JP5140910B2 - Film base and adhesive tape for semiconductor wafer processing - Google Patents

Description

  The present invention relates to a film substrate and an adhesive tape for processing a semiconductor wafer.

  In the process of manufacturing a semiconductor device, an adhesive tape for processing a semiconductor wafer is used when the semiconductor wafer is cut. This adhesive tape is used for picking up (mounting) a semiconductor element obtained by affixing to a semiconductor wafer, dicing, expanding, etc., and cutting the semiconductor wafer.

Such a tape is composed of a base film and an adhesive layer provided on one surface of the base film.
As the base film, a polyvinyl chloride (PVC) resin film has been mainly used. However, due to environmental problems associated with the use of polyvinyl chloride resins and the possibility of contamination of semiconductor elements due to bleeding of additives such as plasticizers used in polyvinyl chloride resins, polypropylene films and ethylene vinyl alcohol films have recently been used. Further, a base film using a polyolefin-based material such as an ethylene methacrylic acid acrylate-based film has been developed (for example, see Patent Document 1).

  In recent years, semiconductor elements have been reduced in size and thickness, and problems such as expandability, chipping of semiconductor elements, and generation of chips, which have not been problems until now, have become apparent. For example, since a polypropylene film has a poor film restoration rate after expansion, when the film is stored in a cassette rack, the loose film may come into contact with the lower wafer surface to destroy the semiconductor element. In addition, the ethylene vinyl alcohol film and the ethylene methacrylate acrylate film have problems that chips are likely to be generated during dicing and that they are easily torn during expansion. Therefore, the performance improvement of the base film in the adhesive tape for semiconductor wafer processing is calculated | required strongly.

JP 09-008111 A

  An object of the present invention is to use a film base material excellent in performance required for an adhesive tape for semiconductor wafer processing, such as an excellent expandability and a high restoration rate of the adhesive tape for semiconductor wafer processing after expansion, and the like. The object is to provide an adhesive tape for processing semiconductor wafers.

Such an object is achieved by the present invention described in the following (1) to (7).
(1) A film substrate used for an adhesive tape for processing a semiconductor wafer, wherein the film substrate is mainly composed of a resin composition containing a propylene-based copolymer, and the film substrate has a tensile modulus of 50 to 50 A film substrate characterized by being 250 MPa.
(2) The film substrate according to (1), wherein the resin composition further includes a thermoplastic elastomer.
(3) The film substrate according to (1) or (2), wherein the content of the propylene-based copolymer is 50 to 75% by weight of the entire resin composition.
(4) The film substrate according to any one of (1) to (3), wherein the propylene copolymer has a tensile modulus of 600 MPa or less.
(5) The film substrate according to any one of (2) to (4), wherein a restoration rate after the thermoplastic elastomer is stretched 100% is 98% or more.
(6) When the 100% modulus in the MD direction of the film substrate is A [g / mm ² ] and the 100% modulus in the TD direction is B [g / mm ² ], the ratio (A / B) is The film substrate according to any one of (1) to (5), which is 1.2 or less.
(7) A semiconductor wafer comprising the film substrate according to any one of (1) to (6) above and an adhesive layer provided on one surface side of the film substrate. Adhesive tape for processing.

According to the present invention, a film base material excellent in performance required for an adhesive tape for semiconductor wafer processing, such as excellent expandability and a high restoration rate of the adhesive tape for semiconductor wafer processing after expansion, and the like are used. An adhesive tape for processing a semiconductor wafer can be obtained.
Moreover, when the resin composition which comprises a film base material contains a thermoplastic elastomer, the restoring property of a film base material can be improved especially.
In addition, when the thermoplastic elastomer having a specific restoration rate is used, it is possible to particularly prevent slack after the processing of the adhesive tape for processing a semiconductor wafer.

Hereinafter, the film base material and the adhesive tape for processing a semiconductor wafer of the present invention will be described in detail.
FIG. 1 is a cross-sectional view schematically showing an adhesive tape for processing a semiconductor wafer.
As shown in FIG. 1, a semiconductor wafer processing adhesive tape 10 includes a film base 1 and an adhesive layer 2 provided on one surface side (upper side in FIG. 1) of the film base 1.

