JP2012036374A - Adhesive tape for wafer processing, method for producing the same, and method of using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape that is used for wafer processing and can minimize the size of fracture and cracking, also can control generation of fracture and cracking when cutting wafer to chips, and to provide an environmentally-friendly method for producing the adhesive tape, further to provide a method for using the adhesive tape for wafer processing by maximizing the performance of the tape.SOLUTION: The adhesive tape for wafer processing has at one side of a base material layer an adhesive layer containing 30 wt.% of a mixture of one or at least two sorts of α-olefin copolymers comprised of propylene, 1-butene, and 5-12C α-olefin as unit components, wherein a storage modulus G' of the adhesive layer is at least 1 MPa at 15-35°C, and tanδ the ratis of the loss modulus G'' to the storage modulus G', is at least 0.05.

Description

  The present invention relates to an adhesive tape for wafer processing, a method for manufacturing the same, and a method for using the same, and more particularly, an adhesive for wafer processing used for fixing and holding a wafer when cutting the wafer into chips mainly in a semiconductor manufacturing process. The present invention relates to a tape, a manufacturing method thereof, and a usage method thereof.

  For semiconductor wafers such as silicon, gallium arsenide, germanium silicon, etc., after forming a circuit pattern in the state of a wafer having a large diameter, the back surface of the wafer is ground and this wafer is cut into chips (dicing). , Moved to the mounting process and mounted. In this dancing process, an adhesive tape for wafer processing is used to fix and hold the semiconductor wafer.

  For this wafer processing adhesive tape, in addition to the pressure sensitive adhesive tape, UV curable or electron beam curable adhesive tape that controls the adhesive force is used. In either case, the wafer is used as a chip. There is a problem that chipping and cracking occur when cutting.

  With this pressure sensitive type or UV or electron beam curing type adhesive tape for wafer processing, when the chip is peeled off from the wafer processing adhesive tape after the wafer is processed, the adhesive or substrate cutting waste is removed from the chip surface. May adhere to. The cutting waste may corrode the circuit portion of the chip or deteriorate the adhesion between the chip and the resin mold, and may cause the chip to be defective.

  Also, wafer processing adhesive tapes with pressure sensitive, ultraviolet or electron beam curable adhesives are inferior in processing stability during production and long-term storage stability, and therefore have a controlled manufacturing environment, transportation and storage environment. There is a problem that it is necessary and the usable period is short. Also, in this type of wafer processing adhesive tape, if the adhesive layer deteriorates due to some variation factors such as manufacturing conditions or storage conditions, a large number of defective chips due to the wafer processing adhesive tape are generated. was there.

  Furthermore, a method for producing a tape having a pressure-sensitive type, ultraviolet ray or electron beam curable type adhesive is prepared by applying a surface treatment after producing a film for a base material layer and applying a composition for an adhesive layer dissolved in a solvent. A method of drying the solvent is common. In this method, an organic solvent is used for coating, and a larger amount of energy is used for a solvent drying process and the like, so that the load on the environment is large and the cost is high.

  On the other hand, as a method for preventing the occurrence of chipping and cracking during cutting processing, a method of cutting a wafer by fixing the wafer with wax is known. However, since productivity is very low, a brittle wafer or high-precision Except when a processing surface is required, it is not generally used for processing a wafer on which a circuit pattern is formed in a semiconductor manufacturing process.

As a method for preventing chip breakage due to chipping or crack enlargement, Japanese Patent Laid-Open No. 5-335411 discloses a semiconductor chip in which a groove having a predetermined depth is formed from the front surface side of a wafer and then ground from the back surface side. A manufacturing method is disclosed. In Japanese Patent Laid-Open No. 2000-68237, a groove having a notch depth shallower than the wafer thickness is formed from the wafer surface on which a circuit pattern is formed, and then the wafer back surface is ground and divided into chips. It is disclosed that a surface protective sheet having an adhesive layer having an elastic modulus at 40 ° C. of 1.0 × 10 ⁵ Pa or more is used. However, the size of chipped chips and cracks that are thought to occur during grinding is not specified.

Japanese Patent Application Laid-Open No. 10-242086 discloses a holding sheet having an adhesive layer having a storage modulus of 3 × 10 ⁶ to 1 × 10 ¹⁰ dye / cm ² in the range of 0 to 10 ° C. However, at the time of dicing processing, the effect of suppressing chipping and cracking is only judged under very gentle evaluation conditions in which the size of chipping or cracking generated in the chip is 75 μm or less.
Thus, an adhesive tape for wafer processing that can minimize the size of chips and cracks generated during wafer processing to the same extent as in the wax fixing method has not been obtained.

Japanese Patent Publication No. 3-39524 discloses that the dynamic elastic modulus E ′ measured at 25 ° C. is in the range of 3 × 10 ^{7 to} 5 × 10 ⁹ dye / cm ² and the loss coefficient tan δ is 0.4 or more. A specific α-olefin copolymer is disclosed, and it is disclosed that when this copolymer is laminated with a metal, it exhibits vibration damping performance. However, there is no specific use description as an adhesive tape for wafer processing.

  Furthermore, JP-A-7-233354, JP-A-10-298514, JP-A-11-43655, JP-A-11-21519, and JP-A-11-106716 are all specified as adhesive layers. A surface protective film containing an α-olefin copolymer of the above is disclosed. However, there is no description about the adhesive tape for wafer processing with severe performance requirements.

JP-A-5-335411 JP 2000-68237 A Japanese Patent Laid-Open No. 10-242086 Japanese Patent Publication No. 3-39524 JP-A-7-233354 Japanese Patent Laid-Open No. 10-298514 JP 11-43655 A Japanese Patent Laid-Open No. 11-21519 JP-A-11-106716

  An object of the present invention is to provide an adhesive tape for wafer processing that can minimize the occurrence of chipping and cracking when cutting a wafer into chips, and suppress the occurrence thereof. Furthermore, the present invention provides an adhesive tape for wafer processing that is made of a material that can reduce contamination of a chip even if a wafer is processed without using a special apparatus, has excellent long-term storage stability, and has a low environmental impact. is there.

  Another object of the present invention is to provide a method for producing an environmentally friendly pressure-sensitive adhesive tape for wafer processing, which can provide stable quality and can minimize harmful substances, waste, energy, etc. generated in the production process. is there.

  Moreover, the objective of this invention is providing the usage method which can exhibit the performance of the adhesive tape for wafer processing to the maximum.

  As a result of diligent research to solve the above problems, the adhesive tape has a pressure-sensitive adhesive layer having a specific elastic modulus in a temperature range where the wafer is processed, or a pressure-sensitive adhesive layer having a specific tan δ in that temperature range. It has been found that the internal stress and vibration generated during wafer processing can be greatly reduced by sticking and fixing to the surface, and by using such a specific adhesive tape, chip cracks and cracks are large. As a result, the present invention has been found out that it can be reduced to a level that cannot be achieved by the conventional wafer processing pressure-sensitive adhesive tape.

  That is, in the present invention, an adhesive tape having an adhesive layer on one side of a base material layer, and a silicon wafer adhered to the adhesive layer of the tape is fully cut with a dicer at a dicing speed of 70 mm / min to obtain a chip. A wafer processing pressure-sensitive adhesive tape is provided in which the maximum length of chipping or cracking is 30 μm or less.

  In a preferred embodiment of the wafer processing pressure-sensitive adhesive tape according to the present invention, the maximum length of chipping or cracking of the chip is preferably 10 μm or less.

  In the present invention, the pressure-sensitive adhesive tape has a pressure-sensitive adhesive layer on one side of the base material layer, and the storage elastic modulus G ′ at 15 to 35 ° C. of the pressure-sensitive adhesive layer is 1 MPa or more. An adhesive tape is provided.

  In a preferred embodiment of the wafer processing pressure-sensitive adhesive tape according to the present invention, tan δ, which is a ratio of the loss elastic modulus G ″ to the storage elastic modulus G ′ at 15 to 35 ° C. of the pressure-sensitive adhesive layer, is 0.05 or more. Preferably there is.

  In this invention, it is preferable that an above described adhesion layer contains an olefin polymer as a main component.

The pressure-sensitive adhesive layer contains 30% by weight of one or a mixture of two or more α-olefin copolymers having propylene, 1-butene and an α-olefin having 5 to 12 carbon atoms as unit components. It is preferable that

  Further, the adhesive layer is composed of the α-olefin copolymer, a thermoplastic elastomer, and a co-oligomer of ethylene and another α-olefin, and the α-olefin copolymer forms a continuous phase, It is preferable that the plastic elastomer forms a dispersed phase.

  The thermoplastic elastomer has the general formula A-B-A or A-B (A represents an aromatic vinyl polymer block or an olefin polymer block exhibiting crystallinity, and B represents a diene polymer block or hydrogenated thereof. It is preferable that the block copolymer is represented by the following formula:

  The α-olefin copolymer is preferably an α-olefin copolymer obtained by copolymerizing propylene, 1-butene and an α-olefin having 5 to 12 carbon atoms.

  The α-olefin having 5 to 12 carbon atoms is preferably 4-methyl-1-pentene.

  In the present invention, the above-mentioned base material layer is preferably composed of one layer or a plurality of layers, and contains an olefin copolymer as a main component.

  Moreover, it is preferable that the said base material layer consists of a surface layer and an intermediate | middle layer, and is an adhesive tape for wafer processing formed by laminating | stacking three layers in order of a surface layer, an intermediate | middle layer, and an adhesion layer.

  The intermediate layer is preferably composed of an olefin polymer and a thermoplastic elastomer, the olefin polymer forms a continuous phase, and the thermoplastic elastomer forms a dispersed phase.

