TW202003738A - Adhesive tape, and method for producing semiconductor device - Google Patents

Abstract

The purpose of the present invention is to reduce transfer failures when transferring chips 21 from backgrinding tape 10 to pickup tape 30 or to adhesive tape, specifically when producing micro-semiconductor chips using the dice-before-grind method. In addition, another purpose thereof is to improve transfer efficiency when transferring chips from the backgrinding tape 10 to the pickup tape 30 or to the adhesive tape. This adhesive tape 10 is favorable for use as a backgrinding tape, includes a substrate 11 and an adhesive layer 12 provided on one surface thereof, and is characterized in that: the adhesive layer 12 comprises an energy ray-curable adhesive; and the adhesive force thereof is no greater than 9.0 N/25mm at 23 DEG C after adhering a silicon wafer mirror surface to the adhesive layer 12, then curing the adhesive layer by irradiation with an energy ray, and then performing thermocompression bonding thereon for five seconds at a temperature of 210 DEG C and a pressure of 0.5N/cm2.

Description

Adhesive tape and manufacturing method of semiconductor device

The present invention relates to an adhesive tape, and more specifically, to the use of adhesives for temporarily fixing semiconductor wafers and wafers when manufacturing semiconductor devices using a so-called predicing method. An adhesive tape and a method of manufacturing a semiconductor device using the adhesive tape.

In the progress of miniaturization and multifunctionalization of various electronic devices, these mounted semiconductor wafers are also required to be miniaturized and thinned. In order to reduce the thickness of the wafer, the back surface of the semiconductor wafer is usually ground to adjust the thickness. In addition, there is also a technique called pre-cutting method, which is to form a groove of a predetermined depth from the surface side of the wafer, then grind from the back side of the wafer, and remove the bottom of the groove by grinding The wafer is singulated and the wafer is obtained. In the pre-dicing method, since the back surface of the wafer can be ground simultaneously with the singulation of the wafer, a thin wafer can be efficiently manufactured.

Previously, when grinding the backside of semiconductor wafers, and when manufacturing wafers using the pre-cut method, an adhesive tape called a backgrinding sheet was usually attached to the wafer surface to protect the circuits on the wafer surface in advance and to The semiconductor wafer and the semiconductor chip are fixed.

Hereinafter, a description will be given of picking up the wafer after dicing the wafer using the pre-dicing method with reference to drawings. By pre-slicing, the semiconductor wafer is singulated, and a wafer group 20 composed of a plurality of singulated wafers 21 can be obtained on the back grinding tape 10 (FIG. 1 ). The wafer group 20 is transferred to an adhesive tape called a pickup tape 30, and the wafer gap is expanded as necessary, and then peeled off from the pickup tape 30 (Patent Document 1: Japanese Patent Laid-Open No. 2012-209385) . As the pickup tape 30, most of them are adhesive tapes which are cutting tapes. The wafer group 20 is transferred from the back polishing tape 10 to the pickup tape 30 as follows. That is, the pickup tape 30 is attached to the wafer group 20 held on the back polishing tape 10. At this time, the outer peripheral portion of the pickup tape 30 is fixed using the ring frame 40 (FIG. 2 ). Next, the wafer group 20 can be transferred to the pickup tape 30 only by peeling the back polishing tape 10.

In the back-grinding step, the back-grinding tape 10 must be capable of stably maintaining the adhesion of the wafer and the wafer group, and when transferring the wafer group to the pickup tape 30, it must be easily peelable from the wafer surface Adhesion. Therefore, most of the adhesive layer 12 of the back grinding tape 10 is an energy ray hardening adhesive that can reduce the adhesive force by energy ray irradiation. For example, Patent Document 2 (Japanese Unexamined Patent Publication No. 2002-053819) discloses a back polishing tape having an adhesive force before energy line curing of 150 g/25 mm or more and an adhesive force after energy line curing of 150 g/25 mm or less. The adhesive force here is an adhesive force measured under the conditions of a peeling speed of 300 mm/min and a peeling angle of 180 degrees using a SUS304-BA board as the adherend according to the method specified in JIS Z-0237.

In addition, Patent Document 3 (Japanese Unexamined Patent Publication No. 2016-72546) discloses an adhesive tape for semiconductor wafer surface protection used in a pre-dicing method. The purpose of the adhesive tape is to suppress kerf shift during pre-cutting and eliminate the transfer of adhesive to the semiconductor wafer and the peeling defect of the semiconductor wafer. The base material of the adhesive tape is specified to have at least 1 The layer has a rigid layer with a tensile modulus of elasticity of 1 to 10 GPa, and the radiation force of the adhesive layer after radiation curing at a peeling angle of 30∘ is 0.1 to 3.0 N/25 mm.

When the back polishing tape 10 is peeled off, the peeling tape 50 which is the beginning of peeling is fixed to the back surface (base material surface) of the back polishing tape 10 (FIG. 3 ). The back polishing tape has almost the same shape as the semiconductor wafer, and since it does not become the starting point of the start of peeling, the thin rectangular peeling tape 50 is fixed to become the starting point of peeling. The peeling tape 50 is strongly fixed to the back surface of the back polishing tape 10 by hot press bonding. Prior technical literature Patent Literature

[Patent Document 1] Japanese Unexamined Patent Publication No. 2012-209385 [Patent Document 2] Japanese Patent Application Publication No. 2002-053819 [Patent Document 3] Japanese Patent Laid-Open No. 2016-72546

Problems to be solved by invention

When the peeling tape 50 is hot-pressed to the back polishing tape 10, it is heated to about 140 to 230°C and pressure is applied to heat seal the peeling tape 50 to the back of the back polishing tape 10. Therefore, the adhesive layer of the back grinding tape located at the position of the heat seal portion is also heated and pressurized. As a result, the adhesive layer hardened by energy ray irradiation flows and becomes activated by heating and pressurization, and the hardened adhesive layer of the back polishing tape and the wafer are thermally pressure-bonded. In this state, when the back grinding tape 10 is peeled using the peeling tape as a starting point, the back grinding tape is peeled off in a state where the wafer 21 is fixed to the back grinding tape 10 at the heat seal portion and its vicinity, causing the wafer The yield was low (Figure 4, Figure 5). In the following, this phenomenon may be referred to as "wafer transfer failure".

When the wafer size is large, although the peeling system between the back polishing tape and the wafer surface can be performed well, as the wafer size becomes smaller, the wafer system is easily buried in the adhesive layer 12 of the back polishing tape. As a result, the wafer peeling system from the back polishing tape becomes more difficult and the transfer failure of the wafer increases. Moreover, since the pre-cutting method mostly uses a harder substrate as the base material 11 of the back polishing tape, the back polishing tape cannot be folded back sufficiently when the back polishing tape is peeled off, which also makes peeling difficult and increases transfer defects. The main reason.

In Patent Document 3, since the base material is hard, it becomes difficult to bend the adhesive tape. Therefore, the peeling angle becomes a sharp angle, so that the peeling force is strong and the peeling takes time.

Therefore, the object of the present invention is to reduce the transfer of the wafer 21 particularly when transferring the wafer group 20 from the back grinding tape 10 to other tapes such as pickup tape or adhesive tape when manufacturing a micro-semiconductor wafer using a pre-cut method bad. Moreover, its purpose is to improve the transfer efficiency of transferring wafers from the back grinding tape to other tapes such as pickup tape or adhesive tape. Means to solve the problem

The purpose of the present invention is to solve such problems, and the gist is as follows. (1) An adhesive tape comprising a base material and an adhesive layer provided on one side of the base material, wherein: the adhesive layer is composed of an energy ray-curable adhesive; and a silicon wafer After the mirror surface is attached to the aforementioned adhesive layer, the adhesive layer is irradiated with energy rays to be hardened, and after 5 seconds of hot-pressing under a pressure of 0.5N/cm ² and 210°C, the adhesion at 23°C is 9.0 N/25mm or less. (2) The adhesive tape as described in (1), which includes attaching an abrasive tape to the surface of a semiconductor wafer with grooves formed on the surface of the semiconductor wafer, and grinding the back surface by grinding The semiconductor wafer is singulated into semiconductor wafers, and then, the method of manufacturing the semiconductor device in the step of transferring the singulated wafer group to the pickup tape or the adhesive tape is used as the aforementioned back grinding tape. (3) A method of manufacturing a semiconductor device, which includes attaching a polishing tape to the surface of a semiconductor wafer with grooves formed on the surface of the semiconductor wafer, and grinding the back surface and thereby grinding the semiconductor wafer After singulation into a semiconductor wafer, the singulated wafer group is transferred to a pickup tape or an adhesive tape, and the adhesive tape as described in (1) is used as the back grinding tape. (4) An application of an adhesive tape, which is the application of the adhesive tape described in (1) above, which includes attaching an abrasive tape to the surface of a semiconductor wafer with a groove formed on the surface of the semiconductor wafer, and grinding the back surface The method of manufacturing a semiconductor device by cutting and singulating a semiconductor wafer into semiconductor wafers by this grinding, and then transferring the singulated wafer group to a pickup tape or an adhesive tape is used as the aforementioned back The purpose of grinding belt. Invention effect

According to the adhesive tape 10 of the present invention, after the energy ray-curable adhesive layer is hardened, even if the peeling tape 50 is hot-pressed, the adhesive force of the adherend (semiconductor chip) and the adhesive tape is suppressed to become very The low level can prevent defective transfer of the wafer.

Forms for carrying out the invention

Hereinafter, the adhesive tape of the present invention will be specifically described. First, the main terms used in this manual will be explained. In this specification, for example, the term "(meth)acrylate" is used as a term for both "acrylate" and "methacrylate", and the same applies to other similar terms.

The so-called adhesive tape means that the laminate including the base material and the adhesive layer provided on one side thereof may include other constituent layers other than the above. For example, a primer layer (easy adhesion layer) may be formed on the surface of the substrate on the side of the adhesive layer. To protect the adhesive layer until use, a release sheet may be laminated on the surface of the adhesive layer. In addition, the base material may be a single layer or a multilayer including a functional layer such as a buffer layer. The same applies to the adhesive layer. The so-called "surface" of a semiconductor wafer refers to the surface where the circuit is formed, and the "back surface" refers to the surface where the circuit is not formed. The so-called singulation of semiconductor wafers refers to the division of semiconductor wafers in units of circuits to obtain semiconductor wafers.

