KR102574149B1 - Dicing tape - Google Patents

Abstract

To provide a dicing tape that can be used for stealth dicing, and which does not hinder laser light irradiation position detection by a camera and formation of a good modified layer.
The dicing tape of the present invention is provided with a base material and an adhesive layer disposed on one side of the base material, and a gray scale image with a luminance of 256 gradations obtained by observing with a laser microscope from the base material side is set to a threshold value of 55% of the maximum luminance. Thus, when binarized into a white portion and a black portion, the area of the white portion is 80% or more of the image area.

Description

Dicing tape {DICING TAPE}

The present invention relates to a dicing tape. When performing stealth dicing through the said dicing tape in more detail, it is related with the dicing tape used suitably.

A work (for example, a semiconductor wafer), which is an assembly of electronic parts, is manufactured with a large diameter, and after forming a pattern on the surface, the back surface is usually ground so that the thickness of the wafer is about 100 to 600 μm, and then the element It is cut and separated into small pieces (diced), and then transferred to the mounting process again. In this dicing step, the workpiece is cut into small pieces. In order to fix the workpiece after dicing, dicing is usually performed after bonding adhesive tape (dicing tape) to the workpiece (for example, Patent Literature 1). As one of the methods of dicing, a method of dicing a workpiece with a laser beam is known. As such a dicing method, a method in which a laser beam is condensed on the surface of a workpiece to form grooves on the surface of the workpiece and then the workpiece is cut is frequently used. On the other hand, in recent years, stealth dicing in which a laser beam is condensed inside a workpiece to modify the workpiece at that location and then the workpiece is cut is also proposed.

As described above, in dicing with a laser beam, when the laser beam is irradiated from the dicing tape side, the dicing tape is required to have characteristics such that the position detection of the laser beam irradiation by a camera can be performed satisfactorily. In particular, when dicing a semiconductor wafer in stealth dicing, it is required to perform position detection in the height direction of the semiconductor wafer for laser light focus adjustment and surface pattern recognition of the semiconductor wafer for laser light irradiation position determination with high accuracy, It is also required to form a modified layer satisfactorily, and the dicing tape is required to have properties that do not hinder the achievement of these requirements.

Japanese Unexamined Patent Publication No. 2003-007646

An object of the present invention is to provide a dicing tape that can be used for stealth dicing, and which does not impede laser light irradiation position detection by a camera and formation of a good modified layer during dicing.

The dicing tape of the present invention includes a base material and an adhesive layer disposed on one side of the base material, and a gray scale image with a luminance of 256 gradations obtained by observing with a laser microscope from the base material side is set at a threshold value of 55% of the maximum luminance. Thus, when binarized into a white portion and a black portion, the area of the white portion is 80% or more of the image area.

In one embodiment, the wettability of one side of the substrate is 40 mN/m or less.

In one embodiment, the said substrate is arrange|positioned so that the surface with wettability of 40 mN/m or less may become the surface on the opposite side to the adhesive layer.

In one embodiment, the base material contains a polyethylene-based resin.

In one embodiment, at least one side of the substrate is a corona treatment surface.

In one embodiment, the tensile elastic modulus at 22 degreeC of the said adhesive layer is 0.05 Mpa - 1 Mpa.

In one embodiment, the said adhesive layer has a two-layer structure, and the said dicing tape is equipped with the said base material, a 1st adhesive layer, and a 2nd adhesive layer in this order.

In one embodiment, the tensile elastic modulus at 22 degreeC of the said 1st adhesive layer is 0.05 Mpa - 1 Mpa.

In one embodiment, the tensile elastic modulus at 22 degreeC of the said 2nd adhesive layer is 0.1 Mpa - 2 Mpa.

In one embodiment, the thickness of the said 1st adhesive layer is 5 micrometers - 468 micrometers.

ADVANTAGE OF THE INVENTION According to this invention, it is a dicing tape which can be used for stealth dicing, and can provide the dicing tape which does not impede laser light irradiation position detection by a camera, and formation of a favorable modified layer.

1 is a schematic cross-sectional view of a dicing tape according to one embodiment of the present invention.

A. dicing tape outline

1 is a schematic cross-sectional view of a dicing tape according to one embodiment of the present invention. The dicing tape 100 according to this embodiment includes a substrate 10 and an adhesive layer 20 disposed on one side of the substrate 10 . Although not shown, in the dicing tape of the present invention, a release liner may be provided on the outer side of the pressure-sensitive adhesive layer for the purpose of protecting the adhesive face during use. In addition, the dicing tape may further contain any appropriate other layer as long as the effect of the present invention is obtained. Preferably, the pressure-sensitive adhesive layer is directly disposed on the substrate.

In another embodiment, the adhesive layer has a two-layer structure, and the dicing tape includes a substrate, a first adhesive layer, and a second adhesive layer in this order.

When a gray scale image of luminance of 256 gradations obtained by observation from the substrate side of the dicing tape with a laser microscope was binarized into a white part (high luminance part) and a black part (low luminance part) with 55% of the maximum luminance as a threshold value. At this time, the area of the white portion is 80% or more of the image area. Here, the binarization with 55% of the maximum luminance as the threshold is a process of dividing the luminance 256 gradations from the low luminance side to the 140 gradations, making the low luminance side a black part and the high luminance side a white part. The binarization process can be performed using, for example, image analysis software Image J (manufactured by Wayne Rasband). When the dicing tape of the present invention configured as described above is used, in the stealth dicing step, camera detection through the dicing tape, that is, by a camera (eg, IR camera, SD camera) Recognition of a surface pattern of a semiconductor wafer, detection of a position in the height direction of a semiconductor wafer, and the like can be performed with high precision. In addition, when the dicing tape of the present invention configured as described above is used, in the stealth dicing step, even when irradiating a laser beam through the dicing tape, the laser beam can be condensed favorably, As a result, the modified layer can be formed favorably inside the semiconductor wafer. More specifically, it can be prevented from forming defective parts such as omissions and meanders in the modified layer.

The area of the white portion is preferably 83% or more, more preferably 85% or more, still more preferably 90% or more of the image area. In such a range, the said effect becomes more remarkable. The area of the white portion is preferably larger, but the upper limit is, for example, 99.5% (preferably 99.8%, more preferably 100%).