  The intermediate layer is composed of a plurality of layers, at least one of which is composed of an olefin polymer and a thermoplastic elastomer, the olefin polymer forms a continuous phase, and the thermoplastic elastomer forms a dispersed phase. It is preferable that

  The thermoplastic elastomer has the general formula A-B-A or A-B (A represents an aromatic vinyl polymer block or an olefin polymer block exhibiting crystallinity, and B represents a diene polymer block or hydrogenated thereof. It is preferable that the block copolymer is represented by the following formula:

  The surface layer preferably contains an olefin polymer as a main component.

  Further, in the pressure-sensitive adhesive tape for wafer processing according to the present invention, the probe tack force measured in accordance with JIS Z0237 (reference) in the temperature range of 20 to 80 ° C. is in the range of 0.01 to 1 N / 5 mmφ. Some are preferred.

  Moreover, in the adhesive tape for wafer processing which concerns on this invention, what was shape | molded by the coextrusion molding method is preferable.

  According to this invention, it is a manufacturing method of the adhesive tape which has the base material layer which consists of one layer or several layers, and the adhesion layer laminated | stacked on the single side | surface of this base material layer, Comprising: The constituent polymer has a melt flow rate (measured according to MFR, ASTM D1238, measured at a temperature of 230 ° C. and a load of 2.16 kg) of 5 to 40 g / 10 min, and the MFR difference between adjacent layers is 10 g / 10 min or less. The above-mentioned pressure-sensitive adhesive tape for wafer processing, which is formed by a coextrusion molding method using a multilayer die so that the melting temperature is 200 to 260 ° C. and the difference in melting temperature between adjacent layers is 30 ° C. or less. A manufacturing method is provided.

  According to the present invention, the wafer processing pressure-sensitive adhesive tape and the wafer are pressure-bonded at 20 to 80 ° C., then the wafer is cut into chips at 15 to 35 ° C., and then the pressure-sensitive adhesive tape is heated to 40 to 80 ° C. A method of using the adhesive tape for wafer processing is provided, wherein the chip is picked up at room temperature and then peeled off from the adhesive tape.

  In the method for using the wafer processing pressure-sensitive adhesive tape according to the present invention, it is preferable that the wafer is a semiconductor wafer having a circuit pattern formed on a surface thereof, and the cutting process is dicing.

The wafer processing pressure-sensitive adhesive tape of the present invention can reduce the size of chipping and cracking of the wafer to 30 μm or less and cut the occurrence rate at the time of cutting by wafer dicing. Occurrence can be prevented epoch-making. Further, since the wafer can be fixed and held with a low probe tack force, cutting can be performed without using a special device such as a light or electron beam curing device.
According to the manufacturing method of the present invention, the pressure-sensitive adhesive tape of the present invention having a multilayer structure in which the thickness uniformity and surface property of each layer composed of different materials is good and no foreign matter is generated can be produced with a simple manufacturing process with high productivity. Can be manufactured.
According to the method of using the wafer processing pressure-sensitive adhesive tape of the present invention, the chip can be peeled from the pressure-sensitive adhesive tape of the present invention without using a special device for reducing the adhesive force.

It is sectional drawing which shows one Embodiment of the adhesive tape for wafer processing of this invention. It is sectional drawing which shows another embodiment of the adhesive tape for wafer processing of this invention. It is sectional drawing which shows other embodiment of the adhesive tape for wafer processing of this invention. It is sectional drawing which shows other embodiment of the adhesive tape for wafer processing of this invention. It is sectional drawing which shows other embodiment of the adhesive tape for wafer processing of this invention. It is sectional drawing which shows other embodiment of the adhesive tape for wafer processing of this invention. It is a side view which shows the state which wound up the adhesive tape for wafer processing of this invention in roll shape. It is another side view which shows the state which wound up the adhesive tape for wafer processing of this invention in roll shape. It is the schematic diagram seen from the perpendicular | vertical direction of the chip | tip upper surface. It is the schematic diagram seen from the perpendicular | vertical direction of the chip | tip upper surface about the chip | tip or crack which generate | occur | produced in the corner part of the chip | tip. It is another schematic diagram seen from the perpendicular direction of the chip upper surface about the chip | tip or the crack which generate | occur | produced in the corner part of the chip | tip. It is a figure which shows the measurement result of storage elastic modulus G ', loss elastic modulus G ", and tan-delta of an adhesion layer. It is an electron microscope cross-sectional photograph perpendicular | vertical to the flow direction of an adhesion layer. It is an electron microscope cross-sectional photograph parallel to the flow direction of the adhesion layer.

Hereinafter, the wafer processing pressure-sensitive adhesive tape of the present invention (hereinafter referred to as “the pressure-sensitive adhesive tape of the present invention”), its production method (hereinafter referred to as “the production method of the present invention”) and its method of use (hereinafter referred to as “the method of use of the present invention”). ) Will be specifically described with reference to the accompanying drawings.
In all drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a cross-sectional view showing an embodiment of the pressure-sensitive adhesive tape of the present invention. As shown in the figure, the pressure-sensitive adhesive tape 10 of the present invention comprises a base material layer 1 and a pressure-sensitive adhesive layer 2 laminated on one side of the base material layer 1.

The constituent component of the base material layer 1 is not particularly limited, and various thin-layer products such as synthetic resin, paper, metal foil , natural resin, and the like can be used. Among these, in the present invention, those having a non-halogen synthetic resin as a main component are preferable from the viewpoint of water resistance, heat resistance, disposal property, etc. Specific examples include olefin polymers, polyamides, polyesters, polyethers, Examples include polycarbonate and polyurethane. In particular, carbon such as olefin polymers, polyesters, polyethers, etc., which does not generate toxic gases such as sulfur oxides, nitrogen oxides or halogen compounds represented by dioxins when incinerated after use. A synthetic resin composed of oxygen, that is, a synthetic resin having a low load on the environment is preferable.

  The base material layer 1 has a variety of characteristics and is compounded with other materials in response to demands such as strength to hold and hold the wafer, expandability after cutting into chips, productivity of itself, storage stability, etc. In terms of its ability to impart functions by making it easy, environmentally friendly points, and the ability to form strong bonds with each other when it consists of multiple layers, its constituent components are, among other things, olefin polymers as the main component Are preferred.

Specific examples of the olefin polymer include low density polyethylene, ultra low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, and ethylene and a carbon number of 3 to 12. Α-olefin, styrene, vinyl acetate, (meth) acrylic acid, (meth) acrylic acid ester, copolymers with various vinyl compounds such as ionomer, and the like. Polymer, block type propylene / ethylene copolymer, random type propylene / ethylene copolymer, block type propylene / ethylene / butylene copolymer, random type propylene / ethylene / butylene copolymer, ultra high molecular weight polypropylene And propylene-based polymers such as polybutene and poly Chirupenten, ultra high molecular weight polybutene, can be mentioned an ultra-high molecular weight polymethyl pentene etc. 4 carbon atoms or more α- olefin polymer.
In the present invention, the main component refers to a constituent component that is contained in a relatively large proportion as compared to the other constituent components contained therein.

  When the base material layer is composed of two or more layers, each layer can be configured to share and bear various properties required for the wafer processing pressure-sensitive adhesive tape. For example, the intermediate layer is provided with elongation characteristics during processing and tear resistance, and a weather resistance stabilizer is added to provide weather resistance, and the outermost layer is easily resistant to surface defects and a rolled up protective film. The aspect which provided the peelability with the adhesion layer so that it can rewind is mentioned. Further, the adjacent layers may be any layers as long as their constituent components can be firmly bonded by melt coextrusion. In a preferred embodiment, the main component of the outermost layer (surface layer) on the side opposite to the adhesive layer is an ethylene copolymer.

  FIG. 2 is a cross-sectional view showing another embodiment of the pressure-sensitive adhesive tape of the present invention. As shown in FIG. 1, the pressure-sensitive adhesive tape 10 of the present invention includes a base material layer 1 composed of an intermediate layer 3 and a surface layer 4, and a pressure-sensitive adhesive layer 2 laminated on one surface of the intermediate layer 3.

  As a constituent component of the intermediate layer, one having an olefin polymer as a main component is preferable. Further, the constituent component of the intermediate layer is composed of the olefin polymer and the thermoplastic elastomer, the olefin polymer forms a continuous phase, and the thermoplastic elastomer forms a dispersed phase. Is preferred. In this way, the strength to fix and hold the wafer without loosening is increased, and the groove formed by cutting to a part of the intermediate layer does not expand during wafer processing, and when the tape is expanded after processing The groove does not tear and the tape does not sag (so-called necking does not occur). In addition, there is a feature that the chip interval (groove interval) is sufficiently expanded uniformly in both the vertical and horizontal directions of the chip.

Examples of the olefin polymer are the same as those described above.
Examples of the thermoplastic elastomer include polystyrene elastomers, polyolefin elastomers, polyamide elastomers, polyurethane elastomers, and polyester elastomers. Of these, polystyrene elastomers, polyolefin elastomers, and polyester elastomers are carbon, hydrogen, and the like that do not generate toxic gases such as sulfur oxides, nitrogen oxides, or halogen compounds represented by dioxins when incinerated after use, for example. It is preferable in that it is a thermoplastic elastomer made of oxygen, that is, a thermoplastic elastomer with a low environmental load.

  Among them, the general formula A-B-A or A-B (A represents an aromatic vinyl polymer block or an olefin polymer block exhibiting crystallinity, and B represents a diene polymer block or a hydrogenated product thereof. The block copolymer represented by (showing an olefin polymer block) is preferable because a phase dispersed in a continuous phase composed of the olefin polymer is easily formed.