The bare silicon wafer is a silicon wafer in a state before processing such as patterning, and its surface is mirror-polished. The so-called pre-cut method refers to a method in which a groove of a predetermined depth is formed from the front side of the wafer, and then the wafer is ground from the back side of the wafer and the wafer is singulated by grinding.

The back-grinding tape is an adhesive tape used to protect the circuit surface of the wafer during grinding of the back surface of the semiconductor wafer. In particular, in this specification, it refers to an adhesive tape that can be suitably used in the pre-cut method. The pickup tape is an adhesive tape used to transfer the wafer group and pick up the wafer. Typically, an adhesive tape called a dicing tape can be used. The adhesive tape means a thin layer having a function as an adhesive, and various adhesive tapes used to transfer the adhesive layer to other adherends. Specifically, a laminate of a film-like adhesive and a release sheet, a laminate of a dicing tape and a film-like adhesive, and an adhesive layer and a release sheet composed of both the cutting tape and the die bonding tape Cutting･die bonding tape, etc.

The adhesive tape of the present invention can be used particularly as the back grinding tape. The adhesive tape 10 of the present invention includes a substrate 11 and an adhesive layer 12 provided on one side thereof. Hereinafter, the structure of each member of the adhesive tape 10 of the present invention will be described in more detail. [Substrate 11] The base material 11 of the adhesive tape 10 can use various resin films used as the base material of the back polishing tape.

Hereinafter, an example of the base material 11 used in the present invention will be described in detail, but it is described only because the base material is easily available and should not be interpreted in any limited manner.

The substrate system of the present invention may be a hard resin film, for example. In addition, a buffer layer composed of a softer resin film may be laminated on one side or both sides of the base material.

The Young's modulus of the preferred substrate is 1000 MPa or more. When a substrate with a Young's modulus of less than 1000 MPa is used, the holding performance of the adhesive tape on the semiconductor wafer or semiconductor wafer is reduced, and vibration and the like cannot be suppressed during back grinding, and the semiconductor wafer is prone to defects and damage. On the other hand, by setting the Young's modulus of the base material to 1000 MPa or more, the holding performance of the adhesive tape on the semiconductor wafer or semiconductor wafer is improved, vibration and the like can be suppressed during back grinding, and the semiconductor wafer can be prevented from being damaged or damaged. . In addition, it is possible to reduce the stress when peeling the adhesive tape from the semiconductor wafer, and it is possible to prevent wafer chipping, damage, and the like generated when the tape is peeled. Moreover, the workability when attaching the adhesive tape to the semiconductor wafer can also be good. From such a viewpoint, the Young's modulus of the base material is preferably 1800 to 30,000 MPa, preferably 2500 to 6000 MPa.

The thickness (D1) of the substrate 11 is not particularly limited, but is preferably 500 μm or less, preferably 15 to 350 μm, and more preferably 20 to 160 μm. By setting the thickness of the base material to 500 μm or less, it is easy to control the peeling force of the adhesive tape. In addition, by setting the thickness of the base material to 15 μm or more, the base material easily functions as a support for the adhesive tape.

As the material of the base material 11, various resin films can be used. Here, examples of the base material having a Young's modulus of 1000 MPa or more include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and wholly aromatic polyester. Such as polyester, polyimide, polyamide, polycarbonate, polyacetal, modified polyphenylene ether, polyphenylene sulfide, polysulfene, polyetherketone, biaxially extended polypropylene, etc. Resin film. Among these resin films, a film containing one or more kinds selected from a polyester film, a polyamide film, a polyimide film, and a biaxially stretched polypropylene film is preferred, and a polyester film is preferred, including Polyethylene terephthalate film is better.

In addition, the base material may contain plasticizers, slip agents, infrared absorbers, ultraviolet absorbers, fillers, colorants, antistatic agents, antioxidants, catalysts, etc. as long as the effects of the present invention are not impaired. In addition, the base material is transparent to the energy rays irradiated when the adhesive layer is hardened. Furthermore, at least one surface of the base material may be subjected to a subsequent treatment such as corona treatment to improve adhesion with at least one of the buffer layer and the adhesive layer. Moreover, the base material may be an object having the above-mentioned resin film and an easy adhesion layer (primer layer) of the film on at least one surface of the resin film.

The composition for forming an easy-adhesive layer for forming an easy-adhesive layer is not particularly limited, and examples thereof include polyester-based resins, urethane-based resins, polyester urethane-based resins, and acrylic-based resins. combination. The composition for easy adhesion layer formation may contain a crosslinking agent, photopolymerization initiator, antioxidant, softener (plasticizer), filler, rust inhibitor, pigment, dye, etc. as needed. The thickness of the easy adhesion layer is preferably 0.01 to 10 μm, preferably 0.03 to 5 μm. In addition, because the thickness of the easy-adhesion layer is relatively small and the material is relatively soft relative to the thickness of the substrate, the impact on the Young's modulus is small. The number system is substantially the same as the Young's modulus of the resin film.

[The buffer layer] A buffer layer may be provided on one side or both sides of the base material 11. The buffer layer is composed of a relatively soft resin film, which can alleviate vibration caused by grinding of the semiconductor wafer and prevent cracks and defects from occurring on the semiconductor wafer. In addition, the semiconductor wafer to which the adhesive tape is attached is arranged on the adsorption machine during back grinding, and the adhesive tape is provided with a buffer layer so that it can be easily held on the adsorption machine properly.

The thickness (D2) of the buffer layer is preferably 8 to 80 μm, more preferably 10 to 60 μm.

The buffer layer consists of polypropylene film, ethylene-vinyl acetate copolymer film, ionic polymer resin film, ethylene･(meth)acrylic copolymer film, ethylene(meth)acrylate copolymer film, LDPE film, LLDPE film Better. Alternatively, it may be a layer formed of a buffer layer-forming composition containing an energy ray polymerizable compound. The base material having a buffer layer can be obtained by bonding the base material to the film. In addition, it is also preferable to apply a composition for forming a buffer layer containing an energy ray polymerizable compound on the above-mentioned substrate and harden it to form a buffer layer. The composition for forming a buffer layer containing an energy ray polymerizable compound hardens and forms a buffer layer by irradiating an energy ray by containing an energy ray polymerizable compound. The "energy rays" refer to ultraviolet rays, electron beams, etc., and ultraviolet rays are preferably used.

Furthermore, more specifically, the composition for buffer layer formation is a polymerizable compound containing urethane (meth)acrylate (a1), an alicyclic group having 6 to 20 ring-forming atoms or a heterocyclic group ( a2) is better. In addition to the components (a1) and (a2), the composition for buffer layer formation is preferably a polymerizable compound (a3) having a functional group. In addition, the composition for forming a buffer layer is preferably a photopolymerization initiator in addition to the components (a1) and (a2) or (a1) to (a3) above, so long as the effects of the present invention are not impaired, It may also contain other additives and resin components. Hereinafter, each component contained in the composition for forming a buffer layer will be described in detail.

(Ethyl urethane (meth)acrylate (a1)) The urethane (meth)acrylate (a1) is a compound having at least a (meth)acryloyl group and a urethane bond, and has a property of being polymerized and hardened by energy beam irradiation. Urethane (meth)acrylate (a1) is an oligomer or polymer.

The mass average molecular weight (Mw) of the component (a1) is preferably 1,000 to 100,000, preferably 2,000 to 60,000, and more preferably 3,000 to 20,000. In addition, the mass average molecular weight (Mw) is a polystyrene conversion value measured using a gel permeation chromatography (GPC) method, and specifically, it can be measured under the following conditions. (Measurement conditions) ･Column: "TSK guard column HXL-H" "TSK gel GMHXL (X2)" "TSK gel G2000HXL" (Either is made by TOSOH Corporation) ･Column temperature: 40℃ ･Expanding solvent: Tetrahydrofuran ･Flow rate: 1.0mL/min In addition, the number of (meth)acryloyl groups (hereinafter also referred to as "number of functional groups") in the component (a1) may be monofunctional, bifunctional, or trifunctional or more, preferably monofunctional or bifunctional. The component (a1) can be obtained by reacting a (meth)acrylate having a hydroxyl group on a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound and a polyisocyanate compound, for example. Moreover, component (a1) may be used individually or in combination of 2 or more types.

The polyol compound that becomes the raw material of the component (a1) is not particularly limited as long as it has two or more hydroxyl groups. Examples of specific polyol compounds include alkanediol, polyether polyol, polyester polyol, and polycarbonate polyol. Among these, polyester polyols are preferred. The polyol compound may be any of a bifunctional diol, a trifunctional triol, and a polyhydric alcohol of four or more. A bifunctional diol is preferred, and a polyester diol is preferred. good.

Examples of the polyisocyanate compound include aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; isophorone diisocyanate, norbranched Alicyclic diisocyanates such as alkane diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, ω,ω'-diisocyanate dimethylcyclohexane Isocyanates; 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, xylylene diisocyanate, triamine diisocyanate, tetramethylene xylylene diisocyanate, naphthalene-1,5- Aromatic diisocyanates such as diisocyanates. Among these, isophorone diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are preferred.

The (meth)acrylate having a hydroxyl group is reacted with the terminal isocyanate urethane prepolymer obtained by reacting the polyol compound and the polyisocyanate compound to obtain ethyl urethane (meth)acrylic acid Ester (a1). The (meth)acrylate having a hydroxyl group is not particularly limited as long as it has a hydroxyl group and a (meth)acryloyl group in at least one molecule.

Examples of the (meth)acrylate having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and (meth) Group) 4-hydroxyhexyl acrylate, 5-hydroxyoctyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, neopentaerythritol tri(meth)acrylate, poly Hydroxyalkyl (meth)acrylates such as ethylene glycol mono(meth)acrylate and polypropylene glycol mono(meth)acrylate; hydroxyl groups such as N-methylol (meth)acrylamide contain (methyl ) Acrylamide; reactants obtained by reacting (meth)acrylic acid with vinyl alcohol, vinyl phenol, and bisphenol A diglycidyl ester. Among these, hydroxyalkyl (meth)acrylate is preferred, and 2-hydroxyethyl (meth)acrylate is preferred.

