Kit for forming a laminate body including a light-to-heat conversion layer, a laminate body including a light-to-heat conversion layer, and a manufacturing method thereof

Abstract

A kit for forming a laminate body including a light-to-heat conversion layer comprises a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound, a light-to-heat conversion layer ink composition containing a thermally decomposable light absorbing agent and a binder or precursor thereof, and a curing accelerator containing a β-dicarbonyl compound or salt thereof. The laminate body can be rapidly cured at room temperature or by relatively gentle heating without requiring UV irradiation, and which allows long-term storage at room temperature and a long usable life.

Description

[0001] KIT FOR FORMING A LAMINATE BODY INCLUDING A LIGHT-TO-HEAT CONVERSION LAYER, A LAMINATE BODY INCLUDING A LIGHT-TO-HEAT CONVERSION LAYER, AND A MANUFACTURING METHOD THEREOF

[0002] Field of the Invention

[0003] The present disclosure relates to a kit for forming a laminate body including a light-to-heat conversion layer, a laminate body including a light-to-heat conversion layer, and a method for producing the same. Furthermore, the present disclosure also relates to a method for producing a thinned base material using the laminate body, and a method for producing a semiconductor substrate laminate body.

[0004] Conventional Technology

[0005] In the semiconductor industry, in order to meet the demand for thinner packages and higher density through chip stacking technology, semiconductor wafers are being made thinner by grinding the surface opposite to the surface on which patterns are formed, which is known as back surface grinding. Conventional technology in which the wafer is supported only by protective tape during back surface grinding and transport processes is insufficient to meet the requirements of various newly proposed manufacturing processes. Therefore, a technique has been proposed in which the semiconductor wafer is supported on a hard transparent supporting body, such as a glass substrate or the like having a light-to- heat conversion (LTHC) layer, via an adhesive during back surface grinding and, if necessary, subsequent steps, and the light-to-heat conversion layer is finally destroyed by laser scanning, thereby separating the semiconductor wafer, or a semiconductor chip obtained by dicing the semiconductor wafer, from the support without stress.

[0006] Patent Document 1 (Japanese Unexamined Patent Application Publication 2004-064040) describes “a laminate body including a base material for grinding, a bonding layer in contact with the base material for grinding, a photothermal conversion layer containing a light absorbing agent and a thermally decomposable resin, and a light-transmitting supporting body, wherein the light-to-heat conversion layer decomposes when irradiated with radiant energy after grinding the surface of the base material for grinding on the opposite side as the bonding layer, thereby separating the base material after grinding from the light-transmitting supporting body”.

[0007] Patent Document 2 (Japanese PCT Patent Application Publication 2013-534721) describes “a laminate body including a substrate, a bonding layer located adjacent to the substrate, a light-to-heat conversion layer located adjacent to the bonding layer and including a metal absorption layer, and a lighttransmitting supporting body located adjacent to the light-to-heat conversion layer”.

[0008] Patent Document 3 (Japanese Unexamined Patent Application Publication 2019-189868) describes a method for temporarily bonding a workpiece, comprising: a bonding step of forming a bonding layer on a surface of at least one substrate and / or at least one workpiece; an adhering step of adhering and bonding the substrate and the workpiece using the bonding layer; a processing step of processing the workpiece; and a peeling step of irradiating the bonding layer with a laser to separate the workpiece from the substrate; wherein the bonding layer is made of an adhesive containing a polymer and a light absorbing substance; the solid fraction of the adhesive contains 50 wt.% to 98 wt.% polymer; the solid fraction of the adhesive contains 2 wt.% to 50 wt.% light absorbing substance; the polymer is a polyimide or (amic acid / imide) copolymer; the skeleton of the polymer contains 5 wt.% to 45 wt.% of hydroxyl-containing units, and further contains 5 wt.% to 40 wt.% of aliphatic ether-containing units or siloxane-containing unit; and the cyclization rate of the polymer is 90% or more.

[0009] Patent Document 4 (Japanese Unexamined Patent Application Publication 2015-199794) describes a peeling method including: a step of irradiating an energy beam from a supporting body side of a laminate body including a light-transmitting supporting body and an adherend fixed to the supporting body via an adhesive, thereby separating the supporting body and the adherend; wherein the adhesive contains a condensation resin and boron-containing carbon particles; and the adherend contains at least one of an inorganic material and an organic material.

[0010] Patent Document 5 (Japanese Unexamined Patent Application Publication 2012-052031) describes a method for processing a process target layer, comprising, in order: (1) a step of forming, on a supporting body, an adhesive layer containing a polymer (A) and a photoradical generator (B), the adhesive layer having a polymerizable compound content of 10 wt.% or less in 100 wt.% of the adhesive layer; (2) a step of forming a process target layer on the adhesive layer; (3) a step of processing the process target layer; (4) a step of irradiating the adhesive layer with light from the supporting body side; and (5) a step of peeling off the process target layer from the supporting body after processing.

[0011] Patent Document 6 (Japanese Unexamined Patent Application Publication 2017-011279) describes “a method for manufacturing a semiconductor device, comprising: a step of separating a wafer from a supporting body of the wafer by swelling an adhesive layer that bonds the wafer and the supporting body of the wafer, the adhesive layer formed using an adhesive composition containing 40 wt.% or more of an elastomer that contains styrene units as constituent units of the main chain, the styrene unit content being more than 50 wt.% and not more than 90 wt.%, and having a weight average molecular weight of 10,000 or more and 200,000 or less, without the adhesive layer being dissolved by a solvent”.

[0012] Patent Document 7 (Japanese Unexamined Patent Application Publication 2019-119762) describes an adhesive composition containing an elastomer having a structural unit (ul) expressed by the following general formula (ul-1): [Chem. Fig. 1] [In general formula (ul-1), Ralrepresents an alkyl group having 1 to 5 carbon atoms or a hydrogen atom. R01represents a group containing an alicyclic group. R02represents a group not corresponding to R01, selected from the group consisting of halogen atoms, alkyl groups having 1 to 8 carbon atoms which may be substituted with a halogen atom, aryl groups having 6 to 12 carbon atoms which may be substituted with a halogen atom, cyano groups, nitro groups, hydroxyl groups, carboxy groups, groups represented by -OR, or groups represented by -COOR (wherein R is an alkyl group having 1 to 8 carbon atoms which may be substituted with a halogen atom), m is a natural number from 1 to 5, and nl is an integer of 0 or more. However, the sum of m and nl does not exceed 5.]

[0013] Summary of the Invention

[0014] Problem to be Solved by the Invention

[0015] The UV-curable adhesive used to temporarily fix a semiconductor wafer onto a supporting body having a light-to-heat conversion layer is applied in a liquid state and cured by UV irradiation. Rapid curing by UV irradiation is a major advantage of using a UV-curable adhesive, but special devices and manufacturing line design suitable for UV irradiation may be required, and the supporting body is required to be transparent to ultraviolet light. Furthermore, when temporary fixing is performed using a UV-curable adhesive, use of bonding equipment designed for thermosetting materials used in other steps of semiconductor manufacturing may not be possible.

[0016] When a semiconductor wafer is temporarily fixed using a thermosetting adhesive, heating the laminate body including the semiconductor wafer, the thermosetting adhesive, and the supporting body to a high temperature (for example, about 200°C) for a relatively long period of time (for example, about 60 minutes) may be required. Storage of a one-component heat-curable adhesive containing an adhesive component and a curing agent may require refrigeration or freezing. In addition, one-component thermosetting adhesives generally have a limited pot life, so if the adhesive remains in the equipment for a long time after being loaded into the equipment due to a malfunction or breakdown of the equipment, gelation may occur, causing problems in the operation of the equipment.

[0017] The present disclosure provides an adhesive kit for forming a laminate body including a light- to-heat conversion layer, which can be rapidly cured at room temperature or by relatively gentle heating without requiring UV irradiation, and which allows long-term storage at room temperature and a long usable life.

[0018] Means for Solving the Problem

[0019] One embodiment of the present disclosure provides a kit for forming a laminate body including a light-to-heat conversion layer, comprising: a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radically polymerizable compound; a light-to-heat conversion layer ink composition containing a thermally decomposable light absorbing agent and a binder or a precursor thereof; and a curing accelerator containing a P-dicarbonyl compound expressed by the following formula or a salt thereof

[0020] [Chem. Fig. 2] where X1and X2independently represent a covalent bond, O, S, [Chem. Fig. 3] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0021] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0022] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0023] Another embodiment of the present disclosure provides a kit for forming a laminate body including a light-to-heat conversion layer, comprising: a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radically polymerizable compound; and a light-to-heat conversion layer ink composition containing a thermally decomposable light absorbing agent, a binder or a precursor thereof, and a p-dicarbonyl compound expressed by the following formula or a salt thereof [Chem. Fig. 5] where X1and X2independently represent a covalent bond, O, S,

[0024] [Chem. Fig. 6] or

[0025] [Chem. Fig. 7] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0026] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0027] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0028] Another embodiment of the present disclosure provides a laminate body, comprising: a light-transmitting supporting body; a light-to-heat conversion layer provided on the light-transmitting supporting body; and a curing accelerator layer provided on the light-to-heat conversion layer; wherein the light-to-heat conversion layer contains a thermally decomposable light absorbing agent and a binder, and the curing accelerator layer is a [3-dicarbonyl compound or salt thereof expressed by the following formula:

[0029] [Chem. Fig. 8] where X1and X2independently represent a covalent bond, O, S, [Chem. Fig. 9] or

[0030] [Chem. Fig. 10] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0031] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0032] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0033] Another embodiment of the present disclosure provides a laminate body, comprising: a light-transmitting supporting body; and a light-to-heat conversion layer provided on the light-transmitting supporting body; wherein the light-to-heat conversion layer contains a thermally decomposable light absorbing agent, a binder, and a (3-dicarbonyl compound or a salt thereof expressed by the following formula:

[0034] [Chem. Fig. 11] where X1and X2independently represent a covalent bond, O, S,

[0035] [Chem. Fig. 12] or

[0036] [Chem. Fig. 13] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms; R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0037] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0038] Another embodiment of the present disclosure provides a method for producing a laminate body containing a light-to-heat conversion layer, comprising: applying a free radical polymerizable liquid adhesive to a base material to form a bonding precursor layer on the base material; applying the light-to-heat conversion layer ink composition to a light-transmitting supporting body to form a light-to-heat conversion layer on the light-transmitting supporting body; applying a curing accelerator onto the light-to-heat conversion layer to form a curing accelerator layer on the light-to-heat conversion layer; and bonding the base material and the light-transmitting supporting body so that the bonding precursor layer and the curing accelerator layer are in mutual contact, and at least partially curing the bonding precursor layer to form a bonding layer; wherein the free radical polymerizable liquid adhesive contains at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound; the light-to-heat conversion layer ink composition contains a thermally decomposable light absorbing agent and a binder or a precursor thereof; and the curing accelerator contains a [l-dicarbony I compound expressed by the following formula or salt thereof

[0039] [Chem. Fig. 14]

[0040] (where X1and X2independently represent a covalent bond, O, S, [Chem. Fig. 15] or [Chem. Fig. 16] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0041] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0042] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0043] Another embodiment of the present disclosure provides

[0044] A method for producing a laminate body containing a light-to-heat conversion layer, comprising: applying a free radical polymerizable liquid adhesive to a base material to form a bonding precursor layer on the base material; applying the light-to-heat conversion layer ink composition to a light-transmitting supporting body to form a light-to-heat conversion layer on the light-transmitting supporting body; and bonding the base material and the light-transmitting supporting body so that the bonding precursor layer and the light-to-heat conversion layer are in mutual contact, and at least partially curing the bonding precursor layer to form a bonding layer; wherein the free radical polymerizable liquid adhesive contains at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound; and the light-to-heat conversion layer ink composition contains a thermally decomposable light absorbing agent, a binder or a precursor thereof, and a (3-dicarbonyl compound or salt thereof expressed by the following formula:

[0045] [Chem. Fig. 17] where X1and X2independently represent a covalent bond, O, S, [Chem. Fig. 18] or

[0046] [Chem. Fig. 19] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0047] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0048] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0049] Another embodiment of the present disclosure provides a method for producing a thinned base material, comprising: preparing a laminate body obtained by the aforementioned method, the base material being a base material for grinding; grinding the base material to be base material with a desired thickness; irradiating the light-to-heat conversion layer with radiant energy through the light-transmitting supporting body to decompose the light-to-heat conversion layer, thereby separating the ground base material having the bonding layer from the light-transmitting supporting body; and optionally removing the bonding layer from the base material after the grinding.