  Examples of the polystyrene-based elastomer include a block copolymer of a polystyrene block that becomes a hard part (crystal part) and a diene monomer polymer block that becomes a soft part, or a hydrogenated polymer thereof. More specifically, Styrene / isoprene / styrene block copolymer (SIS), styrene / butadiene / styrene block copolymer (SBS), styrene / ethylene / butylene / styrene block copolymer (SEBS), styrene / ethylene / propylene / styrene block copolymer A polymer (SEPS) etc. can be illustrated. These may be used singly or in combination of two or more.

  Examples of the polyolefin-based elastomer include a block copolymer of a polyolefin block that forms a highly crystalline polymer such as polypropylene as a hard part and a monomer copolymer block that exhibits an amorphous property as a soft part. Specifically, olefin (crystalline) / ethylene / butylene / olefin (crystalline) block copolymers, polypropylene / polyethylene oxide / polypropylene block copolymers, polypropylene / polyolefin (amorphous) / polypropylene block copolymers, etc. Can be illustrated.

  Specific examples of the polyester elastomer include polybutylene terephthalate / polyether / polybutylene terephthalate block copolymer.

FIG. 3 is a cross-sectional view showing another embodiment of the pressure-sensitive adhesive tape of the present invention. As shown in the figure, the pressure-sensitive adhesive tape 10 of the present invention has a base layer 1 laminated in the order of a first intermediate layer 3a, a second intermediate layer 3b, and a surface layer 4, and one side of the first intermediate layer 3a. It consists of the adhesion layer 2 laminated | stacked.
When the base material layer 1 is three layers, either the first intermediate layer 3a or the second intermediate layer 3b or two layers form a disperse phase with an olefin polymer that forms a continuous phase. A desirable embodiment is a thermoplastic elastomer. In this case, it is a more desirable embodiment that the second intermediate layer 3b is an olefin polymer that forms a continuous phase and a thermoplastic elastomer that forms a dispersed phase. In addition, the thickness of the intermediate | middle layer 3a is about 10-200 micrometers, for example, Preferably it is 30-150 micrometers. Moreover, the thickness of the intermediate | middle layer 3b is about 1-100 micrometers, for example, Preferably it is 5-50 micrometers.

Among the base material layers, the intermediate layer in contact with the adhesive layer (first intermediate layer 3a in FIG. 3) contains, as a main component, one kind of a polymer containing the α-olefin or a mixture of two or more kinds. You may do it. In addition to the polymer containing α-olefin, the intermediate layer on the side in contact with the adhesive layer is not a bleed-out and does not affect the adhesive layer. A resin having a group in the molecule may be included as a subcomponent.
The content of the polymer containing the α-olefin in the intermediate layer in contact with the adhesive layer is usually about 50 to 100% by weight, preferably about 70 to 100% by weight.

  In the pressure-sensitive adhesive tape of the present invention, the main component of the surface layer 4 which is the outermost layer of the base material layer 1 is preferably an olefin polymer. Of these, ethylene / (meth) acrylic acid copolymers are preferred. In this case, the content of the ethylene / (meth) acrylic acid copolymer in the surface layer 4 which is the outermost layer of the base material layer 1 is usually about 50 to 100% by weight, preferably 70 to 100% by weight. Examples of components other than the main component include α-olefin (co) polymers.

  Further, as the main component of the surface layer, the main component is a mixture containing ethylene / (meth) acrylic acid copolymer, polyethylene, and a metal ion cross-linked resin of ethylene / (meth) acrylic acid copolymer, Alternatively, in addition to the polymer containing the α-olefin, those containing a small amount of a reaction product (peeling agent) of polyvinyl alcohol or ethylene / vinyl alcohol copolymer and a long-chain alkyl isocyanate are preferable. An adhesive tape having a force of 5 N / 25 mm or less can be obtained.

  In the pressure-sensitive adhesive tape of the present invention, the surface layer 4 which is the outermost layer of the base material layer 1 contains a metal ion crosslinked resin of ethylene / (meth) acrylic acid copolymer together with an ethylene / (meth) acrylic acid copolymer. In the case of a layer, the content of the metal ion-crosslinked resin of the ethylene / (meth) acrylic acid copolymer is preferably 1 to 50% by weight, particularly preferably 3 to 40% by weight.

  In the pressure-sensitive adhesive tape of the present invention, when the surface layer 4 which is the outermost layer of the base material layer 1 is mainly composed of a polymer containing α-olefin, in addition to these, a small amount of polyvinyl alcohol or ethylene / vinyl alcohol It is desirable to blend a release agent such as a reaction product of a copolymer and a long-chain alkyl isocyanate, but the content of the release agent is usually 0.5 to 20% by weight of the layer of the base material layer 1, Among these, 1 to 10% by weight is particularly preferable.

  The base material layer 1 may contain various additives generally used for the base material layer of this type of wafer processing pressure-sensitive adhesive tape. For example, various fillers, pigments, ultraviolet absorbers, antioxidants, heat stabilizers, lubricants, and the like may be contained to such an extent that they do not affect wafer processing or chips.

  In the pressure-sensitive adhesive tape of the present invention, the thickness of the base material layer 1 is preferably about 10 to 200 μm, and more preferably about 30 to 150 μm in terms of wrinkle prevention, application workability, and cost. Moreover, when a base material layer consists of an intermediate | middle layer and a surface layer, the thickness of an intermediate | middle layer becomes like this. Preferably it is about 10-200 micrometers, More preferably, it is about 30-150 micrometers, The surface layer becomes like this. Preferably it is about 1-100 micrometers. More preferably, it is about 5-50 micrometers.

  The pressure-sensitive adhesive tape of the present invention is a laminated film having a multilayer structure of two or more layers having a base material layer and a pressure-sensitive adhesive layer laminated on one side of the base material layer, and the silicon wafer as the adherend is the pressure-sensitive adhesive layer When the wafer is cut into a rectangular chip by full-cutting with a dicer at a dicing speed of 70 mm / min after being attached to the wafer processing pressure-sensitive adhesive tape, The maximum length of the crack is 30 μm or less, preferably 10 μm or less. At this level, chip defects due to chipping and cracking during wafer processing are eliminated, and a quality close to that of the wax fixing method can be achieved.

  In the present invention, a method for measuring the maximum length of chipping or cracking of a chip is as follows: a silicon wafer is fixed to a frame with a wafer processing adhesive tape and fixed at once with a diamond cutting blade by a dicer at a specific processing speed. When cutting into a rectangular chip with a full cut, the method is to measure the distance of chipping or cracking that can occur from the chip processing surface. An example of the measurement method is shown below.

  FIG. 9 is a schematic view of the chipped portion 22 or the crack 23 generated on the straight processed surface of the chip 20 as viewed from the vertical direction of the upper surface of the chip. A chipped portion 22 indicates a portion peeled off from the chip by hatching, and a crack 23 is a crack generated in the chip and indicated by a thick solid line.

10 and 11 are schematic views of the chipped portion 22 or the crack 23 generated on the corner machining surface of the chip 20 when viewed from the vertical direction of the chip upper surface. In the processing of the corner portion, since the vertical and horizontal cutting directions intersect, there is a strong tendency that the chipping or cracking is maximized. FIG. 10 is an example in which the chip 22 in the corner portion has a long side shape, and the longer distance from the vertical or horizontal processed surface is the maximum length 24 of the chip. FIG. 11 shows an example of the crack 23 in the corner portion, and the longer distance from the vertical or horizontal processed surface is the maximum length 24 of the chip.

  The pressure-sensitive adhesive layer 2 of the present invention has a storage elastic modulus G ′ of 1 MPa or more, preferably 1 to 200 MPa in the range of 15 to 35 ° C., which is an environment for wafer processing. Furthermore, it is desirable that tan δ, which is a ratio of the loss elastic modulus G ″ to the storage elastic modulus G ′, is in the range of 0.05 or more. This causes a resonance phenomenon of internal stress generated in the wafer by the rotating blade to be cut. Amplification can be suppressed, the chip chipping rate or crack generation rate can be minimized, and the size of the chip can be minimized.

  The pressure-sensitive adhesive layer 2 of the pressure-sensitive adhesive tape of the present invention is preferably laminated on one side of the base material layer 1 and contains an olefin polymer as its main component. Furthermore, the main component is one or a mixture of two or more α-olefin copolymers containing at least two α-olefins selected from α-olefins having 2 to 12 carbon atoms as main unit components. Those are preferred. In particular, the α-olefin copolymer is composed of a thermoplastic elastomer, a co-oligomer of ethylene and another α-olefin, the α-olefin copolymer forms a continuous phase, and the thermoplastic elastomer forms a dispersed phase. What is doing is preferable.

  The fact that the α-olefin copolymer forms a continuous phase and the thermoplastic elastomer forms a dispersed phase is apparent from the cross-sectional photographs of the adhesive layer in FIGS. 13 and 14. FIG. 13 is a cross-sectional photograph perpendicular to the flow direction of the adhesive layer, and FIG. 14 is a cross-sectional photograph parallel to the flow direction of the adhesive layer. By doing so, since the glass transition temperature of the adhesive layer is lowered, the adhesive tape of the present invention and the wafer can be brought into close contact with each other even when the application temperature is lowered, which is indicated by the probe tack force. The initial adhesive strength can be adjusted to an appropriate range. That is, the low temperature adhesive property can be improved. In addition, since the α-olefin copolymer forms a continuous layer, an adhesive layer having a high storage elastic modulus G ′ and tan δ can be obtained.