As a condition for reacting the terminal isocyanate urethane prepolymer with a (meth)acrylate having a hydroxyl group, it is allowed to react at 60 to 100°C for 1 to 1 in the presence of a solvent catalyst added as needed. The condition of 4 hours is preferable. The content of the component (a1) in the composition for buffer layer formation is preferably 10 to 70% by mass relative to the total amount of the composition for buffer layer formation (100% by mass), preferably 10 to 70% by mass. It is 20 to 60% by mass, more preferably 25 to 55% by mass, and still more preferably 30 to 50% by mass.

(Polymer compound (a2) having an alicyclic group or heterocyclic group having 6 to 20 ring-forming atoms) The component (a2) is a polymerizable compound having an alicyclic or heterocyclic group having 6 to 20 ring-forming atoms, preferably a compound having at least one (meth)acryloyl group. By using this component (a2), the film-forming property of the obtained composition for buffer layer formation can be improved.

The number of ring forming atoms of the alicyclic group or heterocyclic group possessed by the component (a2) is preferably 6-20, preferably 6-18, more preferably 6-16, and particularly preferably 7-12. Examples of the atoms forming the ring structure of this heterocyclic group include carbon atoms, nitrogen atoms, oxygen atoms, and sulfur atoms. In addition, the number of ring-forming atoms refers to the number of atoms in the ring itself of a compound in which the atoms are bonded into a ring structure, not the atoms that constitute the ring (for example, hydrogen atoms bonded to the atoms that constitute the ring), the ring is The atoms contained in the substituent when substituted by the substituent are not included in the number of atoms forming the ring.

Specific components (a2) include, for example, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentyl (meth)acrylate, and dicyclopentyl (meth)acrylate. Aliphatic group-containing (meth)acrylates such as oxyalkylene, cyclohexyl (meth)acrylate, adamantyl (meth)acrylate; tetrahydrofurfuryl (meth)acrylate, (meth)acrylic acid Heterocyclic group-containing (meth)acrylates such as morpholinate. In addition, the component (a2) may be used alone or in combination of two or more kinds. Among them, the alicyclic group-containing (meth)acrylate is preferred, and the isobornyl (meth)acrylate is preferred.

The content of the component (a2) in the composition for buffer layer formation is preferably 10 to 70% by mass, preferably 20 to 60% by mass relative to the total amount (100% by mass) of the composition for buffer layer formation. It is more preferably 25 to 55% by mass, and particularly preferably 30 to 50% by mass.

(Polymerizable compound with functional group (a3)) Component (a3)) is a polymerizable compound containing functional groups such as a hydroxyl group, an epoxy group, an amide group, and an amine group, and it is preferably a compound having at least one (meth)acryl amide group. The component (a3) has good compatibility with the component (a1), and it is easy to adjust the viscosity of the buffer layer forming composition to an appropriate range. In addition, examples of the component (a3) include hydroxyl-containing (meth)acrylates, epoxy-containing compounds, amide group-containing compounds, and amine group-containing (meth)acrylates.

Examples of hydroxyl-containing (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and (meth) Group) 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenylhydroxypropyl (meth)acrylate, and the like. Examples of the epoxy group-containing compound include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, furyl glycidyl ether, etc. Among these, ( Epoxy group-containing (meth)acrylates such as glycidyl methacrylate and methylglycidyl (meth)acrylate are preferred. Examples of the amide group-containing compound include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, and N-hydroxyl Methyl (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (methyl) Acrylic amide and so on. Examples of the amine group-containing (meth)acrylate include, for example, a first-stage amine group-containing (meth)acrylate, a second-stage amine group-containing (meth)acrylate, and a third-stage amine group. (Meth)acrylate and so on.

Among these, a hydroxyl group-containing (meth)acrylate is preferred, and a hydroxyl group-containing (meth)acrylate having an aromatic ring such as phenylhydroxypropyl (meth)acrylate is preferred. Moreover, component (a3) may be used individually or in combination of 2 or more types.

In order to improve the film-forming properties of the buffer layer forming composition, the content of the component (a3) in the buffer layer forming composition is preferably 5 relative to the total amount of the buffer layer forming composition (100% by mass). ~40% by mass, preferably 7~35% by mass, more preferably 10-30% by mass, particularly preferably 13-25% by mass. In addition, the content ratio of the component (a2) to the component (a3) in the composition for buffer layer formation [(a2)/(a3)] is preferably 0.5 to 3.0, preferably 1.0 to 3.0, and more preferably 1.3 ~3.0, especially good is 1.5~2.8.

(Polymerizable compound other than components (a1) to (a3)) The composition for buffer layer formation may contain other polymerizable compounds other than the aforementioned components (a1) to (a3) as long as the effects of the present invention are not impaired. Examples of other polymerizable compounds include alkyl (meth)acrylates having a C 1-20 alkyl group; styrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, and N-vinylformamide , N-vinylpyrrolidone, vinyl compounds such as N-vinylcaprolactam, etc. In addition, these other polymerizable compounds may be used alone or in combination of two or more.

The content of other polymerizable compounds in the buffer layer forming composition is preferably 0-20% by mass, preferably 0-10% by mass, more preferably 0-5% by mass, and particularly preferably 0-2% by mass .

(thioxanthone)化合物、過氧化化合物、以及胺、苯醌等的光敏化劑等，更具體地，例如可舉出1-羥基環己基苯基酮、2-羥基-2-甲基-1-苯基-丙烷-1-酮、苯偶姻、苯偶姻甲醚、苯偶姻乙醚、苯偶姻異丙醚、苄基苯基硫醚、四甲基秋蘭姆一硫醚、偶氮雙異丁腈、聯苄(dibenzyl)、聯乙醯、8-氯蒽醌、雙(2,4,6-三甲基苯甲醯基)苯基氧化膦等。 這些光聚合起始劑係能夠單獨或組合2種以上而使用。 緩衝層形成用組合物中的光聚合起始劑含量，係相對於能量線聚合性化合物的合計量100質量份，良好為0.05~15質量份，較佳為0.1~10質量份，更佳為0.3~5質量份。(Photopolymerization initiator) When forming the buffer layer, the polymerization time by light irradiation is shortened, and from the viewpoint of reducing the light irradiation amount, the composition for forming a buffer layer further contains a photopolymerization initiator Better. Examples of the photopolymerization initiator include benzoin compounds, acetophenone compounds, acetylphosphine oxide compounds, titanocene compounds, and 9-oxosulfur.

(thioxanthone) compounds, peroxide compounds, photosensitizers such as amines, benzoquinones, etc., more specifically, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-benzene -Propane-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl phenyl sulfide, tetramethyl thiuram monosulfide, azobis Isobutyronitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzyl) phenylphosphine oxide, etc. These photopolymerization initiator systems can be used alone or in combination of two or more. The content of the photopolymerization initiator in the buffer layer forming composition is 100 parts by mass relative to the total amount of the energy ray polymerizable compound, preferably 0.05 to 15 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.3~5 parts by mass.

(Other additives) The composition for forming a buffer layer is within a range that does not impair the effects of the present invention, and may contain other additives. Examples of other additives include antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, pigments, and dyes. When these additives are blended, the content of each additive in the buffer layer forming composition is preferably 0.01 to 6 parts by mass, preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the total energy ray polymerizable compound.

(Resin component) The composition for forming a buffer layer is within a range that does not impair the effects of the present invention, and may contain a resin component. Examples of the resin component include polyene-thiol-based resins, polyolefin-based resins such as polybutene, polybutadiene, and polymethylpentene, and thermoplastic resins such as styrene-based copolymers. The content of these resin components in the buffer layer forming composition is preferably 0-20% by mass, preferably 0-10% by mass, more preferably 0-5% by mass, and particularly preferably 0-2% by mass.

[Adhesive layer 12] The adhesive layer 12 is formed on one side of the base material 11 directly or via a buffer layer. In the present invention, the adhesive layer is composed of an energy ray-curable adhesive, which is characterized in that after the silicon wafer is mirror-attached to the adhesive layer, the adhesive layer is irradiated with energy rays to be hardened, and then the pressure is 0.5N/ After cm ² and 210°C for 5 seconds, the adhesion between the mirror surface of the silicon wafer at 23°C and the adhesive layer is 9.0N/25mm or less. Hereinafter, there are cases where the above-mentioned adhesive force is referred to as "adhesive force after hot-press bonding".

After hot pressing, the adhesive force can be controlled by the composition of the adhesive. The general policy for controlling the adhesive force after hot pressing is described later. The adhesive force after hot pressing is preferably in the range of 0.001 to 7N/25mm, more preferably in the range of 0.1 to 1N/25mm. The adhesive force after hot press bonding is within the above range, even after the adhesive layer is hardened, the wafer group 20 can be stably held, and the wafer group can be easily transferred without leaving residues when transferring the wafer group to the pickup tape 30 or the adhesive tape The adhesive layer is peeled from the wafer group. When measuring the adhesive force after hot pressing, the adhesive is completely hardened by irradiating energy rays. That is, it hardens to such an extent that the adhesive force does not change even if the energy beam is further irradiated. At this time, on the surface of the base material side of the adhesive tape, the peeling tape 50 described later is simultaneously hot-pressed at the same time. The peeling tape 50 is a starting point for peeling, and can also be used in conjunction with a measuring device. In addition, in the measurement of the adhesive force after hot-press bonding described later, the measured adhesive force may also vary with the progress of peeling. In the present invention, the maximum value until the peeling of the adhesive tape 10 is completed is referred to as the adhesive force after hot press bonding.

Generally, the adhesive after hardening has a reduced adhesive strength at room temperature, but when hot-press bonding is performed, it tends to be firmly adhered to the adherend and peeling becomes difficult. However, even if the adhesive system of the present invention is hot-pressed after hardening, the adhesive force does not excessively increase and maintains a low adhesive force. Since the adhesive force after thermocompression bonding is within the above range, even if the peeling tape 50 is thermocompression-bonded at high pressure, the wafer or the like is not buried in the adhesive layer and the transfer failure of the wafer can be greatly reduced.

In addition, the storage elastic modulus of the adhesive at 23°C before the energy ray curing is preferably 0.05 to 0.50 MPa. Moreover, the loss positive connection (tanδ=loss elastic modulus/storage elastic modulus) at 23° C. before the energy ray hardening is preferably 0.2 or more. On the surface of the semiconductor wafer, circuits and the like are formed and usually have irregularities. When the storage elastic modulus and tan δ of the adhesive are within the above range, when the adhesive tape is attached to the surface of the wafer with unevenness, the unevenness of the wafer surface can be fully contacted with the adhesive layer and the adhesive layer can be made Then sex is properly played. Therefore, it is possible to securely fix the adhesive tape to the semiconductor wafer and to properly protect the wafer surface during back grinding. From these viewpoints, the storage elastic modulus at 23° C. before the energy ray of the adhesive is preferably 0.10 to 0.35 MPa.

