Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/16—Nitrogen-containing compounds
  • C08K5/29—Compounds containing one or more carbon-to-nitrogen double bonds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
  • C09J133/04—Homopolymers or copolymers of esters
  • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
  • C09J133/08—Homopolymers or copolymers of acrylic acid esters
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/38—Pressure-sensitive adhesives [PSA]
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/38—Pressure-sensitive adhesives [PSA]
  • C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C09J7/385—Acrylic polymers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
  • H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
  • H01L21/6835—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support
  • H01L21/6836—Wafer tapes, e.g. grinding or dicing support tapes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
  • C09J2203/326—Applications of adhesives in processes or use of adhesives in the form of films or foils for bonding electronic components such as wafers, chips or semiconductors

Definitions

• the present invention relates to an adhesive tape and a tape for semiconductor wafer processing.
• the manufacturing process of semiconductor chips includes the dicing process, which separates the semiconductor wafer into individual chips, and the die bonding process, which adheres the separated chips to lead frames, package substrates, etc.
• semiconductor chips may be stacked and bonded together in a die bonding process.
• the integrated dicing and die bonding tape is used to secure the wafer so that the cut chips do not scatter during the process of dicing the semiconductor wafer.
• the process of picking up the chip it is required to be able to reduce the adhesive strength so that it can be easily peeled off from the chip.
• Patent Documents 1 and 2 by using a photocurable adhesive for the adhesive tape, the adhesive strength of the adhesive layer is reduced by light irradiation after dicing, and then the pickup process is performed. Accordingly, it has been proposed to achieve both high adhesive strength required for dicing and low adhesive strength required for pickup. Further, for example, in Patent Document 3, it is proposed to achieve both high adhesive force required during dicing and low adhesive force required during pick-up by adding a (meth)acryl-modified silicone resin.
• Patent Documents 1 and 2 require a sufficient adhesive force to prevent the wafer from peeling off during dicing, and therefore the adhesive force is too high to allow easy peeling during pick-up. cannot be fully satisfied. Moreover, even if the chip can be picked up, a large force must be applied when picking up the chip, and there is a risk of process defects such as chipping of the chip.
• the individualized chips may peel off due to the influence of cutting water during blade dicing, or the adhesive layer may melt due to the heat of friction with the blade, and the scraped-up glue will fix the chips. There was a possibility that the pick-up performance would be degraded due to the loss.
• dicing a high shear force is generated in the adhesive layer, and the effect of friction between the blade and the adhesive layer becomes more pronounced, resulting in insufficient properties for small chip applications.
• the present invention has been made in view of the above matters, and an adhesive tape that can be easily picked up without melting of the adhesive layer during dicing and can suppress chip flying and peeling from the ring frame during dicing, and the same.
• An object of the present invention is to provide a semiconductor wafer processing tape suitable for the blade dicing method used.
• the present inventors diligently studied the adhesive design of the adhesive tape. As a result, the inventors have found that the above problems can be solved by using a pressure-sensitive adhesive layer having a predetermined storage modulus and loss modulus.
• the present invention is as follows. [1] Having a base layer and an adhesive layer provided on the base layer, In the temperature range of 23°C to 150°C, The loss elastic modulus G′′ of the adhesive layer is 1.0 ⁇ 10 2 Pa or more and 1.6 ⁇ 10 5 Pa or less, and the storage elastic modulus G′ of the adhesive layer and the loss elastic modulus at the same temperature The minimum value M 1 of the difference (G'-G") of the ratio G" is 1.0 ⁇ 10 5 Pa or more, Adhesive tape. [2] The Young's modulus of the adhesive layer is 0.5 MPa or more and 7.0 MPa or less. The adhesive tape according to [1].
• the 180° peel strength of the pressure-sensitive adhesive layer against a silicon wafer under a temperature condition of 23° C. is 0.03 N/20 mm or more and 0.35 N/20 mm or less.
• the pressure-sensitive adhesive layer has a tack of 0.03 N/20 mm 2 or more and 0.65 N/20 mm 2 or less under a temperature condition of 23°C.
• [5] In the temperature range of 70°C to 110°C, The minimum value M2 of the difference (G' - G") between the storage modulus G' and the loss modulus G" at the same temperature is 1.0 ⁇ 10 5 Pa or more.