First, the film substrate 1 will be described.
The film substrate 1 is mainly composed of a resin composition containing a propylene-based copolymer. Thereby, when expanded, the distance between the semiconductor elements can be greatly increased, so that pick-up performance is improved and generation of chips can be suppressed.

  Examples of the propylene-based copolymer include a random copolymer of propylene and other components, a block copolymer of propylene and other components, and an alternating copolymer of propylene and other components. Among these, a random copolymer of propylene and other components or a block copolymer of propylene and other components is preferable. Thereby, chips generated when the semiconductor wafer is cut can be suppressed. Examples of a method for polymerizing such a propylene copolymer include a solvent polymerization method, a bulk polymerization method, and a gas phase polymerization method. For such polymerization, for example, a titanium trichloride type catalyst, a magnesium chloride type supported catalyst, a metallocene catalyst or the like can be used.

  Specifically, other components of the propylene copolymer include α-olefins such as ethylene, butene, pentene, hexene, heptene, copolymers composed of at least two α-olefins, and styrene-diene copolymer. Examples include coalescence. Among these, ethylene or ethylene-propylene copolymer (EPR) is preferable. Thereby, it is possible to particularly suppress chips generated when the semiconductor wafer is cut.

  The resin composition mainly contains the propylene-based copolymer as described above, and the content thereof is not particularly limited as long as it is 50% by weight or more of the whole resin composition, but is 50 to 75% by weight or more. 60 to 70% by weight is particularly preferable. When the content is less than the lower limit, in addition to the effect of suppressing the generation of chips, the adhesiveness of the film substrate 1 is increased (blocking phenomenon), which may lead to a decrease in productivity. is there. Further, when the upper limit is exceeded, the expansion rate in the MD and TD directions becomes non-uniform, and the separated semiconductor elements may be slanted or may be in contact with adjacent semiconductor elements. In some cases, the image of the element cannot be recognized, or the semiconductor element is missing.

The tensile elastic modulus of the propylene-based copolymer is not particularly limited, but is preferably 600 MPa or less, and particularly preferably 300 to 550 MPa. If the tensile elastic modulus exceeds the upper limit, a large tension is required to expand the film substrate 1, so that the distance between the semiconductor elements becomes small when expanded, and the effect of improving the pickup property may be reduced. . On the other hand, if it is less than the lower limit, the effect of suppressing the generation of chips may be reduced, and the rigidity of the film substrate 1 may be reduced, which may cause tearing when expanded. Moreover, the said tensile elasticity modulus produced the 100-micrometer film, for example with the said propylene-type copolymer alone, and produced the 1st type | mold tensile test piece prescribed | regulated to JISK6301. Using the obtained No. 1 type tensile test piece, a stress-strain curve was created with a Tensilon universal testing machine manufactured by A & D, and the tensile modulus E (the following formula) was obtained from the initial slope of the stress-strain curve. .
Formula) Tensile modulus E = δσ (stress) / δε (strain)

The resin composition preferably further includes a thermoplastic elastomer. Thereby, it can expand uniformly, without tearing the adhesive tape for semiconductor wafer processing, and the restoring property of the film base material 1 can be improved more.
The thermoplastic elastomer is not particularly limited as long as it is a natural and synthetic polymer exhibiting elasticity at room temperature. For example, natural rubber, polybutadiene, polyisoprene, polychlorobutadiene, ethylene-propylene rubber, olefin such as ethylene-butene rubber Thermoplastic elastomer, styrene-butadiene copolymer (random copolymer, block copolymer, graft copolymer, etc.), styrene-isoprene copolymer (random copolymer, block copolymer, graft copolymer) Styrenic thermoplastic elastomer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, ethylene-propylene-butene ternary copolymer Polymer, thiolol Polymers, polyvulcanized rubbers, polyurethane rubbers, polyether rubbers, epichlorohydrin rubbers and the like, and polymers obtained by adding water to these thermoplastic elastomers, such as hydrogenated styrene-butadiene copolymers and hydrogenated styrene-isoprene copolymers. It is done. Of these, styrene-based thermoplastic elastomers are particularly preferred. Thereby, while restoring property improves, it can suppress that the film base material 1 tears when processing a semiconductor wafer.