Moreover, the storage elastic modulus E'200 of the cured adhesive at 200°C is preferably 1.5 MPa or more. Hereinafter, the storage elastic modulus at 200° C. after curing of the adhesive may be referred to as the storage elastic modulus after curing.

The storage elastic modulus system after hardening is more preferably 2.0 to 100 MPa, and particularly preferably 2.5 to 70 MPa. Since the storage elastic modulus E'200 after hardening is in the above range, even after the adhesive layer is hardened, the wafer group 20 can be held stably and the wafer group can be transferred to the pickup tape 30 or the adhesive tape without leaving residues It is easy to peel the adhesive layer from the wafer group. When measuring the storage modulus after hardening, the adhesive is completely hardened by energy beam irradiation. That is, it is hardened to such an extent that the elastic modulus does not change even if energy beam irradiation is further performed. Normally, the cured elastic modulus at room temperature is higher, and the storage elastic modulus tends to decrease as the temperature becomes higher. However, the adhesive system of the present invention maintains a high elastic modulus after hardening even at high temperature. Therefore, even if the condition when the adhesive tape 50 for peeling is hot-pressed is high temperature, when the adhesive tape of the present invention is used, the hardened adhesive layer is not easily softened. As a result, even if the peeling tape is subjected to hot press bonding at a high temperature, the transfer failure of the wafer can be greatly reduced.

In addition, the adhesive layer has proper pressure-sensitive adhesiveness at room temperature before the energy ray is hardened. The adhesion force of the adhesive layer before the energy ray hardening to the mirror surface of the silicon wafer at 23° C. is preferably in the range of 10 to 1500 mN/25 mm, more preferably 10 to 700 mN/25 mm.

The thickness (D3) of the adhesive layer 12 is preferably less than 200 μm, preferably 5 to 55 μm, and more preferably 10 to 50 μm. When the adhesive layer is thinned in this way, since the proportion of the portion with low rigidity can be reduced in the adhesive tape, it is easy to further prevent the semiconductor wafer from being damaged during back grinding.

The adhesive layer 12 is formed of, for example, an energy line curable adhesive such as an acrylic adhesive, a urethane adhesive, a rubber adhesive, a polysiloxane adhesive, etc. as a main agent, and an acrylic energy line Hardening adhesives are preferred.

In addition, the adhesive layer 12 is formed of an energy ray-curable adhesive. Before curing by energy ray irradiation, the elastic modulus at 23° C. can be set in the above range, and after curing, it can be easily changed The peeling force is set below 1000mN/50mm. In addition, the adhesive force here means the adhesive force of the adhesive tape of the part except the heat seal part mentioned later.

Moreover, the fracture stress of the adhesive layer 12 in the state after the energy ray is hardened is preferably 10 MPa or more, particularly preferably 15 MPa or more. In addition, the elongation at break after energy ray hardening is preferably 15% or more, particularly preferably 20% or more. In this way, when the value of the breaking stress is 10 MPa or more and the value of the breaking elongation is 15% or more, the tensile properties of the energy ray-curable adhesive layer are good, even if the irradiation of ultraviolet rays or the like is insufficient and the energy ray-curable adhesive layer When it is not sufficiently hardened, the adhesive residue can be prevented from adhering to the wafer.

Hereinafter, specific examples of the adhesive will be described in detail, but this is a non-limiting example, and the adhesive layer system of the present invention should not be construed as being limited to these specific examples. As the energy ray-curable adhesive, for example, in addition to the non-energy ray-curable adhesive resin (also called "adhesive resin I"), energy ray-curable compounds containing energy ray-curable compounds other than the adhesive resin can also be used Adhesive composition (hereinafter also referred to as "X-type adhesive composition"). In addition, as the energy ray-curable adhesive, an energy ray-curable adhesive resin (hereinafter also referred to as "adhesive resin") containing an unsaturated group introduced into the side chain of the non-energy ray-curable adhesive resin can also be used II") as the main component, an adhesive composition that does not contain an energy ray-curable compound other than the adhesive resin (hereinafter also referred to as "Y-type adhesive composition").

Furthermore, as an energy ray-curable adhesive, a combination of X-type and Y-type, that is, energy ray-curable, which contains an energy ray-curable compound other than the adhesive resin in addition to the energy-ray-curable adhesive resin II, can also be used Sexual adhesive composition (hereinafter also referred to as "XY type adhesive composition"). Among these, it is preferable to use an XY-type adhesive composition. By using an XY type object, it has sufficient adhesive properties before curing, and on the other hand, the peeling force on the semiconductor wafer can be sufficiently reduced after curing.

In the following description, "adhesive resin" is used as a term referring to one or both of the above-mentioned adhesive resin I and adhesive resin II. Specific adhesive resins include, for example, acrylic resins, urethane resins, rubber resins, silicone resins, etc. Acrylic resins are preferred. Hereinafter, as the adhesive resin, an acrylic adhesive using an acrylic resin will be described in more detail.

For the acrylic resin system, the acrylic polymer (b) can be used. The acrylic polymer (b) is obtained by polymerizing a monomer containing at least alkyl (meth)acrylate and contains a structural unit derived from alkyl (meth)acrylate. Examples of alkyl (meth)acrylates include alkyl groups having 1 to 20 carbon atoms. The alkyl group may be linear or branched. Specific examples of alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, N-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, (meth) Group) isodecyl acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, etc. Alkyl (meth)acrylate can be used individually or in combination of 2 or more types.

From the viewpoint of improving the adhesive force of the adhesive layer, the acrylic polymer (b) is preferably a structural unit containing an alkyl (meth)acrylate having a carbon number of 4 or more derived from an alkyl group. The carbon number of the alkyl (meth)acrylate is preferably 4-12, and more preferably 4-6. The alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms is preferably an alkyl acrylate.

In the acrylic polymer (b), the alkyl (meth)acrylate having an alkyl group of 4 or more carbon atoms is relative to the total amount of monomers constituting the acrylic polymer (b) (hereinafter also referred to as "monomer" Total"), good is 40 to 98 mass%, preferably 45 to 95 mass%, more preferably 50 to 90 mass%.

The acrylic polymer (b) contains, in addition to the structural unit of alkyl (meth)acrylate derived from an alkyl group having a carbon number of 4 or less, in order to adjust the elastic modulus and adhesive properties of the adhesive layer, to contain A copolymer derived from an alkyl group having a structural unit of an alkyl (meth)acrylate having 1 to 3 carbon atoms is preferred; and the alkyl (meth)acrylate is a (methyl) group having 1 or 2 carbon atoms. Alkyl acrylate is preferred, methyl (meth)acrylate is preferred, and methyl methacrylate is most preferred. In the acrylic polymer (b), the alkyl (meth)acrylate having 1 to 3 carbon atoms in the alkyl group is preferably 1 to 30% by mass relative to the total amount of monomers, preferably 3 to 26% by mass %, more preferably 6 to 22% by mass.

In addition to the structural unit derived from the alkyl (meth)acrylate, the acrylic polymer (b) system is preferably a structural unit derived from a functional group-containing monomer. Examples of the functional group of the functional group-containing monomer include a hydroxyl group, a carboxyl group, an amine group, and an epoxy group. The functional group-containing single system can react with a crosslinking agent described later and become a crosslinking starting point, or react with an unsaturated group-containing compound to introduce an unsaturated group into the side chain of the acrylic polymer (b).

Examples of the functional group-containing monomer include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amine group-containing monomer, an epoxy group-containing monomer, and the like. These monomers can be used individually or in combination of 2 or more types. Among these, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferred, and a hydroxyl group-containing monomer is preferred.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and (meth)acrylic acid 2. -Hydroxyalkyl (meth)acrylates such as hydroxybutyl ester, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohols Class etc.

Examples of carboxyl group-containing monomers include ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; fumaric acid, itaconic acid, maleic acid, and citraconic acid. Ethylene unsaturated dicarboxylic acid and its anhydride, 2-carboxyethyl methacrylate, etc.

The functional group single system is preferably 1 to 35% by mass, preferably 3 to 32% by mass, and more preferably 6 to 30% by mass relative to the total amount of monomers constituting the acrylic polymer (b). In addition to the above, the acrylic polymer (b) system may contain styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide, etc. The structural unit of the monomer copolymerized with the acrylic monomer.

The acrylic polymer (b) system can be used as a non-energy ray-curable adhesive resin I (acrylic resin). In addition, examples of the energy ray-curable acrylic resin include a compound having a photopolymerizable unsaturated group (also referred to as an unsaturated group-containing compound), which reacts with the functional group of the acrylic polymer (b) Made of things.

The unsaturated group-containing compound is a compound having both a substituent capable of bonding to the functional group of the acrylic polymer (b) and a photopolymerizable unsaturated group. Examples of the photopolymerizable unsaturated group include (meth)acryloyl, vinyl, and allyl groups, and (meth)acryloyl is preferred. In addition, examples of the substituent that the unsaturated group-containing compound has that can be bonded to the functional group include isocyanate groups and epoxypropyl groups. Therefore, examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

In addition, the unsaturated group-containing compound is preferably reacted with a part of the functional group of the acrylic polymer (b). Specifically, the unsaturated group-containing compound is used for the acrylic polymer (b). The reaction of 50 to 98 mol% of the functional group is preferable, and the reaction of 55 to 93 mol% is preferable. In this way, with the energy ray-curable acrylic resin, a part of the functional group does not react with the unsaturated group-containing compound and remains, and is easily crosslinked by the crosslinking agent. In addition, the weight average molecular weight (Mw) of the acrylic resin is preferably 300,000 to 1.6 million, preferably 400,000 to 1.4 million, and more preferably 500,000 to 1.2 million. In addition, the glass transition temperature (Tg) of the acrylic resin is preferably -70 to 10°C.

