CN111164737B - Workpiece processing sheet and method for manufacturing processed workpiece - Google Patents
Workpiece processing sheet and method for manufacturing processed workpiece Download PDFInfo
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- CN111164737B CN111164737B CN201880063268.6A CN201880063268A CN111164737B CN 111164737 B CN111164737 B CN 111164737B CN 201880063268 A CN201880063268 A CN 201880063268A CN 111164737 B CN111164737 B CN 111164737B
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/20—Adhesives in the form of films or foils characterised by their carriers
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
- C09J133/04—Homopolymers or copolymers of esters
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
- H01L21/6835—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support
- H01L21/6836—Wafer tapes, e.g. grinding or dicing support tapes
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
- C09J2203/326—Applications of adhesives in processes or use of adhesives in the form of films or foils for bonding electronic components such as wafers, chips or semiconductors
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2301/00—Additional features of adhesives in the form of films or foils
- C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
- C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2301/00—Additional features of adhesives in the form of films or foils
- C09J2301/40—Additional features of adhesives in the form of films or foils characterized by the presence of essential components
- C09J2301/416—Additional features of adhesives in the form of films or foils characterized by the presence of essential components use of irradiation
Abstract
The present invention provides a sheet for workpiece processing, comprising a base material and an adhesive layer, wherein the adhesive layer is composed of an active energy ray-curable adhesive formed from an adhesive composition containing an acrylic copolymer containing an alkoxy (meth) acrylate, the adhesive force F1 of the sheet for workpiece processing to a silicon wafer is obtained, and the adhesive force F2 of the sheet for workpiece processing to a silicon wafer after the sheet for workpiece processing is immersed in distilled water at 23 ℃ for 12 hours and dried at 23 ℃ for 24 hours, and the reduction rate of the adhesive force calculated by the reduction rate (%) = { (F1-F2)/F1 } ×100 of the adhesive force is 20% to 50%. The work piece processing sheet can satisfactorily remove an adhesive agent from an adhesive layer attached to a work piece such as a semiconductor wafer when the work piece is processed, from the work piece while suppressing penetration of water into an interface between the work piece processing sheet and the work piece or a chip obtained.
Description
Technical Field
The present invention relates to a workpiece processing sheet that can be suitably used for cutting and a method for manufacturing a processed workpiece using the workpiece processing sheet.
Background
Semiconductor wafers such as silicon and gallium arsenide and various packages (hereinafter, they may be collectively referred to as "cut objects") are manufactured in a large-diameter state, and they are cut (diced) into element chips (hereinafter, they may be referred to as "chips") and separated (picked up) respectively, and then transferred to a mounting (mount) step as a subsequent step. At this time, the cut object such as a semiconductor wafer is attached to the work piece processing sheet including the base material and the adhesive layer, and various steps such as dicing, cleaning, drying, expanding (expanding), picking up, and mounting are performed.
The cutting step heats the cutting blade, the workpiece to be cut, and the workpiece processing piece by using frictional heat generated between the rotating cutting blade and the workpiece to be cut or the workpiece processing piece. In the cutting step, a cutting piece may be generated in the cut object and the workpiece processing piece, and the cutting piece may adhere to the cut object.
Therefore, in the cutting step, water is generally supplied to the cut portion to cool the cutting blade or the like, and the generated cutting blade is removed from the object to be cut.
Patent document 1 discloses a sheet for workpiece processing for the purpose of promoting removal of such a cutting sheet by flowing water, wherein a contact angle of the adhesive layer before ultraviolet irradiation against pure water on the opposite side of the substrate is 82 ° to 114 °, a contact angle against diiodomethane is 44 ° to 64 °, and a peak value of a probe tack test (probe tack test) of the adhesive layer before ultraviolet irradiation is 294 to 578kPa.
Prior art literature
Patent literature
Patent document 1: japanese patent No. 5019657
Disclosure of Invention
Technical problem to be solved by the invention
However, when the conventional work processing sheet disclosed in patent document 1 is used for the dicing step, the adhesive agent originating from the adhesive agent layer of the work processing sheet cannot be sufficiently removed from the object to be cut.
In addition, water may infiltrate into the interface between the workpiece processing sheet and the cut object or the interface between the workpiece processing sheet and the obtained chip, usually due to the supply of the running water at the time of cutting. If such infiltration of water occurs, chip scattering or chip defects may occur.
The present invention has been made in view of such circumstances, and an object thereof is to provide a workpiece processing sheet capable of satisfactorily removing an adhesive agent derived from an adhesive layer attached to a workpiece such as a semiconductor wafer when the workpiece is processed from the workpiece by flowing water while suppressing penetration of water into an interface between the workpiece processing sheet and the workpiece or an interface between the workpiece processing sheet and a chip to be obtained, and a method for manufacturing a processed workpiece using the workpiece processing sheet.
Technical means for solving the technical problems
In order to achieve the above object, in a first aspect, the present invention provides a sheet for workpiece processing comprising a base material and an adhesive layer laminated on one side of the base material, wherein the adhesive layer is composed of an active energy ray-curable adhesive formed of an adhesive composition containing an acrylic copolymer containing an alkoxy (meth) acrylate as a monomer unit constituting a polymer, the adhesive force of the sheet for workpiece processing to a silicon wafer is F1, the adhesive force of the sheet for workpiece processing to a silicon wafer after being immersed in distilled water at 23 ℃ for 12 hours, and the adhesive force of the sheet for workpiece processing to a silicon wafer after being dried at 23 ℃ for 24 hours is F2, the reduction ratio of the adhesive force calculated by the following formula (1) is 20% to 50%,
reduction in adhesion (%) = { (F1-F2)/F1 } ×100·· (1) (invention 1).
In the workpiece processing sheet according to the invention (invention 1), the rate of decrease in the adhesive force is set to the above range, whereby penetration of water into the interface between the workpiece processing sheet and the object to be cut or the interface between the workpiece processing sheet and the obtained chip can be suppressed. Further, by forming the adhesive constituting the adhesive layer from an adhesive composition containing an acrylic copolymer containing an alkoxy (meth) acrylate as a monomer unit constituting the polymer, the adhesive has a predetermined affinity for water, and by setting the reduction ratio of the adhesive force to the above range, the adhesive force of the adhesive adhering to the object to be cut is moderately reduced by contact with water, and the adhesive adhering to the object to be cut can be removed satisfactorily by running water.
In the above invention (invention 1), the content of the (meth) acrylic acid alkoxy ester in the acrylic copolymer is preferably 10 parts by mass or more and 85 parts by mass or less (invention 2).
In the above inventions (inventions 1, 2), the alkoxy (meth) acrylate is preferably 2-methoxyethyl acrylate (invention 3).
In the above inventions (inventions 1 to 3), the adhesive layer preferably has a water contact angle of 50 ° or more and 80 ° or less on the surface opposite to the base material (invention 4).
In the above inventions (inventions 1 to 4), the adhesive force F1 is preferably 1000mN/25mm or more and 10000mN/25mm or less (invention 5).
In the above inventions (inventions 1 to 5), the adhesive force F2 is preferably 900mN/25mm or more and 8000mN/25mm or less (invention 6).
In the above inventions (inventions 1 to 6), the workpiece processing sheet is preferably a dicing sheet (invention 7).