  Examples of the α-olefin having 2 to 12 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, and 3-methyl. Examples include -1-pentene, 1-heptene, 1-octene, 1-decene, and 1-dodecene. When a copolymer composed of at least two monomers selected from these α-olefins is used as the main component of the adhesive layer 2, the total content of the α-olefin copolymer in the adhesive layer 2 is Usually, it is preferably 30% by weight or more, especially 50% by weight or more.

  Among these α-olefin copolymers, an adhesive layer containing a copolymer obtained by copolymerizing three components of propylene, 1-butene and an α-olefin having 5 to 12 carbon atoms is preferable. In particular, the pressure-sensitive adhesive layer containing a copolymer having a structural unit composition of 10 to 85 mol% of propylene, 3 to 60 mol% of 1-butene and 10 to 85 mol% of an α-olefin having 5 to 12 carbon atoms is It is preferable in that it has excellent adhesive properties in the vicinity, and further contains a copolymer containing 15 to 70 mol% of propylene, 5 to 50 mol% of 1-butene and 15 to 70 mol% of α-olefin in a proportion of structural unit composition. An adhesive layer is preferred. As the α-olefin having 5 to 12 carbon atoms, 4-methyl-1-pentene is preferable.

  In addition, when the adhesive layer contains a copolymer formed by copolymerizing three components of propylene, 1-butene and an α-olefin having 5 to 12 carbon atoms, the content of the copolymer in the adhesive layer The proportion is usually 20% by weight or more, preferably 30% by weight or more.

Specific examples of the thermoplastic elastomer include polystyrene elastomers, polyolefin elastomers, polyamide elastomers, polyurethane elastomers, and polyester elastomers.
As a preferable structure of this thermoplastic elastomer, a block copolymer which is a structural element is represented by a general formula ABA or AB. Here, A represents an aromatic vinyl polymer block or an olefin polymer block exhibiting crystallinity, and B represents a diene polymer block or an olefin polymer block obtained by hydrogenating this.

  Examples of the polystyrene-based elastomer include a block copolymer of a polystyrene block that becomes a hard part (crystal part) and a diene monomer polymer block that becomes a soft part, or a hydrogenated polymer thereof. More specifically, Styrene / isoprene / styrene block copolymer (SIS), styrene / butadiene / styrene block copolymer (SBS), styrene / ethylene / butylene / styrene block copolymer (SEBS), styrene / ethylene / propylene / styrene block copolymer A polymer (SEPS) etc. can be illustrated. These may be used singly or in combination of two or more.

  For example, a styrene / isoprene / styrene block copolymer contains about 12,000 to 100,000 when the styrene polymer block is converted into an average molecular weight, and about 10,000 to 300,000 when the isoprene polymer block is converted into an average molecular weight. The content ratio of the styrene polymer block / isoprene polymer block in this SIS is usually 5 to 50/50 to 95, preferably 10 to 30/70 to 90, by weight.

The styrene / ethylene / propylene / styrene block copolymer is obtained by hydrogenating a styrene / isoprene / styrene block copolymer.
Specific examples of this SIS include those commercially available from JSR Corporation as trade name: JSR SIS, or from Shell Chemical Co., Ltd. as trade name: Clayton D. Specific examples of SEPS include those sold by Kuraray Co., Ltd. under the trade name: Septon.

  Examples of the polyolefin-based elastomer include a block copolymer of a polyolefin block that forms a highly crystalline polymer such as polypropylene as a hard part and a monomer copolymer block that exhibits an amorphous property as a soft part. Specifically, olefin (crystalline) / ethylene / butylene / olefin (crystalline) block copolymers, polypropylene / polyethylene oxide / polypropylene block copolymers, polypropylene / polyolefin (amorphous) / polypropylene block copolymers, etc. Can be illustrated. As a specific example, what is marketed by SR Inc. as a brand name: DYNARON is mentioned.

  Specific examples of the polyester elastomer include polybutylene terephthalate / polyether / polybutylene terephthalate block copolymer.

  When using the said thermoplastic elastomer as a component of the adhesion layer of the adhesive tape of this invention, the content rate of the thermoplastic elastomer which occupies for an adhesion layer is 0-60 weight% normally, Preferably, it is 5-50 weight% It is.

  In the pressure-sensitive adhesive tape of the present invention, an α-olefin copolymer obtained by copolymerizing three components of the α-olefin having 2 to 12 carbon atoms in order to improve the pressure-sensitive adhesive performance indicated by the probe tack force of the pressure-sensitive adhesive layer 2 In addition to the above, an adhesive layer containing another α-olefin copolymer can be obtained. At this time, the total content of the copolymer composed of the three components of propylene, 1-butene and α-olefin having 5 to 12 carbon atoms and the other α-olefin copolymer in the adhesive layer is 50% by weight or more is preferable.

  The other α-olefin copolymer is preferably a copolymer comprising at least two α-olefins selected from ethylene, propylene, 1-butene and 1-hexene. Examples of the α-olefin copolymer include an ethylene / propylene copolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, a propylene / 1-butene copolymer, and a propylene / 1-hexene copolymer. Examples thereof include a polymer and a 1-butene / 1-hexene copolymer. Specific examples of this copolymer include those commercially available from Mitsui Chemicals, Inc. under the trade names: Tuffmer A, Tuffmer P, and the like.

  The co-oligomer of ethylene and another α-olefin is a low molecular weight copolymer of ethylene and another α-olefin, and is a liquid at normal temperature. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 4-methyl- C3-C20 alpha olefins, such as 1-pentene, are mentioned. Among these, a C3-C14 alpha olefin is preferable.

で表される構造単位を有するものである。前記式中、ＲはＣnＨ2n+1（ｎは正の整数である）で表される基であり、ｘ、ｙおよびｐは正の整数である。 This co-oligomer has the following formula:

It has a structural unit represented by these. In the above formula, R is a group represented by CnH2n + 1 (n is a positive integer), and x, y and p are positive integers.

  This co-oligomer usually has a number average molecular weight in the range of 100 to 10,000, preferably a number average molecular weight in the range of 200 to 5,000. Moreover, ethylene unit content in this co-oligomer is 30-70 mol% normally, Preferably it is 40-60 mol%.

  When using the said co-oligomer in the structural component of the adhesive layer of the adhesive tape of this invention, the content rate which occupies for the adhesive layer of this co-oligomer is 0-20 weight% normally, Preferably it is 0-10 weight%. .

  In the pressure-sensitive adhesive tape of the present invention, as a constituent component of the pressure-sensitive adhesive layer, in addition to the α-olefin copolymer obtained by copolymerizing the three components of the α-olefin having 2 to 12 carbon atoms, the other α- Use of an olefin copolymer is advantageous in that the glass transition temperature is lowered, the initial adhesive strength can be adjusted to an appropriate range, and the low-temperature adhesive property can be improved.

  In addition, when a mixed resin composed of a combination of the α-olefin copolymer and a co-oligomer of ethylene and another α-olefin is used as a constituent component of the adhesive layer, the glass transition temperature is lowered and the initial adhesive strength is reduced. This is advantageous in that it can be adjusted to an appropriate range and the viscosity can be adjusted to an appropriate range.

  Further, when a mixed resin composed of the α-olefin copolymer and the thermoplastic elastomer is used as a constituent component of the adhesive layer, the glass transition temperature is lowered and the initial adhesive strength can be adjusted to an appropriate range. At the same time, it is advantageous in that the low-temperature adhesive properties can be improved.

   In the adhesive layer of the adhesive tape of the present invention, in addition to the α-olefin copolymer, the thermoplastic elastomer, and a co-oligomer of ethylene and another α-olefin, various subcomponents are further added. May be included in a range that does not impair. For example, a plasticizer such as liquid butyl rubber, a tackifier such as polyterpene, and the like may be included. In the present invention, among these subcomponents, those having an adhesive functional group or an unsaturated bond cause a change with time in the adhesive strength after application (due to heating, pressure, humidity, ultraviolet rays, etc.). It is preferable to adjust the type, blending amount, etc.

  Moreover, the adhesive layer of the adhesive tape of this invention may contain the various additives generally mix | blended with the raw material of this kind of adhesive layer. For example, various fillers, pigments, ultraviolet absorbers, antioxidants, heat stabilizers, lubricants and the like may be contained.

In the pressure-sensitive adhesive tape of the present invention, the thickness of the pressure-sensitive adhesive layer is usually about 1 to 50 μm, and preferably about 5 to 30 μm.
Moreover, the whole thickness of an adhesive tape is about 30-200 micrometers normally, Preferably it is about 60-180 micrometers from the point of wrinkle prevention property, affixing workability | operativity, and a price.

The adhesive tape of the present invention has a tensile elastic modulus in the range of 100 to 500 MPa.
Furthermore, regarding the adhesive strength of the adhesive tape of the present invention, the probe tack force measured in accordance with JIS Z0237 (reference) after adjusting the adhesive tape to a range of 20 to 60 ° C. is 0.01 to 1N. It is preferable to fall within the range of / 5 mmφ. Usually, the adhesive strength of the adhesive tape is measured by sticking at 23 ° C., but in the case of the adhesive tape of the present invention, it is heated and adjusted in the range of 20 to 60 ° C. in order to improve the adhesion to the adherend. It is preferable.

  Further, if the probe tack force is too small exceeding 0.01 N / 5 mmφ, it is difficult to prevent the occurrence of tip fly, which is not preferable. On the other hand, if the probe tack force exceeds 1 N / 5 mmφ, the pick-up property may be deteriorated, which is not preferable. When the probe tack force is 0.01 N / 5 mmφ or more, the pressure-sensitive adhesive tape of the present invention and the wafer can be surely adhered to each other, so that the chip fly during processing of the wafer is eliminated, and the length and occurrence rate of chipping or cracking can be minimized. It is thought that a favorable effect is given to the point, the point where adhesion of cutting waste, etc. is lost. When the probe tack force is 1 N / 5 mmφ or less, the pressure-sensitive adhesive tape and the chip of the present invention can be easily peeled off, which gives a good effect on the pickup property.