The initial adhesive strength at 23°C when the dicing tape of the present invention is adhered to a stainless steel plate is preferably 0.2 N/20 mm to 8 N/20 mm, more preferably 0.5 N/20 mm to 5 N/20 mm. It is 20 mm. Adhesion is measured according to JIS Z 0237:2000. Specifically, a dicing tape is adhered to a stainless steel plate (arithmetic mean surface roughness Ra: 50 ± 25 nm) by one reciprocating motion of a 2 kg roller, and then left at 23°C for 30 minutes, followed by peeling angle of 180° and peeling rate. (Tension rate) It peels and measures the dicing tape on conditions of 300 mm/min. As will be described later, the adhesive strength of the pressure-sensitive adhesive layer may be changed by irradiation with active energy rays. In this specification, "initial adhesive strength" means adhesive strength before irradiation with active energy rays.

In one embodiment, the adhesive strength at 23° C. after attaching the dicing tape to a silicon mirror wafer and irradiating with 460 mJ/cm 2 ultraviolet rays is preferably 0.01 N/20 mm to 0.3 N/20 mm. , more preferably from 0.02 N/20 mm to 0.2 N/20 mm. If it is this range, the adhesive force will fall by ultraviolet irradiation after dicing, and the dicing tape which pick-up of the small-piece work (for example, semiconductor chip) becomes easy can be obtained. The ultraviolet irradiation is carried out using, for example, an ultraviolet irradiation device (manufactured by Nitto Seimitsu Kikai Co., Ltd., trade name "UM-810"), using ultraviolet rays of a high-pressure mercury lamp (characteristic wavelength: 365 nm, integrated light amount: 460 mJ/cm 2 , irradiation energy : 70 W/cm 2 , irradiation time: 6.6 seconds) to the pressure-sensitive adhesive layer.

The thickness of the dicing tape is preferably 35 μm to 500 μm, more preferably 60 μm to 300 μm, still more preferably 80 μm to 200 μm.

The total light transmittance of the dicing tape is preferably 70% or more, more preferably 80% or more, still more preferably 90% or more, and particularly preferably 95% or more. If it is such a range, camera detection through a dicing tape can be performed satisfactorily, and the dicing tape which does not impede transmission and condensation of a laser beam can be obtained easily. The upper limit of the total light transmittance of the dicing tape is, for example, 98% (preferably 99%).

In the dicing tape, the transmittance of light having a wavelength of 1064 nm is preferably 70% or more, more preferably 80% or more, still more preferably 90% or more, and particularly preferably 95% or more. If it is this range, it is possible to obtain a dicing tape that is difficult to inhibit transmission and condensation of laser light. The upper limit of the light transmittance of the dicing tape at a wavelength of 1064 nm is, for example, 98% (preferably 99%).

The haze value of the dicing tape is preferably 20% or less, more preferably 10% or less, still more preferably 5% or less. If it is such a range, camera detection through a dicing tape can be performed satisfactorily, and the dicing tape which does not impede transmission and condensation of a laser beam can be obtained easily. The lower limit of the haze value of the dicing tape is, for example, 1%.

B. Description

The substrate may be made of any suitable resin. Examples of the resin include polyolefin-based resins such as polyethylene-based resins, polypropylene-based resins, polybutene-based resins, and polymethylpentene-based resins, polyurethane-based resins, polyester-based resins, polyimide-based resins, and polyether ketone-based resins. resins, polystyrene-based resins, polyvinyl chloride-based resins, polyvinylidene chloride-based resins, fluorine-based resins, silicone-based resins, cellulose-based resins, and ionomer resins. Among them, polyolefin-based resins are preferred.

In one embodiment, the base material contains a polyethylene-based resin. If a substrate made of a polyethylene-based resin is used, a dicing tape having a large white area of the binarized image can be obtained. Examples of the polyethylene-based resin include low-density polyethylene, linear polyethylene, medium-density polyethylene, high-density polyethylene, and ultra-low-density polyethylene.

In the polyethylene-based resin, the ethylene-derived constituent unit content is preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more. As structural units other than ethylene-derived structural units, structural units derived from monomers copolymerizable with ethylene and copolymers are exemplified, for example, propylene, 1-butene, isobutene, 1-pentene, 2-methyl-1- Butene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetra Decene, 1-hexadecene, 1-octadecene, 1-icosene, etc. are mentioned.

The content of the polyethylene-based resin is preferably 80 parts by weight or more, more preferably 85 parts by weight to 100 parts by weight, still more preferably 95 parts by weight to 100 parts by weight, based on 100 parts by weight of the substrate.

The substrate may further include any suitable additive. As an additive, a lubricant, an antioxidant, a ultraviolet absorber, a processing aid, a filler, an antistatic agent, a stabilizer, an antibacterial agent, a flame retardant, a coloring agent etc. are mentioned, for example.

In one embodiment, the base material contains a lubricant. By including a lubricant, blocking when the dicing tape is made into a roll shape can be prevented. As a result, a dicing tape having a large white area of the binarized image can be obtained. Examples of the lubricant include fatty acid amide lubricants, silicone lubricants, fluorine lubricants, and long-chain alkyl lubricants. Among them, a fatty acid amide-based lubricant is preferable from the viewpoint of low risk of contamination of impurities and high effect as a lubricant. The content of the lubricant is preferably from 0.1 part by weight to 30 parts by weight, more preferably from 0.5 part by weight to 15 parts by weight, still more preferably from 0.8 part by weight to 10 parts by weight, based on 100 parts by weight of the base material. , particularly preferably 1 to 5 parts by weight.