In a second aspect, the present invention provides a method for manufacturing a machined workpiece, comprising: a bonding step of bonding a surface of the adhesive layer of the workpiece processing sheet (inventions 1 to 7) on the opposite side of the base material to a workpiece; a processing step of processing the workpiece on the workpiece processing sheet to obtain a processed workpiece laminated on the workpiece processing sheet; an irradiation step of irradiating the adhesive layer with an active energy ray to cure the adhesive layer, thereby reducing the adhesion of the workpiece processing sheet to the processed workpiece; and a separation step (invention 8) of separating the processed workpiece from the workpiece processing sheet after irradiation with the active energy rays.
Effects of the invention
The present invention provides a sheet for processing a workpiece, which can satisfactorily remove an adhesive agent from an adhesive layer attached to a workpiece such as a semiconductor wafer when processing the workpiece, from the workpiece by flowing water while suppressing penetration of water into the interface between the sheet for processing a workpiece and the workpiece or the interface between the sheet for processing a workpiece and the obtained chip. Further, according to the method of manufacturing a processed workpiece of the present invention, the processed workpiece can be manufactured efficiently.
Detailed Description
Hereinafter, embodiments of the present invention will be described.
[ sheet for workpiece processing ]
The workpiece processing sheet of the present embodiment includes a base material and an adhesive layer laminated on one side of the base material.
The adhesive layer of the present embodiment is composed of an active energy ray-curable adhesive formed from an adhesive composition containing an acrylic copolymer containing an alkoxy (meth) acrylate as a monomer unit constituting a polymer.
Further, in the workpiece processing sheet of the present embodiment, when the adhesion of the workpiece processing sheet to the silicon wafer is F1, and the workpiece processing sheet is immersed in distilled water at 23 ℃ for 12 hours, and further, the adhesion of the workpiece processing sheet dried at 23 ℃ for 24 hours is F2, the reduction ratio of the adhesion calculated by the following formula (1) is 20% or more and 50% or less. In the present specification, the adhesion force F1 and the adhesion force F2 are both measured before the active energy ray is irradiated to the workpiece processing sheet. The details of the method for measuring the adhesive force F1 and the adhesive force F2 are as described in the test examples described later,
The reduction in adhesion (%) = { (F1-F2)/F1 } ×100·· (1).
In the work processing sheet of the present embodiment, since the adhesive layer is formed of the adhesive composition and the above-described reduction ratio of the adhesive force is simultaneously exhibited, when the work processing sheet of the present embodiment is used for cutting an object to be cut, the adhesive adhering to the object to be cut can be removed well by running water while suppressing penetration of water into the interface between the work processing sheet and the object to be cut or the interface between the work processing sheet and the obtained chip.
In particular, by setting the reduction ratio of the adhesive force to the above range, even when the adhesive layer is exposed to flowing water, the adhesive force of the adhesive layer to the cut object remains moderately, and penetration of water into the interface between the work piece processing sheet and the cut object or the interface between the work piece processing sheet and the obtained chip can be suppressed. This can satisfactorily suppress chip scattering and chip defects caused by such water penetration.
On the other hand, by forming the adhesive layer from the adhesive composition, the adhesive layer has a moderate affinity for water, and by setting the reduction ratio of the adhesive force to the above range, even when the adhesive derived from the adhesive layer adheres to the cut object in the cutting step, the adhesive force of the adhesive can be moderately reduced by flowing water, and the adhesive can be satisfactorily removed from the cut object.
If the reduction ratio of the adhesive force is less than 20%, the adhesive force of the adhesive to the object to be cut is maintained even after the adhesive from the adhesive layer is exposed to the running water, and the adhesive adhering to the object to be cut cannot be sufficiently removed by the running water. If the reduction ratio of the adhesive force is more than 50%, the adhesive force of the adhesive layer to the cut object is excessively reduced, and the cut object or the obtained chip cannot be held on the adhesive layer satisfactorily, and peeling of the cut object or chip scattering and chip defects occur at the time of dicing. From such a viewpoint, the reduction rate of the adhesive force is preferably 23% or more. The reduction rate of the adhesive force is preferably 40% or less.
1. Physical properties of sheet for workpiece processing
In the workpiece processing sheet of the present embodiment, the adhesion F1 is preferably 1000mN/25mm or more, particularly preferably 2000mN/25mm or more, and further preferably 3000mN/25mm or more. The adhesion F1 is preferably 10000mN/25mm or less, particularly preferably 7000mN/25mm or less.
In the workpiece processing sheet of the present embodiment, the adhesion force F2 is preferably 900mN/25mm or more, particularly preferably 1500mN/25mm or more, and further preferably 2000mN/25mm or more. The adhesion F2 is preferably 8000mN/25mm or less, particularly preferably 5000mN/25mm or less.
By setting the adhesion force F1 and the adhesion force F2 to the above ranges, respectively, the reduction rate of the adhesion force can be easily adjusted to the above ranges.
In the work processing sheet of the present embodiment, the water contact angle of the surface of the adhesive layer opposite to the base material (hereinafter, sometimes referred to as "adhesive surface") is preferably 50 ° or more, particularly preferably 55 ° or more, and further preferably 60 ° or more. The water contact angle is preferably 80 ° or less, particularly preferably 75 ° or less, and further preferably 70 ° or less. When the water contact angle is 50 ° or more, the affinity of the adhesive layer for water does not become excessively high, and thus, when the workpiece processing sheet is used for cutting a cut object, penetration of water into the interface between the workpiece processing sheet and the cut object or the interface between the workpiece processing sheet and the obtained chip can be effectively suppressed. In addition, by setting the water contact angle to 80 ° or less, the adhesive layer exhibits a moderate affinity for water, and the adhesive adhering to the object to be cut can be effectively removed by flowing water. In the present specification, the water contact angle refers to a value measured before active energy rays are irradiated to a workpiece processing sheet. The details of the method for measuring the water contact angle are described in the test examples described below.
2. Component of sheet for processing workpiece
(1) Substrate material
In the work processing sheet of the present embodiment, the base material is not particularly limited as long as it exhibits a desired function in the work processing sheet use process, and preferably exhibits good transmittance for active energy rays irradiated for curing the adhesive layer.
For example, the base material is preferably a resin film mainly composed of a resin material, and specific examples thereof include an ethylene-vinyl acetate copolymer film; ethylene copolymer films such as ethylene- (meth) acrylic acid copolymer films, ethylene- (meth) acrylic acid methyl ester copolymer films, and other ethylene- (meth) acrylic acid ester copolymer films; polyolefin films such as polyethylene film, polypropylene film, polybutylene film, polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film, and norbornene resin film; polyvinyl chloride films such as polyvinyl chloride films and vinyl chloride copolymer films; polyethylene terephthalate film, polybutylene terephthalate film, polyethylene naphthalate and other polyester films; (meth) acrylate copolymer films; a polyurethane film; a polyimide film; a polystyrene film; a polycarbonate film; a fluororesin film, and the like. Examples of the polyethylene film include a Low Density Polyethylene (LDPE) film, a Linear Low Density Polyethylene (LLDPE) film, and a High Density Polyethylene (HDPE) film. In addition, modified membranes such as crosslinked membranes, ionomer membranes, and the like of the above membranes may also be used. The substrate may be a laminated film in which a plurality of the above films are laminated. In the laminated film, the materials constituting the respective layers may be the same or different. As the base material, an ethylene-methyl methacrylate copolymer film is preferably used from among the films described above in view of excellent flexibility. In the present specification, "meth) acrylic" refers to acrylic acid and methacrylic acid. Other similar terms are also the same.
