which a circuit having an electrode on a surface thereof is formed in a rectangular region surrounded by a dividing line provided vertically and horizontally on a first surface;
(B) a step of attaching a die attach film to a second surface opposite to the first surface of the semiconductor wafer;
(C) attaching the semiconductor wafer to a dicing tape through the die attach film;
(D) forming the die by dividing the semiconductor wafer at the dividing line;
(E) peeling from the dicing tape in a state where the die attach film is attached to each die, and bonding the die onto a substrate having a wire connection portion via the die attach film;
(F) temporarily heating and curing the die attach film, and pressurizing and fixing the die to the substrate;
(G) connecting the electrode of the die and the wire connecting portion with a conductive wire;
Before the formation of the die of step (d),
(H) Laser light is irradiated from the first surface or second surface side of the semiconductor wafer by an optical system, and the laser light is focused inside the semiconductor wafer by the optical system. A step of forming a deteriorated layer continuously or partially on the semiconductor wafer by being moved so as to coincide with the dividing line;
(I) irradiating laser light from the first surface or the second surface side of the semiconductor wafer by an optical system, and focusing the laser light inside the die attach film by the optical system; Moving the die attach film so as to coincide with the dividing line, and continuously or partially semi-curing the die attach film,
In the step (d), the dicing tape is expanded to divide the semiconductor wafer and the die attach film along the dividing line, thereby forming each die.

Images