In one embodiment, the wettability of one side of the substrate is 40 mN/m or less. In one embodiment, the said base material is arrange|positioned so that the surface with wettability of 40 mN/m or less may become the surface on the opposite side to the adhesive layer. If the base material is disposed so that the surface having wettability becomes the surface opposite to the pressure-sensitive adhesive layer, blocking when the dicing tape is made into a roll shape can be prevented. As a result, a dicing tape having a large white area of the binarized image can be obtained. The wettability of one side of the substrate is preferably 39 mN/m or less, more preferably 38 mN/m or less, still more preferably 30 mN/m to 38 mN/m. The wettability of the substrate depends on the type of substrate material; Presence, type, and amount of additives added to the substrate; It can be adjusted by the presence or absence of surface treatment of the wettability control surface, type, conditions, and the like. In one embodiment, a base material having wettability within the above range can be obtained by using a polyolefin-based resin (preferably a polyethylene-based resin) as the base material and not performing a surface treatment such as corona treatment. In addition, the wettability can be measured according to JIS K6768.

In one embodiment, corona treatment is performed on at least one side of the substrate. Preferably, the corona treatment is performed only on one side of the substrate, and the corona treatment side is the side of the pressure-sensitive adhesive layer. By corona-treating the surface on the side of the pressure-sensitive adhesive layer, the adhesion between the pressure-sensitive adhesive layer and the base material can be improved. In another embodiment, corona treatment is not performed on both surfaces of the substrate. Blocking at the time of making a dicing tape into roll shape can be prevented by making the surface on the opposite side to the adhesive layer of a base material into a corona non-treated surface. As a result, when the roll-shaped dicing tape is wound and unwound, the dicing tape is less likely to be damaged, and a dicing tape having a large white area of the binarized image can be obtained. The corona treatment may be performed under conditions of, for example, speed: 20 m/min, discharge power: 0.7 kw, and discharge electrode length: 1550 mm.

In one embodiment, one side of the substrate is embossed. Preferably, the embossing treatment is performed only on one side of the base material, and the embossing treatment side is the side on the side of the pressure-sensitive adhesive layer. By embossing the surface on the side of the pressure-sensitive adhesive layer, the adhesion between the pressure-sensitive adhesive layer and the substrate can be improved. Preferably, the embossing process is not given to the surface of the base material opposite to the pressure-sensitive adhesive layer. A dicing tape having a large white area of the binarized image can be obtained by smoothing the surface on the opposite side of the pressure-sensitive adhesive layer of the substrate without embossing. The arithmetic mean surface roughness Ra (JIS B 0601) of the non-embossed surface of the substrate is preferably less than 1.0 μm, more preferably 0.8 μm or less, still more preferably 0.5 μm or less, and particularly preferably 0.01 μm. to 1 μm. The arithmetic mean surface roughness Ra (JIS B 0601) of the embossed surface of the substrate is preferably 1.0 μm to 3 μm, more preferably 1.4 μm to 2 μm. When the arithmetic average surface roughness Ra of the embossed surface of the base material exceeds 3 μm, there is a possibility that a gap is easily formed between the pressure-sensitive adhesive layer and the base material, and the white area of the binarized image increases. In addition, when the Ra is smaller than 1 μm, blocking may occur during storage of the base material.

The thickness of the substrate is preferably 30 μm to 300 μm, more preferably 53 μm to 200 μm, still more preferably 70 μm to 160 μm.

The total light transmittance of the substrate is preferably 70% or more, more preferably 80% or more, still more preferably 90% or more, and particularly preferably 95% or more. The upper limit of the total light transmittance of the substrate is, for example, 98% (preferably 99%).

The tensile modulus of elasticity of the substrate at 22°C is preferably 50 MPa to 120 MPa, more preferably 70 MPa to 90 MPa. Within this range, a dicing tape excellent in expandability can be obtained. The measurement of the tensile modulus of elasticity of the substrate is performed using a tensile tester (manufactured by SHIMADZU, "AG-IS") under conditions of a distance between chucks of 50 mm, a tensile speed of 300 mm/min, and a width of the substrate of 10 mm.

C. adhesive layer

C-1. Single-layer adhesive layer

In one embodiment, the pressure-sensitive adhesive layer is composed of a single layer. The pressure-sensitive adhesive layer may be composed of any suitable pressure-sensitive adhesive. Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, silicone pressure-sensitive adhesives, and polyvinyl ether pressure-sensitive adhesives.

In one embodiment, the pressure-sensitive adhesive layer is composed of an active energy ray-curable pressure-sensitive adhesive. If the pressure-sensitive adhesive layer is composed of an active energy ray-curable pressure-sensitive adhesive, the adhesive strength is reduced by irradiation with active energy rays (typically, ultraviolet rays) after dicing, and it is easy to pick up the workpiece (eg, semiconductor chip) cut into small pieces. A dicing tape capable of doing so can be obtained.

The active energy ray-curable pressure-sensitive adhesive may contain a base polymer exhibiting adhesiveness. As a monomer which comprises a base polymer, a hydrophilic monomer is mentioned, for example. As the hydrophilic monomer, any suitable monomer having a polar group can be used. Specifically, Carboxyl group-containing monomers, such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, (meth)acrylate 4-hydroxybutyl, (meth)acrylate 6-hydroxyhexyl, (meth)acrylate 8-hydroxyoctyl, hydroxyl group-containing monomers such as 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl methacrylate; Sulfonic acid groups such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl(meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid containing monomers; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, acryloyl (N-substituted) amide type monomers such as morpholine; aminoalkyl (meth)acrylate monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; alkoxyalkyl (meth)acrylate monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-cyclohexyl itaconimide itaconimide-based monomers such as mead and N-laurylitaconimide; N- (meth) acryloyloxymethylene succinimide, N- (meth) acroyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide, etc. succinimide-based monomers; Vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinyl vinyl monomers such as morpholine, N-vinylcarboxylic acid amides, styrene, α-methylstyrene, and N-vinyl caprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth)acrylate; glycol-based acrylic ester monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; acrylic acid ester-based monomers having heterocycles such as (meth)acrylate tetrahydrofurfuryl, fluorine (meth)acrylate, and silicon (meth)acrylate, halogen atoms, silicon atoms, and the like; Hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate Polyfunctionals such as acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate A monomer is mentioned. As the hydrophilic monomer, a hydroxyl group-containing monomer and/or an (N-substituted) amide type monomer can be suitably used. A hydrophilic monomer may be used alone or in combination of two or more.