[0050] Another embodiment of the present disclosure provides a method for producing a semiconductor substrate laminate body, comprising: providing a laminate body obtained by the aforementioned method, the base material being a semiconductor substrate, the semiconductor substrate having an insulating layer provided on a surface of the semiconductor substrate opposite the bonding layer, and one or a plurality of conductive connections penetrating the insulating layer and electrically connecting to the semiconductor substrate; providing a second semiconductor substrate having a second insulating layer provided on a surface of the second semiconductor substrate and one or a plurality of second conductive connections passing through the second insulating layer and electrically connecting to the second semiconductor substrate; forming a semiconductor substrate laminate body in which the conductive connections of the semiconductor substrate and the second conductive connections of the second semiconductor substrate are opposing each other, by heating and pressing together the semiconductor substrate and the second semiconductor substrate so that the conductive connections and the second conductive connections are bonded together, and the insulating layer and the second insulating layer are bonded together; irradiating the light-to-heat conversion layer with radiant energy through the light-transmitting supporting body to decompose the light-to-heat conversion layer, thereby separating the semiconductor substrate laminate body having the bonding layer from the light-transmitting supporting body; and optionally removing the bonding layer from the surface of the semiconductor substrate laminate body.

[0051] Effect of the Invention

[0052] The present disclosure can provide an adhesive kit for forming a laminate body including a light-to-heat conversion layer, which can be rapidly cured at room temperature or by relatively gentle heating without requiring UV irradiation, and which allows long-term storage at room temperature and a long usable life. A laminate body including a light-to-heat conversion layer formed using the adhesive kit can be used in various processes in semiconductor device manufacturing, such as thinning a base material, forming a semiconductor substrate laminate body, and the like.

[0053] The above description should not be considered to be a disclosure of all embodiments of the present invention nor all advantages associated with the present invention.

[0054] Brief Description of the Drawings

[0055] FIG. 1 is a schematic cross-sectional view of a laminate body (laminate body A) of the third embodiment;

[0056] FIG. 2 is a schematic cross-sectional view of a laminate body (laminate body B) of the fourth embodiment;

[0057] FIG. 3 is a schematic cross-sectional view of a laminate body (laminate body C) of the fifth embodiment;

[0058] FIG. 4 is an explanatory diagram of a method for producing a thinned base material according to an embodiment;

[0059] FIG. 5 is a schematic cross-sectional view of a laminate body (laminate body D) of another embodiment; and

[0060] FIG. 6 is an explanatory diagram of a method for producing a semiconductor substrate laminate body according to an embodiment.

[0061] Embodiments for Carrying out the Invention

[0062] Hereinafter, for the purpose of illustrating typical embodiments of the present invention, a more detailed description will be provided with reference to the drawings as necessary. However, the present invention is not limited to these embodiments.

[0063] In the present disclosure, “(meth)acrylic” refers to acrylic or methacrylic, and (meth)acrylate refers to acrylate or methacrylate.

[0064] In the present disclosure, “hydrocarbyl” refers to a monovalent group derived from a hydrocarbon. Examples of hydrocarbyl groups include methyl, phenyl, and methylcyclohexyl groups. In the present disclosure, “hydrocarbylene” refers to a divalent group derived from a hydrocarbon. Examples of hydrocarbylene groups include methylene, phenylene, and 1,3-propane-diyl groups.

[0065] In the present disclosure, the “free radical polymerizable liquid adhesive” may also be referred to simply as a “liquid adhesive”.

[0066] In the present disclosure, “solid fraction” refers to the total mass of a component in a composition excluding a solvent.

[0067] The kit for forming a laminate body including a light-to-heat conversion layer according to the first embodiment contains: a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound; a light-to-heat conversion layer ink composition containing a thermally decomposable light absorbing agent, and a binder or precursor thereof; and a curing accelerator containing a 0-dicarbonyl compound or salt thereof.

[0068] The kit for forming a laminate body including a light-to-heat conversion layer according to the second embodiment contains: a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound; a thermally decomposable light absorbing agent, and a binder or precursor thereof; and a light-to-heat conversion layer ink composition containing a (3- dicarbonyl compound or salt thereof.

[0069] The (3-dicarbonyl compounds of the first and second embodiments are expressed by the following formulas.

[0070] [Chem. Fig. 20]

[0071] (where X1and X2independently represent a covalent bond, O, S,

[0072] [Chem. Fig. 21] or

[0073] [Chem. Fig. 22] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms; R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0074] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0075] In the first embodiment, the polyvalent metal compound is included in the liquid adhesive, and the P-dicarbonyl compound or a salt thereof is included in the curing accelerator. The curing accelerator is applied onto the light-to-heat conversion layer formed using the light-to-heat conversion layer ink composition to form a curing accelerator layer. The liquid adhesive containing the polyvalent metal compound comes into contact with the curing accelerator layer containing the P-dicarbonyl compound or a salt thereof, such that a radical reaction proceeds and the liquid adhesive is cured. In the first embodiment, the P-dicarbonyl compound or a salt thereof is present in the curing accelerator layer, i.e., the P-dicarbonyl compound or a salt thereof is unevenly distributed on the light-to-heat conversion layer, and therefore, a small amount of the p-dicarbonyl compound can effectively promote the radical reaction.

[0076] In the second embodiment, the polyvalent metal compound is included in the liquid adhesive, and the P-dicarbonyl compound or a salt thereof is included in the light-to-heat conversion layer ink composition. The liquid adhesive containing the polyvalent metal compound comes into contact with the light-to-heat conversion layer containing the P-dicarbonyl compound or a salt thereof, such that a radical reaction proceeds and the liquid adhesive is cured. In the second embodiment, the radical reaction can be caused to proceed without providing a separate curing accelerator layer, and therefore, the manufacturing process of a laminate body can be simplified.

[0077] In the present disclosure, a radical reaction known as Bredereck’s Reaction, which is expressed by the following formula, is used. In the presence of the polyvalent metal compound, the P-dicarbonyl compound or a salt thereof reacts with oxygen (O2) to generate an active species having an oxy radical, and this active species promotes the radical reaction. If necessary, the coexistence of halogen ions promotes uniform curing in a depth direction. In other words, initiators of Bredereck Chemistry include a P-dicarbonyl compound or a salt thereof, a polyvalent metal compound, and optionally a halogen ion. The radical reaction using Bredereck Chemistry proceeds rapidly even at room temperature, and is further accelerated when heated to, for example, 100°C. While oxygen (O2) is required to drive the radical reaction in Bredereck Chemistry, the present inventor unexpectedly discovered that dissolved oxygen included in the adhesive is sufficient to drive the radical reaction in applications envisioned by the present disclosure, such as temporarily securing a semiconductor wafer to a supporting body. Furthermore, the present inventor discovered that oxygen inhibition, which is a problem in UV curing or thermal curing using a peroxide, or in other words, inferior curing at an end part of a bonding region that comes into contact with the atmosphere, can be prevented or suppressed by utilizing a radical reaction system based on Bredereck Chemistry. [Chem. Fig. 23]

[0078] In the present disclosure, the (3-dicarbonyl compound or a salt thereof converted into an active species that promotes a radical reaction is included in the curing accelerator layer on the light-to-heat conversion layer or included in the light-to-heat conversion layer, and the polyvalent metal compound that promotes the generation of the active species is included in the liquid adhesive. The (3-dicarbonyl compound or a salt thereof and the polyvalent metal compound are themselves thermally stable. As long as the curing accelerator layer or the light-to-heat conversion layer and the adhesive are stored separately, radical reactions of the liquid adhesive do not occur, and therefore these layers or components can be stored at room temperature for long periods of time and a long pot life can be ensured.

[0079] The free radical polymerizable liquid adhesive of the first and second embodiments contains at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound.

[0080] The at least one free radical polymerizable compound can include, for example, (meth)acrylates, (meth)acrylamides, other vinyl compounds, and combinations of two or more thereof. The free radical polymerizable compound may include an ethylenically unsaturated compound having one or more (for example, one, two, three, four or more) free radical polymerizable groups.

[0081] The at least one free radical polymerizable compound preferably contains a free radical polymerizable (meth)acrylate oligomer. By using such a (meth)acrylate oligomer, the time required for curing the liquid adhesive can be reduced. Examples of the (meth)acrylate oligomer include oligomers having a free radical polymerizable vinyl group, such as urethane acrylate, epoxy acrylate, polyester acrylate, and the like.

[0082] The amount of the (meth)acrylate oligomer in the liquid adhesive is not particularly limited, but can be, for example, approximately 20 mass% or more and approximately 80 mass% or less on the basis of the total mass of the free radical polymerizable compound.

[0083] The at least one free radical polymerizable compound preferably contains a free radical polymerizable and polyfunctional (meth)acrylate. Examples of polyfunctional (meth)acrylates include: 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol (di)methacrylate, trimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, bisphenol A di(meth)acrylate, ethoxylated bisphenol A diacrylate, propoxy lated bisphenol A diacrylate, 2-[5-ethyl-5- [(acryloyloxy)methyl]-l,3-dioxane-2-yl]-2,2-dimethylethyl acrylate, tricyclo[5.2.1.02,6] decanedimethanol di(meth)acrylate, and other bifunctional (meth)acrylates; pentaerythritol tri(meth)acrylate, isocyanuric acid EO-modified tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, and other trifunctional (meth)acrylates; dipentaerythritol tetra(meth)acrylate; and dipentaerythritol penta(meth)acrylate. When the number of polymerizable functional groups is large, even a small added amount thereof tends to affect the storage elastic modulus of the adhesive after curing, and therefore, bifunctional (meth)acrylates and trifunctional (meth)acrylates are preferred, and bifunctional (meth)acrylates are more preferred. The bifunctional (meth)acrylate can be used, for example, for the purpose of introducing a crosslinked structure into a cured product and adjusting the storage elastic modulus in a mbber-like flat region.

[0084] The amount of the polyfunctional (methjacrylate in the liquid adhesive is not particularly limited, but can be, for example, approximately 70 mass% or more and approximately 100 mass% or less on the basis of the total mass of the free radical polymerizable compound.

[0085] The at least one free radical polymerizable compound may include a monofunctional (methjacrylic monomer. The monofunctional (methjacrylic monomer can adjust the viscosity of the liquid adhesive to an appropriate range depending on the application. Examples of monofunctional (methjacrylic monomers include: butyl (methjacrylate, pentyl (methjacrylate, hexyl (methjacrylate, heptyl (methjacrylate, octyl (methjacrylate, 2-ethylhexyl (methjacrylate, nonyl (methjacrylate, decyl (methjacrylate, dodecyl (methjacrylate, and other alkyl (methjacrylates; cyclohexyl (methjacrylate and other alicyclic (methjacrylates; phenyl (methjacrylate, phenylethyl (methjacrylate, and other aromatic (methjacrylates; and 2-hydroxyethyl (methjacrylate, 3-hydroxypropyl (methjacrylate, 2-hydroxy-3- phenoxypropyl (methjacrylate, 2-(meth)acryloyloxyethyl-2 -hydroxyethyl phthalic acid, 2- (methjacryloyloxy ethyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl succinic acid, (methjacryloyloxypropyl trimethoxysilane, and other monofunctional (methjacrylates having a polar functional group.

[0086] The amount of the monofunctional (methjacrylic monomer in the liquid adhesive is not particularly limited, but can be, for example, approximately 0 mass% or more and approximately 30 mass% or less, on the basis of the total mass of the free radical polymerizable compound.

[0087] A salt, complex, or chelate of a polyvalent metal ion and an organic anion (for example, a conjugate base of an organic acid having 1 to 18 carbon atoms) can be used as the at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound.