The base material may contain various additives such as flame retardants, plasticizers, antistatic agents, lubricants, antioxidants, colorants, infrared absorbers, ultraviolet absorbers, ion capturing agents, and the like. The content of these additives is not particularly limited, but is preferably set in a range where the base material exhibits a desired function.
In order to improve the adhesion to the adhesive layer, the surface of the substrate on which the adhesive layer is laminated may be subjected to surface treatments such as primer treatment, corona treatment, and plasma treatment.
The thickness of the base material may be appropriately set according to the method of using the work piece, but is usually preferably 20 μm or more, and particularly preferably 25 μm or more. The thickness is usually 450 μm or less, and particularly 300 μm or less.
(2) Adhesive layer
In the sheet for workpiece processing of the present embodiment, the adhesive layer is not particularly limited as long as it is composed of an active energy ray-curable adhesive formed from an adhesive composition containing an acrylic copolymer containing an alkoxy (meth) acrylate as a monomer unit constituting a polymer and exhibiting a desired adhesive force to a cut object, and the sheet for workpiece processing can achieve the above-mentioned rate of decrease in adhesive force. When the adhesive layer is made of an active energy ray-curable adhesive, the adhesive layer can be cured by irradiation of active energy rays at the time of separating the cut object attached to the adhesive surface of the adhesive layer from the adhesive surface, and the adhesion of the workpiece processing sheet to the cut object can be reduced. This facilitates separation of the adhesive surface of the adhesive layer from the cut object.
The active energy ray-curable adhesive constituting the adhesive layer may contain a polymer having active energy ray-curability as a main component, or may contain a mixture of an inactive energy ray-curable polymer (a polymer having no active energy ray-curability) and a monomer and/or oligomer having at least one or more active energy ray-curable groups as a main component. In addition, the polymer may be a mixture of an active energy ray-curable polymer and a non-active energy ray-curable polymer. Further, the polymer may be a mixture of a polymer having active energy ray curability and a monomer and/or oligomer having at least one active energy ray curability group. Further, the polymer may be a mixture of an active energy ray-curable polymer, an inactive energy ray-curable polymer, and a monomer and/or oligomer having at least one active energy ray-curable group.
When the active energy ray-curable adhesive constituting the adhesive layer contains the polymer having active energy ray-curability, the monomer unit constituting the polymer preferably contains the (meth) acrylic acid alkoxy ester. When the active energy ray-curable adhesive constituting the adhesive layer contains the above-mentioned inactive energy ray-curable polymer, the monomer unit constituting the polymer preferably contains the above-mentioned (meth) acrylic acid alkoxy ester. These details are described below.
First, the case where the active energy ray-curable adhesive contains an active energy ray-curable polymer as a main component will be described below.
The polymer having active energy ray curability is preferably a (meth) acrylate (co) polymer (a) having an active energy ray-curable functional group (active energy ray-curable group) introduced into a side chain (hereinafter, sometimes referred to as "active energy ray-curable polymer (a)"). The active energy ray-curable polymer (a) is preferably obtained by reacting an acrylic copolymer (a 1) with an unsaturated group-containing compound (a 2), the acrylic copolymer (a 1) having a functional group-containing monomer unit, the unsaturated group-containing compound (a 2) having a functional group bonded to the functional group of (a 1).
The acrylic copolymer (a 1) preferably contains an alkoxy (meth) acrylate as a monomer unit constituting the polymer. Thus, when the workpiece processing sheet is used for cutting an object to be cut, the adhesive adhering to the object to be cut can be effectively and satisfactorily removed by flowing water. Specific examples of the alkoxy (meth) acrylate include 2-methoxyethyl (meth) acrylate, ethyl carbitol (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, and methoxyethylene glycol (meth) acrylate, and among them, 2-methoxyethyl (meth) acrylate is preferably used, and 2-methoxyethyl acrylate is particularly preferably used, from the viewpoint of easily obtaining the above-mentioned effects.
When the acrylic copolymer (a 1) contains an alkoxy (meth) acrylate as a monomer unit constituting the polymer, the content of the alkoxy (meth) acrylate is preferably 10% by mass or more, particularly preferably 20% by mass or more, and further preferably 30% by mass or more. The content of the alkoxy (meth) acrylate is preferably 85% by mass or less, particularly preferably 80% by mass or less, and further preferably 70% by mass or less. By setting the content of the (meth) acrylic acid alkoxy ester to 10 mass% or more, the adhesive layer easily has a predetermined hydrophilicity to water, and the adhesive adhering to the object to be cut can be easily removed by running water. Further, when the sheet for workpiece processing according to the present embodiment is used for cutting a workpiece to be cut, penetration of water into the interface between the sheet for workpiece processing and the workpiece to be cut or the interface between the sheet for workpiece processing and the obtained chip can be effectively suppressed by setting the content of the alkoxy (meth) acrylate to 85 mass% or less, the adhesive layer can be suppressed from exhibiting excessive affinity for water. In the present specification, the content (mass%) of the above-mentioned (meth) acrylic acid alkoxy ester means the content of all monomers constituting the acrylic copolymer (a 1). The content (mass%) of the other monomer described later also refers to the content of all the monomers constituting the acrylic copolymer (a 1).
In addition, it is also preferable that the acrylic copolymer (a 1) contains methyl acrylate as a monomer unit constituting the polymer. Since the hydrophilicity of the acrylic copolymer (a 1) can be improved as in the case of the methyl acrylate and the (meth) acrylic acid alkoxy ester, the effect of suppressing the penetration of water and the effect of removing the adhesive agent with running water can be more favorably achieved by containing the acrylic copolymer (a 1) with the (meth) acrylic acid alkoxy ester and the methyl acrylate as monomer units constituting the polymer.
When the acrylic copolymer (a 1) contains methyl acrylate as a monomer unit constituting the polymer, the content of methyl acrylate is preferably 10% by mass or more, particularly preferably 20% by mass or more, and further preferably 30% by mass or more. The content of methyl acrylate is preferably 85 mass% or less. By setting the content of methyl acrylate to the above content, the effect of suppressing the penetration of water and the effect of removing the adhesive agent with flowing water as described above can be more effectively achieved.
When the acrylic copolymer (a 1) contains an alkoxy (meth) acrylate and a methyl acrylate as monomer units constituting the polymer, the total content of the alkoxy (meth) acrylate and the methyl acrylate is preferably 10% by mass or more, particularly preferably 30% by mass or more, and further preferably 50% by mass or more. The total value is preferably 90 mass% or less, and particularly preferably 85 mass% or less. When the total value is within the above range, it is possible to effectively prevent water from penetrating into the interface between the workpiece processing sheet and the workpiece to be cut or the interface between the workpiece processing sheet and the obtained chip, and to easily remove the adhesive adhering to the workpiece by flowing water when the workpiece processing sheet of the present embodiment is used for cutting the workpiece to be cut.
In addition to the above-mentioned alkoxy (meth) acrylate and methyl acrylate, the acrylic copolymer (a 1) preferably further contains a structural unit derived from a functional group-containing monomer.