• the adhesive tape according to any one of [1] to [4].
• the pressure-sensitive adhesive layer contains a (meth) acrylic acid ester copolymer, The (meth)acrylic acid ester-based copolymer has a linear, branched, or crosslinked shape, [1] The adhesive tape according to any one of [5].
• [7] In the (meth)acrylic acid ester copolymer The content of structural units having a hydroxyl group is 1.0 mol% or more and 30 mol% or less with respect to 100 mol% of all structural units, The content of structural units having a carboxyl group is 0.1 mol% or more and 10 mol% or less with respect to 100 mol% of all structural units.
• the pressure-sensitive adhesive layer further contains a curing agent, The adhesive tape according to any one of [1] to [7].
• the curing agent contains an isocyanate compound, The adhesive tape according to [8].
• the isocyanate compound contains a polyfunctional isocyanate compound having a functionality of 2 or more, The adhesive tape according to [9].
• an adhesive tape that can be easily picked up without melting of the adhesive layer during dicing and that can suppress chip flying and peeling from the ring frame during dicing, and a tape for semiconductor wafer processing using the adhesive tape. be able to.
• this embodiment an embodiment of the present invention (hereinafter referred to as “this embodiment”) will be described in detail, but the present invention is not limited to this, and various modifications are possible without departing from the gist thereof. is.
• the pressure-sensitive adhesive tape according to the present embodiment has a base layer and a pressure-sensitive adhesive layer provided on the base layer, and the pressure-sensitive adhesive layer has a loss elastic modulus of 1.0 in a temperature range of 23 ° C. to 150 ° C. ⁇ 10 2 Pa or more and 1.6 ⁇ 10 5 Pa or less, and the minimum value M 1 of the difference (G'-G") between the storage elastic modulus G' and the loss elastic modulus G" of the pressure-sensitive adhesive layer at the same temperature is 1.0 ⁇ 10 5 Pa or more.
• the adhesive tape of the present embodiment has predetermined viscoelastic properties, the adhesive layer has excellent melting resistance during dicing, and the chip holding property and peeling resistance from the ring frame are improved. Also, the pick-up property is further improved at the time of pick-up.
• the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape of the present embodiment has predetermined dynamic viscoelastic properties, so that generation of high shear force in the pressure-sensitive adhesive layer during dicing can be suppressed. As a result, the friction generated between the blade and the adhesive layer is reduced, and the melting of the adhesive can be suppressed. In addition, since scraping up of glue due to melting of the adhesive is reduced, it is possible to suppress fixation of the chip by scraping up glue, and good pick-up property is obtained.
• the loss elastic modulus G′′ of the adhesive layer in the temperature range of 23° C. to 150° C. is 1.0 ⁇ 10 2 to 1.6 ⁇ 10 5 Pa, preferably 1.0 ⁇ 10 3 to 9.0 ⁇ . 10 3 Pa, more preferably 4.0 ⁇ 10 3 to 8.0 ⁇ 10 3 Pa.
• the loss elastic modulus G′′ of the adhesive layer at 23° C. to 150° C. is 1.0 ⁇ 10 2 Pa or more.
• the loss elastic modulus G′′ is less than 1.0 ⁇ 10 2 Pa, the adhesive strength to the wafer during dicing is insufficient, and a sufficient chip holding force cannot be maintained, possibly resulting in chip flying.
• the loss elastic modulus G′′ is 1.6 ⁇ 10 5 Pa or less, it is suppressed that the melted adhesive is scraped up by friction between the dicing blade and the adhesive layer during dicing. , it is possible to prevent the chips from being fixed by the adhesive that has been scraped up.
• the loss elastic modulus G′′ is greater than 1.6 ⁇ 10 5 Pa, the chip is likely to be fixed by scraping up the adhesive, and the pick-up property may deteriorate.
• the minimum value M 1 of the difference (G'-G) between the storage modulus G' and the loss modulus G”) In the temperature range of 23° C. to 150° C., the minimum value M1 of the difference (G′ ⁇ G′′) between the storage elastic modulus G′ and the loss elastic modulus G′′ of the pressure-sensitive adhesive layer at the same temperature is 1.0 ⁇ 10 5 Pa or higher, preferably 5.0 ⁇ 10 5 Pa or higher, more preferably 1.0 ⁇ 10 6 Pa or higher.