[0088] The at least one polyvalent metal compound preferably contains at least one metal selected from the group consisting of copper (II), vanadium (IV), iron (II), iron (III), cobalt (II), cobalt (III), manganese (II), and manganese (III). These polyvalent metal compounds can further promote the radical reaction.

[0089] Examples of polyvalent metal compounds include: copper (II) acetylacetonate, copper (II) naphthenate, copper (II) acetate, copper (II) (methjacrylate, copper (II) salicylate, copper thiourea or ethylenediaminetetraacetic acid complexes, and other copper (II) compounds; vanadyl acetylacetonate and other vanadium (IV) compounds; iron (II) phenanthroline and other iron (II) compounds; iron (III) (methjacrylate, iron (III) acetoacetonate, and other iron (III) compounds; cobalt (II) octoate, cobalt (II) succinate, cobalt (II) naphthenate, cobalt (II) resinate, cobalt (II) linoleate, cobalt acetoacetate, compounds having dicarboxylic acid semiester and chelate bonded copper (for example, cobalt (II) bis(acetylacetonate), cobalt (III) tris(acetylacetonate)), cobalt chelates of 2-acetylcyclopentanone and methyl cyclopentanone-2 -carboxylates, and other cobalt (II) and cobalt (III) compounds; manganese (II) bis(acetylacetonate) and other manganese (II) compounds; manganese (III) tris(acetylacetonate) and other manganese (III) compounds; and cobalt (III) tris(acetylacetonate) and other cobalt (III) compounds.

[0090] Examples of other polyvalent metal compounds that can be used include chlorides, hydroxides, carbonates, bicarbonates, sulfates, nitrates, and acetates of copper (II), vanadium (IV), iron (II) and iron (III), cobalt (II) and cobalt (III), and manganese (II) and manganese (III).

[0091] The polyvalent metal compound preferably contains at least one selected from the group consisting of copper (II) compounds and vanadium (IV) compounds.

[0092] The liquid adhesive can include an effective amount of the polyvalent metal compound. The liquid adhesive can include approximately 0.05 parts by mass or more, approximately 0.25 parts by mass or more, or approximately 0.40 parts by mass or more, and approximately 2 parts by mass or less, approximately 1 part by mass or less, or approximately 0.6 parts by mass or less of the polyvalent metal compound, on the basis of 100 parts by mass of the total of the free radical polymerizable compounds. For example, the liquid adhesive preferably contains approximately 0.05 parts by mass to approximately 2 parts by mass, more preferably approximately 0.25 parts by mass to approximately 1 part by mass, and even more preferably approximately 0.4 parts by mass to approximately 0.6 parts by mass of the polyvalent metal compound, on the basis of a total of 100 parts by mass of the free radical polymerizable compounds.

[0093] The liquid adhesive preferably further contains a quaternary ammonium halide. The quaternary ammonium halide is preferably at least partially soluble in the liquid adhesive. Quaternary ammonium halides can be used to internally cure liquid adhesives that are applied relatively thickly. Without being bound by any theory, it is believed that the halide ions of the quaternary ammonium halide promote the generation of active species, accelerating the radical reaction, and that the relatively inactive halide radicals thus generated diffuse and cause the radical reaction to proceed within the liquid adhesive.

[0094] Suitable quaternary ammonium halides include those having four hydrocarbyl groups (for example, alkyl, alkenyl, cycloalkyl, aralkyl, alkaryl, aryl, or combinations thereof). Each hydrocarbyl group is independently selected from hydrocarbyl groups having preferably 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 4 carbon atoms. Examples of suitable hydrocarbyl groups include methyl, ethyl, propyl, butyl, hexyl, octyl, dodecyl, hexadecyl, octadecyl, benzyl, phenyl, tolyl, cyclohexyl, and methylcyclohexyl. Examples of suitable quaternary ammonium compounds include tetramethylammonium halide, tetraethylammonium halide, tetrapropylammonium halide, tetrabutylammonium halide, ethyltrimethylammonium halide, diethyldimethylammonium halide, butyltrimethylammonium halide, methyltrioctylammonium halide, and benzyltributylammonium halide. Any halide (for example, F, Cl, Br, I) ion may be used in the quaternary ammonium halide. The halide ion is preferably O' or Bf, and more preferably O'. When a quaternary ammonium halide is used, the amount is not particularly limited, but the liquid adhesive can contain the quaternary ammonium halide at an amount of approximately 0.03 parts by mass or more, approximately 0.1 parts by mass or more, or approximately 0.2 parts by mass or more, and approximately 1 part by mass or less, approximately 0.6 parts by mass or less, or approximately 0.4 parts by mass or less, on the basis of a total of 100 parts by mass of the free radical polymerizable compounds. For example, the liquid adhesive preferably contains approximately 0.03 parts by mass to approximately 1 part by mass, more preferably approximately 0.1 parts by mass to approximately 0.6 parts by mass, and even more preferably approximately 0.2 parts by mass to approximately 0.4 parts by mass of the quaternary ammonium halide, on the basis of a total of 100 parts by mass of the free radical polymerizable compounds.

[0095] The liquid adhesive may contain a solvent. Examples of the solvent include: acetone, methyl ethyl ketone, cyclohexanone, and other ketones; ethyl acetate, butyl acetate, and other esters; and ethanol, butanol, and other alcohols.

[0096] In one embodiment, the liquid adhesive is solvent-free. Solvent-free liquid adhesives can be suitably used in applications where the liquid adhesive is cured in a sealed space.

[0097] The liquid adhesive may further contain, as an optional additive, a thickener, plasticizer, dispersant, filler, flame retardant, or heat aging inhibitor.

[0098] The liquid adhesive can be manufactured by mixing the abovementioned components. Components that do not flow at room temperature may be heated before mixing with the other components.

[0099] In one embodiment, the viscosity of the liquid adhesive is approximately 100 mPa s or more and approximately 10,000 mPa s or less at 25°C. When the liquid adhesive is applied by spin coating, the viscosity of the liquid adhesive at 25°C can be set to approximately 1,000 mPa s or more or approximately 2,000 mPa s or more, and approximately 8,000 mPa s or less or approximately 5,000 mPa s or less, such that the liquid adhesive can be uniformly applied onto a wafer at a desired thickness. The viscosity was measured using a cone-plate viscometer (HAAKE (trademark) rheometer, Thermo Fisher Scientific K.K., Minato-ku, Tokyo, Japan) at a temperature of 25°C, a cone diameter of 35 mm, a cone angle of 1 degree, and a rotational speed of 1 degree / min. The viscosity is a value measured after setting the liquid adhesive between a cone and plate, waiting for 60 seconds, and then reading the value 30 seconds after the start of measurement.

[0100] The light-to-heat conversion layer ink composition of the first and second embodiments both contain a thermally decomposable light absorbing agent, and a binder or a precursor thereof. The light- to-heat conversion layer ink composition according to the second embodiment further contains a 0- dicarbonyl compound or a salt thereof, which will be described in detail later.

[0101] A thermally decomposable light absorbing agent (hereinafter, simply referred to as a “light absorbing agent”) is a substance that absorbs radiant energy, such as laser radiation or the like, and converts the energy to heat, which then itself thermally decomposes. For example, in the case of carbon black particles, which is one type of thermally decomposable light absorbing agent, when the particles absorb light and increase in temperature, combustion (in the presence of oxygen) or graphitization occurs, and the particles decomposes while generating gas, thereby losing particle shape. As a result, a void is generated in the light-to-heat conversion layer, and the light-to-heat conversion layer is decomposed and separated into two layers. This allows the supporting body and the base material on either side of the light-to-heat conversion layer to be easily separated without applying unnecessary stress.

[0102] The light absorbing agent can be selected to absorb radiant energy at the wavelengths used. As the radiant energy, a laser beam having a wavelength of usually 150 to 2000 nm, and preferably 300 to 1100 nm, can be used. Specific examples include YAG lasers generating light having a wavelength of 1064 nm, second harmonic YAG lasers having a wavelength of 532 nm, semiconductor lasers having a wavelength of 780 to 1300 nm, KrF excimer lasers (wavelength: 248 nm), ArF excimer lasers (wavelength: 193 nm), F2 excimer lasers (wavelength: 157 nm), XeCl lasers (wavelength: 308 nm), XeF lasers (wavelength: 351 nm), and solid-state UV lasers (wavelength: 355 nm). The radiant energy can also be ultraviolet rays generated from a high-pressure mercury lamp (wavelength: 254 nm or more and 436 nm or less). For example, g-rays (wavelength: 436 nm), h-rays (wavelength: 405 nm), or i-rays (wavelength: 365 nm) can be used.

[0103] Examples of the light absorbing agent include: inorganic materials that specifically absorb laser wavelengths, such as carbon black, graphite powder, black titanium oxide, and other black pigments, cesium-doped tungsten oxide (CWO), and the like; black dyes, red dyes, and violet dyes, such as aromatic diamine metal complexes, aliphatic diamine metal complexes, aromatic dithiol metal complexes, mercaptophenol metal complexes, squarylium compounds, cyanine dyes, methine dyes, naphthoquinone dyes, anthraquinone dyes, and the like; and UV-absorbing compounds, such as octyl methoxycinnamate, octyl dimethoxybenzylidene dioxoimidazolidine propionate, hexyl diethylamino hydroxybenzoyl benzoate, t-butyl methoxydibenzoylmethane, octyl triazone, 2-ethylhexyl paramethoxycinnamate, dihydroxybenzophenone, and the like.

[0104] The light absorbing agent is preferably in particulate form in the light-to-heat conversion layer ink composition. In other words, the particulate light absorbing agent preferably has low compatibility with the binder and precursor thereof, or with a solvent of the light-to-heat conversion layer ink composition, and is preferably dispersed in the light-to-heat conversion layer ink composition without being dissolved. Even when particulate light absorbing agent increases in temperature during the process of absorbing light and converting the light to heat, oxidation, decomposition, phase change, and other changes progress gradually from the particle surface to the inside of the particle, allowing the inside of the particle to retain its light absorption ability for some time. Therefore, when the particulate light absorbing agent is viewed on a particle-by -particle basis, light-to-heat conversion occurs continuously for a longer period of time at a location inside the light-to-heat conversion layer where the particulate light- to-heat conversion layer is present, and a void can be effectively created inside the light-to-heat conversion layer. From this perspective, the particulate light absorbing agent is preferably a black pigment.

[0105] The particulate light absorbing agent preferably has an average primary particle size of approximately 10 nm or more or approximately 20 nm or more, and approximately 400 nm or less or approximately 300 nm or less. In the present disclosure, the average primary particle size of a particulate substance is a value obtained by disintegrating aggregates into primary particles using an ultrasonic disperser in a solvent in which the substance is insoluble, then measuring the particle diameters (circular equivalent diameters) of 1,000 or more primary particles randomly in an image taken at a magnification range of 50,000 to 200,000 using a transmission electron microscope, and averaging the measured particle diameters.

[0106] In one embodiment, the light absorbing agent contains carbon black particles. Examples of carbon black particles include thermal black particles, acetylene black particles, gas furnace black particles, oil furnace black particles, and channel black particles. The carbon black particles can significantly reduce the force required to separate the base material from the light-transmitting supporting body after irradiation with radiant energy.

[0107] The amount of the carbon black particles in the light absorbing agent can be approximately 40 mass% or more, approximately 50 mass% or more, or approximately 60 mass% or more, on the basis of the mass of the light absorbing agent. In one embodiment, the light absorbing agent is carbon black particles.

[0108] The carbon black particles preferably have an average primary particle size of approximately 10 nm or more or approximately 20 nm or more, and approximately 400 nm or less or approximately 300 nm or less.

[0109] The carbon black particles preferably contains hydrophilic carbon black particles. The hydrophilic carbon black particles have hydrophilic functional groups, such as carboxy groups, on surfaces thereof. Therefore, the hydrophilic carbon black particles exhibit self-dispersibility and can be highly dispersed in the light-to-heat conversion layer ink composition. The use of hydrophilic carbon black particles can also improve the storage stability of the light-to-heat conversion layer ink composition by avoiding the use of a dispersant that may gel the binder or precursor thereof in the light-to-heat conversion layer ink composition.