You may combine the said hydrophilic monomer and a hydrophobic monomer. As the hydrophobic monomer, any suitable monomer may be used as long as it is a monomer having hydrophobicity. Specifically, vinylalkyl having an alkyl group having 9 to 30 carbon atoms, such as vinyl 2-ethylhexanoate, vinyl laurate, vinyl stearate, and stearyl vinyl ether, and aryl ether; Hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl acrylate, isononyl acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, (meth) 2-ethylhexyl acrylate, (meth)acrylate benzyl, (meth)acrylate lauryl, (meth)acrylate oleyl, (meth)acrylate palmityl and (meth)acrylate stearyl, (meth)acrylic acid having 6 to 30 carbon atoms alkyl ester; unsaturated vinyl esters of (meth)acrylic acid derived from fatty acids and fatty alcohols; monomers derived from cholesterol; and olefin monomers such as 1-butene, 2-butene, 1-pentene, 1-hexene, 1-octene, isobutylene, and isoprene. As for a hydrophobic monomer, only 1 type may be used and may be used in combination of 2 or more types. In addition, the hydrophobic monomer used in the present invention refers to a monomer having a solubility of 0.02 g or less in 100 g of water.

The base polymer may further contain monomer components other than the hydrophilic monomer and hydrophobic monomer. As another monomer component, alkyl acrylates, such as butyl acrylate and ethyl acrylate, etc. are mentioned. As for the other monomer component, only 1 type may be used, and may be used in combination of 2 or more types.

The base polymer may further contain a structural unit derived from an isocyanate-based compound having a curable functional group in the molecule. A base polymer containing a structural unit derived from an isocyanate compound can be obtained by reacting a substituent (eg, OH group) of the structural unit derived from the hydrophilic monomer with an NCO group of the isocyanate compound. Examples of the isocyanate compound include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, 2-acryloyloxyethyl isocyanate, and m-isopropenyl-α,α-dimethylbenzyl isocyanate. there is.

The weight average molecular weight of the base polymer constituting the pressure-sensitive adhesive is preferably 300,000 to 2,000,000, more preferably 500,000 to 1,500,000. A weight average molecular weight can be measured by GPC (solvent: THF).

The active energy ray-curable pressure-sensitive adhesive may contain a photopolymerization initiator.

As the photopolymerization initiator, any suitable initiator can be used. As a photoinitiator, for example, 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2 - α-ketol compounds such as hydroxypropiophenone and 1-hydroxycyclohexylphenyl ketone; Methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane acetophenone-based compounds such as -1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; ketal-based compounds such as benzyldimethyl ketal; aromatic sulfonyl chloride-based compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime-based compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; Thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone thioxanthone-based compounds such as xanthones and 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketones; acylphosphine oxide; Acyl phosphonate etc. are mentioned. The usage amount of the photopolymerization initiator may be set to any appropriate amount.

As said photoinitiator, you may use a commercial item. For example, "Irgacure 651", "Irgacure 184", "Irgacure 369", "Irgacure 819", "Irgacure 2959" etc. made by BASF are mentioned.

Preferably, the active energy ray-curable pressure-sensitive adhesive contains a crosslinking agent. Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, A bodyimide type crosslinking agent, an amine type crosslinking agent, etc. are mentioned.

When the pressure-sensitive adhesive layer is composed of a single layer, the content of the crosslinking agent is preferably 0.5 part by weight to 10 parts by weight, more preferably 1 part by weight to 8 parts by weight, based on 100 parts by weight of the base polymer of the pressure-sensitive adhesive. Within this range, a pressure-sensitive adhesive layer having an appropriate elastic modulus can be formed.

In one embodiment, an isocyanate-based crosslinking agent is preferably used. An isocyanate-type crosslinking agent is preferable in that it can react with a variety of functional groups. Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate; Trimethylolpropane/tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Kogyo Co., Ltd., trade name “Coronate L”), trimethylolpropane/hexamethylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Kogyo Co., Ltd., trade name “Coronate L”) Isocyanate adducts, such as Nate HL") and the isocyanurate body of hexamethylene diisocyanate (Nippon Polyurethane Kogyo Co., Ltd. make, brand name "Coronate HX"); etc. can be mentioned. Preferably, a crosslinking agent having three or more isocyanate groups is used.

The active energy ray-curable pressure-sensitive adhesive may further contain any appropriate additives as needed. As additives, for example, active energy ray polymerization accelerators, radical scavengers, tackifiers, plasticizers (eg, trimellitic acid ester plasticizers, pyromellitic acid ester plasticizers, etc.), pigments, dyes, fillers, anti-aging agents , conductive materials, antistatic agents, ultraviolet absorbers, light stabilizers, peeling regulators, softeners, surfactants, flame retardants, antioxidants, and the like.

When the pressure-sensitive adhesive layer has a single-layer structure, the tensile modulus of elasticity at 22°C of the pressure-sensitive adhesive layer is preferably 0.05 MPa to 1 MPa, more preferably 0.1 MPa to 0.8 MPa, still more preferably 0.15 MPa to 0.6 MPa. is MPa. Within this range, a pressure-sensitive adhesive layer having sufficient strength can be formed, the pressure-sensitive adhesive layer and the base material adhere well, and generation of voids in the vicinity of the interface between the base material and the pressure-sensitive adhesive layer can be suppressed. As a result, a dicing tape having a large white area of the binarized image can be obtained. In particular, when using a base material on which an embossing treatment has been applied to the surface of the pressure-sensitive adhesive layer, voids tend to occur normally, but by setting the tensile modulus of elasticity of the pressure-sensitive adhesive layer within the above range, generation of voids can be suppressed. In other words, when the tensile modulus of elasticity exceeds 1 MPa, when the pressure-sensitive adhesive layer is laminated on the embossed surface of the base material, there is a risk that the pressure-sensitive adhesive layer does not follow the unevenness of the base material. Further, when the tensile modulus of elasticity is less than 0.5 MPa, the pressure-sensitive adhesive layer may not maintain its shape and may not have sufficient characteristics. In addition, as described above, when the pressure-sensitive adhesive layer is composed of an active energy ray-curable pressure-sensitive adhesive, it is preferable that the tensile modulus at 22°C before active energy ray irradiation is within the concerned range. A method for measuring the tensile modulus of elasticity of the pressure-sensitive adhesive layer will be described later.