• the upper limit of the minimum value M 1 is preferably 8.0 ⁇ 10 5 Pa or less, more preferably 7.0 ⁇ 10 5 Pa or less, and even more preferably 6.0 ⁇ 10 5 Pa or less. .
• the minimum value M 1 is 1.0 ⁇ 10 5 Pa or more, friction between the dicing blade and the adhesive layer is less likely to occur during dicing, and scraping up of the molten adhesive is suppressed. . Therefore, it is possible to prevent the chip from being fixed by the adhesive that has been scraped up.
• the minimum value M 1 is less than 1.0 ⁇ 10 5 Pa, a high shear force is generated in the adhesive layer during dicing, and friction is likely to occur between the dicing blade and the adhesive layer. It becomes easy to melt and scrape up the adhesive. As a result, the chip is fixed and the pick-up property is deteriorated.
• the minimum value M2 of the difference (G′ ⁇ G′′) between the storage elastic modulus G′ and the loss elastic modulus G′′ of the pressure-sensitive adhesive layer at the same temperature is preferably 1.0 ⁇ . It is 10 5 Pa or more, more preferably 1.5 ⁇ 10 5 to 8.0 ⁇ 10 5 Pa, still more preferably 2.5 ⁇ 10 5 to 7.0 ⁇ 10 5 Pa.
• the frictional heat of the dicing blade is approximately 80°C. Therefore, the minimum value M2 in the temperature range of 70 ° C. to 110 ° C. is within the above range, and the melting resistance of the adhesive layer during dicing, chip retention, and peeling resistance from the ring frame are improved. , the pick-up property tends to be more improved at the time of pick-up.
• Loss modulus G'' and “storage modulus G'” described in this specification are obtained by using an adhesive cut into a predetermined size in a temperature range of 23 ° C to 150 ° C and a temperature increase of 3 ° C / min. can be obtained by measuring in shear mode at a frequency of 1 Hz under temperature conditions of .
• the Young's modulus of the adhesive layer is preferably 0.5 to 7.0 MPa, more preferably 1.0 to 5.5 MPa, still more preferably 2.0 to 4.0 MPa.
• the Young's modulus of the adhesive layer is within the above range, it is possible to prevent the adhesive from shaking due to vibration during dicing, and the adhesive tends to be suppressed from peeling due to vibration from the ring frame.
• the Young's modulus is 0.5 MPa or more
• the adhesive tends to be hard, and chipping of the chip due to vibration during dicing shakes the chip and collides with the blade. There is a tendency.
• the Young's modulus is 7.0 MPa or less, the adhesive tends to become soft, and the adhesive does not follow the ring frame and may be peeled off from the ring frame due to vibration during dicing and cutting water. tend to be more restrained.
• the "Young's modulus" described in this specification is obtained by using a pressure-sensitive adhesive cut into a width of 1 cm, a length of 10 cm, and a thickness of 60 to 110 ⁇ m at a temperature of 23° C. with a universal tensile tester at a tensile speed of 5 mm / min. , Young's modulus measured at a chuck-to-chuck distance of 50 mm.
• the 180° peel strength of the pressure-sensitive adhesive layer to a silicon wafer under a temperature condition of 23° C. is preferably 0.03 to 0.35 N/20 mm, and more preferably. is 0.05 to 0.20 N/20 mm, more preferably 0.08 to 0.12 N/20 mm or less.
• the 180° peel strength of the pressure-sensitive adhesive layer is within the above range, the individualized chips can be easily peeled off, so pick-up properties tend to be further improved.
• the 180° peeling strength is 0.03 N/20 mm or more, the adhesive strength tends to be stronger, making it difficult for peeling from the ring frame to maintain adhesion of the wafer during dicing, and chip flying. tend to be more suppressed.
• the 180° peel strength is 0.30 N/20 mm or less, the adhesive strength tends to be smaller, and the peelability of chips separated into individual pieces during picking up tends to be further improved.
• the 180° peel strength is 0.30 N/20 mm or less, it is possible to pick up the chip even if the force applied to the chip during picking up is weak, so chip chipping tends to be suppressed.