[0110] A dye that selectively absorbs wavelengths of radiant energy and transmits other wavelengths may also be used in conjunction with the carbon black particles. vThis is useful when forming the light- to-heat conversion layer that selectively transmits alignment light in a dicing step.

[0111] The amount of the light absorbing agent in the light-to-heat conversion layer ink composition varies depending on the type, particle form, and dispersibility of the light absorbing agent, but can be approximately 5 vol% or more, approximately 10 vol% or more, or approximately 15 vol% or more, and approximately 60 vol% or less, approximately 45 vol% or less, or approximately 35 vol% or less, on the basis of the volume of the solid fraction. By setting the amount of the light absorbing agent to approximately 5 vol% or more, a void can be more effectively generated inside the light-to-heat conversion layer, and the base material and the light-transmitting supporting body can be separated with low stress. By setting the amount of the light absorbing agent to approximately 60 vol% or less, it is possible to ensure the film-forming properties of the light-to-heat conversion layer and the adhesiveness to an adjacent layer.

[0112] The amount of the light absorbing agent in the light-to-heat conversion layer ink composition varies depending on the type, particle form, and dispersibility of the light absorbing agent, but can be approximately 10 mass% or more, approximately 15 mass% or more, or approximately 18 mass% or more, and approximately 65 mass% or less, approximately 55 mass% or less, or approximately 45 mass% or less, on the basis of the volume of the solid fraction. By setting the amount of the light absorbing agent to approximately 10 mass% or more, a void can be more effectively generated inside the light-to- heat conversion layer, and the base material and the light-transmitting supporting body can be separated with low stress. By setting the amount of the light absorbing agent to approximately 65 mass% or less, it is possible to ensure the film-forming properties of the light-to-heat conversion layer and the adhesiveness to an adjacent layer.

[0113] As the binder or precursor thereof, a thermally decomposable resin can be used. Examples of the thermally decomposable resin include gelatin, cellulose, cellulose acetate, nitrocellulose, and other cellulose esters, polyphenols, polyvinyl butyral, polyvinyl acetal, polycarbonate, polyurethane, polyester, polyorthoester, polyacetal, polyvinyl alcohol, polyvinylpyrrolidone, vinylidene chloride and acrylonitrile copolymers, poly(meth)acrylate, polyvinyl chloride, silicone resins, and block copolymers containing a polyurethane unit. The thermally decomposable resin can be used alone or in combination of two or more types thereof. In order to prevent the light-to-heat conversion layer, which has been separated by forming a void layer due to the thermal decomposition of the thermally decomposable resin, from readhering, the glass transition temperature (Tg) of the thermally decomposable resin is preferably 20°C or higher, and more preferably 100°C or higher. When the light-transmitting supporting body is glass, a thermally decomposable resin having, in a molecule, a polar group (for example, -COOH, -OH, and the like) capable of forming a hydrogen bond with a silanol group on a glass surface can be used to increase the adhesive strength between the glass and the light-to-heat conversion layer. In applications that use a chemical solution, such as wet etching and the like, in order to impart chemical resistance to the light-to- heat conversion layer, a thermally decomposable resin having, in a molecule, a functional group that can self-crosslink by heat treatment, or a thermally decomposable resin or a precursor thereof that can be crosslinked by ultraviolet rays or visible light can also be used.

[0114] The total amount of the binder and precursor thereof in the light-to-heat conversion layer ink composition can be approximately 30 vol% or more, approximately 40 vol% or more, or approximately 45 vol% or more, and approximately 95 vol% or less, approximately 80 vol% or less, or approximately 65 vol% or less, on the basis of the volume of the solid fraction. By setting the total amount to approximately 30 vol% or more, it is possible to ensure the film-forming properties of the light-to-heat conversion layer and the adhesiveness to an adjacent layer, and increase the chemical resistance of the light-to-heat conversion layer. By setting the total amount to approximately 95 vol% or less, a void can be more effectively generated inside the light-to-heat conversion layer, and the base material and the light-transmitting supporting body can be separated with low stress.

[0115] The total amount of the binder and precursor thereof in the light-to-heat conversion layer ink composition can be approximately 25 mass% or more, approximately 35 mass% or more, or approximately 40 mass% or more, and approximately 80 mass% or less, approximately 70 mass% or less, or approximately 60 mass% or less, on the basis of the volume of the solid fraction. By setting the total amount to approximately 25 mass% or more, it is possible to ensure the film-forming properties of the light-to-heat conversion layer and the adhesiveness to an adjacent layer, and increase the chemical resistance of the light-to-heat conversion layer. By setting the total amount to approximately 80 mass% or less, a void can be more effectively generated inside the light-to-heat conversion layer, and the base material and the light-transmitting supporting body can be separated with low stress.

[0116] In one embodiment, the light-to-heat conversion layer ink composition further contains a transparent filler. The transparent filler acts to prevent the light-to-heat conversion layer, which has been separated due to a void generated by the thermal decomposition of the light absorbing agent, from readhering. Examples of transparent fillers include silica, talc, and barium sulfate. The transparent filler can improve the peelability between the base material and the light-transmitting supporting body after irradiation with radiant energy.

[0117] The average primary particle size of the transparent filler can be approximately 7 nm or more, approximately 10 nm or more, or approximately 15 nm or more, and approximately 40 nm or less, approximately 30 nm or less, or approximately 25 nm or less.

[0118] The total amount of the light absorbing agent and the transparent filler, which is an optional component, in the light-to-heat conversion layer ink composition is preferably approximately 5 vol% or more, approximately 20 vol% or more, or approximately 35 vol% or more, and approximately 70 vol% or less, approximately 60 vol% or less, or approximately 55 vol% or less, on the basis of the volume of the solid fraction. By setting the total amount to approximately 5 vol% or more, a void can be more effectively generated inside the light-to-heat conversion layer, and the base material and the lighttransmitting supporting body can be separated with low stress. By setting the total amount to approximately 70 vol% or less, it is possible to ensure the film-forming properties of the light-to-heat conversion layer and the adhesiveness to an adjacent layer, and increase the chemical resistance of the light-to-heat conversion layer.

[0119] The total amount of the light absorbing agent and the transparent filler, which is an optional component, in the light-to-heat conversion layer ink composition is preferably approximately 10 mass% or more, approximately 25 mass% or more, or approximately 40 mass% or more, and approximately 75 mass% or less, approximately 65 mass% or less, or approximately 60 mass% or less, on the basis of the volume of the solid fraction. By setting the total amount to approximately 10 mass% or more, a void can be more effectively generated inside the light-to-heat conversion layer, and the base material and the light-transmitting supporting body can be separated with low stress. By setting the total amount to approximately 75 mass% or less, it is possible to ensure the film-forming properties of the light-to-heat conversion layer and the adhesiveness to an adjacent layer, and increase the chemical resistance of the light-to-heat conversion layer.

[0120] The light-to-heat conversion layer ink composition may contain another additive as necessary. Examples of other additives include leveling agents, silane coupling agents, foaming agents, sublimation agents, thickeners, and viscosity modifiers.

[0121] The light-to-heat conversion layer ink composition may contain a solvent for dissolving or dispersing another component. Examples of the solvent include: water, methanol, ethanol, isopropanol, and other alcohols, acetone, methyl ethyl ketone, and other ketones, and ethyl acetate, butyl acetate, and other esters. The solvent is preferably water, alcohol, or a mixed solvent of water and alcohol.

[0122] The solid fraction of the light-to-heat conversion layer ink composition can be appropriately determined taking into consideration the coatability, drying properties or curing properties of the light-to- heat conversion layer ink composition, and the thickness of the light-to-heat conversion layer to be formed. In one embodiment, the solid fraction of the light-to-heat conversion layer ink composition is approximately 3 mass% or more, approximately 5 mass% or more, or approximately 10 mass% or more, and approximately 30 mass% or less, approximately 25 mass% or less, or approximately 20 mass% or less.

[0123] The viscosity of the light-to-heat conversion layer ink composition can be appropriately determined taking into consideration the coatability, drying properties or curing properties of the light-to- heat conversion layer ink composition, and the thickness of the light-to-heat conversion layer to be formed. In one embodiment, the viscosity of the light-to-heat conversion layer ink composition is approximately 3 mPa s or more, approximately 5 mPa s or more, or approximately 10 mPa s or more, and approximately 200 mPa s or less, approximately 100 mPa s or less, or approximately 50 mPa s or less. The light-to-heat conversion layer ink composition having a viscosity of approximately 10 mPa s or more and approximately 50 mPa s or less can be suitably used for spin coating. The viscosity is a value measured using a rheometer (RotoViscol, manufactured by HAAKE) at a temperature of 25 °C and a shear rate of 100 sec'1.

[0124] A curing accelerator of the first embodiment and the light-to-heat conversion layer ink composition of the second embodiment contain a 0-dicarbonyl compound or a salt thereof. The (3- dicarbonyl compound is expressed by the following formula. [Chem. Fig. 24] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms. R1and R2each preferably have 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 4 carbon atoms. Examples of R1and R2include methyl, ethyl, isopropyl, n-propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, hexadecyl, and octadecyl. In general, the nature of the substitution group in any substituted hydrocarbyl group (which may be mono- or polysubstituted) is not particularly critical, except that the use of a substituted hydrocarbyl group which interferes with free radical polymerization is to be avoided whenever possible. Examples of substituted hydrocarbyl groups include hydroxyhydrocarbyl groups (for example, hydroxyethyl and hydroxypropyl), alkoxyhydrocarbyl groups (for example, methoxyethyl and methoxyethoxy), alkanoylhydrocarbyl groups (for example, acetylethyl and benzoylethyl), haloalkyl groups (for example, chloroethyl and dichloropropyl), and dialkylaminohydrocarbyl groups (for example, dimethylaminopropyl and diethylaminoethyl) .

[0125] In some embodiments, any two of R1, R2, and R3taken together form a 5- or 6-membered ring. In these embodiments, for example, two of R1, R2, and R3taken together may represent a divalent group selected from [Chem. Fig. 25]

[0126] O, S,

[0127] [Chem. Fig. 26]

[0128] [Chem. Fig. 27] and combinations thereof. In the formula, each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms; and y is 1, 2, or 3. The hydrocarbyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 4 carbon atoms. For example, the (3-dicarbonyl compound may be 2, 2-dimethyl-l,3-dioxane-4, 6-dione (Meldrum's acid). Examples of R4include hydrogen, methyl, ethyl, isopropyl, n-propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, phenyl, and benzyl. Examples of divalent groups formed by two of R1, R2, and R3taken together include alkylene, alkyleneoxy, oxycarbonyloxy, carbonylalkylene, alkylenecarbonyloxy, alkyleneoxycarbonyl, alkylene(alkyl)amino, and dialky lene(alkyl)amino. When R1and R2are taken together to form a 5 -membered ring, at least one of X1or X2is a covalent bond.

[0129] - l- R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms. Examples of R3include methyl, ethyl, isopropyl, n-propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, hexadecyl, phenyl, cyclohexyl, methylcyclohexyl, and octadecyl. Substituted hydrocarbyls include, for example, -CH2C(=O)OR4. In the formula, R4is as defined above, i.e., H, or a hydrocarbyl group having 1 to 18 carbon atoms. For example, R4may be H, methyl, ethyl, dodecyl, or octadecyl.

[0130] X1and X2each independently represent a covalent bond, O, S, [Chem. Fig. 28] or

[0131] [Chem. Fig. 29]

[0132] In the formula, R4is as defined above.

[0133] In some embodiments, the (3-dicarbonyl compound is a barbituric acid (i.e., R3= H and both

[0134] X1and X2are

[0135] [Chem. Fig. 30] where R4= H and R1and R2taken together form a carbonyl) or a derivative thereof (for example, 1,3- dialkylbarbituric acid). Examples of suitable barbituric acid derivatives include 1,3,5-trimethylbarbituric acid, 1,3,5-triethylbarbituric acid, 1, 3 -dimethy 1-5 -ethylbarbituric acid, 1,5-dimethylbarbituric acid, 1- methyl-5-ethylbarbituric acid, 1-methy 1-5 -propylbarbituric acid, 5 -ethylbarbituric acid, 5 -propylbarbituric acid, 5 -butylbarbituric acid, l-benzyl-5-phenylbarbituric acid, and 1-cyclohexy 1-5 -ethylbarbituric acid.