In one embodiment, when the pressure-sensitive adhesive layer has a single-layer structure, the tensile modulus of elasticity at 22° C. after irradiation with ultraviolet rays (460 mJ/cm 2 ) of the pressure-sensitive adhesive layer is preferably 50 MPa to 3000 MPa, more preferably It is 100 Mpa - 1500 Mpa, More preferably, it is 200 Mpa - 1000 Mpa. Within this range, a dicing tape excellent in pick-up properties can be obtained.

When the pressure-sensitive adhesive layer is composed of a single layer, the thickness of the pressure-sensitive adhesive layer is preferably 5 μm to 470 μm, more preferably 7 μm to 247 μm, still more preferably 10 μm to 130 μm. Within this range, when the pressure-sensitive adhesive layer is formed on the embossed surface, the pressure-sensitive adhesive layer satisfactorily embeds the embossing, and unnecessary voids can be prevented from occurring. As a result, a dicing tape having a large white area of the binarized image can be obtained.

The total light transmittance of the pressure-sensitive adhesive layer is preferably 70% or more, more preferably 80% or more, still more preferably 90% or more, and particularly preferably 95% or more. The upper limit of the total light transmittance of the pressure-sensitive adhesive layer is, for example, 98% (preferably 99%).

The haze value of the pressure-sensitive adhesive layer is preferably 20% or less, more preferably 10% or less, still more preferably 5% or less. The lower limit of the haze value of the pressure-sensitive adhesive layer is, for example, 1%.

C-2. Two-layer adhesive layer

In one embodiment, the pressure-sensitive adhesive layer is composed of two layers. Hereinafter, for convenience, the pressure-sensitive adhesive layer on the base material side is referred to as a first pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer on the opposite side to the base material is referred to as a second pressure-sensitive adhesive layer. The first pressure sensitive adhesive layer and the second pressure sensitive adhesive layer can be distinguished by a difference in tensile elastic modulus. It is preferable that the 1st adhesive layer has lower elasticity than the 2nd adhesive layer. By placing the low-elastic first pressure-sensitive adhesive layer on the base material side, the pressure-sensitive adhesive layer and the base material adhere well, and generation of voids in the vicinity of the interface between the base material and the pressure-sensitive adhesive layer can be suppressed. As a result, a dicing tape having a large white area of the binarized image can be obtained. Furthermore, by providing the highly elastic second pressure-sensitive adhesive layer, a dicing tape capable of contributing to high-precision dicing can be obtained.

The tensile modulus of elasticity at 22°C of the first pressure sensitive adhesive layer is preferably 0.05 MPa to 1 MPa, more preferably 0.06 MPa to 0.8 MPa, still more preferably 0.07 MPa to 0.5 MPa. Within this range, the pressure-sensitive adhesive layer and the base material adhere well, and generation of voids in the vicinity of the interface between the base material and the pressure-sensitive adhesive layer can be remarkably suppressed. As a result, a dicing tape having a large white area of the binarized image can be obtained. In particular, when using a base material on which an embossing treatment has been applied to the surface of the pressure-sensitive adhesive layer, voids tend to occur normally, but by setting the tensile modulus of elasticity of the pressure-sensitive adhesive layer within the above range, generation of voids can be suppressed. Moreover, when the 1st adhesive layer is comprised by the active energy ray-curable adhesive, it is preferable that the tensile elasticity modulus in 22 degreeC before active energy ray irradiation is the said range.

In one embodiment, the tensile modulus of elasticity at 22 ° C. after irradiation with ultraviolet rays (460 mJ / cm 2) of the first pressure-sensitive adhesive layer is preferably 50 MPa to 300 MPa, more preferably 100 MPa to 1500 MPa, More preferably, it is 200 Mpa - 1000 Mpa. Within this range, a dicing tape excellent in pick-up properties can be obtained.

The tensile elastic modulus of the second pressure sensitive adhesive layer at 22°C is preferably 0.1 MPa to 2 MPa, more preferably 0.15 MPa to 1.5 MPa, still more preferably 0.2 MPa to 1 MPa. Within this range, a dicing tape having appropriate rigidity as a whole of the pressure-sensitive adhesive layer and contributing to high-precision dicing can be obtained. In addition, when the second pressure-sensitive adhesive layer is composed of an active energy ray-curable pressure-sensitive adhesive, it is preferable that the tensile modulus at 22°C before active energy ray irradiation is within the range concerned.

The thickness of the first pressure-sensitive adhesive layer is preferably 5 μm to 468 μm, more preferably 7 μm to 244 μm. When the thickness of the first pressure-sensitive adhesive layer is 5 μm or more, when the first pressure-sensitive adhesive layer is formed on the embossed surface, the first pressure-sensitive adhesive layer satisfactorily embeds the embossing, and unnecessary voids can be prevented from occurring. As a result, a dicing tape having a large white area of the binarized image can be obtained. Moreover, if the 1st adhesive layer is 468 micrometers or less, the dicing tape which pick-up of the workpiece|work (for example, semiconductor chip) cut into pieces easily can be obtained.

The thickness of the second pressure-sensitive adhesive layer is preferably 2 μm to 465 μm, more preferably 3 μm to 240 μm.

When the pressure-sensitive adhesive layer has a two-layer structure, the total thickness of the pressure-sensitive adhesive layer is preferably 7 μm to 470 μm, more preferably 10 μm to 247 μm, still more preferably 15 μm to 130 μm.

When the pressure-sensitive adhesive layer has a two-layer structure, the total light transmittance of the pressure-sensitive adhesive layer is preferably 70% or more, more preferably 80% or more, still more preferably 90% or more, and particularly preferably 95% or more. . The upper limit of the total light transmittance of the pressure-sensitive adhesive layer is, for example, 98% (preferably 99%).

When the pressure-sensitive adhesive layer has a two-layer structure, the haze value of the pressure-sensitive adhesive layer is preferably 20% or less, more preferably 10% or less, still more preferably 5% or less. The lower limit of the haze value of the pressure-sensitive adhesive layer is, for example, 1%.

As the pressure-sensitive adhesive constituting the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, the pressure-sensitive adhesive described in item C-1 may be used. Preferably, an active energy ray-curable pressure-sensitive adhesive is used.