The restoration rate after 100% elongation of the thermoplastic elastomer is not particularly limited, but is preferably 98% or more, and particularly preferably 99% or more. When the restoration rate is within the above range, it is possible to suppress the slackness of the film substrate 1 after processing. For example, a No. 1 tensile test piece defined in JIS K 6301 was prepared from the film base 1 of an adhesive tape for processing semiconductor wafers. Draw a 40 mm long marked line on the obtained No. 1 type tensile test piece and set it to a Tensilon universal testing machine (manufactured by A & D) with the gap between the chucks set to 40 mm and set it at a speed of 200 mm / min. % Stretch (40 mm stretch), hold for 2 minutes, then release the chuck, and after 5 minutes from the chuck release, measure the distance between marked lines of type 1 tensile test piece to calculate the restoration rate (the following formula) .
Expression) Restoration rate (%) = (80−distance between marked lines after chuck release) / 40 × 100

  Although content of such a thermoplastic elastomer is not specifically limited, 25 to 50 weight% of the whole said resin composition is preferable, and 30 to 40 weight% is especially preferable. If the content is less than the lower limit, the effect of improving the recoverability is reduced, which may cause problems such as being unable to be stored in the cassette due to the slackness of the film base 1 after processing. The effect of preventing the generation of waste may be reduced.

  The resin composition is generally known to be a crystal nucleating agent, anionic, cationic, nonionic or amphoteric, as long as the object of the present invention is not impaired, other than the above-mentioned propylene-based copolymer and thermoplastic elastomer. Additives such as certain antistatic agents, ultraviolet absorbers, lubricants, antioxidants, light stabilizers, antiblocking agents, surfactants, dyes, pigments, flame retardants, fillers and petroleum resins may be added.

The kind of the antistatic agent is not particularly limited, but a polymer type antistatic agent that hardly bleeds on the surface is preferable.
The content of the antistatic agent is not particularly limited, but is 5 for 100 parts by weight of the propylene-based copolymer (when the thermoplastic elastomer is included, the total of the propylene-based copolymer and the thermoplastic elastomer). -50 parts by weight is preferable, and 10-30 parts by weight is particularly preferable. When the content is within the above range, the balance between the mechanical properties of the substrate and the antistatic performance is particularly excellent. Thereby, static electricity generated at the time of expanding or picking up can be suppressed, so that the destruction of the semiconductor element can be suppressed and the yield is improved.

Examples of the method of using the resin composition as the film substrate 1 include a method in which the raw materials constituting the resin composition are mixed (kneaded) and then formed into a film with an extruder or the like.
The mixing (kneading) of the raw materials is not particularly limited, and a dry blending method may be used, but a batch type kneading such as a Banbury mixer, a kneader, or a roll, a continuous type such as a single screw extruder, a twin screw extruder, or a calender roll. It is preferable to use a kneader.
Examples of a method for forming the mixed raw material into a film include T-die extrusion, a calendar method, and the like.

The thickness of the film substrate 1 thus obtained is not particularly limited, but is preferably 0.05 to 0.5 mm, particularly preferably 0.08 to 0.3 mm.
Moreover, you may form an appropriate uneven | corrugated shape on one side or both surfaces of the film base material 1 using an embossing roll. Furthermore, in order to increase the adhesion with the adhesive layer to be applied thereafter, the surface of the film substrate 1 may be subjected to pretreatment such as corona treatment, plasma treatment, or UV-ozone treatment.