• the "180° peel strength to a silicon wafer" described in this specification can be measured in accordance with the adhesive strength measurement method of JIS Z0237 (2009). Specifically, the surface of the adherend (silicon wafer) was pressed using a pressure bonding device (roller weight: 2 kg), and the pressure-sensitive adhesive layer was pressed and peeled off from the adherend at 180 °. Adhesive strength is measured with a universal tensile tester in an environment of temperature 23° C. and humidity 50%.
• the pressure-sensitive adhesive layer adheres to a ring frame, a die bonding film, or the like, and does not directly contact an adherend (silicon wafer).
• adherend silicon wafer
• the adhesive property of the adhesive layer may be indicated by the 180° peel strength against a silicon wafer as a parameter that can be generally compared. Therefore, in this embodiment as well, the 180° peel strength with respect to the silicon wafer is used as one of the criteria indicating the adhesive strength with respect to the base material and the die bonding film.
• the tack of the pressure-sensitive adhesive layer under temperature conditions of 23° C. (hereinafter simply referred to as “tack”) is preferably 0.03 to 0.65 N/20 mm 2 , more preferably 0.05 to 0.60 N/20 mm. 2 , more preferably 0.10 to 0.50 N/20 mm 2 , more preferably 0.20 to 0.40 N/20 mm 2 .
• the adhesive tends to follow the wafer and chip flying during dicing can be suppressed.
• the tack is 0.05 N/20 mm 2 or more
• peeling from the ring frame tends to be more suppressed
• chip flying during dicing tends to be more suppressed.
• the tack is 0.60 N/20 mm 2 or less
• the pick-up property is further improved, and adhesive residue on the picked-up chip tends to be more suppressed.
• the "tack” described in this specification is the tack measured by a probe tack tester under temperature conditions of 23°C for an adhesive tape cut into a width of 1 cm.
• the pressure-sensitive adhesive layer contains, for example, a polymer and a curing agent, and if necessary, may contain other components.
• the polymer contained in the pressure-sensitive adhesive layer is not particularly limited, but examples thereof include (meth)acrylic acid ester copolymers having a linear, branched, or crosslinked shape.
• branches there are two types of branches possessed by the branched polymer: short-chain branches having a length of up to several carbon atoms, and long-chain branches having a length comparable to that of the main chain.
• the crosslinked polymer may also have a three-dimensional network structure.
• the crosslinked polymer also includes those formed by reaction between a curing agent and a polymer, which will be described later.
• Structural units constituting the (meth)acrylic ester-based copolymer include structural units having an alkyl group, structural units having a hydroxyl group, structural units having a carboxyl group, and other structural units. These structural units are mainly derived from (meth)acrylic acid monomers or (meth)acrylic acid ester monomers, but (meth)acrylic acid ester copolymers are only (meth)acrylic acid and its esters.
• the polymer is not limited to a polymer composed of, and may contain a structural unit derived from a monomer having a polymerizable double bond other than (meth)acrylic acid.
• the (meth)acrylic acid ester-based copolymer can undergo a cross-linking reaction with a curing agent, which will be described later, due to a structural unit having a hydroxyl group or a structural unit having a carboxyl group.
• a crosslinked structure can improve the cohesion of the pressure-sensitive adhesive after the pressure-sensitive adhesive is applied.
• by adjusting the degree of cross-linking it is possible to adjust not only the storage modulus and the loss modulus, but also the 180° peel strength and tack against silicon wafers.
• Examples of structural units having an alkyl group include monomers that do not have a functional group that undergoes a cross-linking reaction with a curing agent, which will be described later.
• Monomers that constitute structural units having such a hydrocarbon group are not particularly limited, but examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group and isobutyl group.
• amyl group isoamyl group, hexyl group, heptyl group, cyclohexyl group, 2-ethylhexyl group, octyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, lauryl group, tridecyl group, tetradecyl group , stearyl group, octadecyl group, and dodecyl group. These may be used alone or in combination of two or more.
• the number of carbon atoms in the alkyl group is preferably 3 to 12, more preferably 4 to 10, and still more preferably 6 to 8.
• the alkyl group is preferably branched. More specifically, 2-ethylhexyl acrylate is preferred.
• the content of structural units having an alkyl group is preferably 70 to 97 mol%, more preferably 80 to 97 mol%, relative to 100 mol% of the total structural units of the (meth)acrylic acid ester-based copolymer, More preferably, it is 90 to 97 mol %.