(Energy ray hardening compound) The energy ray-curable compound contained in the X-type or XY-type adhesive composition is preferably a monomer or oligomer having an unsaturated group in the molecule and capable of being polymerized and hardened by energy ray irradiation. Examples of such energy ray-curable compounds include trimethylolpropane tri(meth)acrylate, neopentaerythritol (meth)acrylate, neopentaerythritol tetra(meth)acrylate, and dimethacrylate. Poly(meth)acrylate monomers such as neopentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, etc. Oligomers such as polyester, urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, epoxy (meth)acrylate, etc. The molecular weight of the energy ray-curable compound (weight average molecular weight in the case of an oligomer) is preferably 100 to 12,000, preferably 200 to 10,000, more preferably 400 to 8000, and particularly preferably 600 to 6000.

Among these, the urethane (meth)acrylate oligomer is preferred from the viewpoint that the molecular weight is high and it is not easy to lower the elastic modulus of the adhesive layer.

As a preferred urethane (meth)acrylate oligomer, it is a compound containing an isocyanate unit and a polyol unit and having a (meth)acryloyl group at the terminal. Examples of urethane (meth)acrylates include the formation of urethane oligomers by reacting polyhydric alcohols such as alkylene polyols, polyether compounds, and polyester compounds with hydroxyl groups at the ends. In addition, a compound obtained by reacting a compound having a (meth)acryloyl group with a functional group at this terminal is obtained. Such urethane (meth) acrylate has energy ray hardening property by (meth)acryloyl group.

As the above-mentioned polyisocyanate, isophorone diisocyanate (IPDI), 1,3-bis-(isocyanatomethyl)-cyclohexane (H6XDI), 4,4′-dicyclohexylmethane diisocyanate ( H12MDI) and other diisocyanates. These polyisocyanates are preferably used in energy ray-curable urethane (meth)acrylates at 40 to 49 mole %. In addition, among these diisocyanates, isophorone diisocyanate (IPDI) capable of improving the compatibility of the energy ray-curable urethane (meth) acrylate with the energy ray-curable acrylic polymer is used. It is especially good.

As the acrylate for forming the (meth)acryloyl group, 2-hydroxypropyl acrylate (2HPA), 2-hydroxyethyl acrylate (2HEA), etc. can be used. These acrylates are preferably used in energy ray-curable urethane (meth)acrylates at 4 to 40 mole %.

The energy ray-curable urethane (meth)acrylate system is preferably used at a ratio of 1 to 200 parts by mass, preferably 5 to 100 parts by mass relative to 100 parts by mass of the energy ray curable acrylic polymer. , More preferably 10 to 50 parts by mass. In addition, from the viewpoint of compatibility with the energy ray-curable acrylic polymer, processability of the energy ray-curable adhesive layer, and the like, the molecular weight of the urethane (meth)acrylate is based on the number average molecular weight Good is in the range of about 300 to 30,000, preferably 20,000 or less, for example, 1,000 to 15,000 oligomers.

The content of the energy ray-curable compound in the X-type adhesive composition is preferably 40 to 200 parts by mass, preferably 50 to 150 parts by mass, and more preferably 60 to 90 parts relative to 100 parts by mass of the adhesive resin. Quality parts. On the other hand, the content of the energy ray-curable compound in the XY-type adhesive composition is preferably 1 to 30 parts by mass, preferably 2 to 20 parts by mass, and more preferably 100 parts by mass of the adhesive resin. It is 3~15 parts by mass. In the XY type adhesive composition, since the adhesive resin is energy ray-curable, even if the content of the energy ray-curable compound is small, the peeling force can be sufficiently reduced after the energy ray is irradiated.

(Crosslinking agent) It is preferable that the adhesive composition further contains a crosslinking agent. The crosslinking agent is, for example, a functional group derived from a functional group monomer included in the adhesive resin, and crosslinks the adhesive resins. Examples of the crosslinking agent include isocyanate-based crosslinking agents such as toluene diisocyanate, hexamethylene diisocyanate, and their adducts; 1,3-bis(N,N'-diglycidyl) Aminomethyl) cyclohexane and other epoxy-based crosslinking agents; hexa[1-(2-methyl)-azcyclopropanyl]triphosphoric triazine and other acridine-based crosslinking agents; aluminum clamp Clamp compound-based cross-linking agent, etc. These crosslinking agents may be used alone or in combination of two or more.

Among these, the isocyanate-based crosslinking agent is preferred from the viewpoints of improving cohesion and adhesion, and the viewpoint of ease of acquisition. From the viewpoint of promoting the cross-linking reaction, the compounding amount of the cross-linking agent is preferably 0.01 to 10 parts by mass, preferably 0.03 to 7 parts by mass, and more preferably 0.05 to 4 parts by mass with respect to 100 parts by mass of the adhesive resin. Copies.

(Photopolymerization initiator) In addition, when the adhesive composition is energy ray-curable, it is preferable that the adhesive composition further contains a photopolymerization initiator. By containing the photopolymerization initiator, even the lower energy energy rays such as ultraviolet rays can sufficiently advance the hardening reaction of the adhesive composition.

化合物、過氧化物化合物、以及胺、苯醌等的光敏化劑等，更具體地，例如可舉出1-羥基環己基苯基酮、2-羥基-2-甲基-1-苯基-丙烷-1-酮、苯偶姻、苯偶姻甲醚、苯偶姻乙醚、苯偶姻異丙醚、苄基苯基硫醚、四甲基秋蘭姆一硫醚、偶氮雙異丁腈、聯苄、聯乙醯、8-氯蒽醌、雙(2,4,6-三甲基苯甲醯基)苯基氧化膦等。Examples of the photopolymerization initiator include benzoin compounds, acetophenone compounds, acetylphosphine oxide compounds, titanocene compounds, and 9-oxosulfur.

Compounds, peroxide compounds, photosensitizers such as amines, benzoquinones, etc., more specifically, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl- Propane-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl phenyl sulfide, tetramethyl thiuram monosulfide, azobisisobutyl Nitrile, bibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzyl)phenylphosphine oxide, etc.

These photopolymerization initiators may be used alone or in combination of two or more. The compounding amount of the photopolymerization initiator is preferably 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, and more preferably 0.05 to 5 parts by mass relative to 100 parts by mass of the adhesive resin.

(Other additives) The adhesive composition is in a range that does not impair the effects of the present invention, and may contain other additives. Examples of other additives include antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, pigments, and dyes. When these additives are blended, the blending amount of the additives is preferably 0.01 to 6 mass parts relative to 100 mass parts of the adhesive resin.

In addition, from the viewpoint of improving the applicability to a substrate, a release sheet, and the like, the adhesive composition may be further diluted with an organic solvent to become a solution form of the adhesive composition. Examples of the organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, and isopropanol. In addition, these organic solvents can also directly use the organic solvent used in the synthesis of the adhesive resin, and can also add the organic solvent used in the synthesis in such a manner that the solution of the adhesive composition can be uniformly applied More than one organic solvent.

(Control of adhesive force after hot pressing) The adhesive force after thermal compression bonding of the energy ray-curable adhesive constituting the adhesive layer 12 is within the above range, and even if the peeling tape 50 is thermally pressure bonded, the chip etc. are not buried in the adhesive layer and can be large Reduce the transfer failure of the wafer to a large extent.

After hot pressing, the adhesive force can be controlled by the composition of the adhesive. For example, by increasing the degree of crosslinking of the adhesive after the energy ray is hardened, the adhesive force after hot-press bonding can be reduced. Therefore, by increasing the amount of the cross-linking agent blended in the adhesive or using a cross-linking agent with a larger number of functional groups, the cross-linking degree of the adhesive becomes higher and the adhesive force after hot-press bonding can be reduced. In addition, as an adhesive resin, by using an acrylic resin with a high Tg, the adhesive force after hot-press bonding can be reduced.

However, with these methods, the adhesive force before the energy ray hardening becomes low and the pressure-sensitive adhesiveness before the energy ray hardening may not be obtained. Therefore, for example, it is effective to increase the density of the energy-ray polymerizable unsaturated group contained in the adhesive. Specifically, as the energy ray-curable compound that increases the amount of the energy ray-polymerizable unsaturated group introduced into the energy ray-curable adhesive resin II and increases the amount of the energy ray-curable compound, the number of unsaturated groups used is large By increasing the compounding amount of photopolymerization initiator, by energy ray hardening to form a high degree of cross-linked structure, the adhesive force after thermocompression bonding can be controlled to be low.

Generally, the adhesive after hardening has a low adhesive strength at normal temperature, and the adhesive strength tends to increase as it becomes higher temperature. However, by introducing a high degree of cross-linked structure into the adhesive, the adhesive layer softens at high temperature, the flow is suppressed, and the low adhesive force is maintained. As a result, even if the peeling tape 50 is thermocompression-bonded, the transfer failure can be suppressed without embedding the wafer or the like in the adhesive layer.

In addition, when the adhesive layer is excessively hardened after hardening, it may be difficult to peel off the hardened adhesive tape because the adhesive tape is difficult to deform. At this time, by using a base material with high flexibility as the base material 11, it may be easily deformed. When the base material is relatively soft, the adhesive tape 10 can be folded back during peeling and the peeling angle becomes larger. Therefore, since the contact area between the wafer and the adhesive layer becomes smaller at the part where peeling is in progress, it can be peeled off with a small force. On the other hand, when the substrate is too hard, the peeling angle becomes smaller, and in the part where peeling is in progress, the contact area between the wafer and the adhesive layer becomes larger and the adhesive force (peeling force) becomes higher. For the same reason, it is also effective to reduce the thickness of the base material in terms of easy peeling. However, when the base material is too soft or too thin, the operability of the adhesive tape is degraded, and vibration or the like during back grinding cannot be suppressed, or the semiconductor wafer may be damaged or damaged.

Therefore, it is preferable to control the peelability of the adhesive tape 10 by appropriately setting the physical properties of the adhesive layer 12 and the Young's modulus and thickness of the base material 11.

[Peel sheet] The peeling sheet can also be attached to the surface of the adhesive tape. Specifically, the release sheet is attached to the surface of the adhesive layer of the adhesive tape. The release sheet is attached to the surface of the adhesive layer to protect the adhesive layer during transportation and storage. The release sheet is attached to the adhesive tape in a peelable manner and is removed from the adhesive tape before the adhesive tape is used (that is, before the wafer back surface is ground). As the release sheet, a release sheet having at least one surface subjected to release treatment can be used, and specifically, a product obtained by applying a release agent on the surface of the substrate for release sheets and the like.