In this invention, the tensile elasticity modulus of the film base material 1 obtained in this way is 50-250 MPa, It is characterized by the above-mentioned.
Conventional film substrates include ethylene copolymer alone, ethylene copolymer / thermoplastic elastomer system, polypropylene system / thermoplastic elastomer system, and the like. Here, the elastic modulus of the ethylene copolymer alone, the ethylene copolymer / thermoplastic elastomer system was about 30 to 50 MPa, and the elastic modulus of the polypropylene system / thermoplastic elastomer system was about 300 to 800 MPa. These ethylene copolymers alone and ethylene copolymer / thermoplastic elastomer film base materials are still unsatisfactory with respect to the tear resistance of the film and the suppression of chips generated when cutting semiconductor wafers. It was enough.
On the other hand, the polypropylene-based / thermoplastic elastomer-based film base 1 is excellent in suppressing the generation of chips generated when the semiconductor wafer is cut, but the film base 1 still has expandability and resilience. It was insufficient.
On the other hand, in the present invention, by setting the elastic modulus of the film base 1 composed of a resin composition mainly containing a propylene-based copolymer to 50 to 250 MPa, the distance between the semiconductor elements when expanded is increased. It becomes easy to open, and it can be excellent in suppression of chips generated when the semiconductor wafer is cut.
Specifically, the tensile elastic modulus of the film substrate 1 is preferably 60 to 240 MPa, and particularly preferably 75 to 200 MPa. When the tensile modulus is within the above range, the resilience is further excellent.

  The restoration rate after the film substrate 1 is stretched 100% is not particularly limited, but is preferably 80% or more in both the MD direction and the TD direction, and particularly preferably 90% or more. When the restoration rate is within the above range, the film tearing at the time of expanding and the film substrate 1 after processing are excellent in suppressing the slack.

Also, 100% modulus A in the MD direction of the film substrate 1 [g / mm ^2], the ratio of the 100% modulus B of the TD ^{[g / mm 2] (A} / B) is not particularly limited, It is preferably 1.2 or less, particularly preferably 1.0 to 1.1. When the ratio is within the above range, the distance between the semiconductor elements at the time of expansion can be opened uniformly, and the image recognition performance is improved.

Next, the adhesive layer 2 will be described.
The pressure-sensitive adhesive layer 2 is generally composed of a resin composition composed of an energy ray curable resin, an energy ray polymerization initiator, and a crosslinking agent, in addition to a tackifier component that becomes a base resin.
As the base resin, conventionally known ones can be widely used. From the homopolymers mainly composed of alkyl esters of acrylic acid or methacrylic acid or copolymers with other copolymerizable comonomers and mixtures thereof. An acrylic pressure-sensitive adhesive is preferred.
Examples of the alkyl ester of acrylic acid or methacrylic acid as the main structural unit include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, glycidyl acrylate, methyl methacrylate, and ethyl methacrylate. Propyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, glycidyl methacrylate and the like. Among these, at least one selected from ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and octyl acrylate is preferable. Thereby, in addition to favorable adhesiveness, it can be set as low pollution property. Here, “low contamination” means that the adhesive layer 2 hardly remains on the semiconductor wafer 5 in the pick-up process after the semiconductor wafer is separated.
Examples of the copolymerizable comonomer include methacrylic acid, acrylic acid, itaconic acid, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, acrylamide, methylolacrylamide, maleic anhydride, styrene, vinyl acetate, acrylonitrile, acrylic acid 2- Examples include hydroxyethyl and 2-hydroxyethyl methacrylate.

  The base resin is not particularly limited, but may contain a copolymer of a copolymerizable comonomer containing a functional group capable of reacting with a cross-linking agent described later, but the content thereof is not particularly limited, and the base resin is not limited. The total content is preferably 20% or less, particularly preferably less than 10%. When the content is within the above range, the adhesive force can be appropriately controlled by reaction with the crosslinking agent.

  The base resin is not particularly limited, but may contain a polymer of vinyl acetate monomer, but the content thereof is not limited, and is preferably 50% by weight or more of the total base resin, particularly 60 to 85% by weight. Is preferred. When the content is in the above range, the cohesive force can be increased at a low cost, thereby suppressing chip chipping during dicing and improving the pick-up property of the semiconductor element.