The crosslinking agent content of the active energy ray-curable pressure sensitive adhesive constituting the first pressure sensitive adhesive layer is preferably 0.005 parts by weight to 5 parts by weight, more preferably 0.02 parts by weight to 3 parts by weight, based on 100 parts by weight of the base polymer of the pressure sensitive adhesive. am. Within this range, the elastic modulus can be appropriately adjusted, and a pressure-sensitive adhesive layer capable of well embedding the embossed surface of the base material and maintaining its shape can be formed.

The crosslinking agent content of the active energy ray-curable pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer is preferably 1 part by weight to 20 parts by weight, more preferably 2 parts by weight to 10 parts by weight, based on 100 parts by weight of the base polymer of the pressure-sensitive adhesive. am. Within this range, a pressure-sensitive adhesive layer having an appropriately adjusted modulus of elasticity and adhesive force (adhesive force capable of holding wafers during dicing and picking up chips after dicing) can be formed.

D. dicing How to make the tape

The dicing tape can be manufactured by any suitable method. A dicing tape can be obtained by coating the said adhesive on a base material, for example. As the coating method, various methods such as bar coater coating, air knife coating, gravure coating, gravure reverse coating, reverse roll coating, lip coating, die coating, dip coating, offset printing, flexographic printing, and screen printing can be employed. Alternatively, a method of forming a pressure-sensitive adhesive layer on a release liner and bonding it to a base material or the like may be employed.

[Example]

Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited by these examples. Tests and evaluation methods in Examples are as follows. In addition, "part" and "%" are based on weight unless otherwise specified.

(1) Modulus of elasticity of the pressure-sensitive adhesive layer

The adhesive prepared in Examples and Comparative Examples was applied between a pair of PET separators to form an adhesive layer (thickness of 20 μm), and the adhesive layer was aged in a dryer at 50° C. for 48 hours. Thereafter, the pressure-sensitive adhesive layer was cut to a size of 50 mm × 30 mm, the separator was peeled off, and then it was rounded so as not to contain air bubbles, and a rod-shaped sample having a length of 30 mm and a diameter of 1.13 mm was produced.

The tensile modulus of elasticity of the rod-shaped sample was measured using a tensile tester (manufactured by ORIENTEC, trade name "RTC-1150A") under conditions of a measurement temperature of 22 ° C., a distance between chucks of 10 mm, and a speed of 10 mm / min. The SS curve was measured. An initial modulus of elasticity was obtained from the start of the SS curve, and this was taken as the tensile modulus of elasticity of the pressure-sensitive adhesive layer.

(2) wettability of substrate

The wettability of both surfaces of the substrate was measured according to JIS K6768.

(3) Arithmetic mean surface roughness Ra of substrate

The arithmetic mean surface roughness (linear roughness) Ra of the surface on the opposite side of the base material to the pressure-sensitive adhesive layer was measured according to JIS B 0601-2001 using P-15 manufactured by KLA Tenco.

(4) Total light transmittance

The total light transmittance of the dicing tape was measured according to JIS K 7361 using a haze meter trade name "HM-150" manufactured by Murakami Shikisai Co., Ltd., Kijutsu Genkyujo Co., Ltd.

(5) Haze value

The haze value of the dicing tape was measured according to JIS K 7136 using a haze meter trade name "HM-150" manufactured by Murakami Shikisai Co., Ltd., Kijutsu Genkyujo Co., Ltd.

(6) Light transmittance at a wavelength of 1064 nm

The light transmittance of the dicing tape at a wavelength of 1064 nm was measured using SolidSpec-3700 manufactured by Shimadzu Corporation.

(7) Measurement of binarized white area

A dicing tape was pressed onto the mirror surface of the Si wafer. The dicing tape was observed from the substrate side with a laser microscope VK-X150 (manufactured by Keyence) set at a brightness of 80, and an observation image (range: 5.8 mm × 4.4 mm, luminance of 256 gradations) was introduced into a PC. Using Image J (free software), the observation image was converted into a binarized image at luminance 140, i.e., from the low luminance side to 140 gradations of luminance 256 gradations (with 55% of the maximum luminance as the threshold), and The ratio of the white area (high luminance part) was obtained by macro processing of .

(8) Evaluation of device visibility before stealth dicing

A silicon wafer and a ring frame were attached to a dicing tape, camera visibility was confirmed by the following device, and evaluation was made according to the following criteria.

Device used: Disco DAL7360 (SDE05)

SD Camera: Camera for height adjustment. The rear surface of the wafer is focused with a camera over the dicing tape, and the coordinates are recognized within the device control system with the height at which the focus is met as the position of the rear surface of the wafer. The laser irradiation position inside the wafer is determined based on the height of the back side of the wafer. This laser irradiation positioning operation is continuously repeated during dicing.

IR Camera: A camera for pattern recognition on silicon wafers. A camera used to recognize a pattern on a wafer surface via a dicing tape and determine a laser irradiation start position (XY coordinate setting) within the device.

<Evaluation Criteria>

○·····Position recognition by SD camera and IR camera is possible without any problems.

×·····The precision of height recognition and/or pattern recognition is poor, making it impossible to drive the device in automatic mode.

(9) Divisional aptitude evaluation

A silicon wafer and a ring frame were attached to a dicing tape, and a laser was irradiated through the dicing tape to form a modified portion inside the wafer under the following dividing conditions.

(Division condition)

Device used: Disco DAL7360 (SDE05)

Power: 0.25W

Defocus amount: -2.5um

Feed rate: 350 mm/sec

Frequency: 80kHz

Number of passes: 2 (mapping pass 1 pass + processing 1 pass)

Silicon wafer: diameter 200 mmφ, thickness 50 μm, chip size: 5 mm × 5 mm

Then, using an expander (manufactured by Disco, trade name "DDS-2300"), expand the periphery of the dicing tape at an expand amount of 10 mm, an expand speed of 20 mm/sec, and an expand temperature of 22°C. was performed to singulate the silicon wafer.