The functional group-containing monomer of the structural unit of the acrylic copolymer (a 1) is preferably a monomer having a polymerizable double bond in a molecule and a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group.
Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate, and these hydroxyl group-containing monomers may be used singly or in combination of two or more.
Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. These carboxyl group-containing monomers may be used alone or in combination of two or more.
Examples of the amino group-containing monomer or the substituted amino group-containing monomer include aminoethyl (meth) acrylate, n-butylaminoethyl (meth) acrylate, and the like. These amino group-containing monomers or substituted amino group-containing monomers may be used alone or in combination of two or more.
The acrylic copolymer (a 1) preferably contains 1% by mass or more, particularly preferably 5% by mass or more, and further preferably 10% by mass or more of a structural unit derived from the functional group-containing monomer. The acrylic copolymer (a 1) preferably contains 35% by mass or less, particularly preferably 30% by mass or less of a structural unit derived from the functional group-containing monomer.
In addition to the above-mentioned monomers, the acrylic copolymer (a 1) may contain a structural unit derived from a (meth) acrylic acid ester monomer other than methyl acrylate or a derivative thereof (hereinafter, sometimes referred to as "optional monomer").
As the (meth) acrylate monomer, in addition to the alkyl (meth) acrylate having 1 to 20 carbon atoms in the alkyl group, a monomer having an alicyclic structure in the molecule (alicyclic structure-containing monomer), for example, is preferably used.
As the alkyl (meth) acrylate, an alkyl (meth) acrylate having 1 to 18 carbon atoms in the alkyl group, for example, methyl methacrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, or the like is particularly preferably used, and at least one of methyl methacrylate and n-butyl acrylate is preferably used from the viewpoint of easy adjustment of the adhesive properties. These alkyl (meth) acrylates may be used singly or in combination of two or more.
As the alicyclic structure-containing monomer, for example, cyclohexyl (meth) acrylate, dicyclopentyl (meth) acrylate, adamantyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like are preferably used. These alicyclic structure-containing monomers may be used singly or in combination of two or more.
The acrylic copolymer (a 1) preferably contains 50% by mass or more, particularly preferably 60% by mass or more, and further preferably 70% by mass or more of the above-mentioned optional monomer. The content of the above-mentioned optional monomer is preferably 99% by mass or less, particularly preferably 95% by mass or less, and further preferably 90% by mass or less.
The acrylic copolymer (a 1) is preferably obtained by copolymerizing the above-mentioned (meth) acrylic acid alkoxy ester, methyl acrylate, functional group-containing monomer and any of the above-mentioned monomers by a conventional method, but dimethylacrylamide, vinyl formate, vinyl acetate, styrene and the like may be copolymerized in addition to these monomers.
The active energy ray-curable polymer (a) can be obtained by reacting the acrylic copolymer (a 1) having the functional group-containing monomer unit with the unsaturated group-containing compound (a 2) having the functional group bonded to the functional group of (a 1).
The functional group of the unsaturated group-containing compound (a 2) may be appropriately selected depending on the kind of the functional group-containing monomer unit of the acrylic copolymer (a 1). For example, when the functional group of the acrylic copolymer (a 1) is a hydroxyl group, an amino group or a substituted amino group, the functional group of the unsaturated group-containing compound (a 2) is preferably an isocyanate group or an epoxy group, and when the functional group of the acrylic copolymer (a 1) is an epoxy group, the functional group of the unsaturated group-containing compound (a 2) is preferably an amino group, a carboxyl group or an aziridine group.
The unsaturated group-containing compound (a 2) contains at least 1, preferably 1 to 6, more preferably 1 to 4, active energy ray polymerizable carbon-carbon double bonds in one molecule. Specific examples of the unsaturated group-containing compound (a 2) include, for example, 2-methacryloxyethyl isocyanate, m-isopropenyl- α, α -dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1- (bisacryloxymethyl) ethyl isocyanate; an acryl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth) acrylate; an acryl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth) acrylate; glycidyl (meth) acrylate; (meth) acrylic acid, 2- (1-aziridinyl) ethyl (meth) acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, and the like.
The unsaturated group-containing compound (a 2) is used in a proportion of preferably 50 mol% or more, particularly preferably 60 mol% or more, and further preferably 70 mol% or more, based on the number of moles of the functional group-containing monomer of the acrylic copolymer (a 1). The unsaturated group-containing compound (a 2) is used preferably in an amount of 95 mol% or less, particularly preferably 93 mol% or less, and further preferably 90 mol% or less, based on the number of moles of the functional group-containing monomer of the acrylic copolymer (a 1).
In the reaction of the acrylic copolymer (a 1) and the unsaturated group-containing compound (a 2), the temperature, pressure, solvent, time, presence or absence of a catalyst, and the type of catalyst may be appropriately selected according to the combination of the functional group of the acrylic copolymer (a 1) and the functional group of the unsaturated group-containing compound (a 2). Thus, the functional group present in the acrylic copolymer (a 1) is reacted with the functional group in the unsaturated group-containing compound (a 2), and the unsaturated group is introduced into the side chain in the acrylic copolymer (a 1), to obtain the active energy ray-curable polymer (a).
The weight average molecular weight (Mw) of the active energy ray-curable polymer (a) thus obtained is preferably 1 ten thousand or more, particularly preferably 15 ten thousand or more, and further preferably 20 ten thousand or more. The weight average molecular weight (Mw) is preferably 150 ten thousand or less, and particularly preferably 100 ten thousand or less. The weight average molecular weight (Mw) in the present specification is a value in terms of standard polystyrene measured by Gel Permeation Chromatography (GPC).
Even in the case where the active energy ray-curable adhesive contains a polymer having active energy ray-curability such as the active energy ray-curable polymer (a) as a main component, the active energy ray-curable adhesive may further contain an active energy ray-curable monomer and/or oligomer (B).
As the active energy ray-curable monomer and/or oligomer (B), for example, an ester of a polyol and (meth) acrylic acid or the like can be used.
Examples of the active energy ray-curable monomer and/or oligomer (B) include monofunctional acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; polyfunctional acrylates such as trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and dimethyloltricyclodecane di (meth) acrylate; polyester oligo (meth) acrylate, polyurethane oligo (meth) acrylate, and the like.
When the active energy ray-curable monomer and/or oligomer (B) is blended with the active energy ray-curable polymer (a), the content of the active energy ray-curable monomer and/or oligomer (B) in the active energy ray-curable adhesive is preferably more than 0 part by mass, particularly preferably 60 parts by mass or more, per 100 parts by mass of the active energy ray-curable polymer (a). The content is preferably 250 parts by mass or less, particularly preferably 200 parts by mass or less, based on 100 parts by mass of the active energy ray-curable polymer (a).
Here, when ultraviolet rays are used as active energy rays for curing the active energy ray-curable adhesive, it is preferable to add a photopolymerization initiator (C), and by using the photopolymerization initiator (C), the polymerization curing time and the light irradiation amount can be reduced.
Specific examples of the photopolymerization initiator (C) include benzophenone, acetophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid methyl ester, benzoin dimethyl ketal, 2, 4-diethylthioxanthone, 1-hydroxycyclohexylphenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzil, dibenzoyl, butanedione, β -chloroanthraquinone, (2, 4, 6-trimethylbenzyl diphenyl) phosphine oxide, N-diethyldithiocarbamic acid-2-benzothiazole, oligo { 2-hydroxy-2-methyl-1- [4- (1-propenyl) phenyl ] propanone }, 2-dimethoxy-1, 2-diphenylethane-1-one, and the like. These photopolymerization initiators may be used alone or in combination of two or more.