  As the energy ray curable resin, for example, low molecular weight compounds having at least two polymerizable carbon-carbon double bonds that can be three-dimensionally cross-linked by irradiation with energy rays such as ultraviolet rays and electron beams are widely used. It is done. Specific examples of such energy ray curable resins include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate. 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, etc., and urethane acrylate synthesized from polyol, aromatic isocyanate, and acrylate monomer having OH group Acrylates with oligomers (UAO), polyester polyols, aliphatic isocyanates and OH groups And urethane acrylate polyester UAO such synthesized from monomers (oligomers). Among these, urethane acrylate (oligomer) is preferable. Thereby, adhesiveness with the film base material 1 can be improved.

  Although content of the said energy-beam curable resin is not specifically limited, 60-130 weight part is preferable with respect to 100 weight part of said base resins, and 80-120 weight part is especially preferable. When the content is within the above range, particularly the adhesive strength after energy beam irradiation is moderately reduced, so that the pick-up property of the semiconductor element is improved.

In order to facilitate the initiation of polymerization of the energy beam curable resin, the resin composition may contain an energy beam polymerization initiator.
Examples of the energy linear polymerization initiator include 2-2dimethoxy-1,2-diphenylethane-1-one, benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetra Examples include methyl thiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β-chloranthraquinone and the like.

  The content of the energy linear polymerization initiator is not particularly limited, but is preferably 1 to 15 parts by weight, and particularly preferably 3 to 10 parts by weight with respect to 100 parts by weight of the base resin. When the content is within the above range, the reaction efficiency particularly with respect to energy ray irradiation (particularly ultraviolet irradiation) is improved.

  Examples of the crosslinking agent include epoxy crosslinking agents, isocyanate crosslinking agents, methylol crosslinking agents, chelating crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, and polyvalent metal chelating crosslinking agents. Among these, an isocyanate type crosslinking agent is preferable. Thereby, especially the balance between the affinity of the adhesive layer 2 for the semiconductor wafer and the pickup property can be improved.

  Specific examples of the isocyanate crosslinking agent include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4-4′-diisocyanate. , Diphenylmethane-2-4′-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4-4′-diisocyanate, and dicyclohexylmethane-2-4′-diisocyanate. Among these, at least one selected from 2,4-tolylene diisocyanate, diphenylmethane-4-4'-diisocyanate, and hexamethylene diisocyanate is preferable. Thereby, especially the balance of aggregation and crosslinking of isocyanate itself can be improved.

Further, in the case of using a base resin containing a polymer of a monomer mainly containing a vinyl acetate monomer and a functional group capable of reacting with a crosslinking agent, the crosslinking agent is added in an amount of 8 parts by weight based on 100 parts by weight of the base resin. It is preferable to contain above, and it is preferable to contain especially 9-25 weight part.
Thus, when the polymer of the said vinyl acetate monomer is mainly included as base resin, even if it contains the said crosslinking agent 8 weight part or more with respect to base resin, the initial stage rigidity is fully maintained. . Furthermore, since it contains more crosslinking agent than usual, it can be made an adhesive force that can be easily picked up even for long or thin semiconductor elements after irradiation with energy rays.

  The adhesive resin composition includes a crystal nucleating agent, a rosin resin, a terpene resin, a coumarone resin, a phenol resin, a styrene resin, an aliphatic petroleum resin, an aromatic petroleum resin, a fat as long as the object of the invention is not impaired Tackifiers such as aromatic aromatic copolymer petroleum resins, anionic, cationic, nonionic or amphoteric generally known surfactants and other antistatic agents, ultraviolet absorbers, lubricants, antioxidants, You may add additives, such as a light stabilizer, an antiblocking agent, surfactant, dye, a pigment, a flame retardant, and a filler.

  Although content of the said tackifier is not specifically limited, 5-30 weight part is preferable with respect to 100 weight part of said base resins, and 10-20 weight part is especially preferable. When the content is within the above range, it is possible to improve the adhesive strength without adversely affecting the pickup property.