• the pressure-sensitive adhesive layer has improved melting resistance, chip retention, and peeling resistance from the ring frame during dicing, and pick-up performance during pickup. tend to improve.
• Monomers constituting structural units having a hydroxyl group are not particularly limited, but examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, ( 6-hydroxyhexyl meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 1-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate ) hydroxyl group-containing monomers such as acrylates. These may be used alone or in combination of two or more.
• the number of carbon atoms in the constituent unit having a hydroxyl group is preferably 4-10, more preferably 4-8, and still more preferably 4-6. More specifically, 2-hydroxyethyl acrylate is preferred.
• the content of the structural unit having a hydroxyl group is preferably 1.0 to 30 mol%, more preferably 2.0 to 15 mol%, relative to 100 mol% of the total structural units of the (meth)acrylic acid ester copolymer. Yes, more preferably 3.0 to 10 mol %.
• the content of the structural unit having a hydroxyl group is 1.0 mol% or more, the number of crosslinks is increased, the loss elastic modulus is further improved, and the minimum values M1 and M2 of the difference (G' - G") are reduced.
• the content of the structural unit having a hydroxyl group is 1.0 mol% or more, adhesive residue on the chip tends to be further suppressed.
• the adhesive strength tends to be further improved.This is because the excessive increase in the cross-linking density is suppressed, and the reduction in the adhesive strength due to the excessive hardening of the adhesive layer is prevented. by tending to be suppressed.
• Monomers constituting structural units having a carboxyl group are not particularly limited, but examples include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and Examples include carboxyl group-containing monomers such as crotonic acid. These may be used alone or in combination of two or more.
• acrylic acid and methacrylic acid are preferred, and acrylic acid is more preferred.
• the pressure-sensitive adhesive layer is improved in melting resistance, chip holding property, and peeling resistance from the ring frame during dicing, and pick-up property is further improved during pick-up. There is a tendency.
• the content of the structural unit having a carboxyl group is preferably 0.1 to 10 mol %, preferably 0.15 to 5.0 mol %, relative to 100 mol % of all structural units of the (meth)acrylic acid ester copolymer. 0 mol %, preferably 0.2 to 2.0 mol %.
• the storage elastic modulus is further improved, and the minimum values M1 and M2 of the difference (G' - G'') tend to be further improved.
• the dicing blade suppresses the scraping of the adhesive, and the pick-up property is further improved, and the adhesive residue on the chip tends to be further suppressed.
• the content of the structural unit having a carboxyl group is 10 mol. % or less, the adhesive force tends to be further improved.This is because the excessive increase in cross-linking density is suppressed, and the adhesive layer tends to be too hard to suppress the decrease in adhesive force. due to being in
• Monomers constituting other structural units other than the above are not particularly limited, but examples include acid anhydride monomers such as maleic anhydride and itaconic anhydride; styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide- Sulfonic acid group-containing monomers such as 2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid; phosphoric acid groups such as 2-hydroxyethyl acryloyl phosphate Containing monomer etc. are mentioned.
• the curing agent that constitutes the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include isocyanate curing agents, epoxy curing agents, amine curing agents, and the like. good. Among these, isocyanate compounds are preferred.
• isocyanate compounds include, but are not limited to, aromatic diisocyanates such as tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane-modified tolylene diisocyanate; isophorone diisocyanate, methylenebis(4-cyclohexyl alicyclic diisocyanates such as isocyanate); aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate. These may be used alone or in combination of two or more.
• aromatic diisocyanates such as tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane-modified tolylene diisocyanate
• isophorone diisocyanate methylenebis(4-cyclohexyl alicyclic
• the curing agent is preferably a polyfunctional isocyanate compound having a functionality of 2 or more.
• a curing agent a plurality of (meth)acrylic acid ester-based copolymers can be crosslinked by the curing agent, and a pressure-sensitive adhesive layer with high cohesion can be obtained.
• the anchoring property between the base material and the pressure-sensitive adhesive layer is further improved, and stable pressure-sensitive adhesive properties can be obtained. Furthermore, it becomes easier to adjust the loss elastic modulus, the minimum values M1 and M2 Young's moduli, etc. within the above ranges.
• the content of the curing agent is preferably 1 to 20 parts by mass, more preferably 3 to 15 parts by mass, still more preferably 5 to 10 parts by mass, relative to 100 parts by mass of the polymer.