[0136] Examples of useful salts of (3-dicarbonyl compounds include alkali metal (for example, lithium, sodium, potassium, or cesium) salts, NH4+salts, and primary, secondary, tertiary, or quaternary organic ammonium salts. The organic ammonium salt preferably has 1 to 24 carbon atoms. Examples of organic ammonium salts include tetrabutylammonium salts, dibenzyldimethylammonium salts, benzyltributylammonium salts, and tetraethylammonium salts.

[0137] The amount of the (3-dicarbonyl compound or a salt thereof in the curing accelerator of the first embodiment is not particularly limited, but can be approximately 1 mass% or more, approximately 2 mass% or more, or approximately 5 mass% or more, and approximately 20 mass% or less, approximately 17 mass% or less, or approximately 15 mass% or less. For example, the curing accelerator contains a (3- dicarbonyl compound or a salt thereof in an amount of preferably approximately 1 mass% to approximately 20 mass%, more preferably approximately 2 mass% to approximately 17 mass%, and even more preferably approximately 5 mass% to approximately 15 mass%.

[0138] The amount of the P-dicarbonyl compound or a salt thereof in the light-to-heat conversion layer ink composition of the second embodiment is not particularly limited, but can be approximately 5 mass% or more, approximately 10 mass% or more, or approximately 15 mass% or more, and approximately 50 mass% or less, approximately 40 mass% or less, or approximately 30 mass% or less, on the basis of the mass of the solid fraction. For example, the light-to-heat conversion layer ink composition preferably contains approximately 5 mass% to approximately 50 mass%, more preferably approximately 10 mass% to approximately 40 mass%, and even more preferably approximately 15 mass% to approximately 30 mass% of the P-dicarbonyl compound or a salt thereof.

[0139] The curing accelerator of the first embodiment may contain a solvent. The solvent preferably dissolves the P-dicarbonyl compound, and examples thereof include: acetone, methyl ethyl ketone, cyclohexanone, and other ketones; ethyl acetate, butyl acetate, and other esters; and ethanol, butanol, and other alcohols.

[0140] The kit of one embodiment is essentially free of organic peroxides and photoinitiators. For example, the total amount of the organic peroxide and the photoinitiator in the kit can be less than 1 mass%, less than 0.1 mass%, or less than 0.01 mass%.

[0141] A laminate body of the third embodiment (laminate body A) includes a light-transmitting supporting body, a light-to-heat conversion layer disposed on the light-transmitting supporting body, and a curing accelerator layer disposed on the light-to-heat conversion layer. The light-to-heat conversion layer contains the aforementioned thermally decomposable light absorbing agent and a binder. The curing accelerator layer contains the aforementioned P-dicarbonyl compound or a salt thereof.

[0142] FIG. 1 is a schematic cross-sectional view of the laminate body (laminate body A) of the third embodiment. The laminate body 10 includes a light-transmitting supporting body 12, a light-to-heat conversion layer 14, and a curing accelerator layer 16.

[0143] A laminate body of a fourth embodiment (laminate body B) includes a light-transmitting supporting body and a light-to-heat conversion layer disposed on the light-transmitting supporting body. The light-to-heat conversion layer contains the aforementioned thermally decomposable light absorbing agent, binder, and P-dicarbonyl compound or a salt thereof.

[0144] FIG. 2 is a schematic cross-sectional view of the laminate body (laminate body B) of the fourth embodiment. The laminate body 10 includes the light-transmitting supporting body 12 and the light-to-heat conversion layer 14.

[0145] The light-transmitting supporting body is formed of a material that can transmit radiant energy, such as a laser beam or the like. The light-transmitting supporting body is preferably made of a material that maintains a base material (for example, semiconductor wafer) in a flat state and does not damage the base material during back surface grinding, transportation, or other step. The light-transmitting supporting body preferably has a transmittance of, for example, approximately 50% or more for the target radiant energy.

[0146] Examples of the light-transmitting supporting body include glass and acrylic resin. In order to increase the adhesive strength with an adjacent layer, such as the light-to-heat conversion layer or the like, the light-transmitting supporting body may be surface-treated with a silane coupling agent or the like, if necessary. The shape of the light-transmitting supporting body may be, for example, a circle or a rectangle. The light-transmitting supporting body may be in the form of a plate.

[0147] In one embodiment, the light-transmitting supporting body is glass. Examples of the glass include quartz glass, sapphire glass, and borosilicate glass.

[0148] The light-transmitting supporting body preferably has sufficient rigidity to prevent warping of the base material (for example, semiconductor wafer). The light-transmitting supporting body preferably has a Young's modulus of 1 to 10 MPa and a thickness of 500 pm or more.

[0149] The light-transmitting supporting body may be exposed to high temperatures due to: heat generated in the light-to-heat conversion layer upon irradiation with radiant energy; frictional heat during back surface grinding; and the like. Alternatively, before peeling off a semiconductor chip from the light-transmitting supporting body, a step may be added, such as CMP, resin molding, wet etching, dry etching, or other etching step, vapor deposition, sputtering, or other PVD step, CVD, electrolytic plating, electroless plating, or other plating step, pattern formation by photolithography, high-temperature treatment for forming an oxide film on a silicon wafer surface, or the like. Depending on these steps, a light-transmitting supporting body having heat resistance, chemical resistance, or a low expansion rate can be selected. Examples of light-transmitting supporting bodies having heat resistance, chemical resistance, and a low expansion rate include quartz glass, borosilicate glass, sapphire glass, and other glasses, with specific examples including Pyrex (registered trademark), Coming #1737 and #7059 (Coming Incorporated), and Tempax (Schott).

[0150] After the back surface grinding step and before dicing, wet etching of the semiconductor wafer surface with a chemical solution may be performed as an intermediate step. This step is carried out in order to remove a damaged layer on the back surface of the semiconductor wafer caused by grinding and to increase the flexural strength of the wafer. Alternatively, as the final stage in a semiconductor wafer thinning step, a thickness of several tens of pm may be removed by wet etching. When the semiconductor wafer is made of a single crystal of silicon (Si), a mixed acid containing hydrogen fluoride is generally used as an etching chemical solution. At this time, when the light-transmitting supporting body is made of glass (except for sapphire glass), an end part of the light-transmitting supporting body is also etched by the chemical solution. Therefore, if the light-transmitting supporting body is to be reused, the glass can be protected from corrosion by hydrogen fluoride by providing an acid-resistant (etching chemical solution-resistant) protective coating on the glass in advance. The protective film can be made of an acid-resistant resin. The acid-resistant resin preferably can be secured onto the glass by dissolving the resin in an organic solvent, applying the mixture in the form of a solution, and then drying the mixture. Furthermore, the acid-resistant resin preferably transmits a sufficient amount of light of the wavelength of the laser irradiated to separate the glass from the semiconductor wafer. From this perspective, examples of suitable acid-resistant resins include amorphous polyolefins that do not contain condensation bonds in a molecule, cyclic olefin copolymers, and polyvinyl chloride.

[0151] The light-transmitting supporting body preferably has a uniform thickness. For example, in order to reduce the thickness of a silicon wafer to 50 pm or less and keep the uniformity within ±10%, variations in thickness of the light-transmitting supporting body is preferably ±2 pm or less. If the lighttransmitting supporting body is to be used repeatedly, the light-transmitting supporting body preferably has scratch resistance. If the light-transmitting supporting body is to be used repeatedly, the material of the light-transmitting supporting body is preferably selected in consideration of the wavelength of the radiant energy so as to suppress damage to the light-transmitting supporting body due to the radiant energy. For example, when Pyrex (registered trademark) glass is used as the light-transmitting supporting body and a triple harmonic YAG laser (355 nm) is irradiated, the light-transmitting supporting body can be separated from the semiconductor wafer or semiconductor chip, but the light-transmitting supporting body may absorb the radiant energy and be thermally damaged, making reuse impossible.

[0152] Radiant energy irradiated onto the light-to-heat conversion layer of the laminate body in the form of a laser beam or the like is absorbed by the light absorbing agent and converted into thermal energy. The generated thermal energy rapidly increases the temperature of the light-to-heat conversion layer, and the light absorbing agent itself is thermally decomposed at the temperature. Depending on the types of light absorbing agent and binder, gas may be generated during thermal decomposition of the light absorbing agent. As a result, a void is generated in the light-to-heat conversion layer, causing the light- to-heat conversion layer to decompose and separate into two layers. This allows the supporting body and the base material on either side of the light-to-heat conversion layer to be easily separated without applying unnecessary stress.

[0153] The light-to-heat conversion layer of the laminate body A can be formed on the lighttransmitting supporting body by using the light-to-heat conversion layer ink composition of the first embodiment.

[0154] The light-to-heat conversion layer of the laminate body B can be formed on the lighttransmitting supporting body by using the light-to-heat conversion layer ink composition of the second embodiment. As a result, the laminate body B can be obtained.

[0155] The light-to-heat conversion layer ink composition is applied onto the light-transmitting supporting body by spin coating, bar coating, roll coating, cast coating, spraying, or the like, and heated, for example, to approximately 100°C to approximately 250°C to convert a binder precursor into a binder as necessary, thereby forming a light-to-heat conversion layer.

[0156] The thickness of the light-to-heat conversion layer can be approximately 0.1 pm or more, approximately 0.3 pm or more, or approximately 0.5 pm or more, and approximately 5 pm or less, approximately 3 pm or less, or approximately 2 pm or less. By setting the thickness of the light-to-heat conversion layer to approximately 0.1 pm or more, the film-forming properties and adhesiveness of the light-to-heat conversion layer can be maintained. By setting the thickness of the light-to-heat conversion layer to approximately 5 pm or less, residue on the supporting body can be reduced after the light-to-heat conversion layer is decomposed.

[0157] The curing accelerator layer of the laminate body A can be formed by applying the curing accelerator of the first embodiment onto the light-to-heat conversion layer of the laminate body A by spin coating, bar coating, roll coating, cast coating, spraying, or the like, and then heating to, for example, approximately 40°C to approximately 150°C to volatilize the solvent as necessary. As a result, the laminate body A can be obtained.

[0158] The curing accelerator layer of the laminate body A is preferably thinly formed, and it is often difficult to determine the thickness. The area concentration of the P-dicarbonyl compound or a salt thereof in the curing accelerator layer of the laminate body A can be approximately 2 ng / cm2or more, approximately 5 ng / cm2or more, or approximately 8 ng / cm2or more, and approximately 30 ng / cm2or less, approximately 20 ng / cm2or less, or approximately 15 ng / cm2or less. For example, the area concentration of the P-dicarbonyl compound or a salt thereof in the curing accelerator layer of the laminate body A is preferably approximately 2 ng / cm2to approximately 30 ng / cm2, more preferably approximately 5 ng / cm2to approximately 20 ng / cm2, and even more preferably approximately 8 ng / cm2to approximately 15 ng / cm2. The area concentration is determined by washing to remove the curing accelerator layer with a solvent, such as acetone or the like, and quantifying the amount of washing solutions using a GC-MS.

[0159] The amount of the P-dicarbonyl compound or a salt thereof in the light-to-heat conversion layer of the laminate body B can be approximately 5 mass% or more, approximately 10 mass% or more, or approximately 15 mass% or more, and approximately 50 mass% or less, approximately 40 mass% or less, or approximately 30 mass% or less. For example, the light-to-heat conversion layer of the laminate body B preferably contains approximately 5 mass% to approximately 50 mass%, more preferably approximately 10 mass% to approximately 40 mass%, and even more preferably approximately 15 mass% to approximately 30 mass% of the P-dicarbonyl compound or a salt thereof.

[0160] A laminate body C of the fifth embodiment (laminate body C) includes a light-transmitting supporting body, a light-to-heat conversion layer, a bonding layer disposed on the light-to-heat conversion layer, and a base material disposed on the bonding layer, and the light-to-heat conversion layer and the base material are bonded by the bonding layer. The light-to-heat conversion layer is decomposed and separated into two when irradiated with radiant energy, such as a laser beam or the like, making it possible to separate the layer from the light-transmitting supporting body without damaging the base material.