Observe the cross section of the fragmented chip with a digital microscope (manufactured by KEYENCE, trade name "VHX-1000"), and when the reformed parts are formed by laser in a straight line at regular intervals, ○, the intervals of the modified parts are non-uniform ( omission of the modified layer), and/or a case where the line connecting the modified portion did not form a straight line (meandering) was evaluated as ×.

[Production Example 1] Preparation of active energy ray-curable pressure-sensitive adhesive (1)

A monomer composition was prepared by mixing 100 parts by weight of 2-methoxyethyl acrylate, 27 parts by weight of acroylmorpholine, and 22 parts by weight of 2-hydroxyethyl acrylate.

Subsequently, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet pipe, a thermometer, and a stirrer, and under a nitrogen atmosphere, 500 parts by weight of ethyl acetate, 149 parts by weight of the monomer composition, and 0.2 parts by weight of azoisobutylnitrile (AIBN) were added, , and stirred for 24 hours at 60°C. Then, it cooled to room temperature and obtained acrylic copolymer solution A1 containing acrylic copolymer a1 (weight average molecular weight: 600,000). To the obtained acrylic copolymer solution a, 24 parts by weight of 2-methacryloyloxyethyl isocyanate was added and reacted, an NCO group was added to the terminal OH group of the side chain of 2-hydroxyethyl acrylate in the copolymer, and a carbon-carbon doublet was added to the terminal. An acrylic copolymer solution A2 containing an acrylic copolymer a2 having a weight average molecular weight of 800,000 and having bonds was obtained.

To the acrylic copolymer solution A2 containing 100 parts by weight of the acrylic copolymer a2, 3 parts by weight of a crosslinking agent (Nippon Polyurethane Kogyo Co., Ltd., trade name "Coronate L"), a photopolymerization initiator (manufactured by Chiba Japan Co., Ltd., trade name "Eru 7 parts by weight of "Gacure 184") and 30 parts by weight of a UV effect adjuvant (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name "NK Oligo U-6LPA") were added to obtain an active energy ray-curable pressure-sensitive adhesive (1).

[Production Example 2] Preparation of active energy ray-curable pressure-sensitive adhesive (2)

An active energy ray-curable pressure-sensitive adhesive (2) was obtained in the same manner as in Production Example 1, except that the blending amount of the crosslinking agent (Nippon Polyurethane Kogyo Co., Ltd., trade name "Coronate L") was 0.6 parts by weight.

[Production Example 3] Preparation of active energy ray-curable pressure-sensitive adhesive (3)

An active energy ray-curable pressure-sensitive adhesive (3) was obtained in the same manner as in Production Example 1, except that the blending amount of the crosslinking agent (Nippon Polyurethane Kogyo Co., Ltd., trade name "Coronate L") was 0.025 parts by weight.

[Production Example 4] Preparation of active energy ray-curable pressure-sensitive adhesive (4)

An active energy ray-curable pressure-sensitive adhesive (4) was obtained in the same manner as in Production Example 1, except that the blending amount of the crosslinking agent (Nippon Polyurethane Kogyo Co., Ltd., trade name "Coronate L") was 4 parts by weight.

[Production Example 5] Fabrication of substrate (1)

As the base material forming material, high-pressure polyethylene (PE) (manufactured by Sumitomo Chemical Co., Ltd., trade name "Sumikasen F213-P") was used.

The base material forming material is introduced into an extruder, and T die melt co-extrusion (extruder: manufactured by GM Engineering, trade name "GM30-28" / T die: feed block method; extrusion temperature 240 ° C.) is performed, and embossing is performed on one side of the film ( A film having a thickness of 100 μm was obtained while performing surface roughness Ra: 1.42 μm). In addition, the thickness of the layer was controlled by the shape of the T-die exit. Corona treatment was performed on both surfaces of the obtained film to obtain a base material (1). In addition, Ra of the embossed surface is a numerical value obtained by measuring with Keyence Corporation VK-X150.

[Production Example 6] Fabrication of substrate (2)

A substrate (2) was obtained in the same manner as in Production Example 5, except that only the embossed surface of the film was subjected to corona treatment.

[Production Example 7] Fabrication of substrate (3)

As a substrate forming material, a mixture of 100 parts by weight of high pressure polyethylene (PE) (manufactured by Sumitomo Chemical Co., Ltd., trade name "Sumikasen F213-P") and 1 part by weight of a lubricant (manufactured by Mitsubishi Chemical Corporation, trade name "Amide Ap-1") used

The base material forming material is introduced into an extruder, and T die melt co-extrusion (extruder: manufactured by GM Engineering, trade name "GM30-28" / T die: feed block method; extrusion temperature 240 ° C.) is performed, and embossing is performed on one side of the film ( A film having a thickness of 100 μm was obtained while performing surface roughness Ra: 1.42 μm). In addition, the thickness of the layer was controlled by the shape of the T-die exit. Corona treatment was performed on the embossed surface of the obtained film to obtain a base material (3).

[Example 1]

The active energy ray-curable pressure-sensitive adhesive (1) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm), and then heated at 120° C. for 2 minutes to form a pressure-sensitive adhesive layer having a thickness of 15 μm.

Using a hand roller, the pressure-sensitive adhesive layer was transferred to a substrate to obtain a dicing tape. In addition, "NSO film 100um Tomei" by Okura Kogyo Co., Ltd. was used for the base material. The film concerned is a film to which corona treatment is given to one side and embossing treatment is not performed. The pressure-sensitive adhesive layer was laminated on the corona treatment surface.

The obtained dicing tape was subjected to the above evaluations (1) to (9). The results are shown in Table 1.

[Example 2]

Dicing tape in the same manner as in Example 1, except that the active energy ray-curable pressure-sensitive adhesive (2) was used instead of the active energy ray-curable pressure-sensitive adhesive (1), and the base material (2) produced in Production Example 6 was used as the base material. got The pressure-sensitive adhesive layer was laminated on the embossed surface.

The obtained dicing tape was subjected to the above evaluations (1) to (9). The results are shown in Table 1.

[Example 3]

The active energy ray-curable pressure-sensitive adhesive (3) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm) and then heated at 120° C. for 2 minutes to form a pressure-sensitive adhesive layer a with a thickness of 7 μm.