• a pressure-sensitive adhesive layer with high cohesion can be obtained.
• the anchoring property between the base material and the pressure-sensitive adhesive layer is further improved, and stable pressure-sensitive adhesive properties can be obtained.
• a tackifier, a cross-linking retarder, an antioxidant and the like can be added to the pressure-sensitive adhesive layer as necessary.
• tackifiers include, but are not limited to, petroleum resins, terpene resins, terpene phenol resins, aromatic modified terpene resins, coumarone-indene resins, natural resin rosins, modified rosins, glycerol ester rosins, and pentaerythritol ester rosins. , phenol resins, xylene resins, alicyclic petroleum resins, styrene resins, dicyclopentadiene resins, and the like.
• crosslinking retarder is not particularly limited, for example, in a pressure-sensitive adhesive composition containing an isocyanate-based curing agent, by blocking the isocyanate group of the curing agent, excessive viscosity increase of the pressure-sensitive adhesive composition is suppressed.
• cross-linking retarders include, but are not limited to, ⁇ -diketones such as acetylacetone, hexane-2,4-dione, heptane-2,4-dione, octane-2,4-dione; acetoacetic acid; ⁇ -ketoesters such as methyl, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate and stearyl acetoacetate; benzoylacetone and the like.
• ⁇ -diketones such as acetylacetone, hexane-2,4-dione, heptane-2,4-dione, octane-2,4-dione
• acetoacetic acid such as methyl, ethyl acetoacetate, propyl ace
• antioxidants include, but are not limited to, methylhydroquinone, hydroquinone, 2,2-methylene-bis(4-methyl-6-tertiarybutylphenol), catechol, hydroquinone monomethyl ether, monotertiarybutylhydroquinone, 2 ,5-ditert-butyl hydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-ditert-butyl-p-benzoquinone, picric acid, citric acid, phenothiazine, tert-butyl catechol, 2-butyl -4-hydroxyanisole, 2,6-ditert-butyl-p-cresol and 4-[[4,6-bis(octylthio)-1,3,5-triazin-2-yl]amino]-2,6- ditertiary butyl phenol is mentioned.
• the thickness of the adhesive layer is usually 1-100 ⁇ m, preferably 2-50 ⁇ m, more preferably 5-40 ⁇ m. By setting the thickness of the adhesive layer to 1 ⁇ m or more, it is possible to ensure sufficient adhesive strength with the die bonding film, so it becomes easy to suppress scattering of the semiconductor chips divided by expansion. On the other hand, when the thickness of the pressure-sensitive adhesive layer is 100 ⁇ m or less, the cost tends to be further reduced.
• Base material Materials constituting the substrate are not particularly limited, but examples include polyvinyl chloride, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-acrylic acid-acrylic acid ester film, ethylene-ethyl acrylate copolymer, polyethylene. , polypropylene, propylene-based copolymers, ethylene-acrylic acid copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid-(meth)acrylic acid ester copolymers, etc. Ionomer resins crosslinked with ions are included.
• the base film may be a single resin, a mixture of two or more of these resins, a copolymer, or a laminate thereof.
• the thickness of the base material layer can be appropriately selected within a range that does not impair workability.
• the thickness of the base layer is usually 10-500 ⁇ m, preferably 50-200 ⁇ m, more preferably 70-150 ⁇ m. By adjusting the thickness of the substrate layer within the above range, there is no practical problem and it is economically effective. When the substrate layer is composed of a plurality of substrate films, it is preferable to adjust the thickness of the entire substrate layer within the above range.
• the base layer may be chemically or physically surface-treated as necessary in order to improve adhesion with the pressure-sensitive adhesive layer.
• Examples of the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high voltage shock exposure, and ionizing radiation treatment.
• the thickness of the base material layer and the pressure-sensitive adhesive layer within the above range so that the thickness of the semiconductor wafer processing tape is in the range of 60 to 250 ⁇ m.
• the thickness of the tape for semiconductor wafer processing is more preferably in the range of 70-200 ⁇ m, still more preferably in the range of 70-150 ⁇ m.
• the pressure-sensitive adhesive tape of this embodiment may have a protective film attached to the pressure-sensitive adhesive layer in order to protect the pressure-sensitive adhesive layer. Since the protective film is peeled off when the adhesive tape is used, it is preferable that the protective film has excellent peelability.