As the base material for the release sheet, a resin film is preferred. Examples of the resin constituting the resin film include polyethylene terephthalate resin, polybutylene terephthalate resin, and polynaphthalene dicarboxylic acid. Polyester resin films such as polyester resin films such as ethylene glycol resins, polypropylene resins, and polyethylene resins. Examples of the release agent include rubber-based elastomers such as polysiloxane-based resins, olefin-based resins, isoprene-based resins, and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine Department of resin.

(Manufacturing method of adhesive tape 10) The method for manufacturing the adhesive tape 10 of the present invention is not particularly limited, and can be manufactured using a conventional method. For example, by applying a buffer layer-forming composition on a release sheet and hardening it, a buffer layer provided by bonding to the base material and removing the release sheet provides a laminate of the buffer layer and the base material. Furthermore, the adhesive layer provided on the release sheet can be attached to the base material side of the laminate to produce an adhesive tape in which the release sheet is attached to the surface of the adhesive layer. In addition, when the buffer layer is provided on both sides of the base material, an adhesive layer is formed on the buffer layer. The peeling sheet attached to the surface of the adhesive layer may be properly peeled off and removed before using the adhesive tape.

As a method of forming the buffer layer on the release sheet, a coating film can be formed by directly applying the composition for forming a buffer layer on the release sheet using a conventional coating method and irradiating the coating film with energy rays, and The buffer layer is formed. Alternatively, the buffer layer may be formed by directly applying the composition for forming a buffer layer on one side of the base material, heating and drying, or irradiating the coating film with energy rays.

Examples of the coating method of the buffer layer forming composition include spin coating, spray coating, bar coating, blade coating, roll coating, blade coating, and die coating. , Gravure coating method, etc. In addition, in order to improve the applicability, the buffer layer forming composition may be blended with an organic solvent and in the form of a solution, and may be applied on the release sheet.

When the composition for forming a buffer layer contains an energy ray polymerizable compound, it is preferable to irradiate the coating film of the composition for forming a buffer layer with energy rays to harden it to form a buffer layer. The hardening of the buffer layer may be performed by one hardening process, or may be divided into plural times. For example, the coating film on the release sheet may be completely cured to form a buffer layer, and then bonded to the substrate, or the coating film may not be completely cured to form a semi-hardened buffer layer forming film, and the buffer layer forming film may be pasted. After being bonded to the substrate, the energy beam is irradiated again to completely harden to form a buffer layer. As the energy rays irradiated in this hardening treatment, ultraviolet rays are preferable. In addition, during curing, the coating film of the composition for forming a buffer layer may be exposed, but the coating film may be covered with a release sheet, a base material, etc., and energy rays may be irradiated in a state where the coating film is not exposed. And hardening is better.

As a method of forming the adhesive layer on the release sheet, the adhesive (adhesive composition) can be directly coated on the release sheet using a known coating method, and the coating film is heated and dried to form an adhesive layer.

In addition, an adhesive (adhesive composition) may be directly coated on one side of the substrate or the buffer layer to form an adhesive layer. Examples of the method of applying the adhesive include the spin coating method, spray coating method, and bar coating method shown in the method for manufacturing the buffer layer. Blade coating method, roll coating method, blade coating method, die coating method, gravure coating method, etc.

[Manufacturing method of semiconductor device] The adhesive tape 10 of the present invention is particularly suitable for use as a back-grinding tape to be attached to the wafer circuit surface when the backside grinding is performed while protecting the semiconductor wafer circuit surface by the pre-cut method. For a non-limiting example of use as a back polishing tape, the manufacturing of a semiconductor device will be taken as an example and will be described more specifically.

Specifically, the manufacturing method of the semiconductor device includes at least the following steps 1 to 4. Step 1: the step of forming a trench from the surface side of the semiconductor wafer; Step 2: The step of attaching the above adhesive tape 10 (back polishing tape) to the surface of the semiconductor wafer; Step 3: The step of attaching the semiconductor wafer with the adhesive tape 10 on the surface and forming the above-mentioned groove, grinding it from the back side and removing the bottom of the groove into a plurality of wafers (wafer group 20) (Refer to Figure 1); and Step 4: The step of transferring the wafer group 20 to the pickup tape 30 or the adhesive tape (refer to FIGS. 2 to 5), and peeling each wafer from the pickup tape or the adhesive tape.

Hereinafter, each step of the method of manufacturing the semiconductor device will be described in detail. (step 1) In step 1, a trench is formed from the surface side of the semiconductor wafer. The trench formed in this step is a trench with a shallower depth than the thickness of the semiconductor wafer. The groove can be formed by dicing using a conventionally known wafer dicing device or the like. In addition, the semiconductor wafer is divided into a plurality of semiconductor wafers along the trench by removing the bottom of the trench in step 3 described later.

The semiconductor wafer used in this manufacturing method may be a silicon wafer, and may also be a wafer such as gallium and arsenic, a glass wafer, a sapphire wafer, or the like. The thickness of the semiconductor wafer before grinding is not particularly limited, but is generally about 500 to 1000 μm. In addition, semiconductor wafer systems usually have circuits formed on their surfaces. The formation of a circuit on the surface of a wafer can be performed using a variety of methods including previously widely used methods such as an etching method and a lift-off method.

(Step 2) In step 2, the adhesive tape 10 of the present invention is attached to the surface of the semiconductor wafer with the groove formed through the adhesive layer.

(Step 3) After step 1 and step 2, the back surface of the semiconductor wafer on the adsorption machine is ground and the semiconductor wafer is singulated into a plurality of semiconductor wafers. Here, when a groove is formed on the semiconductor wafer, back grinding is performed to thin the semiconductor wafer to at least the bottom of the groove. By back grinding, the groove becomes a cut through the wafer, and the semiconductor wafer is divided and singulated into individual semiconductor chips by the cut.

The shape of the singulated semiconductor wafer may be square or elongated such as rectangular. In addition, the thickness of the singulated semiconductor wafer is not particularly limited, but it is preferably about 5 to 100 μm, preferably 10 to 45 μm. The size of the singulated semiconductor wafer is not particularly limited. The wafer size is preferably less than 200 mm ² , preferably less than 150 mm ² , and more preferably less than 120 mm ² .

Through the above steps, the wafer group 20 can be obtained on the adhesive tape (back polishing tape) 10 as shown in FIG. 1. In addition, after the back grinding is completed, dry polishing may be performed before the wafer is picked up.

(Step 4) Next, the singulated wafer group 20 is transferred from the back grinding tape to the pickup tape 30 or the adhesive tape, and each wafer 21 is peeled from the pickup tape or the adhesive tape. Hereinafter, this step will be described based on an example of using a pickup tape.

First, the adhesive layer 12 of the adhesive tape 10 is irradiated with energy rays to harden the adhesive layer. Next, the pickup tape 30 is attached to the back side (FIG. 2) of the wafer group 20 so that the position and direction can be aligned so that it can be picked up. At this time, the ring frame 40 disposed on the outer peripheral side of the wafer group 20 is also attached to the pickup tape 30, and the outer peripheral edge portion of the pickup tape 30 is fixed to the ring frame 40. The pickup tape 30 may be attached to the wafer group 20 and the ring frame 40 at the same time, or may be attached according to different timings. Next, only the back grinding tape 10 is peeled off and the wafer group 20 is transferred onto the pickup tape.

When the back polishing tape 10 is peeled off, the peeling tape 50 which is the beginning of peeling is fixed to the back surface (base material surface) of the back polishing tape 10 (FIG. 3 ). The back polishing tape has almost the same shape as the semiconductor wafer, and since it does not become the starting point of the peeling, a thin rectangular peeling tape 50 is fixed as the starting point of peeling. The peeling tape 50 is strongly fixed to the back surface of the back polishing tape 10 by hot press bonding. The peeling system of the back polishing tape 10 is shown in FIGS. 4 and 5, and it is preferable to peel the back polishing tape 10 using the peeling tape 50 as a starting point and folding back the back polishing tape 10.

Subsequently, the pickup tape 30 is expanded and the wafer spaces are separated as needed, and each semiconductor wafer 21 located on the pickup tape 30 is picked up and becomes fixed on a substrate or the like to manufacture a semiconductor device.

In addition, the pickup tape 30 is not particularly limited, and may be composed of an adhesive tape called a dicing tape provided with a base material and an adhesive layer provided on one side of the base material. The adhesive force of the pickup tape 30 may be greater than the adhesive force of the back grinding tape 30 when peeled off. In addition, it is preferable that the wafer 21 has a property capable of reducing the adhesive force when the wafer 21 is peeled from the pickup tape 30. Therefore, as a pickup tape, an energy ray-curable adhesive tape can be suitably used.

Furthermore, it is also possible to use an adhesive tape instead of a pickup tape. The adhesive tape includes a laminate of a film-like adhesive and a release sheet, a laminate of a dicing tape and a film-like adhesive, and is composed of an adhesive layer and a release sheet having functions of both a dicing tape and a die bonding tape. Cutting, die bonding tape, etc. In addition, before attaching the pickup tape, a film-like adhesive may be attached to the back side of the singulated semiconductor wafer. When a film-like adhesive is used, the film-like adhesive may have the same shape as the wafer.

When using adhesive tape, when attaching a film-like adhesive to the back side of a singulated semiconductor wafer before attaching the pickup tape, etc., a plurality of semiconductor chips on the adhesive tape, pickup tape, etc. The semiconductor wafer is picked up together with the adhesive layer divided into the same shape. Then, the semiconductor wafer is fixed on the upper surface of the substrate or the like via the adhesive layer to manufacture a semiconductor device. The division of the adhesive layer can be performed using laser and expansion.

In addition, the peeling tape 50 is not particularly limited as long as it can be firmly heat-sealed to the back surface of the base material of the adhesive tape 10. Therefore, the peeling tape 50 can be appropriately selected in consideration of the material of the base material 11 of the adhesive tape 10. The substrate 11 of the present invention is preferably composed of a polyester film such as polyethylene terephthalate. Therefore, for the peeling tape 50 series, a polyolefin tape having good heat sealability with a polyester film can be suitably used. Examples of such polyolefin-based tapes include polyethylene tapes and polypropylene tapes, but are not limited thereto.

The peeling tape 50 is cut into a thin rectangular shape, although it is not limited at all, but usually has a width of about 50 mm and a length of about 60 mm. In addition, the thickness of the peeling tape 50 should just be about 10-150 micrometers.