The adhesive tape of the present invention does not use a special device as in the method of reducing the adhesive force by curing the adhesive layer using light or an electron beam when peeling off after adhesion. Easy to peel.
Further, after peeling, there is no adhesive residue on the chip, and there is no adhesion of components or the like that obstruct the subsequent bonding and molding steps.

  FIG. 4 is a cross-sectional view showing another embodiment of the wafer processing pressure-sensitive adhesive tape of the present invention. As shown in the figure, the wafer processing pressure-sensitive adhesive tape 10 of the present invention comprises a base material layer 1, a pressure-sensitive adhesive layer 2 laminated on the surface of the base material layer 1, and a release tape 5 provided on the pressure-sensitive adhesive layer 2 side. It is done.

  FIG. 5 is a cross-sectional view showing another embodiment of the wafer processing pressure-sensitive adhesive tape of the present invention. As shown in the figure, the wafer processing pressure-sensitive adhesive tape 10 of the present invention comprises a base material layer 1 comprising an intermediate layer 3 and a surface layer 4, and an adhesive layer 2 laminated on the surface of the intermediate layer 3, A release tape 5 is provided on the adhesive layer 2 side.

  FIG. 6 is a cross-sectional view showing another embodiment of the wafer processing pressure-sensitive adhesive tape of the present invention. As shown in the figure, the wafer processing pressure-sensitive adhesive tape 10 of the present invention has a base material layer 1 laminated in the order of a first intermediate layer 3a, a second intermediate layer 3b, and a surface layer 4, and the surface of the intermediate layer 3a. The release tape 5 is provided on the adhesive layer 2 side.

  FIG. 7 is a view showing a state in which the wafer processing pressure-sensitive adhesive tape 10 of the present invention is wound and stored as it is on a roll 6, and FIG. 8 is released to the pressure-sensitive adhesive layer side of the wafer processing pressure-sensitive adhesive tape 10 of the present invention. It is a figure which shows the state which affixed the tape 5 and wound around the roll 6, and is stored.

  As the release tape, for example, a thermoplastic film having a release layer made of a UV curable siloxane-based crosslinking compound is used. Since the unevenness of the release tape is transferred to the surface of the adhesive layer, it is preferable that the surface roughness is 1 μm or less. Also. The thickness of the release tape is a thickness that does not hinder the roll winding, and is preferably as thin as possible from the viewpoint of reducing the amount of disposal, and is, for example, 5 to 200 μm, and preferably 10 to 100 μm.

  As a method for producing the pressure-sensitive adhesive tape of the present invention, the base material layer (surface layer and intermediate layer) and the material constituting the pressure-sensitive adhesive layer are melt-heated and co-extruded to form a multilayer structure having a predetermined thickness. The method for producing a film is preferable in that the pressure-sensitive adhesive tape of the present invention can be produced at low cost because of high efficiency and energy saving. Moreover, it can also carry out according to methods, such as carrying out melt extrusion lamination of the adhesion layer to a base material layer.

  The production method of the present invention is a method for producing an adhesive tape having a base material layer composed of one or more layers and an adhesive layer laminated on one side of the base material layer, the base material layer and The polymer constituting the adhesive layer has a melt flow rate (measured according to MFR, ASTM D1238 at a temperature of 230 ° C. and a load of 21.18 N) of 5 to 40 g / 10 minutes, and the MFR difference between adjacent layers is 10 g / 10 minutes. It is preferable to form by a coextrusion method using a multilayer die so that the melting temperature is 200 to 260 ° C. and the difference in melting temperature between adjacent layers is 30 ° C. or less.

  As a coextrusion molding method using a multilayer die, for example, a method in which melts of layers are combined in advance in a layered form and fed into a flat die and adhered in a die (feed block method), and a melt of each layer is flattened. Sending to another manifold in the die, and joining the layers together in layers at a common location in the die (generally before the entrance to the die lip) and feeding them to the flat die and bonding them in the die (multiple manifolds And a combination of a feed block method and a multi-manifold method.

  When the MFR is 5 to 40 g / 10 min and the MFR difference between adjacent layers is 10 g / 10 min or less, the thickness of each layer made of different materials becomes uniform, the surface property is good, and the multilayer structure Is preferable. Moreover, when the melting temperature is 200 to 260 ° C. and the difference in melting temperature between adjacent layers is 30 ° C. or less, the thickness of each layer made of different materials becomes uniform, the surface property is good, and the generation of foreign matters This is preferable in that a multilayer structure can be formed.

  The method of use of the present invention is that the wafer processing pressure-sensitive adhesive tape and the wafer are pressure-bonded at 20 to 80 ° C., then the wafer is cut into chips at 15 to 35 ° C., and then the pressure-sensitive adhesive tape is bonded to 40 to 80 It consists of extending at 0 ° C. and then picking up the chip at room temperature and peeling it off the adhesive tape.

The wafer may be any general solid material. For example, the insulator may be glass, ceramic, hard plastic or the like, the semiconductor may be elemental semiconductor such as silicon, germanium, selenium, or tellurium; GaAs Binary compound semiconductors such as GaP, InSb; ternary compound semiconductors such as AlGaAs; quaternary compound semiconductors such as AlGaInAs; metal oxide semiconductors such as SnO ₂ , ZnO, TiO ₂ , Y ₂ O _5, etc. What consists of another metal oxide is mentioned. A wafer having a thickness of several tens of μm to several mm and a wafer area of several tens of mm ² to several 10000 mm ² can be used, and the shape may be any of a circle, a square, a rectangle, and the like.

  By pressure-bonding the pressure-sensitive adhesive tape and the wafer of the present invention at 20 to 80 ° C., the tape and the wafer can be adhered to each other without any gap, and alteration due to heating of the tape and the wafer can be prevented. Further, if the wafer is cut into chips at 15 to 35 ° C., no special cooling device or heating device is required, and the adhesive tape is expanded at 40 to 80 ° C., so that a tear is generated from the cutting groove of the tape. Therefore, the chip interval can be expanded uniformly.

  In a preferred embodiment of the method of use of the present invention, the wafer is a semiconductor wafer having a circuit pattern formed on the surface, and the cutting process is dicing. In addition, the adhesive tape of the present invention reduces the thickness of the wafer by forming grooves with a depth of cut shallower than the wafer thickness from the surface of the semiconductor wafer on which the circuit pattern is formed, and then grinding the back surface of the semiconductor wafer. In addition, the present invention can also be applied to a surface protection sheet used in wafer back surface grinding that is finally divided into individual chips.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
In the following examples and comparative examples, viscoelasticity, MFR, probe tack force, temperature dependency of adhesive force, unwinding force, chip fly, chipping and crack length and occurrence rate, cutting dust contamination, expandability The pick-up property was tested and evaluated by the following measuring method.

(1) Viscoelasticity Using a rheometric scientific mechanical spectrometer RMS-800, a parallel plate having a diameter of 8 mm was used, the gap between the plates was set to 1.5 mm, and the test piece was 8 mmφ × 1. Using a 5 mm (thickness) disk, at a frequency ω = 100 rad / sec, in the range of −50 ° C. to 350 ° C. at a rate of temperature increase of 3 ° C./min, storage elastic modulus G ′ (Pa) and loss elastic modulus A value obtained by measuring G ″ (Pa) was used. Tan δ was calculated by substituting the measured storage elastic modulus G ′ and loss elastic modulus G ″ into the relational expression tan δ = G ″ / G ′.

(2) Melt flow rate (MFR)
Based on the MFR test described in ASTM D1238, values measured under test conditions of a temperature of 230 ° C. and a load of 21.18 N (2.16 kgf) were used.
(3) Probe tack force Based on the probe tack test described in JIS Z0237-1991 (reference), it was measured using a probe tack tester MODEL TM1 manufactured by Toyo Seiki Seisakusho. Under a measurement temperature of 23 ° C. and a humidity of 50% (RH), a 10 gf load was brought into contact with the adhesive surface of the test piece for 10 seconds, and then the probe was peeled off at a speed of 10 mm / second in the vertical direction. The required force (unit: N / 5 mmφ) was measured. The test was repeated for five test pieces, and the average value was taken as the probe tack force.

(4) Temperature dependence of adhesive force It measured based on the adhesive force measuring method described in JIS Z0237-1991. However, after sticking the test piece on the silicon mirror surface at 23 ° C and placing it in an environment of 23 ° C and 50 ° C for 30 minutes, it is measured as 180 degree peeling adhesive strength (unit: N / 25mm) to the silicon mirror surface. The temperature dependence was evaluated according to the following criteria. (Adhesive strength at 50 ° C.) / (Adhesive strength at 23 ° C.) is a pass (indicated by ○) in the range of 0.7 to 1.3, and (Adhesive strength at 50 ° C.) / (Adhesive strength at 23 ° C. A force (force) of less than 0.7 and greater than 1.3 was determined to be rejected (indicated by x).

(5) Rewind force It measured based on the measuring method of the high-speed rewind force described in JISZ0237-1991. However, the resistance force when the wafer processing pressure-sensitive adhesive tape wound as a test piece was rewound at a speed of 30 m / min was measured as a high-speed rewound force (unit: N / 25 mm).