The photopolymerization initiator (C) is preferably used in an amount of 0.1 part by mass or more, particularly preferably 0.5 part by mass or more, per 100 parts by mass of the active energy ray-curable polymer (a) (when the active energy ray-curable monomer and/or oligomer (B) is blended, the total amount of the active energy ray-curable polymer (a) and the active energy ray-curable monomer and/or oligomer (B) is 100 parts by mass. When the active energy ray-curable monomer and/or oligomer (B) is blended with 100 parts by mass of the active energy ray-curable polymer (a), the photopolymerization initiator (C) is preferably used in an amount of 10 parts by mass or less, particularly preferably 6 parts by mass or less, relative to 100 parts by mass of the total amount of the active energy ray-curable polymer (a) and the active energy ray-curable monomer and/or oligomer (B).
In addition to the above components, other components may be appropriately blended in the active energy ray-curable adhesive. Examples of the other component include an inactive energy ray-curable polymer component (D) and an oligomer component (E).
Examples of the inactive energy ray-curable polymer component or oligomer component (D) include polyacrylate, polyester, polyurethane, polycarbonate, polyolefin, and the like, and polymers or oligomers having a weight average molecular weight (Mw) of 3000 to 250 ten thousand are preferable. By blending this component (D) into the active energy ray-curable adhesive, the adhesiveness and peelability before curing, the strength after curing, the adhesiveness to other layers, the storage stability, and the like can be improved. The blending amount of the component (D) is not particularly limited, and may be appropriately determined within a range of more than 0 parts by mass and 50 parts by mass or less with respect to 100 parts by mass of the active energy ray-curable polymer (a).
As the crosslinking agent (E), a polyfunctional compound reactive with the functional group of the active energy ray-curable polymer (a) or the like can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, reactive phenolic resins, and the like.
The blending amount of the crosslinking agent (E) is preferably 0.01 parts by mass or more, particularly preferably 3 parts by mass or more, relative to 100 parts by mass of the active energy ray-curable polymer (a). The blending amount of the crosslinking agent (E) is preferably 20 parts by mass or less, particularly preferably 17 parts by mass or less, per 100 parts by mass of the active energy ray-curable polymer (a).
Next, a case will be described below in which the active energy ray-curable adhesive contains, as a main component, a mixture of an inactive energy ray-curable polymer component and a monomer and/or oligomer having at least one active energy ray-curable group.
As the inactive energy ray-curable polymer component, for example, the same component as the acrylic copolymer (a 1) can be used.
The monomer and/or oligomer having at least one active energy ray-curable group may be selected from the same components as the component (B). The blending ratio of the inactive energy ray-curable polymer component and the monomer and/or oligomer having at least one active energy ray-curable group is preferably 1 part by mass or more, particularly preferably 60 parts by mass or more, with respect to 100 parts by mass of the inactive energy ray-curable polymer component. Further, the blending ratio is preferably 200 parts by mass or less, particularly preferably 160 parts by mass or less of a monomer and/or oligomer having at least one active energy ray-curable group per 100 parts by mass of the inactive energy ray-curable polymer component.
In this case, the photopolymerization initiator (C) and the crosslinking agent (E) may be appropriately blended in the same way as described above.
The thickness of the adhesive layer is preferably 1 μm or more, and particularly preferably 5 μm or more. The thickness is preferably 50 μm or less, and particularly preferably 40 μm or less. By setting the thickness of the adhesive layer to the above range, the above reduction ratio of the adhesive force can be easily achieved.
(3) Stripping sheet
In the work processing sheet of the present embodiment, a release sheet may be laminated on the surface of the adhesive layer for the purpose of protecting the adhesive surface until the adhesive layer is attached to the object to be cut. The release sheet may be any one, and examples thereof include a release sheet in which a plastic film is peeled with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin films such as polypropylene and polyethylene. As the stripping agent, silicone, fluorine, long chain alkyl, and the like can be used, and among them, silicone which is inexpensive and can obtain stable performance is preferable. The thickness of the release sheet is not particularly limited, but is usually 20 μm or more and 250 μm or less.
(4) Other components
In the work processing sheet of the present embodiment, the pressure-sensitive adhesive layer may be laminated on the adhesive surface of the pressure-sensitive adhesive layer. In this case, the work processing sheet of the present embodiment may be used as a dicing die bonding (die bonding) sheet by providing the adhesive layer as described above. The cut object is attached to a surface of the adhesive layer of the work processing sheet opposite to the adhesive layer, and the adhesive layer is cut together with the cut object, whereby a chip having the adhesive layer laminated with singulation can be obtained. The chip can be easily fixed to an object on which the chip is mounted by using the singulated adhesive layer. As a material constituting the adhesive layer, a material containing a thermoplastic resin and a thermosetting adhesive component having a low molecular weight, a material containing a thermosetting adhesive component in a B-stage (semi-cured state), or the like is preferably used.
In the work processing sheet according to the present embodiment, a protective film forming layer may be laminated on the adhesive surface of the adhesive layer. In this case, the workpiece processing sheet according to the present embodiment can be used as a protective film forming and cutting sheet. The cut object is attached to the surface of the protective film forming layer of the work sheet opposite to the adhesive layer, and the protective film forming layer is cut together with the cut object, whereby a chip having the protective film forming layer laminated with the individual protective film forming layers can be obtained. As the object to be cut, an object to be cut having a circuit formed on one surface is preferably used, and in this case, a protective film formation layer is generally laminated on a surface opposite to the surface on which the circuit is formed. By curing the singulated protective film forming layer at a prescribed point in time, a protective film having sufficient durability can be formed on the chip. The protective film forming layer is preferably formed of an uncured curable adhesive.
In addition, the work processing sheet according to the embodiment of the present application satisfies the reduction ratio of the adhesive force, but when the adhesive layer or the protective film forming layer is laminated on the adhesive layer, the adhesive layer before lamination of these layers may satisfy the adhesive force.
3. Method for manufacturing sheet for processing workpiece
The method for producing the workpiece processing sheet of the present embodiment is not particularly limited, and the workpiece processing sheet of the present embodiment is preferably produced by laminating an adhesive layer on one side of a base material.
The adhesive layer may be laminated on one side of the substrate using known methods. For example, it is preferable to transfer the adhesive layer formed on the release sheet to one side of the substrate. In this case, a coating liquid containing an adhesive composition constituting the adhesive layer and a solvent or a dispersion medium further contained as needed can be prepared by preparing a coating liquid, and applying the coating liquid to a surface of a release sheet subjected to a release treatment (hereinafter, sometimes referred to as a "release surface") by a die coater, a curtain coater, a spray coater, a slit coater, a doctor blade coater, or the like, to form a coating film, and drying the coating film. The properties of the coating liquid are not particularly limited as long as the coating liquid can be applied, and may contain a component for forming an adhesive layer as a solute or a component for forming an adhesive layer as a dispersion medium. The release sheet in the laminate may be peeled off as a process material, or may be used to protect the adhesive surface of the adhesive layer until the work piece processing sheet is attached to the cut object.