When the peeling tape 50 is fixed to the back surface (base material 11) of the adhesive tape 10, both can be firmly heat-sealed by hot-press bonding. The thermocompression bonding conditions are various according to the material of the base material 11 and the material of the peeling tape 50, and are usually carried out under the conditions of a pressure of about 0.2 to 1 N/cm ² and a temperature of about 120 to 250°C About 0.5~10 seconds. In addition, at the time of thermocompression bonding, the peeling tape 50 is provided with the heat-sealed portion on the base material 11 with an area that can be sufficiently fixed. For example, it is preferable that a region of about 0.1 to 3 mm from the outer edge portion of the base material 11 toward the center of the base material 11 be a heat seal portion.

As described above, when the peeling tape 50 is hot-pressed and adhered to the back surface (substrate 11) of the adhesive tape 10, heat and pressure are also transferred to the adhesive layer 12 of the adhesive tape 10 and the wafer 21 and the adhesive layer 12 are hot-pressed sticky. When the adhesive force increases after the hot press bonding, the wafer is firmly adhered to the adhesive layer 12, and when the adhesive tape 10 is peeled off, the wafer may be peeled together with the adhesive tape 10 and a wafer transfer failure may occur. However, in the present invention, since the adhesive force of the adhesive tape 10 after thermal compression bonding is controlled within a predetermined range, it is possible to reduce wafer transfer defects.

Further, in "the hot sticky adhesive force" of the present invention based hot press adhesion at 23 ℃ viscous after 5 seconds as above, it means the pressure of 0.5N / cm Condition ^2, 210 ℃ of. It has been confirmed by experiments that even if the pressure during hot press bonding is increased, the temperature is increased, or the growth time is increased, the adhesion force is not significantly different. That is, the thermocompression bonding conditions (5 seconds at a pressure of 0.5 N/cm ² and 210° C.) when measuring the adhesive force after thermocompression bonding specified in the present invention are sufficiently severe conditions and even Severely above this, the difference in adhesion is not large. Therefore, by controlling the adhesive force after hot-press bonding to the range specified in the present application, the adhesive force of the wafer surface and the adhesive tape 10 can be kept at a low level and achieved under various hot-press bonding conditions The effect of the present invention.

Above, the adhesive tape of the present invention mainly describes an example used by a method of singulating semiconductor wafers by a pre-cut method. The adhesive tape of the present invention can also be used for normal back grinding, and, in It can also be used to temporarily fix the workpiece during processing of glass, ceramics, and the like. In addition, it can be used as a variety of re-peelable adhesive tapes. Examples

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

The measurement method and evaluation method in the present invention are as follows.

[Storage elastic modulus after hardening] The adhesive composition prepared in Examples and Comparative Examples is coated on one surface of a polyethylene terephthalate film using a silicone-based peeling agent and peeled off. The peeling sheet (made by LINTEC, SP-PET3801, thickness: 38 μm) was dried to produce an adhesive layer with a thickness of 20 μm. The obtained adhesive layer was laminated with a plurality of layers so that the thickness became 3 mm. From the obtained laminate of the adhesive layer, a cylindrical body (height 3 mm) with a diameter of 8 mm was die-cut and used as a sample. The sample is irradiated with ultraviolet rays and the adhesive layer is completely hardened. In addition, the above-mentioned ultraviolet irradiation conditions are a wavelength of 365 nm, an illuminance of 150 mW/cm ² , and a light amount of 300 mJ/cm ² .

For the hardened samples, a dynamic viscoelastic device (manufactured by ORIENTEC, trade name "Rheovibron DDV-11-EP1") was used to measure the storage elastic modulus for 10 samples at a frequency of 11 Hz and a temperature of 200 °C. E'. [Adhesive force after hot pressing] The adhesive tape with a peeling sheet obtained in Examples and Comparative Examples was peeled off and attached to a tape bonding machine (manufactured by Lintec Corporation, trade name "RAD-3510F/12") and attached to Polished surface of bare wafer (12-inch diameter, 740 μm thickness, #2000 polishing). Subsequently, the outer peripheral portion of the adhesive tape is cut off and becomes the same shape as the bare wafer.

Subsequently, using an ultraviolet irradiation/mounting machine with a tape peeling device (made by LINTEC Corporation, trade name "RAD-2700"), ultraviolet rays were irradiated from the substrate surface side of the adhesive tape to completely harden the adhesive layer. In addition, the ultraviolet irradiation conditions are a wavelength of 365 nm, an illuminance of 150 mW/cm ² , and a light amount of 300 mJ/cm ² . Next, the dicing tape (Adwill ID-175 manufactured by LINTEC) was attached to the other side of the bare wafer as a pickup tape. Next, a polypropylene film (manufactured by LINTEC, Adwill S-750) with a width of 50 mm and a length of 60 mm was prepared as a tape for peeling. Using a heat sealing device, heat sealing was performed under the conditions of a pressure of 0.5 N/cm ² and 210° C. for 5 seconds, and the peeling tape was hot-pressed to the outer edge of the adhesive tape. The heat-sealed portion is set to a region 2 mm from the outer edge of the adhesive tape toward the center.

Using a tensile tester (Shimadzu Corporation, AUTOGRAPH AG-IS), the tape for peeling was peeled from the bare wafer at a peeling speed of 300 mm/min and a peeling angle of 180∘. The maximum peeling force (about 1 cm) from the start of peeling until the heat-sealed portion was completely peeled off was measured. The maximum peel force was measured for 10 adhesive tapes. The average value is used as the adhesive force after hot press bonding.

[Stripping evaluation] In the same way as the measurement of the adhesive force after the hot press bonding, the polishing surface of the bare wafer was cut into grooves with a depth of 70 μm and a width of 30 μm at intervals of 1 mm in the longitudinal and lateral directions of the wafer, and the adhesive tape (back polishing tape) was applied. ) Attached to the same side. Subsequently, the back side of the wafer was ground and singulated using a pre-cut method to a thickness of 30 μm and a wafer size of 1 mm×1 mm.

After the back grinding is completed, use an ultraviolet irradiation and placement machine with a tape peeling device (made by LINTEC Co., Ltd., trade name "RAD-2700") to irradiate ultraviolet rays from the side of the substrate surface of the adhesive tape and completely harden the adhesive layer . In addition, the above-mentioned ultraviolet irradiation conditions are a wavelength of 365 nm, an illuminance of 150 mW/cm ² , and a light amount of 300 mJ/cm ² . Subsequently, the dicing tape (Adwill D-175 manufactured by LINTEC) was used as a pickup tape and attached to the wafer group, and the outer peripheral portion of the dicing tape was fixed using a ring frame. Next, a polypropylene film (Adwill S-750 manufactured by Lintec Corporation) with a width of 50 mm and a length of 60 mm was prepared as a tape for peeling. Using a heat sealing device, heat sealing was performed under the conditions of a pressure of 0.5 N/cm ² and 210° C. for 5 seconds, and the peeling tape was hot-pressed to the outer edge of the adhesive tape. The heat-sealed portion was set to a region 2 mm from the outer edge of the adhesive tape toward the center.

Holding the peeling tape, fold back the adhesive tape and peel the wafer group from the adhesive tape. Confirm the number of wafers remaining on the adhesive layer of the adhesive tape. The number of wafers remaining stuck to the adhesive tape in the above operation was totaled and evaluated based on the following criteria. Excellent: less than 10 Good: more than 10 and less than 30 Bad: more than 30

In addition, the mass parts of the following examples and comparative examples are all solid content values. Prepare the following multi-layer substrate. (1) Multilayer substrate 1 A polyethylene terephthalate film (Young's modulus: 2500 MPa) with a thickness of 50 μm as a base material was used. A multi-layer substrate 1 provided with the following buffer layer on this substrate is prepared.

(Composition for buffer layer formation) (Synthesis of urethane acrylate oligomer) The terminal isocyanate urethane prepolymer obtained by reacting polycarbonate diol and isophorone diisocyanate is reacted with 2-hydroxyethyl acrylate to obtain an amine with a mass average molecular weight (Mw) of 5000 Ethyl formate acrylate oligomer (UA-1).

50 parts by mass of the urethane acrylate oligomer (UA-1) synthesized above, 30 parts by mass of isobornyl acrylate (IBXA), 40 parts by mass of tetrahydrofurfuryl acrylate (THFA), and two 15 parts by mass of neopentaerythritol hexaacrylate (DPHA), and then 2-hydroxy-2-methyl-1-phenyl-propane-1-one (manufactured by BASF JAPAN, product name) as a photopolymerization initiator "DAROCUR1173") 1.0 parts by mass to prepare the buffer layer forming composition.

(Production of multi-layer base material 1) The composition for forming a buffer layer is applied to the peeling treatment surface of a release sheet (manufactured by LINTEC, trade name "SP-PET381031") to form a coating film. Next, the coating film was irradiated with ultraviolet rays, and the coating film was semi-cured to form a buffer layer forming film having a thickness of 53 μm. In addition, the above-mentioned ultraviolet irradiation system uses a conveyor belt type ultraviolet irradiation device (manufactured by EYEGRAPHICS, device name "US2-0801") and a high-pressure mercury lamp (manufactured by EYEGRAPHICS company, device name "H080-L41") at a lamp height of 230 mm and output The power was 80 mW/cm, the light wavelength was 365 nm, and the illuminance was 90 mW/cm ² , and the irradiation amount was 50 mJ/cm ² .

Then, the surface of the formed buffer layer-forming film was bonded to the PET substrate, and ultraviolet rays were irradiated from the side of the release sheet on the buffer layer-forming film again to completely harden the buffer layer-forming film to form a buffer layer with a thickness of 53 μm. A multi-layer substrate 1 composed of a PET substrate and a buffer layer. In addition, the above-mentioned ultraviolet irradiation is performed under the irradiation conditions of the lamp height of 220 mm, the converted output power of 120 mW/cm, the illuminance of 160 mW/cm ^{2 of the} light wavelength of 365 nm, and the irradiation amount of 350 mJ/cm ² using the above-mentioned ultraviolet irradiation device and high-pressure mercury lamp .