Separately, the active energy ray-curable pressure-sensitive adhesive (1) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm), and then heated at 120° C. for 2 minutes to form a pressure-sensitive adhesive layer b having a thickness of 8 μm. .

Using a hand roller, the pressure-sensitive adhesive layer a is transferred to the base material 2, and the pressure-sensitive adhesive layer b is transferred to the pressure-sensitive adhesive layer a to form a dicing tape (substrate 2/first pressure sensitive adhesive layer a/second pressure sensitive adhesive layer b) got The pressure-sensitive adhesive layer was laminated on the embossed surface.

The obtained dicing tape was subjected to the above evaluations (1) to (9). The results are shown in Table 1.

[Example 4]

The active energy ray-curable pressure-sensitive adhesive (3) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm) and then heated at 120° C. for 2 minutes to form a pressure-sensitive adhesive layer a with a thickness of 7 μm.

Separately, the active energy ray-curable pressure-sensitive adhesive (4) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm), and then heated at 120° C. for 2 minutes to form a pressure-sensitive adhesive layer c having a thickness of 8 μm. .

Using a hand roller, the pressure-sensitive adhesive layer a is transferred to the base material 2, and the pressure-sensitive adhesive layer c is transferred onto the pressure-sensitive adhesive layer a to form a dicing tape (substrate 2/first pressure sensitive adhesive layer a/second pressure sensitive adhesive layer c) got The pressure-sensitive adhesive layer was laminated on the embossed surface.

The obtained dicing tape was subjected to the above evaluations (1) to (9). The results are shown in Table 1.

[Example 5]

A dicing tape was obtained in the same manner as in Example 4, except that the base material (3) was used instead of the base material (2).

The obtained dicing tape was subjected to the above evaluations (1) to (9). The results are shown in Table 1.

[Comparative Example 1]

As the substrate, a dicing tape was obtained in the same manner as in Example 1, except that the substrate (1) produced in Production Example 5 was used. The pressure-sensitive adhesive layer was laminated on the embossed surface.

The obtained dicing tape was subjected to the above evaluations (1) to (9). The results are shown in Table 1.

[Comparative Example 2]

As the substrate, a dicing tape was obtained in the same manner as in Example 2, except that the substrate (1) produced in Production Example 5 was used. The pressure-sensitive adhesive layer was laminated on the embossed surface.

The obtained dicing tape was subjected to the above evaluations (1) to (9). The results are shown in Table 1.

[Comparative Example 3]

The active energy ray-curable pressure-sensitive adhesive (3) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm), and then heated at 120° C. for 2 minutes to form a pressure-sensitive adhesive layer a′ having a thickness of 5 μm.

Separately, the active energy ray-curable pressure-sensitive adhesive (4) is applied to the silicone-treated surface of a PET separator (thickness: 38 μm), and then heated at 120° C. for 2 minutes to form a pressure-sensitive adhesive layer c′ having a thickness of 10 μm. did

Using a hand roller, the pressure-sensitive adhesive layer a' is transferred to the base material 2, and the pressure-sensitive adhesive layer c' is transferred onto the pressure-sensitive adhesive layer a to form a dicing tape (base material (2)/first pressure sensitive adhesive layer a'/second pressure sensitive adhesive layer a'). Layer c') was obtained. The pressure-sensitive adhesive layer was laminated on the embossed surface.

The obtained dicing tape was subjected to the above evaluations (1) to (9). The results are shown in Table 1.

As is clear from Table 1, when the dicing tape of the present invention is used, the binarized white area is greater than or equal to a specific value, so that in the stealth dicing step, the camera is detected through the dicing tape, that is, the camera (for example For example, surface pattern recognition of a semiconductor wafer by an IR camera or SD camera, position detection in the height direction of a semiconductor wafer, etc. can be performed with high precision. Also, a modified layer can be favorably formed inside the semiconductor wafer. Further, in the examples, preventing blocking of the substrate; And dicing tape was formed by eliminating substrate embossing, adjusting the elastic modulus of the pressure-sensitive adhesive layer, etc. so as not to generate voids in the vicinity of the interface between the substrate and the pressure-sensitive adhesive layer; thereby, the binarized white area can be increased. . Further, in Comparative Example 3, although the surface roughness of the substrate is relatively small, since the binarized white area is below a specific value, it is shown that the accuracy of dicing is poor.

10: materials
20: adhesive layer
100: dicing tape

Claims (10)

A base material and an adhesive layer disposed on one side of the base material,
A gray scale image of 256 gradations in luminance obtained by observing with a laser microscope from the substrate side in a state where dicing tape was pressed against the Si wafer mirror surface was binarized into white and black portions with 55% of the maximum luminance as the threshold. When the area of the white portion is 80% or more of the image area,
A dicing tape in which an embossing treatment is performed on only one side of the substrate, the embossed surface is the surface on the pressure-sensitive adhesive layer side, and the arithmetic average surface roughness Ra of the embossed surface of the substrate is 1.0 μm to 3 μm. . According to claim 1,
The dicing tape, wherein the wettability of one side of the substrate is 40 mN/m or less. According to claim 2,
The dicing tape in which the said base material is arrange|positioned so that the surface with wettability of 40 mN/m or less may become the surface on the opposite side to the adhesive layer. According to claim 1,
The dicing tape in which the said base material contains a polyethylene-type resin. According to claim 1,
A dicing tape wherein at least one surface of the substrate is a corona treated surface. According to claim 1,
The dicing tape whose tensile modulus of elasticity at 22 degreeC of the said adhesive layer is 0.05 Mpa - 1 Mpa. According to claim 1,
The pressure-sensitive adhesive layer has a two-layer structure,
A dicing tape comprising the base material, a first pressure sensitive adhesive layer, and a second pressure sensitive adhesive layer in this order. According to claim 7,
The dicing tape whose tensile elasticity modulus at 22 degreeC of the said 1st adhesive layer is 0.05 Mpa - 1 Mpa. According to claim 7 or 8,
The dicing tape whose tensile elastic modulus at 22 degreeC of the said 2nd adhesive layer is 0.1 Mpa - 2 Mpa. According to claim 7,
The dicing tape whose thickness of the said 1st adhesive layer is 5 micrometers - 468 micrometers.