When the coating liquid for forming the adhesive layer contains a crosslinking agent, the active energy ray-curable polymer (a) or the inactive energy ray-curable polymer in the coating film may be crosslinked with the crosslinking agent by changing the drying conditions (temperature, time, etc.) or by additionally providing a heat treatment, and a crosslinked structure may be formed in the adhesive layer at a desired existing density. In order to sufficiently carry out the crosslinking reaction, the adhesive layer is laminated on the base material by the above-mentioned method or the like, and the obtained sheet for processing a work is cured by standing for several days at 23 ℃ under an environment having a relative humidity of 50%, for example.
Instead of the method of transferring the adhesive layer formed on the release sheet to the one side of the substrate as described above, the adhesive layer may be formed directly on the substrate. At this time, the adhesive layer is formed by applying the coating liquid for forming the adhesive layer to one side of the substrate to form a coating film and drying the coating film.
4. Method for using workpiece processing sheet
The workpiece processing sheet according to the present embodiment can be used for processing a workpiece (cut object). That is, the adhesive surface of the workpiece processing sheet according to the present embodiment can be attached to the workpiece, and then the workpiece can be processed on the workpiece processing sheet. According to this processing, the workpiece processing sheet of the present embodiment can be used as a back grinding sheet, a dicing sheet, an expanding sheet, a pickup sheet, or the like. Examples of the object to be cut include semiconductor members such as a semiconductor wafer and a semiconductor package; glass members such as glass plates.
Further, when the work processing sheet of the present embodiment is provided with the above-described adhesive layer, the work processing sheet can be used as a dicing die bonding sheet. Further, when the workpiece processing sheet of the present embodiment is provided with the protective film forming layer, the workpiece processing sheet can be used as a protective film forming and cutting sheet.
Even when the adhesive agent derived from the adhesive agent layer adheres to the cut object, the workpiece processing sheet of the present embodiment is easy to remove the adhesive agent by flowing water, and at the same time, can suppress infiltration of water due to the flowing water into the interface between the workpiece processing sheet and the cut object or the interface between the workpiece processing sheet and the obtained chip. Therefore, the workpiece processing sheet according to the present embodiment is suitably used for processing using flowing water, and particularly suitably used for cutting accompanied by supplying flowing water to a cutting portion. That is, the workpiece processing sheet of the present embodiment is suitably used as a dicing sheet.
When the workpiece processing sheet according to the present embodiment is used as a dicing sheet, normal conditions can be used as conditions for dicing and conditions for supplying running water. In particular, as for the supply conditions of the flowing water, pure water or the like is preferably used as the water to be used. The water supply amount is preferably 0.5L/min or more, and particularly preferably 1L/min or more. The water supply amount is preferably 2.5L/min or less, and particularly preferably 2L/min or less. The temperature of the water is not particularly limited, and is preferably, for example, about room temperature.
[ method for producing processed workpiece ]
The method for manufacturing a machined workpiece according to one embodiment of the present invention includes the steps of: a bonding step of bonding a surface of the adhesive layer of the workpiece processing sheet, which is opposite to the base material, to a workpiece; a processing step of processing a workpiece on a workpiece processing sheet to obtain a processed workpiece laminated on the workpiece processing sheet; an irradiation step of irradiating the adhesive layer with active energy rays to cure the adhesive layer, thereby reducing the adhesion of the workpiece processing sheet to the processed workpiece; and a separation step of separating the processed workpiece from the workpiece processing sheet irradiated with the active energy rays.
The workpiece processing sheet used in the method for manufacturing a processed workpiece according to the present embodiment can satisfactorily remove an adhesive adhering to a workpiece when the workpiece is processed by running water while suppressing penetration of water into an interface between the workpiece processing sheet and the workpiece or between the workpiece processing sheet and the processed workpiece. Therefore, according to the method for manufacturing a machined workpiece of the present embodiment, the machined workpiece can be efficiently manufactured.
Hereinafter, each step of the method for manufacturing a machined workpiece according to the present embodiment will be described.
(1) Bonding step
The bonding of the workpiece and the workpiece processing sheet in the bonding step can be performed by a conventionally known method. In addition, when cutting the workpiece in the subsequent processing step, it is preferable that the annular frame is bonded to the outer peripheral region of the region bonded to the workpiece in the surface of the adhesive layer side of the workpiece processing sheet. The workpiece to be used may be a desired workpiece corresponding to a machined workpiece to be manufactured, and as a specific example, the above-described workpiece may be used.
(2) Processing procedure
In the machining step, a workpiece may be subjected to a desired machining, for example, back grinding, cutting, or the like. These processes can be performed by conventionally known methods.
In addition, when cutting with a blade using a rotary blade is performed as the above-described processing, generally, a part of the adhesive layer of the workpiece processing sheet is cut together with the workpiece. At this time, the adhesive constituting the adhesive layer may be rolled up by the blade and attached to the work piece. However, as described above, the workpiece processing sheet used in the method for producing a processed workpiece according to the present embodiment can satisfactorily remove the adhering adhesive by flowing water. From this point of view, the processing in the present embodiment is suitably cutting, and particularly, cutting with a blade using a rotary blade.
(3) Irradiation step
In the irradiation step, the irradiation condition of the active energy ray is not limited as long as the adhesion of the workpiece processing sheet to the processed workpiece can be reduced to a desired extent, and the irradiation can be performed by a conventionally known method. Examples of the type of active energy ray used include ionizing radiation, that is, X-rays, ultraviolet rays, electron beams, and the like, and among them, ultraviolet rays that are relatively easy to introduce into the irradiation apparatus are preferable.
(4) Separation process
In the separation step, separation is performed by a method corresponding to the type of processing or the processed workpiece obtained. For example, when dicing is performed as processing and chips obtained by singulating a workpiece by the dicing are obtained, the obtained chips are picked up one by one from a workpiece processing sheet using a conventionally known pickup device. In order to facilitate this pickup, the work processing sheet may be expanded to separate the processed works from each other.
(5) Others
In the method for manufacturing a machined workpiece according to the present embodiment, steps other than the above steps may be provided. For example, a conveying step of conveying the obtained laminate of the workpiece and the workpiece processing sheet to a predetermined position, a storage step of storing the laminate for a predetermined period, and the like may be provided after the bonding step. Further, a mounting step of mounting the obtained machined workpiece on a predetermined base plate or the like may be provided after the separation step.
The embodiments described above are described for easy understanding of the present invention, and are not described for limiting the present invention. Accordingly, each element disclosed in the above embodiments also covers all design changes and equivalents that fall within the technical scope of the present invention.
For example, another layer may be provided between the substrate and the adhesive layer or on the surface of the substrate opposite to the adhesive layer.
Examples
The present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited to these examples.
Example 1
(1) Preparation of adhesive composition
An acrylic copolymer obtained by copolymerizing 60 parts by mass of methyl acrylate, 20 parts by mass of 2-methoxyethyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate was reacted with 21.4g (corresponding to 80 mol% relative to the number of moles of 2-hydroxyethyl acrylate) of methacryloxyethyl isocyanate (MOI) per 100g of the acrylic copolymer to obtain an active energy ray-curable polymer. The weight average molecular weight (Mw) of the active energy ray-curable polymer was measured by the method described below, and found to be 60 ten thousand.