[0161] FIG. 3 is a schematic cross-sectional view of the laminate body (laminate body C) of the fifth embodiment. A laminate body 20 includes the light-transmitting supporting body 12, the light-to-heat conversion layer 14, a bonding layer 22 disposed on the light-to-heat conversion layer 14, and a base material 24 disposed on the bonding layer 22, and the light-to-heat conversion layer 14 and the base material 24 are bonded via the bonding layer 22.

[0162] The laminate body C can be manufactured by the following method using the kit of the first embodiment. The method includes: applying a free radical polymerizable liquid adhesive to a base material to form a bonding precursor layer on the base material; applying the light-to-heat conversion layer ink composition to a light-transmitting supporting body to form a light-to-heat conversion layer on the light-transmitting supporting body; applying a curing accelerator onto the light-to-heat conversion layer to form a curing accelerator layer on the light-to-heat conversion layer; and bonding the base material and the light-transmitting supporting body so that the bonding precursor layer and the curing accelerator layer are in mutual contact, and at least partially curing the bonding precursor layer to form a bonding layer.

[0163] The bonding precursor layer can be formed by applying a liquid adhesive onto the base material by spin coating, bar coating, roll coating, cast coating, spraying, or the like, and then volatilizing the solvent as necessary.

[0164] Formation of the light-to-heat conversion layer and formation of the curing accelerator layer are as described for the laminate body A. Therefore, instead of carrying out these forming steps, a laminate body A that has been previously prepared can be used.

[0165] The bonding layer is formed by bonding the base material and the light-transmitting supporting body such that the bonding precursor layer and the curing accelerator layer are in contact with each other, and at least partially curing the bonding precursor layer. The polyvalent metal compound included in the bonding precursor layer and the P-dicarbonyl compound or a salt thereof included in the curing accelerator layer are mixed near the interface between these layers, thereby initiating a radical reaction, and the generated active species causes polymerization of the free radical polymerizable compound included in the bonding precursor layer to proceed. As a result, a bonding layer is formed in which the bonding precursor layer is at least partially cured, and the laminate body C is obtained in which the base material and the light-transmitting supporting body are bonded via the bonding layer. The laminate body C is preferably formed under vacuum to prevent the inclusion of air between the layers.

[0166] During the formation of the bonding layer, the laminate body may be left at room temperature or may be heated. If heated, the laminate body can be heated at a temperature of, for example, approximately 40°C or higher, or approximately 60°C or higher, and approximately 250°C or lower, or approximately 150°C or lower.

[0167] The time required for forming the bonding layer may be, for example, approximately 1 hour to approximately 24 hours at room temperature. If the laminate body is heated, the heating time can be, for example, approximately 3 minutes to approximately 3 hours.

[0168] The laminate body C can also be manufactured by the following method using the kit of the second embodiment. The method includes: applying a free radical polymerizable liquid adhesive to a base material to form a bonding precursor layer on the base material; applying the light-to-heat conversion layer ink composition to a light-transmitting supporting body to form a light-to-heat conversion layer on the light-transmitting supporting body; and bonding the base material and the lighttransmitting supporting body so that the bonding precursor layer and the light-to-heat conversion layer are in mutual contact, and at least partially curing the bonding precursor layer to form a bonding layer.

[0169] Formation of the bonding precursor layer is as described above. Formation of the light-to-heat conversion layer is as described for the laminate body B. Therefore, instead of carrying out steps for forming the light-to-heat conversion layer, a laminate body B that has been previously prepared can be used.

[0170] The bonding layer is formed by bonding the base material and the light-transmitting supporting body such that the bonding precursor layer and the light-to-heat conversion layer are in contact with each other, and at least partially curing the bonding precursor layer. The polyvalent metal compound included in the bonding precursor layer and the 0-dicarbonyl compound or a salt thereof included in the light-to-heat conversion layer are mixed near the interface between these layers, thereby initiating a radical reaction, and the generated active species causes polymerization of the free radical polymerizable compound included in the bonding precursor layer to proceed. As a result, a bonding layer is formed in which the bonding precursor layer is at least partially cured, and the laminate body C is obtained in which the base material and the light-transmitting supporting body are bonded via the bonding layer. The laminate body C is preferably formed under vacuum to prevent the inclusion of air between the layers.

[0171] During the formation of the bonding layer, the laminate body may be left at room temperature or may be heated. The laminate body is preferably heated in order to promote diffusion of the 0- dicarbonyl compound or a salt thereof included in the light-to-heat conversion layer and increase the opportunity for reaction with the polyvalent metal compound included in the bonding precursor layer. The heating temperature of the laminate body can be, for example, approximately 40°C or higher, or approximately 60°C or higher, and approximately 250°C or lower, or approximately 150°C or lower.

[0172] The time required for forming the bonding layer may be, for example, approximately 1 hour to approximately 24 hours at room temperature. If the laminate body is heated, the heating time can be, for example, approximately 3 minutes to approximately 3 hours.

[0173] The base material is separated from the light-transmitting supporting body, generally leaving the base material with the bonding layer adhered thereto. Therefore, the bonding layer is preferably easily peelable from the base material. The bonding layer preferably has a sufficient adhesive strength (holding strength) to secure the base material to the light-transmitting supporting body, but has low adhesive strength so as to be peelable after heat treatment.

[0174] The thickness of the bonding layer is preferably such that the bonding layer can absorb unevenness on the surface of the base material, ensure the thickness uniformity required for steps such as back surface grinding and the like, and ensure the tearing strength required when peeling off the bonding layer. When the bonding layer is removed using a chemical solution, the bonding layer does not need to have a particular tearing strength. In one embodiment, the thickness of the bonding layer is approximately 3 pm or more, or approximately 10 pm or more, and approximately 150 pm or less, or approximately 100 pm or less.

[0175] Examples of the base material include III-V compound semiconductors of silicon (Si), germanium (Ge), silicon germanium (SiGe), silicon carbide (SiC), gallium arsenide (GaAs), and the like, or II- VI compound semiconductors of zinc sulfide (ZnS) and the like. The base material may be in the form of a semiconductor wafer, and a structure, such as a circuit pattern or the like, may be formed on a surface that contacts the bonding layer. In one embodiment, it is contemplated that the base material is reduced in thickness while in the laminate body state by back surface grinding. Examples of other base material include quartz wafers, sapphire, glass, and quartz.

[0176] When the base material is a semiconductor wafer having a circuit pattern, the circuit may be damaged by radiant energy of a laser beam or the like that passes through the light-transmitting supporting body, light-to-heat conversion layer, and bonding layer to reach the semiconductor wafer. In order to avoid such damage, a dye that absorbs light at the wavelength of the radiant energy or a pigment that reflects the light may be included in any of the layers forming the laminate body, or a layer containing such a dye or pigment may be further provided between the light-to-heat conversion layer and the semiconductor wafer. Examples of dyes that absorb laser beams include phthalocyanine dyes, cyanine dyes, and the like that have an absorption peak near the wavelength of the laser beam used. Examples of pigments that reflect laser beams include titanium oxide and other inorganic white pigments.

[0177] A method for manufacturing a thinned base material in one embodiment includes: preparing a laminate body C having a base material for grinding; grinding the base material for grinding to a desired thickness; irradiating a light-to-heat conversion layer with radiant energy through a light-transmitting supporting body to decompose the light-to-heat conversion layer, thereby separating the ground base material having a bonding layer from the light-transmitting supporting body; and if necessary, removing the bonding layer from the ground base material.

[0178] FIG. 4 depicts an explanatory diagram of a method for manufacturing a thinned base material according to one embodiment. FIG. 4(a) depicts the laminate body 20 (laminate body C). As depicted in (b), a base material 24 for grinding is ground to form a thinned base material 25. As depicted in (c), the light-to-heat conversion layer 14 is irradiated with radiant energy (indicated by an upward arrow), such as a laser beam or the like, through the light-transmitting supporting body 12 to decompose the light-to-heat conversion layer 14. In (c), the light-to-heat conversion layer 14 is separated into two at the position indicated by the dashed line. As depicted in (d), the ground thinned base material 25 having the bonding layer 22 is separated from the light-transmitting supporting body (not depicted). As depicted in (e), the bonding layer 22 is removed from the ground thinned base material 25, thereby obtaining the thinned base material 25.

[0179] Grinding of the base material for grinding can be performed using a grinding device that includes: a base capable of suction-securing a workpiece to be ground; a spindle; and a grinding wheel rotatably attached to a lower end part of the spindle. The light-transmitting supporting body side of the laminate body C is placed on the base of the grinding device, and the laminate body C is suction-secured to the base. Thereafter, the rotating grinding wheel is brought into contact with the laminate body C while a water flow is being supplied to the laminate body C, thereby grinding the base material for grinding. Grinding can be carried out until the thickness of the base material for grinding is approximately 150 pm or less, preferably approximately 50 pm or less, and more preferably approximately 25 pm or less.

[0180] The irradiation of radiant energy can be performed using a laser beam. Examples of the laser beam include: YAG lasers (wavelength: 1064 nm), second harmonic YAG lasers (wavelength: 532 nm), semiconductor lasers (wavelength: 780 to 1300 nm), KrF excimer lasers (wavelength: 248 nm), ArF excimer lasers (wavelength: 193 nm), F2excimer lasers (wavelength: 157 nm), XeCl lasers (wavelength: 308 nm), XeF lasers (wavelength: 351 nm), and solid-state UV lasers (wavelength: 355 nm). Irradiation with the radiant energy can also be performed using ultraviolet rays generated from a high-pressure mercury lamp (wavelength: 254 nm or more and 436 nm or less), i.e., g-rays (wavelength: 436 nm), h- rays (wavelength: 405 nm), or i-rays (wavelength: 365 nm).

[0181] The irradiation of radiant energy can be carried out in a state where the ground laminate body is suction-secured to a securing base such that the light-transmitting supporting body is an upper surface. When a laser beam is used, the focal depth of the laser beam is preferably approximately 30 pm or more deep in order to stably separate the base material and the light-transmitting supporting body. The laser output can be 0.3 to 100 W, the scanning speed can be 0.1 to 40 m / sec, and the beam diameter can be 5 pm to 300 pm. The process may be sped up by increasing the laser output and increasing the scanning speed. If there is a margin in the laser output, the processing speed may be increased by increasing the beam diameter and reducing the number of scans. The laser beam scanning is preferably performed from an end part of the ground laminated body, without leaving a gap. For example, the laser beam may be scanned back and forth linearly from an end part of the base material in a tangential direction, or may be scanned spirally from the end part toward the center.

[0182] After the light-to-heat conversion layer is decomposed by irradiation with radiant energy, the light-transmitting supporting body is separated from the ground base material using a vacuum pickup or the like.

[0183] After the light-transmitting supporting body is separated from the base material, the bonding layer is removed from the ground base material, if necessary. To remove the bonding layer, a pressuresensitive adhesive tape for removing the bonding layer can be used, which can form an adhesive strength between the bonding layer and the base material that is stronger than the adhesive strength between the ground base material and bonding layer. The pressure-sensitive adhesive tape for removing the bonding layer can be adhered onto the bonding layer, and the bonding layer can be peeled off from the ground base material. Alternatively or additionally, the bonding layer may be washed away using a solvent. Examples of the solvent include acetone, methyl ethyl ketone, N-methylpyrrolidone, N-ethylpyrrolidone, N-methylsuccinimide, dimethylfuran, toluene, N,N' -dimethylacetamide, tris(dimethylamino)phosphine oxide, dimethylsulfoxide, and y-butyrolactone.

[0184] A step may be performed after the grinding step as necessary, such as chemical mechanical polishing (CMP), resin molding, wet etching, dry etching, or other etching step, vapor deposition, sputtering, or other physical vapor deposition (PVD) step, chemical vapor deposition (CVD), electrolytic plating, electroless plating, or other plating step, pattern formation by photolithography, formation of an oxide film on a silicon wafer surface, or the like. After the grinding step, and before the irradiation with radiant energy or after the bonding layer removing step, dicing may be performed to separate the thinned base material into a plurality of small pieces. When the thinned base material is a semiconductor wafer, the small piece is a semiconductor chip. The dicing step can be carried out using a dicing tape and a die frame, and optionally a die bonding tape.