(2) Multi-layer substrate 2~4 Polyethylene terephthalate (PET) film is used as a substrate. A multi-layer substrate provided with the following buffer layer on this substrate is prepared. For any buffer layer, low-density polyethylene (LDPE) with a thickness of 27.5 µm is used. Multilayer substrate 2: LDPE (27.5μm)/PET (25.0μm)/LDPE (27.5μm) Multilayer substrate 3: LDPE (27.5μm)/PET (50μm)/LDPE (27.5μm) Multilayer substrate 4: LDPE (27.5μm)/PET (75.0μm)/LDPE (27.5μm)

(3) Adhesive layer The following adhesive compositions A to E were prepared. (Preparation of Adhesive Composition A) Acrylic polymerization obtained by copolymerizing 65 parts by mass of n-butyl acrylate (BA), 20 parts by mass of methyl methacrylate (MMA), and 15 parts by mass of 2-hydroxyethyl acrylate (2HEA) in ethyl acetate Energy-curable acrylic resin by reacting 2-methacryloxyethyl isocyanate (MOI) with 80 mol% of the total hydroxyl groups of the acrylic polymer (Mw: 500,000).

To 100 parts by mass of the above energy ray-curable acrylic polymer, 1 part by mass (solid ratio) of a toluene diisocyanate-based crosslinking agent (manufactured by TOSOH Corporation, product name "CORONATE L") and a photopolymerization initiator ( Ciba Specialty Chemicals Co., Ltd., product name "IRGACURE 184") 3.5 parts by mass (solid ratio) to obtain an energy ray-curable adhesive composition A.

(Preparation of adhesive composition B) 89 parts by mass of n-butyl acrylate (BA), 8 parts by mass of methyl methacrylate (MMA), and 3 parts by mass of 2-hydroxyethyl acrylate (2HEA) were copolymerized to obtain an acrylic polymer (Mw: 800,000 ).

To 100 parts by mass of the above energy ray-curable acrylic polymer, 1 part by mass (solid content) of a toluene diisocyanate-based crosslinking agent (manufactured by TOSOH Corporation, product name "CORONATE L") and an epoxy-based crosslinking agent ( 1,3-bis(N,N-diglycidylpropylmethyl)cyclohexane) 2 parts by mass (solid content), UV-curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name ``Purple UV- 3210EA") 45 parts by mass (solid content) and 1 part by mass (solid content) of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., product name "IRGACURE 184") to obtain an energy ray-curable adhesive composition B. Using the obtained adhesive composition, the storage elastic modulus after hardening was measured.

(Preparation of adhesive composition C) An acrylic polymer obtained by copolymerizing 50 parts by mass of n-butyl acrylate (BA), 25 parts by mass of methyl methacrylate (MMA), and 25 parts by mass of 2-hydroxyethyl acrylate (2HEA) is added in This acrylic polymer reacts with 2-methacryl oxyethyl isocyanate (MOI) to obtain an energy ray-curable acrylic resin (Mw: 500,000) by 90 mol% of the total hydroxyl groups of the acrylic polymer ).

6 parts by mass of urethane acrylate oligomer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name "UT-4220") was mixed with 100 parts by mass of the above energy ray curable acrylic polymer. Parts, 1 part by mass (solid content) of toluene diisocyanate-based crosslinking agent (manufactured by TOSOH, trade name "CORONATE"), and 1.16 parts by mass (solid) of photopolymerization initiator (manufactured by Ciba Specialty Chemicals, IRGACURE 184) Ratio) to obtain the energy ray-curable adhesive composition C. Using the obtained adhesive composition, the storage elastic modulus after hardening was measured.

(Preparation of adhesive composition D) An acrylic polymer obtained by copolymerizing 50 parts by mass of n-butyl acrylate (BA), 20 parts by mass of methyl methacrylate (MMA), and 20 parts by mass of 2-hydroxyethyl acrylate (2HEA) is added in Energy-curable acrylic resin (Mw: 450,000) was obtained by reacting 2-methacryloxyethyl isocyanate (MOI) with 80 mol% of the total hydroxyl groups of this acrylic polymer ).

To 100 parts by mass of the above energy ray-curable acrylic polymer, 0.7 parts by mass (solid content) of a toluene diisocyanate-based crosslinking agent (manufactured by TOSOH Co., Ltd., trade name "CORONATE") and a photopolymerization initiator ( Ciba Specialty Chemicals, IRGACURE 184) 1.16 parts by mass (solid ratio) to obtain an energy ray-curable adhesive composition D. Using the obtained adhesive composition, the storage elastic modulus after hardening was measured.

(Preparation of adhesive composition E) 89 parts by mass of n-butyl acrylate (BA), 8 parts by mass of methyl methacrylate (MMA), and 3 parts by mass of 2-hydroxyethyl acrylate (2HEA) were copolymerized to obtain an acrylic polymer (Mw: 800,000 ).

Relative to 100 parts by mass of the above energy ray-curable acrylic polymer, 1 part by mass (solid content) of toluene diisocyanate-based cross-linking agent (manufactured by TOSOH Co., Ltd., product name "CORONATE L"), ultraviolet curing Type resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name ``UV-curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd. product name, ``Purple UV-3210EA'')) 22 parts by mass (solid content) and photopolymerization initiator ( Ciba Specialty Chemicals Co., Ltd., product name "IRGACURE 184") 1.16 parts by mass (solid content) to obtain an energy ray-curable adhesive composition E. Using the obtained adhesive composition, the storage elastic modulus after curing was measured.

[Example 1] The coating solution of the energy ray-curable adhesive composition A obtained above was applied to the peeling surface of a peeling sheet (manufactured by LINTEC, trade name "SP-PET381031"), and heated and dried at 100°C for 1 minute. An adhesive layer with a thickness of 20 μm was formed on the release sheet.

The adhesive layer is attached to the surface of the multi-layer base material 1 opposite to the surface on which the buffer layer is formed to produce an adhesive tape. The adhesive force of the obtained adhesive tape after hot-press bonding was measured, and peeling evaluation was performed.

[Example 2] An adhesive tape was produced in the same manner as in Example 1, except that the multi-layer base material 2 and the adhesive composition B were used and the thickness of the adhesive layer was 50 μm. The adhesive layer is provided on the LDPE layer of the buffer layer. The adhesive force of the obtained adhesive tape after hot press bonding was measured, and the peeling evaluation was performed.

[Example 3] An adhesive tape was produced in the same manner as in Example 1, except that the multi-layer base material 3 and the adhesive composition C were used and the thickness of the adhesive layer was 20 μm. The adhesive layer is provided on the LDPE layer of the buffer layer. The adhesive force of the obtained adhesive tape after hot press bonding was measured, and the peeling evaluation was performed.

[Example 4] An adhesive tape was produced in the same manner as in Examples, except that the multi-layer base material 4 and the adhesive composition D were used and the thickness of the adhesive layer was 40 μm. The adhesive layer is provided on the LDPE layer of the buffer layer. The adhesive force of the obtained adhesive tape after hot press bonding was measured, and the peeling evaluation was performed.

[Comparative Example 1] An adhesive tape was produced in the same manner as in Example 1 except that the multilayer base material 3 and the adhesive composition E were used and the thickness of the adhesive layer was 20 μm. The adhesive layer is provided on the LDPE layer of the buffer layer. The adhesive force of the obtained adhesive tape after hot press bonding was measured, and the peeling evaluation was performed.

[Table 1]

From the above results, it is known that when the adhesive force after hot press bonding is 9.0 N/25 mm or less, even if the hot press bonding of the peeling tape is performed, there is no defect in wafer transfer at the heat-sealed portion, and the wafer can be transferred well to Pick up tape or adhesive tape. In addition, according to tests using the adhesive tapes described in detail in Examples and Comparative Examples, and various other adhesive tapes, it was confirmed that good results can be obtained when the adhesive force after hot press bonding is 9.0 N/25 mm or less.

10‧‧‧ Adhesive tape (back grinding tape) 11‧‧‧ Base material 12‧‧‧Adhesive layer 20‧‧‧chip group 21‧‧‧chip 30‧‧‧ Pickup tape 40‧‧‧Ring frame 50‧‧‧ Stripping tape

FIG. 1 shows a state where the wafer group 20 is obtained on the back polishing tape 10 using the pre-cut method. FIG. 2 shows the steps of transferring the wafer group 20 from the back grinding tape 10 to the pickup tape 30. FIG. 3 shows the state after hot-pressing the peeling tape 50 to the back surface of the back polishing tape 10. FIG. 4 shows a state where the back grinding tape 10 is peeled off using the peeling tape 50 as a starting point. Figure 5 shows a perspective view of Figure 4.

10‧‧‧ Adhesive tape (back grinding tape)

20‧‧‧chip group

21‧‧‧chip

30‧‧‧ Pickup tape

40‧‧‧Ring frame

50‧‧‧ Stripping tape

Claims (4)

An adhesive tape comprising a substrate and an adhesive layer provided on one side of the substrate, wherein: the adhesive layer is composed of an energy ray-curable adhesive; and the silicon wafer is mirror-attached After the aforementioned adhesive layer, the adhesive layer is irradiated with energy rays to be hardened, and after hot pressing for 5 seconds under the condition of pressure 0.5N/cm ² and 210°C, the adhesion force at 23°C is 9.0N/25mm the following. The adhesive tape as described in item 1 of the scope of the patent application includes attaching the back polishing tape to the surface of the semiconductor wafer with grooves formed on the surface of the semiconductor wafer, and grinding the back surface by the grinding The semiconductor wafer is singulated into semiconductor wafers, and then, the singulated wafer group is transferred to a method of manufacturing a semiconductor device in a step of picking up a tape or following a tape, and is used as the aforementioned back grinding tape. A method of manufacturing a semiconductor device, comprising attaching a back grinding tape to the surface of a semiconductor wafer with grooves formed on the surface of the semiconductor wafer, and grinding the back surface of the semiconductor wafer into single pieces by the grinding After turning into a semiconductor wafer, and then transferring the singulated wafer group to the pickup tape or the adhesive tape, the adhesive tape as described in item 1 of the patent application scope is used as the back grinding tape. An application of an adhesive tape is the application of the adhesive tape as described in item 1 of the scope of the patent application, which includes attaching a back polishing tape to the surface of a semiconductor wafer with a groove formed on the surface of the semiconductor wafer, and grinding the back surface The method of manufacturing a semiconductor device by cutting and singulating a semiconductor wafer into semiconductor wafers by this grinding, and then transferring the singulated wafer group to a pickup tape or an adhesive tape is used as the aforementioned back The purpose of grinding belt.

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