The pressure-sensitive adhesive layer 2 composed of the resin composition can be formed on the film substrate 1 to obtain the pressure-sensitive adhesive tape 10 for processing a semiconductor wafer of the present invention.
As a method for forming the adhesive layer 2 on the film substrate 1, for example, the resin composition is dissolved in a solvent and applied by a known method such as a comma coater, gravure coater, die coater, reverse coater, or micro gravure coater. A method is mentioned.
Specifically, the adhesive layer 2 can be formed by applying the resin composition to the film substrate 1 by the above-described method and drying it at 60 to 100 ° C. for 30 seconds to 10 minutes.

  Although the thickness of such an adhesion layer 2 is not specifically limited, 5-30 micrometers is preferable and 10-20 micrometers is especially preferable. When the thickness is less than the lower limit value, the adhesive force is not sufficient and the semiconductor element may be scattered during dicing, and when the thickness exceeds the upper limit value, it may be difficult to pick up the semiconductor element.

Next, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.
Example 1
1. Manufacture of film base material As propylene-based copolymer, MFR 0.7, density 0.9 g / cm ³ , tensile elastic modulus 540 MPa propylene / ethylene block copolymer (manufactured by Sun Allomer), 60% by weight, styrene content 20 %, A density of 0.9 g / cm ³ , and a resin composition containing 40% by weight of a styrene-isoprene-styrene block copolymer (made by Kuraray Co., Ltd.) having a recovery rate of 99% is dry blended, and then extrusion molding of a T-die is performed. The film base material (100 micrometers in thickness) with a tensile elasticity modulus of 110 Mpa was obtained by extruding with a machine.

2. Manufacture of adhesive tape for semiconductor wafer processing 2-ethylhexyl acrylate 29.7% by weight, vinyl acetate 69.3% by weight and 2-hydroxyethyl methacrylate 1% by weight were solution-polymerized in a toluene solvent by a conventional method, and the weight average molecular weight 150 1,000 base resin A was obtained.
With respect to 100 parts by weight of this base resin, 100 parts by weight of bifunctional urethane acrylate (produced by Mitsubishi Rayon Co., Ltd., weight average molecular weight 11,000) as an energy ray curable resin, and polyisocyanate compound (Coronate L, Japan as a crosslinking agent) Polyurethane Co., Ltd.) 15 parts by weight and 2,2-dimethoxy-2-phenylacetophenone as an energy ray polymerization initiator in 5 parts by weight were dissolved in ethyl acetate. It apply | coated so that it might become 10 micrometers, and obtained the adhesive tape for semiconductor wafer processing by making it dry at 80 degreeC for 5 minute (s).

(Example 2)
The procedure was the same as Example 1 except that the blending amount of the styrene-isoprene-styrene block copolymer was 50% by weight. The film substrate obtained had a tensile modulus of 50 MPa.

(Example 3)
The procedure was the same as Example 1 except that the blending amount of the styrene-isoprene-styrene block copolymer was 25% by weight. The film substrate obtained had a tensile modulus of 210 MPa.

Example 4
The same procedure as in Example 1 was performed except that a propylene / ethylene block copolymer (manufactured by Sun Allomer Co., Ltd.) having an MFR of 2.3, a density of 0.9 g / cm ³ and a tensile elastic modulus of 620 MPa was used as the propylene-based copolymer. . The film substrate obtained had a tensile modulus of 150 MPa.

(Comparative Example 1)
The same as Example 1 except that the blending amount of the styrene-isoprene-styrene block copolymer was 60% by weight. The film substrate obtained had a tensile modulus of 20 MPa.

(Comparative Example 2)
The procedure was the same as Example 1 except that the blending amount of the styrene-isoprene-styrene block copolymer was 15% by weight. The film substrate obtained had a tensile modulus of 340 MPa.

(Comparative Example 3)
An ethylene-vinyl acetate copolymer (VA: 10%, manufactured by Sumitomo Chemical Co., Ltd.) was used instead of the propylene-based copolymer, and the same procedure as in Example 1 was performed except that the thermoplastic elastomer was not used. The film substrate obtained had a tensile modulus of 50 MPa.