[0185] A laminate body of a sixth embodiment (laminate body D) further includes the lighttransmitting supporting body, the light-to-heat conversion layer, the bonding layer disposed on the light- to-heat conversion layer, and a semiconductor substrate disposed on the bonding layer. The semiconductor substrate has: an insulating layer disposed on a surface of the semiconductor substrate opposite the bonding layer; and one or a plurality of conductive connections passing through the insulating layer and electrically connected to the semiconductor substrate.

[0186] FIG. 5 depicts a schematic cross-sectional view of the laminate body (laminate body D) of this embodiment. A laminate body 30 further includes the light-transmitting supporting body 12, the light-to- heat conversion layer 14, a bonding layer 32 disposed on the light-to-heat conversion layer 14, and a semiconductor substrate 34 disposed on the bonding layer 32. The semiconductor substrate 34 has: an insulating layer 342 disposed on a surface of the semiconductor substrate 34 opposite the bonding layer 32; and one or a plurality of conductive connections 344 passing through the insulating layer 342 and electrically connected to the semiconductor substrate 34.

[0187] Examples of the semiconductor substrate include a silicon wafer and an SOI substrate on which a plurality of semiconductor chips are formed. The semiconductor chip includes, for example, an integrated circuit such as an IC, LSI, or the like or an imaging element such as a CCD or the like.

[0188] The insulating layer and the conductive connection can be formed using a known semiconductor processing technique, for example, photolithography, evaporation, sputtering, or other physical vapor deposition (PVD) technique, electrolytic plating, electroless plating, or other plating technique, and wet etching, dry etching, or other etching technique. In one embodiment, the insulating layer includes silicon oxide (SiCh) or a polyimide resin. In one embodiment, the conductive connection includes copper.

[0189] The laminate body D can be manufactured in the same manner as the laminate body C, except that the base material is a semiconductor substrate.

[0190] A method for manufacturing a semiconductor substrate laminate body in one embodiment includes: preparing a laminate body D having base material that is a semiconductor substrate; providing a second semiconductor substrate having a second insulating layer provided on a surface of the second semiconductor substrate and one or a plurality of second conductive connections passing through the second insulating layer and electrically connected to the second semiconductor substrate; forming a semiconductor substrate laminate body in which the conductive connections of the semiconductor substrate and the second conductive connections of the second semiconductor substrate are opposing each other, by heating and pressing together the semiconductor substrate and the second semiconductor substrate such that the conductive connections and the second conductive connections are bonded together, and the insulating layer and the second insulating layer are bonded together; irradiating the light-to-heat conversion layer with radiant energy through the light-transmitting supporting body to decompose the light-to-heat conversion layer, thereby separating the semiconductor substrate laminate body having the bonding layer from the light-transmitting supporting body; and optionally removing the bonding layer from the surface of the semiconductor substrate laminate body. This manufacturing method is a type of hybrid bonding.

[0191] FIG. 6 depicts an explanatory diagram of a method for manufacturing a semiconductor substrate laminate body of this embodiment. FIG. 6(a) depicts the laminate body 30 (laminate body D) and a second semiconductor substrate 44. The second semiconductor substrate 44 has: a second insulating layer 442 disposed on a surface thereof; and one or a plurality of second conductive connections 444 passing through the second insulating layer 442 and electrically connected to the second semiconductor substrate 44. The conductive connection 344 of the semiconductor substrate 34 included in the laminate body 30 opposes the second conductive connection 444 of the second semiconductor substrate 44. In (b), the semiconductor substrate 34 and the second semiconductor substrate 44 are heated and pressed together. As a result, the conductive connection 344 and the second conductive connection 444 are bonded together, and the insulating layer 342 and the second insulating layer 442 are bonded together. As depicted in (c), the light-to-heat conversion layer 14 is irradiated with radiant energy (indicated by an upward arrow), such as a laser beam or the like, through the light-transmitting supporting body 12 to decompose the light-to-heat conversion layer 14. In (c), the light-to-heat conversion layer 14 is separated into two at the position indicated by the dashed line. As depicted in (d), the semiconductor substrate laminate body having the bonding layer 14 is separated from the lighttransmitting supporting body member (not depicted). As depicted in (e), the bonding layer 32 is removed from the surface of the semiconductor substrate laminate body, thereby obtaining a semiconductor substrate laminate body 50.

[0192] As the second semiconductor substrate, a substrate similar to the semiconductor substrate in the laminate body D can be used.

[0193] The thermal compression bonding of the semiconductor substrate and the second semiconductor substrate can be performed under a temperature of 300°C to 450°C and a pressure of 200 to 400 MPa for 20 to 60 minutes. In one embodiment, the insulating layer and the conductive connection of the semiconductor substrate, and the second insulating layer and the second conductive connection of the second semiconductor substrate are formed by a CMP method (damascene method) using copper in the conductive connection and the second conductive connection, and a silicon oxide (SiCh) film in the insulating layer and the second insulating layer. In the CMP step, the etching rate of copper is higher than the etching rate of silicon oxide, and thus the copper surface after the CMP step is slightly recessed (dished) below the surface of the surrounding silicon oxide insulating layer. Furthermore, the copper surface being lower than the surface of the surrounding silicon oxide insulating layer is advantageous for reliable bonding between the insulating layer and the second insulating layer in the thermal compression bonding step. The coefficient of thermal expansion of copper is greater than the coefficient of thermal expansion of silicon oxide. Therefore, during the thermal compression bonding step, the copper expands and the conductive connection and the second conductive connection come into contact with each other, and mutual diffusion of copper occurs at the contact portion, thereby filling the gap formed by the recess on the copper surface and electrically connecting the conductive connection and the second conductive connection by penetrating the oxide film and impurities on the copper surface. Furthermore, a condensation reaction of silicon oxide proceeds in the high-temperature environment of the thermal compression bonding step, such that the insulating layer and the second insulating layer are simultaneously bonded to each other.

[0194] The irradiation of radiant energy and the separation of the semiconductor substrate laminate body from the light-transmitting supporting body can be carried out in the same manner as in the abovementioned method for manufacturing a thinned base material.

[0195] The bonding layer can be removed from the surface of the semiconductor substrate laminate body in the same manner as in the abovementioned method for manufacturing a thinned base material.

[0196] The kit and laminate body of the present disclosure can be used in a variety of applications, including temporary securing applications. Specifically, the kit and the laminate body can be suitably used for manufacturing semiconductor chips using high-density mounted stacked CSPs (Chip Scale Packages), through-type CSPs that require high functionality and high speed, ultra-thin compound semiconductors (GaAs, and the like) that require improved heat dissipation efficiency, electrical properties, and stability, and large wafers such as 16-inch silicon wafers.

[0197] [Examples]

[0198] The following examples describe specific embodiments of the present disclosure, but the present invention is not limited thereto. All parts and percentages are by mass unless otherwise stated. Numerical values inherently contain error arising from the measurement principles and measuring devices. Numbers are shown to significant digits with normal rounding.

[0199] The materials, reagents, and the like used in the examples and comparative examples are shown in Table 1. Table 1

[0200] Examples 1 to 4 and Comparative Examples 1 to 8

[0201] 1. Preparation of liquid adhesive For the Examples and Comparative Examples other than Comparative Example 8, UV-3300B and Light Acrylate 1.6HX-A were placed in a light-resistant plastic bottle and mixed for 5 minutes using a planetary centrifugal mixer. The remaining ingredients listed in Table 2 were then added and mixed for an additional 5 minutes in a planetary centrifugal mixer to prepare a liquid adhesive. For Comparative Example 8, the Light Acrylate 1.6HX-A and Omnirad™ 819 were stirred until the Omnirad™ 819 was completely dissolved. Then, UV-3300B was placed in a light-resistant plastic bottle and mixed for 5 minutes using a planetary centrifugal mixer to prepare a UV-curable liquid adhesive. 2, Preparation of curing accelerator

[0202] The components shown in Table 2 were mixed to prepare a curing accelerator.

[0203] The formulation of the liquid adhesive and curing accelerator is shown in Table 2.

[0204]

[0205] 3. Formation of light-to-heat conversion (LTHC) layer

[0206] The components shown in Table 3 were mixed using a bead mill to prepare a light-to-heat conversion layer ink composition. The light-transmitting supporting body is a disk-shaped glass substrate having a diameter of 154 mm and a thickness of 800 pm. The light-to-heat conversion layer ink composition was applied onto a glass substrate using a spin coater, heated at 100°C for 5 minutes, and then further heated at 200°C for 1 hour to form an LTHC layer.

[0207] Table 3

[0208] 4, Formation of curing accelerator layer

[0209] In the examples and comparative examples other than Comparative Examples 1 to 3 and 8, the curing accelerator was applied onto the LTHC layer using a spin coater at a rotational speed of 700 rpm for 10 seconds, and then dried for 3 minutes in a drying oven set at 40°C to form a curing accelerator layer. After the curing accelerator layer was formed, the curing accelerator layer was stored under the conditions described in the “Storage condition of the curing accelerating layer” column in Table 4, and then used to form a laminate body.

[0210] The amount of initiator applied onto the glass substrate was determined by washing off the curing accelerator layer with acetone and measuring the amount of the washings using a GC-MS.

[0211] 5, Formation of the laminate body

[0212] A silicon wafer having a diameter of 152 mm and a thickness of 750 pm was used as the semiconductor device wafer model. The liquid adhesive was applied onto the silicon wafer using a spin coater. A glass substrate having an LTHC layer and a silicon wafer coated with an adhesive were bonded together using a coating and bonding device WSS8101M (Tatsumo Co., Ltd., Okayama, Okayama, Japan), and the laminate body was then heat-treated under the conditions described in Table 4 to cure the liquid adhesive. Only in Comparative Example 8, the liquid adhesive was cured by irradiating the laminate body with ultraviolet rays from the glass substrate side. The laminate body had a structure of glass substrate / LTHC layer / bonding layer / silicon wafer, with the LTHC layer having a thickness of 0.9 gm and the bonding layer having a thickness of 50 gm.

[0213] 6, Laser separation

[0214] A dicing tape and a dicing frame were placed on the silicon wafer of the laminate body, and the laminate body was transferred onto a stage of a supporting body peeling device TWS (Tatsumo Co., Ltd., Okayama, Okayama, Japan). The laminate body was then adsorbed and fixed onto the stage by reducing the pressure from below using a vacuum device. Laser irradiation was performed from the glass substrate side of the laminate body using a YAG laser (wavelength 1064 nm) under conditions of a laser output of 6.0 W, a beam diameter of 100 gm, a scanning pitch of 100 gm, and a laser scanning speed of 1.0 m / sec. The laser light was made to travel linearly back and forth in the tangential direction from the edge of the laminate body to irradiate the entire surface of the laminate body. A suction device was attached to the glass substrate of the laser-irradiated laminate body, and the suction device manually confirmed whether the glass substrate and the silicon wafer could be easily separated.

[0215] 7, Evaluation of adhesive curing performance

[0216] Twenty hours after the formation of the laminate body, the glass substrate was removed from the laminate body, and the bonding layer was peeled from the silicon wafer. Next, the peeled bonding layer was cut to a suitable size to prepare a sample, and the mass of the sample was weighed using a precision balance. During measurement, the samples were exposed to ionized air to ensure that the measurements were not affected by static electricity. The sample was then immersed in methylethylketone and kept for 12 hours. The sample was removed from the methylethylketone and dried in a drying oven set at 60°C for 3 hours, and then the mass of the sample was weighed in the same manner as before immersion. The mass retention rate was calculated using the following formula:

[0217] Mass retention rate (%, gel fraction) = mass after immersion (g) / mass before immersion (g)

[0218] Table 4 depicts the mass retention rates and the observation results of the cured bonding layers in the examples and comparative examples, as well as the evaluation results of laser separation. Table 4 depicts the storage conditions of the curing accelerator layer, the storage conditions of the liquid adhesive before application, and the heat treatment conditions of the laminate body.