100 parts by mass (solid content equivalent, hereinafter the same) of the obtained active energy ray-curable polymer, 3 parts by mass of 1-hydroxycyclohexyl phenyl ketone (product name "IRGACURE 184" manufactured by basf corporation) as a photopolymerization initiator, and 12.43 parts by mass of toluene diisocyanate (product name "CORONATE L" manufactured by TOSOH CORPORATION) as a crosslinking agent were mixed in a solvent to obtain an adhesive composition.
(2) Formation of adhesive layer
The adhesive composition was applied to a release sheet (manufactured by LINTEC CORPORATION, product name "SP-PET 381031") having a silicone-based release agent layer formed on one surface of a polyethylene terephthalate film having a thickness of 38 μm, and the release sheet was dried by heating and cured under conditions of 23 ℃ and 50% rh for 7 days, whereby an adhesive layer having a thickness of 5 μm was formed on the release sheet.
(3) Production of sheet for workpiece processing
The adhesive layer formed in the step (2) was bonded to one surface of an ethylene-methacrylic acid copolymer (EMAA) film having a thickness of 80 μm as a base material on the side opposite to the release sheet, thereby obtaining a sheet for workpiece processing.
Here, the weight average molecular weight (Mw) is a weight average molecular weight in terms of standard polystyrene measured using gel permeation chromatography (GPC measurement).
Examples 2 to 7 and comparative examples 1 to 3
A sheet for workpiece processing was produced in the same manner as in example 1, except that the composition of the acrylic copolymer was changed to that shown in table 1 and the content of the crosslinking agent was changed to that shown in table 2.
[ test example 1] (measurement of Water contact Angle)
The release sheet was peeled from the work processing sheet produced in examples and comparative examples, and the water contact angle (°) of the exposed surface of the exposed adhesive layer was measured using a fully automatic contact angle meter (Kyowa Interface Science, manufactured by Inc, product name "DM-701"), under the following conditions. The results are shown in Table 3.
Drop amount of purified water: 2 μl
Measurement time: after 3 seconds of dripping
Image analysis method: theta/2 process
Test example 2 (measurement of adhesion)
The release sheet was peeled from the work processing sheet produced in examples and comparative examples, the exposed surface of the exposed adhesive layer was laminated on the mirror surface of the mirror-finished 6-inch silicon wafer, and the lamination was carried out by once reciprocating a 2kg roller, and the lamination was carried out for 20 minutes. Then, the work piece processing sheet was peeled from the silicon wafer at a peeling speed of 300 mm/min and a peeling angle of 180 °, and the adhesion F1 (mN/25 mm) to the silicon wafer was measured by a 180 ° peeling method based on JIS Z0237:2009. The results are shown in Table 3.
The release sheet was peeled off from the work piece processing sheet produced in examples and comparative examples, and the exposed surface of the exposed adhesive layer was immersed in distilled water at 23 ℃ for 12 hours, and then dried at 23 ℃ for 24 hours. Then, the exposed surface was laminated on the mirror surface of the mirror-finished 6-inch silicon wafer, and the laminate was allowed to stand for 20 minutes by applying a load by once reciprocating a 2kg roller. Then, the work piece processing sheet was peeled from the silicon wafer at a peeling speed of 300 mm/min and a peeling angle of 180 °, and the adhesion F2 (mN/25 mm) to the silicon wafer after the dipping and drying was measured by a 180 ° peeling method based on JIS Z0237:2009. The results are shown in Table 3.
Further, the decrease rate (%) of the adhesive force was calculated from the following formula (1) using the values of the adhesive force F1 (mN/25 mm) and the adhesive force F2 (mN/25 mm) obtained in the above-described manner. The results are shown in Table 3.
Reduction in adhesion (%) = { (F1-F2)/F1 } ×100·· (1)
Test example 3 (evaluation of adhesive removing Property)
The adhesive compositions prepared in examples and comparative examples were applied to the release surface of a release sheet (manufactured by LINTEC CORPORATION, product name "SP-PET 381031") having a silicone-based release agent layer formed on one side of a polyethylene terephthalate film having a thickness of 38 μm, and dried by heating, whereby an adhesive layer having a thickness of 5 μm was formed on the release sheet. From the laminate of the adhesive layer and the release sheet obtained in this way, 20 pieces of the laminate having dimensions of 5mm×5mm were cut.
Next, the adhesive layer side surfaces of the 20 chips obtained in the above manner were each attached to a polished surface of a 6-inch silicon wafer (thickness: 150 μm) polished by #2000, and then release sheets were each peeled from the adhesive layer. In the attaching, the chips are attached so that the distance between the chips is 1mm or more.
Then, the release sheet was peeled off from the work processing sheet produced in the examples and comparative examples, and the surface of the 6-inch silicon wafer opposite to the surface to which the die was attached to the exposed surface of the adhesive layer using a die bonder (manufactured by LINTEC CORPORATION under the product name "Adwill RAD2500 m/12"). Next, a dicing apparatus (manufactured by DISCO Corporation, product name "DFD-6361") was used to perform an operation simulating dicing from the 6-inch silicon wafer side while supplying running water to the dicing portion under the following operation conditions.
< operating Condition >
Cutting device: DISCO Corporation DFD-6361
Blade: DISCO Corporation NBC-2H 2050 27HECC
Blade width: 0.025 to 0.030mm
Blade extension: 0.640-0.760 mm
Blade rotation speed: 50000rpm
Cutting speed: 20 mm/sec
Blade height (blade height): 5mm of
Running water supply amount: 1.0L/min
Running water temperature: room temperature
Cut size: 10mm by 10mm
In addition, the "blade height: by 5mm "is meant that the distance between the blade and the 6 inch silicon wafer is set to 5mm, and it is understood that the 6 inch silicon wafer is not cut by the blade in the above operation.
After the dicing was completed, it was confirmed whether or not the adhesive derived from the above-mentioned small pieces remained on the silicon wafer, and the removability of the adhesive was evaluated based on the following criteria. The results are shown in Table 3.
O: the adhesive was completely free of residue.
X: at least a portion of the adhesive remains.
Test example 4 (evaluation of Water penetration)
The release sheet was released from the work processing sheets produced in examples and comparative examples, and a polished surface of a #2000 polished 6-inch silicon wafer (thickness: 150 μm) was attached to the exposed surface of the adhesive layer using a die bonder (manufactured by LINTEC CORPORATION under the product name "Adwill RAD2500 m/12"). Next, a dicing apparatus (manufactured by DISCO Corporation, product name "DFD-6361") was used to cut the wafer from the 6-inch silicon wafer side while supplying running water to the dicing portion under the following dicing conditions.
< cutting Condition >
Cutting device: DISCO Corporation DFD-6361
Blade: DISCO Corporation NBC-2H 2050 27HECC
Blade width: 0.025 to 0.030mm
Blade extension: 0.640-0.760 mm
Blade rotation speed: 50000rpm
Cutting speed: 20 mm/sec
Incision depth: 15 μm from the surface of the adhesive layer side of the sheet for workpiece processing
Running water supply amount: 1.0L/min
Running water temperature: room temperature
Cut size: 10mm by 10mm
After the dicing was completed, all the chips obtained were removed from the work piece processing sheet, and the adhesive layer side surface of the work piece processing sheet was observed by a digital microscope (manufactured by KEYENCE corporation, product name "VHX-1000", magnification: 500 times), and water penetration at the interface between the chips and the work piece processing sheet was evaluated according to the following criteria. The results are shown in Table 3.