• the protective film include, but are not limited to, a film made of a fluororesin having a low surface energy, a polyethylene terephthalate film obtained by treating the surface with a silicone-based release agent, and the like.
• the semiconductor wafer processing tape of the present embodiment includes the adhesive tape described above and a die bonding film laminated on the adhesive layer of the adhesive tape.
• the die bonding film is not particularly limited, and a commercially available one can be used.
• a method for producing the adhesive tape is not particularly limited, but includes a method of forming an adhesive layer on a substrate layer.
• the base layer of the adhesive tape of this embodiment can be manufactured according to known techniques.
• Means for forming the base material layer are not particularly limited, but the various materials mentioned above are melt-kneaded and various mixing devices (single-screw or twin-screw extruders, rolls, Banbury mixers, various kneaders, etc.) are used. Then, each component is mixed so as to be uniformly dispersed, and the mixture is formed into a substrate by a T-die method, a calender method, or an inflation method.
• Preferred is a method of forming a film using a T-die method using an extruder with good thickness accuracy.
• the adhesive layer of the adhesive tape of this embodiment can be manufactured according to known techniques.
• the means for forming the pressure-sensitive adhesive layer is not particularly limited, but the above various materials are dissolved in a solvent such as an organic solvent to form a varnish, which is applied onto the protective film by a knife coating method, a roll coating method, or a spraying method.
• a pressure-sensitive adhesive layer is formed by coating by a coating method, gravure coating method, bar coating method, curtain coating method, or the like, and removing the solvent.
• a pressure-sensitive adhesive tape is produced by laminating this onto the base material layer.
• aging treatment may be performed after forming the pressure-sensitive adhesive layer.
• the pressure-sensitive adhesive layer formed is stored at a predetermined temperature.
• the temperature conditions are not particularly limited, but are preferably 30 to 50°C, more preferably 35 to 45°C.
• Aging time is not particularly limited, but preferably 24 to 150 hours, more preferably 48 to 100 hours.
• the adhesive strength and dynamic viscoelastic properties of the adhesive layer change. For example, with aging time, the reaction between the polymer and the curing agent gradually progresses, the adhesive strength decreases, and tends to stabilize at a predetermined value. Dynamic viscoelastic properties may also change with aging time.
• the processing method of the present embodiment includes a bonding step of bonding the adhesive tape and the adherend together, and a dicing step of separating the adherend into individual pieces while the adhesive tape and the adherend are bonded together. and a pick-up step of picking up the individualized chips.
• the singulation method by the dicing process is not particularly limited, and conventionally known methods can be used.
• a silicon wafer can be cut into semiconductor chips by rotating a dicing blade containing diamond abrasive grains at high speed using a dicing machine.
• the pick-up method is not particularly limited, but conventionally known methods can be used.
• an expanding device can be used to stretch the adhesive tape after being irradiated with ultraviolet rays in the surface direction, and the chips can be picked up by a pickup device in a state in which each chip is separated.
• Example 1 96 mol% of 2-ethylhexyl acrylate, 3.75 mol% of 2-hydroxyethyl acrylate, and 0.25 mol% of acrylic acid are mixed, and an initiator (azobisisobutyronitrile) is used in ethyl acetate. and 65° C. for 24 hours to obtain a solution containing acrylic polymer A.
• an initiator azobisisobutyronitrile
• a solution containing 100 parts by mass of the acrylic polymer A obtained as described above was added with 8.0 of a trimethylolpropane-modified tolylene diisocyanate curing agent (manufactured by Nippon Polyurethane Co., Ltd.: Coronate L-45E) as a curing agent A. Parts by mass were added to prepare a resin composition as a general pressure-sensitive adhesive.
• a trimethylolpropane-modified tolylene diisocyanate curing agent manufactured by Nippon Polyurethane Co., Ltd.: Coronate L-45E
• This resin composition is coated on the release-treated surface of a polyethylene terephthalate protective film that has been subjected to release treatment in advance so that the thickness of the adhesive layer after drying is 5 ⁇ m, and dried at 100 ° C. for 1 minute.