(6) Using a chip fly mounter (HS-7800 manufactured by Hugle Electronics), a silicon wafer is passed through a wafer processing adhesive tape, which is a test piece, at three bonding temperatures of 20 ° C., 40 ° C., and 60 ° C. (P-type, thickness 400μm, diameter 6 inches) is fixed on the frame (Disco MDFTF-2-6-1-H), then set on a dicer (Disco 320) and blade (NBC-ZH-2500) , Size: 27HEDD), rotating speed 30000 rotation / min, cutting speed 70mm / min, cutting depth is to cut the film to a depth of 30μm with full cutting, cutting water amount (using constant temperature water at 20 ° C) nozzle on wafer surface And 1.5 L / min from the rotating blade epi-illumination nozzle, and 0.50 mm square and 1 mm square chips were diced.

  Observe all 0.50 mm square or 1.0 mm square chips obtained by dicing from the silicon wafer at at least one of the pasting temperatures of 20 ° C., 40 ° C., and 60 ° C., The number of scattered pieces was investigated and chip flies were evaluated according to the following criteria for the scattering rate. If the chip size is 5 mm square or 1 mm square and the scattering rate is 0.3% or less, it is accepted (indicated by a circle), and only one of the chip size 0.5 mm square and 1 mm square has a scattering rate of 0.3% or less. In some cases, it was considered as a semi-pass (indicated by Δ), and a chip size of 0.5 mm square or 1 mm square in both cases exceeding a scattering rate of 0.3% was rejected (indicated by ×).

(7) Length or incidence of chipping or cracking Using a mounter (HS-7800 manufactured by Hugle Electronics), the adhesive layer of the wafer processing adhesive tape, which is a test piece, is attached to a silicon wafer (at a bonding temperature at which chip fly does not occur). Affixed to the mirror surface of P-type, thickness 400μm, diameter 6 inches), and a silicon wafer was attached to the frame (MDFTF-2-6-1-H made by Disco) via an adhesive tape, and then dicer (DAD320 made by Disco) ), Blade (NBC-ZH-2500, size: 27HEDD) rotation speed 30000 rotation / min, cutting speed 70 mm / min, cutting depth is to cut the film to a depth of 30 μm, cutting water volume (20 (Use constant temperature water at ℃) 1.5L / min from the nozzle on the wafer surface and 1.0L / min from the rotary blade incident nozzle. Ishingu was processed.

As shown in FIG. 9, the chip or crack that can be generated from the cut surface of the chip is measured by measuring the vertical distance from the cut surface to the tip of the chip or crack as the length of the chip or crack. The maximum value was defined as the maximum length (μm) of chips or cracks generated in the chip. However, the length of the chipping or cracking generated in the corner portion was measured by a method as schematically shown in FIGS. 10a and 10b.
In addition, when a chip or crack exceeding 10 μm occurs even at one location in a 3 mm square chip, the number is measured as a chip having a chip or crack, and the ratio of the number to the total number of chips in a 6-inch wafer is calculated. The crack generation rate (%) was used.

(8) Scrap dust contamination Silicon wafer (P-type, thickness 400μm) through a wafer processing adhesive tape, which is a test piece, at a bonding temperature where chip fly does not occur using a mounter (HS-7800 manufactured by Hugle Electronics). , 6 inches in diameter) attached to the frame (MDFTF-2-6-1-H made by Disco) and then set on a dicer (DAD320 made by Disco), rotating the blade (NBC-ZH-2500, size: 27HEDD) The speed is 30000 revolutions / min, the cutting speed is 70 mm / min, the cutting amount is a full cut so that the film is cut to a depth of 30 μm, the cutting water amount (using constant temperature water at 20 ° C.) is 1.5 L / min from the nozzle to the wafer surface, Dicing was performed on a 3 mm square chip at 1.0 L / min from the rotary blade epi-illumination nozzle.

  Next, with respect to all 3 mm square chips diced from a 6-inch wafer, the presence or absence of cutting waste is observed with an optical microscope (magnification 100 times), and the total number of chips to which cutting chips are attached The occurrence rate relative to the number was investigated, and the chip contamination was evaluated according to the following criteria. An occurrence rate of 0.3% or less was accepted (indicated by ◯), and an occurrence rate exceeding 0.3% was rejected (indicated by x).

(9) Expandability Silicon wafer (P-type, thickness 400 μm, thickness is measured through a wafer processing adhesive tape, which is a test piece, at a bonding temperature where chip fly does not occur using a mounter (HS-7800 manufactured by Hugle Electronics). 6 inches in diameter) is fixed to the frame (Disco made by MDFTF-2-6-1-H), then set on the dicer (Disco made by Disco) and the rotation speed of the blade (NBC-ZH-2500, size: 27HEDD) 30000 rotation / min, cutting speed 70mm / min, cutting depth is to cut the film to a depth of 30μm with full cut, cutting water amount (using constant temperature water at 20 ° C) is 1.5L / min from nozzle to wafer surface, rotation Dicing was performed on a 3 mm square chip at 1.0 L / min from the blade incident nozzle.

Next, using a wafer expander (HS-1800 manufactured by Hugle Electronics), the wafer processing adhesive tape after dicing is heated to 60 ° C., and the adhesive tape portion to which the wafer is adhered is cylindrical with a diameter of 180 mm. The distance between the chips attached on the adhesive tape was expanded by pushing up with a pressing tool up to a stroke of 20 mm. In the evaluation of extensibility, the case where all of the following three criteria (a) to (c) are satisfied is regarded as acceptable (indicated by ○), and the case where any one of the items cannot be achieved is regarded as unacceptable (indicated by ×). .
Reference | standard (a): The adhesive tape thickness which contacted the edge part of the said pressing tool is 90% or more with respect to the thickness of a non-contact part. That is, do not neck.
Standard (b): The extended chip interval is 200 μm or more.
Reference | standard (c): Ratio of the vertical direction of a chip | tip space | interval and a horizontal direction is 0.7 or more and 1.3 or less.

(10) Pick-up property A silicon wafer (P type, thickness 400 μm, with a wafer processing adhesive tape) at a bonding temperature where chip fly does not occur using a mounter (HS-7800 manufactured by Hugle Electronics). 6 inches in diameter) is fixed to the frame (Disco made by MDFTF-2-6-1-H), then set on the dicer (Disco made by Disco) and the rotation speed of the blade (NBC-ZH-2500, size: 27HEDD) 30000 rotation / min, cutting speed 70mm / min, cutting depth is to cut the film to a depth of 30μm with full cut, cutting water amount (using constant temperature water at 20 ° C) is 1.5L / min from nozzle to wafer surface, rotation Dicing was performed on a 3 mm square chip at 1.0 L / min from the blade incident nozzle. However, the UV curable adhesive tape was irradiated with light for 60 seconds using a UV irradiator (DUV100 manufactured by DISCO) after dicing (light amount of about 360 mJ / cm ² ).

  Furthermore, using a pick-and-place device (DE35 manufactured by Hugle Electronics), the wafer processing adhesive tape after dicing is heated to 60 ° C., the interval between the chips is expanded, and 0.3 seconds after the pins are pushed up The capture rate (%) under the conditions for picking up was investigated, and then the picking property was evaluated according to the criteria. 49 chips (1 tray) were picked up three times, and when all could be picked up, it was accepted (indicated by ◯), and when even one chip could not be picked up, it was rejected (indicated by x).

Example 1
The following materials were used as the material of each layer constituting the adhesive tape 10. That is, as components constituting the base material layer 1, 80 parts by weight of propylene / ethylene / 1-butene random copolymer (r-PP; ethylene component 5 mol%, 1-butene component 5 mol%), styrene / ethylene・ Butylene / styrene block copolymer (SEBS; Asahi Kasei Kogyo Co., Ltd., Tuftec ^™ H1052) 20 parts by weight, the component constituting the adhesive layer 2 is propylene / 1-butene / 4-methyl-1-pentene 100 parts by weight of a polymer (PB (4-MP); propylene component 50 mol%, 1-butene component 20 mol%, 4-methyl-1-pentene component 30 mol%) was used. FIG. 12 shows the results of the storage elastic modulus G ′, loss elastic modulus G ″, and tan δ of the adhesive layer measured according to the viscoelasticity measuring method.

The MFR of each layer was adjusted by mixing different resins of the same MFR, and the adhesive layer was 15 g / 10 min and the base material layer was 15 g / 10 min. Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were an adhesive layer: 230 ° C. and a substrate layer: 230 ° C. These two layers of molten resin were laminated in a multilayer die (co-extrusion temperature: 230 ° C.). The extruded adhesive tape was cooled, and a release tape (manufactured by Tosero Co., Ltd., Tosero Separator ^TM SP T-18, thickness 37 μm) was provided on the adhesive layer surface, and then slit and wound up.

  The pressure-sensitive adhesive tape thus obtained is a laminate in which a single-layer base material layer and a pressure-sensitive adhesive layer are laminated, and a release tape is provided on the pressure-sensitive adhesive layer side. The thickness of each layer is the pressure-sensitive adhesive layer: 20 μm. The base material layer was 70 μm and the total thickness was 90 μm.

The probe tack force of the obtained adhesive tape for wafer processing was 0.1 N / 5 mmφ at a pasting temperature of 60 ° C., 0.01 N / 5 mmφ at 40 ° C., and 0 N / 5 mmφ at 20 ° C. As a result, 60 ° C. was determined as the optimum pasting temperature.
About the temperature dependence of 180 degree peeling adhesive strength, it becomes 1N / 25mm at a test temperature of 23 ° C and 1N / 25mm at 50 ° C, and (50 ° C peeling adhesive strength) / (23 ° C peeling adhesive strength) is 1 and no temperature dependence.
The unwinding force from the roll was 0.05 N / 25 mm, and the roll was light and easy to handle. Table 3 shows the results of the above measurements or evaluations.