O: there is no trace of water penetration on the adhesive layer side surface of the sheet for workpiece processing.
X: the adhesive layer side surface of the work piece processing sheet has a trace of water penetration.
Further, the abbreviations and the like described in table 1 are shown in detail below.
BA: acrylic acid n-butyl ester
MMA: methyl methacrylate
MA: acrylic acid methyl ester
2MEA: acrylic acid 2-methoxyethyl ester
HEA: acrylic acid 2-hydroxy ethyl ester
MOI: methacryloxyethyl isocyanate
TABLE 1
TABLE 2
TABLE 3
As is clear from table 3, the work piece processing sheet obtained in the examples can satisfactorily remove the adhesive agent by flowing water and simultaneously satisfactorily suppress infiltration of water.
Industrial applicability
The workpiece processing sheet of the present invention can be suitably used for cutting.
Claims (6)
1. A workpiece processing sheet comprising a base material and an adhesive layer laminated on one side of the base material, characterized in that,
the adhesive layer is composed of an active energy ray-curable adhesive,
the active energy ray-curable adhesive is formed from an adhesive composition containing an acrylic copolymer composed of an alkoxy (meth) acrylate and a monomer other than the alkoxy (meth) acrylate as monomer units constituting the polymer,
the alkoxy (meth) acrylate is 2-methoxyethyl acrylate, and the content of the alkoxy (meth) acrylate in the acrylic copolymer is 10 to 85 parts by mass inclusive;
the monomer except (methyl) acrylic acid alkoxy ester is acrylic acid 2-hydroxy ethyl ester; and at least one monomer selected from n-butyl acrylate, methyl methacrylate and methyl acrylate,
The content of 2-hydroxyethyl acrylate in the acrylic copolymer is 1 to 35 parts by mass,
assuming that the adhesion of the workpiece processing sheet to a silicon wafer is F1, and the adhesion of the workpiece processing sheet to a silicon wafer after being immersed in distilled water at 23 ℃ for 12 hours and being dried at 23 ℃ for 24 hours is F2, the reduction ratio of the adhesion calculated by the following formula (1) is 20% to 50%,
the reduction in adhesion (%) = { (F1-F2)/F1 } ×100·· (1).
2. The sheet for workpiece processing according to claim 1, wherein a water contact angle of a surface of the adhesive layer opposite to the base material is 50 ° or more and 80 ° or less.
3. The sheet for workpiece processing according to claim 1, wherein the adhesive force F1 is 1000mN/25mm to 10000mN/25 mm.
4. The sheet for workpiece processing according to claim 1, wherein the adhesive force F2 is 900mN/25mm to 8000mN/25 mm.
5. The workpiece processing sheet according to claim 1, which is a cut sheet.
6. A method for manufacturing a processed workpiece is characterized by comprising:
A bonding step of bonding a surface of the adhesive layer of the workpiece processing sheet according to any one of claims 1 to 5, which is opposite to the base material, to a workpiece;
a processing step of processing the workpiece on the workpiece processing sheet to obtain a processed workpiece laminated on the workpiece processing sheet;
an irradiation step of irradiating the adhesive layer with an active energy ray to cure the adhesive layer, thereby reducing the adhesion of the workpiece processing sheet to the processed workpiece; a kind of electronic device with high-pressure air-conditioning system
And a separation step of separating the workpiece from the workpiece processing sheet after irradiation with the active energy rays.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017235376 | 2017-12-07 | ||
| JP2017-235376 | 2017-12-07 | ||
| PCT/JP2018/043552 WO2019111759A1 (en) | 2017-12-07 | 2018-11-27 | Sheet for workpiece processing and manufacturing method of processed workpiece |
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| CN111164737A CN111164737A (en) | 2020-05-15 |
| CN111164737B true CN111164737B (en) | 2023-08-29 |
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| CN201880063268.6A Active CN111164737B (en) | 2017-12-07 | 2018-11-27 | Workpiece processing sheet and method for manufacturing processed workpiece |
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| JP (1) | JP7086103B2 (en) |
| KR (1) | KR102579055B1 (en) |
| CN (1) | CN111164737B (en) |
| TW (1) | TWI782146B (en) |
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| WO2022138459A1 (en) * | 2020-12-25 | 2022-06-30 | 日東電工株式会社 | Resin composition |
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| CN1865376A (en) * | 2005-05-16 | 2006-11-22 | 日东电工株式会社 | Pressure-sensitive adhesive sheet for use in dicing and method of processing products worked with it |
| CN101542689A (en) * | 2007-04-20 | 2009-09-23 | 日东电工株式会社 | Pressure-sensitive adhesive sheet for water jet laser dicing |
| CN101831261A (en) * | 2009-03-03 | 2010-09-15 | 日立麦克赛尔株式会社 | Radiation-curable adhesion agent composition, cutting adhesive film, cut off machine method for making |
| JP2011184576A (en) * | 2010-03-09 | 2011-09-22 | Hitachi Maxell Ltd | Radiation-curable self-adhesive composition, self-adhesive film for dicing using the same, and method for producing cut piece |
| CN107112228A (en) * | 2015-03-02 | 2017-08-29 | 古河电气工业株式会社 | The processing method of semiconductor wafer surface protection adhesive tape and semiconductor wafer |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPS5352496Y2 (en) | 1973-06-21 | 1978-12-15 | ||
| JP6390034B2 (en) | 2014-08-01 | 2018-09-19 | リンテック株式会社 | Adhesive sheet |
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2018
- 2018-11-27 WO PCT/JP2018/043552 patent/WO2019111759A1/en active Application Filing
- 2018-11-27 CN CN201880063268.6A patent/CN111164737B/en active Active
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- 2018-11-27 JP JP2019558149A patent/JP7086103B2/en active Active
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1865376A (en) * | 2005-05-16 | 2006-11-22 | 日东电工株式会社 | Pressure-sensitive adhesive sheet for use in dicing and method of processing products worked with it |
| CN101542689A (en) * | 2007-04-20 | 2009-09-23 | 日东电工株式会社 | Pressure-sensitive adhesive sheet for water jet laser dicing |
| CN101831261A (en) * | 2009-03-03 | 2010-09-15 | 日立麦克赛尔株式会社 | Radiation-curable adhesion agent composition, cutting adhesive film, cut off machine method for making |
| JP2011184576A (en) * | 2010-03-09 | 2011-09-22 | Hitachi Maxell Ltd | Radiation-curable self-adhesive composition, self-adhesive film for dicing using the same, and method for producing cut piece |
| CN107112228A (en) * | 2015-03-02 | 2017-08-29 | 古河电气工业株式会社 | The processing method of semiconductor wafer surface protection adhesive tape and semiconductor wafer |
Also Published As
| Publication number | Publication date |
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| TW201927980A (en) | 2019-07-16 |
| CN111164737A (en) | 2020-05-15 |
| JP7086103B2 (en) | 2022-06-17 |
| KR102579055B1 (en) | 2023-09-15 |
| JPWO2019111759A1 (en) | 2020-12-10 |
| TWI782146B (en) | 2022-11-01 |
| WO2019111759A1 (en) | 2019-06-13 |
| KR20200095453A (en) | 2020-08-10 |
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