• the corona-treated surface of an ethylene-methacrylic acid-acrylic acid ester copolymer ionomer film (base film), which has been corona-treated in advance on the surface to be laminated with the adhesive layer is laminated to the base film.
• the adhesive was transferred to the This was aged in an atmosphere of 40° C. for 72 hours to obtain an adhesive tape.
• the polyethylene terephthalate protective film was peeled off, and an epoxy-based die bonding film was laminated on the adhesive layer to obtain a semiconductor wafer processing tape.
• Example 2 and 3 and Comparative Examples 1 to 4 A semiconductor wafer processing tape was produced in the same manner as in Example 1, except that the number of parts of the trimethylolpropane-modified tolylene diisocyanate, which is the curing agent A, was changed as shown in Table 1.
• Example 4 96 mol% of 2-ethylhexyl acrylate and 4 mol% of 2-hydroxyethyl acrylate are mixed and copolymerized using an initiator (azobisisobutyronitrile) in ethyl acetate at 65°C for 24 hours.
• An initiator azobisisobutyronitrile
• a semiconductor wafer processing tape was produced in the same manner as in Example 1, except that the solution containing the acrylic polymer B obtained in 1. was used.
• Examples 5-6 A semiconductor wafer processing tape was produced in the same manner as in Example 4, except that hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd.: Coronate HX), which is a curing agent B, was used instead of trimethylolpropane-modified tolylene diisocyanate. made.
• hexamethylene diisocyanate manufactured by Nippon Polyurethane Co., Ltd.: Coronate HX
• the resin composition which is a general pressure-sensitive adhesive prepared as described above, is applied to the release-treated surface of the release-treated polyethylene terephthalate film and dried at 100° C. for 1 minute to form an adhesive layer. got Then, the pressure-sensitive adhesive layers were superimposed on each other so that the obtained pressure-sensitive adhesive layer had a thickness of 1 mm, and a cylinder with a diameter of 8 mm was die-cut to obtain a sample.
• the adhesive layer of the adhesive tape was cut into 1 cm wide, 10 cm long and 60 to 110 ⁇ m thick pieces to be used as samples.
• the Young's modulus of the pressure-sensitive adhesive layer was measured with a universal tensile tester (Tensilon model number: RTG-1210 manufactured by ORIENTEC) in an environment of temperature 23° C. and humidity 50%. (Measurement condition) Measurement mode: Tensile Tensile speed: 5mm/min Distance between chucks: 50mm
• the adhesive strength of the adhesive tape was measured according to JIS Z0237 (2009), a method for measuring adhesive strength (Method 1: a test method in which a tape and a sheet are peeled off from a stainless test plate at 180°). Specifically, the 180° peel strength when the adherend (silicon wafer) whose surface has been cleaned is crimped using a crimping device (roller mass 2 kg) and peeled off at 180° from the adherend. was measured with a universal tensile tester (Tensilon model number: RTG-1210 manufactured by ORIENTEC) in an environment with a temperature of 23° C. and a humidity of 50%. (Measurement condition) Measurement mode: Tensile Tensile speed: 300mm/min Distance between chucks: 50mm Measurement sample width: 10mm
• ⁇ Dicing property evaluation of melting resistance of pressure-sensitive adhesive layer> After the dicing step, the cut surface by the dicing blade was checked by SEM, and the melting resistance of the adhesive layer was evaluated by whether or not the boundary between the adhesive layer and the die bonding film could be confirmed on the cut surface.
• the adhesive layer melts due to the frictional heat of the dicing blade, the melted adhesive layer makes it difficult to confirm the boundary between the adhesive layer and the die bonding film.
• evaluation criteria ⁇ (excellent): The adhesive layer was not melted, and the boundary between the adhesive layer and the die bonding film was clearly observed.
• ⁇ Pickup evaluation> The pick-up property was evaluated by calculating the percentage of chips that could actually be picked up (pick-up yield) among the semiconductor chips that were attempted to be picked up in the pick-up process, and evaluated the pick-up property based on the following evaluation criteria.
• evaluation criteria ⁇ (Excellent): Pickup yield is 95% or more ⁇ (Good): Pickup yield is 80% or more and less than 95% ⁇ (Poor): Pickup yield is less than 80%
• the adhesive tape of the present invention has industrial applicability as a semiconductor wafer processing tape, particularly as an adhesive tape used in a dicing process.

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• 2022
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