Furthermore, in order to evaluate the workability of the obtained adhesive tape for wafer processing, the adhesive tape is heated to 60 ° C. and attached to the wafer, and the maximum length and occurrence rate of chip fly, chipping or cracking, cutting dust contamination Table 4 shows the results of tests on the property, expandability, and pickup property.
As for the chip fly, no chip scattering occurred, indicating that there was no defect due to the chip fly.
The maximum length and occurrence rate of chips or cracks were almost equal to those of the wax fixing method (maximum length of chips or cracks of 5 μm or less, occurrence rate 0).
As for cutting dust contamination, cutting chips attached to the chip were not observed at all.
Regarding expandability, the standard (a) was 98%, the standard (b) was 400 μm, and the standard (c) was 1.1, which passed all the standards, indicating that the expandability was excellent.
As for the pick-up property, it can be peeled off without picking up all the chips, indicating that the pick-up property is excellent.

(Example 2)
As a material of each layer constituting the adhesive tape 10, as a component of the base material layer 1, 80 parts by weight of r-PP as in Example 1, and a hydrogenated styrene / isoprene / styrene block copolymer (SEPS; Co., Ltd.) 20 parts by weight of Kuraray Septon ^™ 2063), 95 parts by weight of PB (4-MP) as in Example 1, and ethylene / α-olefin co-oligomer (LEO; Mitsui Chemicals) And 5 parts by weight of Lucant ^™ HC-20). The measurement results of the viscoelasticity of the adhesive layer are shown in Table 3 for three points of 15 ° C, 25 ° C and 35 ° C.

Under the conditions shown in Table 1, an adhesive tape was molded in the same manner as in Example 1, and a release tape (manufactured by Tosero Co., Ltd., Tosero Separator ^TM SP T-18, thickness 37 μm) was provided on the adhesive layer surface. Then, it was slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

(Example 3)
As a material of each layer constituting the adhesive tape 10, low density polyethylene (LDPE; density 0.92 g / cm ³ ) is used as a component of the surface layer 4 of the base material layer 1, and the intermediate layer 3 of the base material layer 1 is used. As components, 80 parts by weight of the same r-PP as in Example 1 and 20 parts by weight of a hydrogenated styrene / isoprene / styrene block copolymer (SEPS; Septon ^TM 2063 manufactured by Kuraray Co., Ltd.) were used. As components, 80 parts by weight of PB (4-MP) same as in Example 1, 5 parts by weight of LEO, and 15 parts by weight of styrene / isoprene / styrene block copolymer (SIS; SIS5229N manufactured by JSR Corporation) were used. .

Under the conditions shown in Table 1, a pressure-sensitive adhesive tape was formed in the same manner as in Example 1 except that the surface layer, the intermediate layer, and the coextrusion temperature were 220 ° C., and a release tape (manufactured by Tosero Co., Ltd., Tosero separator) ^TM SP T-18 (thickness 37 μm) was provided on the adhesive layer surface, and then slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

Example 4
As the material of each layer constituting the adhesive tape 10, the same LDPE as in Example 3 is used as the component of the surface layer 4 of the base material layer 1, and the same as in Example 1 as the component of the intermediate layer 3 of the base material layer 1. Using 90 parts by weight of r-PP and 10 parts by weight of a hydrogenated styrene / butadiene copolymer (HSBR; DYNARON ^™ 1321P manufactured by JSR Corporation), the same PB as in Example 3 was used as a component of the adhesive layer 2. 4-MP) 60 parts by weight, SIS 15 parts by weight, LEO 5 parts by weight, and ethylene / propylene copolymer (EP-A; density 0.87 g / cm ² ) 20 parts by weight were used.

Under the conditions shown in Table 1, an adhesive tape was molded in the same manner as in Example 1, and a release tape (manufactured by Tosero Co., Ltd., Tosero Separator ^TM SP T-18, thickness 37 μm) was provided on the adhesive layer surface. Then, it was slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

(Example 5)
As a material of each layer constituting the adhesive tape 10, 95 parts by weight of the same LDPE as in Example 3 as a component of the surface layer 4 in the base layer 1, and a metal ion crosslinked resin (ionomer) of an ethylene / methacrylic acid copolymer ; Mitsui-DuPont Polychemical Co., Ltd. Himiran ^™ 1652) 5 parts by weight, as the component of the intermediate layer 3 of the base material layer 1, 80 parts by weight of r-PP as in Example 4, and 10 parts by weight of HSBR , Using high density polyethylene (HDPE; density 0.96 g / cm ³ ), as components of the adhesive layer 2, 50 parts by weight of PB (4-MP) same as Example 3, 15 parts by weight of SIS, 5 parts by weight of LEO And 30 parts by weight of an olefin crystal / ethylene / butylene / olefin crystal block copolymer (CEBC: DYNARON ^™ 6200P manufactured by JSR Corporation) were used.

Under the conditions shown in Table 1, an adhesive tape was formed in the same manner as in Example 1, slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

(Example 6)
As a material of each layer constituting the adhesive tape 10, 85 parts by weight of LDPE as in Example 5 and 5 parts by weight of ionomer, ethylene / methacrylic acid copolymer (EMAA) are used as components of the surface layer 4 of the base material layer 1. And 10 parts by weight of Mitsui-DuPont Polychemical Co., Ltd. Nucrel ^TM N1108C), and 60 parts by weight of the above LDPE, 20 parts by weight of EMAA, and Example 4 as components of the intermediate layer 3 of the base layer 1 20 parts by weight of the same EP-A, and 40 parts by weight of PB (4-MP) as in Example 4, 30 parts by weight of EP-A, 20 parts by weight of SIS, and LEO 10 as components of the adhesive layer 2 Part by weight was used.

Under the conditions shown in Table 1, an adhesive tape was formed in the same manner as in Example 1, slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

(Example 7)
As the material of each layer constituting the adhesive tape 10, the same LDPE as in Example 3 is used as the component of the surface layer 4 in the base layer 1, and the same as in Example 4 as the component of the intermediate layer 3 in the base layer 1. 15 parts by weight of HSBR and 85 parts by weight of the same r-PP as in Example 1, and 50 parts by weight of PB (4-MP) as in Example 4 and 30 parts by weight of EP-A as components of the adhesive layer 2 The same 20 parts by weight of CEBC as in Example 5 was used.

Under the conditions shown in Table 1, an adhesive tape was molded in the same manner as in Example 1, and a release tape (manufactured by Tosero Co., Ltd., Tosero Separator ^TM SP T-18, thickness 37 μm) was provided on the adhesive layer surface. Then, it was slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

(Example 8)
As the material of each layer constituting the adhesive tape 10, the same LDPE as in Example 3 is used as the component of the surface layer 4 of the base material layer 1, and the same as in Example 1 as the component of the intermediate layer 3 of the base material layer 1. 90 parts by weight of r-PP and 10 parts by weight of CEBC as in Example 5, and 40 parts by weight of PB (4-MP) as in Example 4 and 35 parts by weight of EP-A as components of the adhesive layer 2 , 20 parts by weight of SIS and LEO 5 were used.

Under the conditions shown in Table 1, an adhesive tape was molded in the same manner as in Example 1, and a release tape (manufactured by Tosero Co., Ltd., Tosero Separator ^TM SP T-18, thickness 37 μm) was provided on the adhesive layer surface. Then, it was slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

Example 9
As the material of each layer constituting the adhesive tape 10, 90 parts by weight of LDPE as in Example 6 and 10 parts by weight of EMAA are used as the components of the surface layer 4 and the first intermediate layer 3 a of the base material layer 1. 60 parts by weight of r-PP same as Example 7 and 40 parts by weight of HSBR are used as components of the second intermediate layer 3b of the layer 1, and PB (4-MP) same as that of Example 3 is used as a component of the adhesive layer 2. 85 parts by weight, 10 parts by weight of SIS, and 5 parts by weight of LEO were used.

Under the conditions shown in Table 1, an adhesive tape was formed in the same manner as in Example 1, slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

(Example 10)
As the material of each layer constituting the adhesive tape 10, the same LDPE as in Example 3 is used as the component of the surface layer 4 and the first intermediate layer 3 a in the base material layer 1, and the second intermediate layer 3 b of the base material layer 1 is used. As components, 60 parts by weight of linear low density polyethylene (LLDPE; density: 0.94 g / cm ³ ) and ethylene / vinyl acetate copolymer (EVA; EVAFLEX ^™ P-manufactured by Mitsui DuPont Polychemical Co., Ltd.) 1407) 40 parts by weight were used, and 80 parts by weight of PB (4-MP), 15 parts by weight of CEBC, and 5 parts by weight of LEO were used as the components of the adhesive layer 2.

Under the conditions shown in Table 1, an adhesive tape was molded in the same manner as in Example 1, and a release tape (manufactured by Tosero Co., Ltd., Tosero Separator ^TM SP T-18, thickness 37 μm) was provided on the adhesive layer surface. Then, it was slit and wound up.
Tables 3 and 4 show the measurement and evaluation results of the obtained wafer processing adhesive tape.

(Comparative Example 1) <Example of pressure-sensitive adhesive>
Obtained by copolymerizing 70 parts by weight of methyl acrylate, 30 parts by weight of butyl acrylate, and 5 parts by weight of acrylic acid in toluene using a 70 μm-thick polyvinyl chloride film (PVC) as the base layer of the adhesive tape. An acrylic pressure-sensitive adhesive containing 70 parts by weight of a urethane oligomer and 5 parts by weight of a polyfunctional isocyanate compound per 100 parts by weight of the acrylic copolymer in a solution containing an acrylic copolymer having a number average molecular weight of 300,000 Was coated on one side of the polyvinyl chloride film and heated at 130 ° C. for 3 minutes to form a 15 μm thick adhesive layer to obtain an adhesive tape. The measurement and evaluation results of this adhesive tape are shown in Tables 3 and 4.