The following evaluation was performed about the adhesive tape for semiconductor processing obtained by each Example and each comparative example. The evaluation items are shown together with the contents. The obtained results are shown in Table 1.
1. Modulus of film substrate in adhesive tape for semiconductor processing Type 1 tensile test piece (specified in JISK 6301) of MD tape and TD direction of adhesive tape for semiconductor wafer processing was prepared, and Tensilon Universal Testing Machine (manufactured by A & D) The SS curve was measured. 100% modulus was read from the obtained SS curve and digitized. The MD / TD ratio was determined from the 100% modulus of the obtained MD and TD.

2. Tensile Elastic Modulus of Film Base A film having a thickness of 100 μm was prepared according to the formulation of Examples and Comparative Examples to prepare No. 1 type tensile test pieces (specified in JIS K 6301). Using the obtained No. 1 type tensile test piece, a stress-strain curve is created with a Tensilon universal testing machine (manufactured by A & D), and the tensile modulus E (the following formula) is obtained from the initial slope of the stress-strain curve. It was.
Formula) Tensile modulus E = δσ (stress) / δε (strain)

3. Restoration rate of thermoplastic elastomer and film substrate Restoration rate was a thermoplastic elastomer alone, No. 1 type tensile test piece (specified in JIS K 6301) of the film substrate obtained in each example and each comparative example. . Draw a 40 mm long marked line on the obtained No. 1 type tensile test piece and set it to a Tensilon universal testing machine (manufactured by A & D) with the gap between the chucks set to 40 mm and set it at a speed of 200 mm / min. % Stretch (40 mm stretch), hold for 2 minutes, then release the chuck, and 5 minutes after opening the chuck, measure the distance between marked lines of the type 1 tensile test piece to obtain the restoration rate (the following formula). .
Expression) Restoration rate (%) = (80−distance between marked lines after chuck release) / 40 × 100

As apparent from Table 1, the tensile elastic moduli of the film substrates of Examples 1 to 4 were in the range of 50 to 250 MPa.
In addition, Examples 1, 2, and 4 were particularly excellent in the restoration rate of the film substrate.
Further, the modulus A [g / mm ^2] of the MD direction of the film substrate of Examples 1 to 4, the ratio of the modulus B [g / mm ^2] of the TD direction (A / B) is 1.2 or less Met.

Evaluation of workability of semiconductor wafer (Examples 1A to 4A and Comparative Examples 1A to 3A)
Next, the workability at the time of processing a semiconductor wafer under the following conditions was evaluated using the adhesive tape for semiconductor processing obtained in each Example and each Comparative Example. The evaluation items are shown together with the contents. The obtained results are shown in Table 2.
Semiconductor wafer processing (dividing) conditions (dicing conditions)
Equipment: DAD-3350 made by DISCO
Blade: NBC-2050-SE 27HEDD made by DISCO
Blade rotation speed: 30000 rpm
Feeding speed: 100mm / sec
Film cutting depth: 30 μm

1. Adhesion rate of chips to semiconductor elements Adhesive tape for semiconductor processing was attached to a 6-inch ring, and a 6-inch semiconductor wafer (thickness 300 μm) was mounted. After mounting the semiconductor wafer, it was set in a dicing apparatus and separated into a size of 5 mm × 5 mm. After dividing into pieces, the surface of the semiconductor element was observed with an optical microscope (magnification 200 times), and the proportion of chips attached was determined.
A: The adhesion rate to the semiconductor element is less than 0.1%.
○: Adhesion rate to the semiconductor element is 0.1% or more and less than 0.3%.
(Triangle | delta): The adhesion rate to a semiconductor element is 0.3% or more and less than 0.5%.
X: The adhesion rate to the semiconductor element is 0.5% or more.

2. Tearing on expansion
A 6-inch ring was attached with an adhesive tape for semiconductor processing, and a 6-inch semiconductor wafer (thickness: 625 μm) was mounted. After mounting the semiconductor wafer, it was set in a dicing apparatus and separated into a size of 5 mm × 5 mm. After separating into individual pieces, the wafer was set on a wafer expansion device, and tearing of the adhesive tape for semiconductor wafer processing during expansion was evaluated while changing the amount of the adhesive tape for semiconductor processing. Each code is as follows.
(Double-circle): Even if the amount of withdrawal exceeded 20 mm, the adhesive tape for semiconductor wafer processing did not tear.
◯: The adhesive tape for processing a semiconductor wafer did not tear if the amount of withdrawal exceeded 15 mm and was 20 mm or less.
(Triangle | delta): If the amount of withdrawal exceeded 12 mm and was 15 mm or less, the adhesive tape for semiconductor wafer processing did not tear.
X: The semiconductor wafer processing adhesive tape was torn when the amount of withdrawal was 12 mm or less.