(Comparative Example 2) <Example of pressure-sensitive adhesive>
Using the same polyvinyl chloride film as Comparative Example 1 as the base material layer of the adhesive tape, 80 parts by weight of polycarbonate diol, 20 parts by weight of adipic acid and 0.5 parts by weight of dibutyltin oxide were obtained by copolymerization in toluene. A polyester pressure-sensitive adhesive prepared by adding 5 parts by weight of a polyfunctional isocyanate compound per 100 parts by weight of polyester to a solution containing polyester having a number average molecular weight of 580,000 is coated on one side of the polyvinyl chloride film. An adhesive tape having a thickness of 15 μm was formed by heating at 3 ° C. for 3 minutes to obtain an adhesive tape. The measurement and evaluation results of this adhesive tape are shown in Tables 3 and 4.

(Comparative Example 3) <Example of pressure-sensitive adhesive>
Number average obtained by copolymerizing 90 parts by weight of butyl acrylate, 5 parts by weight of acrylonitrile, and 5 parts by weight of acrylic acid in toluene using the same polyvinyl chloride film as Comparative Example 1 as the base material layer of the adhesive tape In a solution containing an acrylic copolymer having a molecular weight of 500,000, 50 parts by weight of a polyfunctional acrylic monomer, 5 parts by weight of a polyfunctional isocyanate compound, and 5 parts by weight of 100 parts by weight of the acrylic copolymer. A photopolymerization initiator was added to prepare an acrylic pressure-sensitive adhesive, which was coated on one side of the polyvinyl chloride film and heated at 130 ° C. for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 15 μm. Next, it was left for 60 seconds under a high-pressure mercury lamp of 80 W / cm ² to be irradiated with ultraviolet rays to obtain an adhesive tape. The measurement and evaluation results of this adhesive tape are shown in Tables 3 and 4.

(Comparative Example 4) <Example of UV curable adhesive>
An ethylene / methyl methacrylate copolymer (EMMA; methyl methacrylate component content 10% by weight, melting point 100 ° C.) having a thickness of 80 μm was used as the base layer of the adhesive tape, and an acrylic copolymer (n-butyl) was used as the adhesive layer. (A copolymer of acrylate and acrylic acid) 100 parts by weight, 120 parts by weight of urethane acrylate oligomer having a molecular weight of 8000, 10 parts by weight of a curing agent (diisocyanate), 5 parts by weight of an ultraviolet curing reaction initiator (benzophenone) The pressure-sensitive adhesive composition mixed with was applied to a thickness of 10 μm to obtain a pressure-sensitive adhesive tape. The measurement and evaluation results of this adhesive tape are shown in Tables 3 and 4.

(Comparative Example 5) <Example of UV curable adhesive>
A 140 μm thick ethylene / methyl methacrylate copolymer (EMMA; methyl methacrylate component content 10 wt%, melting point 100 ° C.) was used as the base layer of the adhesive tape, and an acrylic copolymer (n-butyl) was used as the adhesive layer. (A copolymer of acrylate and acrylic acid) 100 parts by weight, 70 parts by weight of urethane acrylate oligomer having a molecular weight of 8000, 5 parts by weight of a curing agent (diisocyanate), 5 parts by weight of an ultraviolet curing reaction initiator (benzophenone) The pressure-sensitive adhesive composition mixed with was applied to a thickness of 10 μm to obtain a pressure-sensitive adhesive tape. The measurement and evaluation results of this adhesive tape are shown in Tables 3 and 4.

The wafer processing pressure-sensitive adhesive tape of the present invention can reduce the size of chipping and cracking of the wafer to 30 μm or less and cut the occurrence rate at the time of cutting by wafer dicing. Occurrence can be prevented epoch-making. Further, since the wafer can be fixed and held with a low probe tack force, cutting can be performed without using a special device such as a light or electron beam curing device.
According to the manufacturing method of the present invention, the pressure-sensitive adhesive tape of the present invention having a multilayer structure in which the thickness uniformity and surface property of each layer composed of different materials is good and no foreign matter is generated can be produced with a simple manufacturing process with high productivity. Can be manufactured.
According to the method of using the wafer processing pressure-sensitive adhesive tape of the present invention, the chip can be peeled from the pressure-sensitive adhesive tape of the present invention without using a special device for reducing the adhesive force.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 3 Intermediate | middle layer 3a 1st intermediate | middle layer 3b 2nd intermediate | middle layer 4 Surface layer 5 Release tape 6 Roll 10 Wafer processing adhesive tape 20 Chip 22 Defect 23 Crack 24 Defect or length of crack

Claims (16)

Adhesive layer containing propylene on one side of the substrate layer, 1-butene and α- olefin and units ingredient α- olefin copolymer one 5 to 12 carbon atoms or two or more of the mixture at 30 wt% A storage elastic modulus G ′ at 15 to 35 ° C. of the pressure-sensitive adhesive layer is 1 MPa or more, and a tan δ which is a ratio of the loss elastic modulus G ″ to the storage elastic modulus G ′ is 0.05 or more. An adhesive tape for wafer processing, characterized in that The adhesive layer comprises the α-olefin copolymer, a thermoplastic elastomer, and a co-oligomer of ethylene and another α-olefin, and the α-olefin copolymer forms a continuous phase, and the thermoplastic elastomer The adhesive tape for wafer processing according to claim 1, wherein a dispersed phase is formed. The thermoplastic elastomer has a general formula A-B-A or A-B (A represents an aromatic vinyl polymer block or an olefin polymer block exhibiting crystallinity, and B represents a diene polymer block or hydrogenated thereof. The wafer processing pressure-sensitive adhesive tape according to claim 2, wherein the block copolymer is a block copolymer represented by the following formula: One of the α-olefin copolymers is an α-olefin copolymer obtained by copolymerizing propylene, 1-butene and an α-olefin having 5 to 12 carbon atoms. The adhesive tape for wafer processing as described in any one of 1-3. The adhesive tape for wafer processing according to claim 4 , wherein the α-olefin having 5 to 12 carbon atoms is 4-methyl-1-pentene. The pressure-sensitive adhesive tape for wafer processing according to any one of claims 1 to 5, wherein the base material layer comprises one layer or a plurality of layers and contains an olefin polymer as a main component. The pressure-sensitive adhesive tape for wafer processing according to claim 6, wherein the base material layer comprises a surface layer and an intermediate layer, and is laminated in the order of the surface layer, the intermediate layer, and the adhesive layer. The said intermediate | middle layer consists of an olefin polymer and a thermoplastic elastomer, the olefin polymer forms the continuous phase, and the thermoplastic elastomer forms the disperse | distributed phase of Claim 7 characterized by the above-mentioned. Adhesive tape for wafer processing. The intermediate layer comprises a plurality of layers, at least one of which comprises the olefin polymer and a thermoplastic elastomer, the olefin polymer forms a continuous phase, and the thermoplastic elastomer forms a dispersed phase. The pressure-sensitive adhesive tape for wafer processing according to claim 7, wherein: The thermoplastic elastomer has a general formula A-B-A or A-B (A represents an aromatic vinyl polymer block or an olefin polymer block exhibiting crystallinity, and B represents a diene polymer block or hydrogenated thereof. The wafer processing pressure-sensitive adhesive tape according to claim 8 or 9, wherein the block copolymer is a block copolymer represented by the following formula: The said surface layer contains an olefin polymer as a main component, The adhesive tape for wafer processing as described in any one of Claims 7-10 characterized by the above-mentioned. The probe tack force measured in accordance with JIS Z0237 (reference) in a temperature range of 20 to 80 ° C is in a range of 0.01 to 1 N / 5 mmφ. The pressure-sensitive adhesive tape for wafer processing according to one item. The pressure-sensitive adhesive tape for wafer processing according to any one of claims 1 to 12, wherein the pressure-sensitive adhesive tape is formed by a coextrusion molding method. A main unit component is at least two kinds of α-olefins selected from a base material layer composed of one or more layers and an α-olefin having 2 to 12 carbon atoms laminated on one side of the base material layer. A method for producing an adhesive tape comprising an adhesive layer containing, as a main component, one or a mixture of two or more α-olefin copolymers, and the melt flow of the polymer constituting the base layer and the adhesive layer The rate (measured according to MFR, ASTM D1238 and measured at a temperature of 230 ° C. and a load of 2.16 kg) is 5 to 40 g / 10 minutes, the MFR difference between adjacent layers is 10 g / 10 minutes or less, and the melting temperature is 200 to 260. The wafer according to any one of claims 6 to 11, wherein the wafer is molded by a coextrusion molding method using a multilayer die so that the melting temperature difference between adjacent layers is 30 ° C or less. Manufacturing method of processing adhesive tape. The pressure-sensitive adhesive tape for wafer processing according to any one of claims 1 to 13 and the wafer are pressure-bonded at 20 to 80 ° C, and then the wafer is cut into chips at 15 to 35 ° C. A method for using an adhesive tape for wafer processing, characterized by extending at -80 ° C, and then picking up a chip at room temperature and peeling it from the adhesive tape. The method for using an adhesive tape for wafer processing according to claim 15, wherein the wafer is a semiconductor wafer having a circuit pattern formed on a surface thereof, and the cutting process is dicing.

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