3. Expandability between semiconductor elements Adhesive tape for semiconductor processing was attached to a 6-inch ring, and a 6-inch semiconductor wafer (thickness: 625 μm) was mounted. After mounting the semiconductor wafer, it was set in a dicing apparatus and separated into a size of 5 mm × 5 mm. After separating into individual pieces, the wafer was set on a wafer expansion apparatus and expanded with a withdrawal amount of 15 mm, and the distance between the semiconductor elements was evaluated. Each code is as follows. The evaluation was performed at N = 100.
A: The distance between the semiconductor elements is 150 μm or more.
○: The distance between the semiconductor elements is 100 μm or more and less than 150 μm.
(Triangle | delta): The distance between semiconductor elements is 80 micrometers or more and less than 100 micrometers.
X: The distance between semiconductor elements is less than 80 micrometers.

4). Pickup property Adhesive tape for semiconductor processing was attached to a 4-inch semiconductor wafer (thickness: 100 μm) and separated into a size of 10 × 10 mm. (Film cutting depth was set to 30 μm) After singulation, the wafer was irradiated with ultraviolet rays, then set on the wafer expansion device and expanded with a withdrawal amount of 10 mm, and the needle pick-up amount was changed to pick up the semiconductor element. Evaluated. The pickup evaluation was carried out by Hugle Electronics (DE-35i-8). (Use of four push-up pins and a pin spacing of 8 mm) Evaluation was performed at N = 100. Each code is as follows.
A: All semiconductor elements could be picked up with a push-up amount of less than 1 mm.
A: All semiconductor elements could be picked up with a push-up amount of 1 mm or more and less than 2 mm.
Δ: Less than 5 semiconductor elements could not be picked up with a push-up amount of less than 2 mm.
X: 5 or more semiconductor elements could not be picked up with a push-up amount of less than 2 mm.
Note that “impossible pickup” described here includes “chip cracking”.

As is apparent from Table 2, Examples 1A to 4A had a low chip adhesion rate during dicing. In particular, Examples 1A, 3A, and 4A had low adhesion rates.
In particular, Examples 1A, 2A and 4A showed no tearing during expansion, and excellent expandability.
Examples 1A to 4A were also excellent in expandability between semiconductor elements and pick-up properties of semiconductor elements.

  The pressure-sensitive adhesive tape for processing a semiconductor wafer of the present invention can be suitably used for a dicing tape used for cutting a semiconductor wafer, a protective tape used for polishing a semiconductor wafer, and the like.

It is sectional drawing which shows typically the adhesive tape for semiconductor wafer processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film base material 2 Adhesive layer 10 Adhesive tape for semiconductor wafer processing

Claims (1)

A pressure-sensitive adhesive tape for processing a semiconductor wafer provided with a pressure-sensitive adhesive layer on one surface side of a film substrate,
The film substrate is
A propylene-based copolymer (A);
It is composed of a resin composition comprising a thermoplastic elastomer (B) having a restoration rate of 98% or more after stretching 100%,
The tensile elastic modulus of the propylene copolymer (A) is 600 MPa or less,
The film substrate has a tensile modulus of 50 to 250 MPa,
When the 100% modulus in the MD direction of the film substrate is A [g / mm ² ] and the 100% modulus in the TD direction is B [g / mm ² ], the ratio (A / B) is 1.0. Above 1.1
The pressure-sensitive adhesive tape for processing a semiconductor wafer, wherein the weight ratio (A / B) of the propylene-based copolymer (A) and the thermoplastic elastomer (B) in the resin composition is A / B = 50/50 to 75/25 .

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