[0219]

[0220] Example 1 exhibited high mass retention rate regardless of whether or not heat treatment was performed during curing of the liquid adhesive. No change in the reactivity of the liquid adhesive was observed even after 3 months of storage at room temperature. There was no change in the mass retention rate even after the curing accelerator layer was left at 100°C for 7 days, it was demonstrated that the 1- benzy 1-5 -phenylbarbituric acid included in the curing accelerator layer was very stable. Storage at 100°C for 7 days is equivalent to storage at room temperature for more than 2 years. Examples 2 to 4 also exhibited a high mass retention rate similar to that of Example 1.

[0221] In Comparative Example 1, l-benzyl-5 -phenylbarbituric acid was added to the adhesive. The liquid adhesive of Comparative Example 1 continued to react even when stored at low temperature, and gelled within one month. The liquid adhesive of Comparative Example 2 required refrigerated storage below 5°C. The liquid adhesive of Comparative Example 3 required high temperature curing at 200°C.

[0222] In Comparative Examples 4 and 5, a method was attempted in which a peroxide capable of cleaving and reacting even at room temperature in the presence of a metal catalyst was applied onto the LTHC layer. However, the mass retention rate decreased after storage at room temperature for several days (3 to 5 days). Additionally, the liquid adhesive did not cure at the edges of the laminate body, or in other words, where the liquid adhesive was in contact with the atmosphere.

[0223] In Comparative Examples 6 and 7, a method was attempted in which a peroxide with a cleavage reaction that is accelerated by heating to a temperature exceeding 100°C was applied onto the LTHC layer. However, the reaction was insufficient at 100°C, and the adhesive remained uncured at the end parts of the laminate body.

[0224] The mass retention rate of Comparative Example 8, which used ultraviolet curing, was at the same level as Examples 1 to 4.

[0225] Examples 5 and 6

[0226] 1, Formation of light-to-heat conversion (LTHC) layer

[0227] The components shown in Table 5 were mixed using a bead mill to prepare a light-to-heat conversion layer ink composition. The light-transmitting supporting body is a disk-shaped glass substrate having a diameter of 154 mm and a thickness of 800 pm. The light-to-heat conversion layer ink composition was applied onto a glass substrate using a spin coater, heated at 100°C for 5 minutes, and then further heated at 180°C for 1 hour to form an LTHC layer. The LTHC layer included l-benzyl-5- phenylbarbituric acid as the P-dicarbonyl compound. Table 5 (units are parts by mass)

[0228] 2, Laminate body formation, laser separation, and adhesive curing performance evaluation

[0229] A laminate body was formed following the same procedure as in Example 1, except that a glass substrate having an LTHC layer containing 1-benzy 1-5 -phenylbarbituric acid was used. The laser separation of the laminate body and the curing performance evaluation of the adhesive were carried out in the same manner as in Example 1.

[0230] The mass retention rates and the observation results of the cured bonding layers in Examples 5 and 6 are shown in Table 6. Table 6 also shows the content of the -dicarbonyl compound in the LTHC layer, the storage state of the liquid adhesive before application, and the heat treatment conditions of the laminate body.

[0231] Table 6 (numbers in %)

[0232] 1) V: Vanadyl acetylacetonate, Cl: Methyltrioctylammonium chloride

[0233] 2) End parts did not harden In Example 5, the adhesive was hardened to the end parts by heat treatment at 100°C. The mass retention of the LTHC layer improved after leaving at room temperature for two months. In Example 6, the adhesive was cured all the way to the end parts regardless of whether or not heat treatment was performed, and a relatively high mass retention rate was observed.

[0234] It will be apparent to a person of ordinary skill in the art that various modifications and variations can be made to the present invention without departing from the scope and gist of the present invention. Some embodiments of the present disclosure are described below.

[0235] I Aspect 11

[0236] A kit for forming a laminate body including a light-to-heat conversion layer, comprising: a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radically polymerizable compound; a light-to-heat conversion layer ink composition containing a thermally decomposable light absorbing agent and a binder or a precursor thereof; and a curing accelerator containing a P-dicarbonyl compound expressed by the following formula or a salt thereof [Chem. Fig. 31]

[0237] (where X1and X2independently represent a covalent bond, O, S,

[0238] [Chem. Fig. 32] or

[0239] [Chem. Fig. 33] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0240] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0241] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0242] [ Aspect 21

[0243] A kit for forming a laminate body including a light-to-heat conversion layer, comprising: a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radically polymerizable compound; and a light-to-heat conversion layer ink composition containing a thermally decomposable light absorbing agent, a binder or a precursor thereof, and a p-dicarbonyl compound expressed by the following formula or a salt thereof

[0244] [Chem. Fig. 34]

[0245] (where X1and X2independently represent a covalent bond, O, S,

[0246] [Chem. Fig. 35] or

[0247] [Chem. Fig. 36] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0248] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0249] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0250] [Aspect 3]

[0251] The kit according to aspect 1 or 2, wherein the at least one polyvalent metal compound contains at least one metal selected from the group consisting of copper (II), vanadium (IV), iron (II), iron (III), cobalt (II), cobalt (III), manganese (II), and manganese (III). [Aspect 41

[0252] The kit according to any one of aspects 1 to 3, wherein the free radical polymerizable liquid adhesive also contains a quaternary ammonium halide.

[0253] [Aspect 51

[0254] The kit according to any one of aspects 1 to 4, wherein the (3-dicarbonyl compound is a barbituric acid or a derivative thereof.

[0255] [Aspect 61

[0256] The kit according to any one of aspects 1 to 5, wherein the at least one free radical polymerizable compound contains a free radical polymerizable (meth)acrylate oligomer.

[0257] [Aspect 71

[0258] The kit according to any one of aspects 1 to 6, wherein the at least one free radical polymerizable compound contains a free radical polymerizable polyfunctional (meth)acrylate.

[0259] [Aspect 81

[0260] The kit according to any one of aspects 1 to 7, wherein the kit is essentially free of organic peroxides and photoinitiators.

[0261] [Aspect 91

[0262] A laminate body, comprising: a light-transmitting supporting body; a light-to-heat conversion layer provided on the light-transmitting supporting body; and a curing accelerator layer provided on the light-to-heat conversion layer; wherein the light-to-heat conversion layer contains a thermally decomposable light absorbing agent and a binder, and the curing accelerator layer is a [Tdicarbonvl compound or salt thereof expressed by the following formula:

[0263] [Chem. Fig. 37]

[0264] (where X1and X2independently represent a covalent bond, O, S, [Chem. Fig. 38] or

[0265] [Chem. Fig. 39] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0266] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0267] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0268] 1 Aspect 101

[0269] A laminate body, comprising: a light-transmitting supporting body; and a light-to-heat conversion layer provided on the light-transmitting supporting body; wherein the light-to-heat conversion layer contains a thermally decomposable light absorbing agent, a binder, and a [l-dicarbony I compound or a salt thereof expressed by the following formula: [Chem. Fig. 40]

[0270] (where X1and X2independently represent a covalent bond, O, S, [Chem. Fig. 41]

[0271] R4

[0272] — N — each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0273] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to

[0274] 18 carbon atoms; R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0275] [Aspect 111

[0276] The laminate body according to aspect 9 or 10, wherein the light-transmitting supporting body is glass.

[0277] [Aspect 121

[0278] A method for producing a laminate body containing a light-to-heat conversion layer, comprising: applying a free radical polymerizable liquid adhesive to a base material to form a bonding precursor layer on the base material; applying the light-to-heat conversion layer ink composition to a light-transmitting supporting body to form a light-to-heat conversion layer on the light-transmitting supporting body; applying a curing accelerator onto the light-to-heat conversion layer to form a curing accelerator layer on the light-to-heat conversion layer; and bonding the base material and the light-transmitting supporting body so that the bonding precursor layer and the curing accelerator layer are in mutual contact, and at least partially curing the bonding precursor layer to form a bonding layer; wherein the free radical polymerizable liquid adhesive contains at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound; the light-to-heat conversion layer ink composition contains a thermally decomposable light absorbing agent and a binder or a precursor thereof; and the curing accelerator contains a (3-dicarbonyl compound expressed by the following formula or salt thereof

[0279] [Chem. Fig. 43]

[0280] (where X1and X2independently represent a covalent bond, O, S, [Chem. Fig. 44]

[0281] R4

[0282] — N — or

[0283] [Chem. Fig. 45] each R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0284] R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0285] R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

[0286] 1 Aspect 13]

[0287] A method for producing a laminate body containing a light-to-heat conversion layer, comprising: applying a free radical polymerizable liquid adhesive to a base material to form a bonding precursor layer on the base material; applying the light-to-heat conversion layer ink composition to a light-transmitting supporting body to form a light-to-heat conversion layer on the light-transmitting supporting body; and bonding the base material and the light-transmitting supporting body so that the bonding precursor layer and the light-to-heat conversion layer are in mutual contact, and at least partially curing the bonding precursor layer to form a bonding layer; wherein the free radical polymerizable liquid adhesive contains at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound; and the light-to-heat conversion layer ink composition contains a thermally decomposable light absorbing agent, a binder or a precursor thereof, and a (3-dicarbonyl compound or salt thereof expressed by the following formula:

[0288] [Chem. Fig. 46]

[0289] (where XI and X2 independently represent a covalent bond, O, S, [Chem. Fig. 47] or

[0290] [Chem. Fig. 48] each R4 independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;

[0291] R1 and R2 independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;

[0292] R3 represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of Rl, R2, or R3 join in forming a 5- or 6-membered ring).

[0293] [Aspect 14]

[0294] The method according to aspect 12 or 13, wherein the light-transmitting supporting body is glass.

[0295] [Aspect 15]

[0296] A method for producing a thinned base material, comprising: preparing a laminate body obtained by the method according any one of aspects 12 to 14, the base material being a base material for grinding; grinding the base material to be base material with a desired thickness; irradiating the light-to-heat conversion layer with radiant energy through the light-transmitting supporting body to decompose the light-to-heat conversion layer, thereby separating the ground base material having the bonding layer from the light-transmitting supporting body; and optionally removing the bonding layer from the base material after the grinding.

[0297] [Aspect 16]

[0298] A method for producing a semiconductor substrate laminate body, comprising: providing a laminate body obtained by the method according any one of aspects 12 to 14, the base material being a semiconductor substrate, the semiconductor substrate having an insulating layer provided on a surface of the semiconductor substrate opposite the bonding layer, and one or a plurality of conductive connections penetrating the insulating layer and electrically connecting to the semiconductor substrate; providing a second semiconductor substrate having a second insulating layer provided on a surface of the second semiconductor substrate and one or a plurality of second conductive connections passing through the second insulating layer and electrically connecting to the second semiconductor substrate; forming a semiconductor substrate laminate body in which the conductive connections of the semiconductor substrate and the second conductive connections of the second semiconductor substrate are opposing each other, by heating and pressing together the semiconductor substrate and the second semiconductor substrate so that the conductive connections and the second conductive connections are bonded together, and the insulating layer and the second insulating layer are bonded together; irradiating the light-to-heat conversion layer with radiant energy through the light-transmitting supporting body to decompose the light-to-heat conversion layer, thereby separating the semiconductor substrate laminate body having the bonding layer from the light-transmitting supporting body; and optionally removing the bonding layer from the surface of the semiconductor substrate laminate body.

[0299] Description of symbols

[0300] 10, 20, 30. Laminate body

[0301] 12. Light-transmitting supporting body

[0302] 14. Light-to-heat conversion layer

[0303] 16. Curing accelerator layer

[0304] 22. Bonding layer

[0305] 24. Base material

[0306] 25. Thinned base material

[0307] 32. Bonding layer

[0308] 34. Semiconductor substrate

[0309] 342. Insulating layer

[0310] 344. Conductive connection

[0311] 44. Second semiconductor substrate

[0312] 442. Second insulating layer

[0313] 444. Second conductive connection

[0314] 50. Semiconductor substrate laminate body

Claims

What is claimed is:

1. A kit for forming a laminate body including a light-to-heat conversion layer, comprising: a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radically polymerizable compound; a light-to-heat conversion layer ink composition containing a thermally decomposable light absorbing agent and a binder or a precursor thereof; and a curing accelerator containing a P-dicarbonyl compound expressed by the following formula or a salt thereof(where X1and X2independently represent a covalent bond, O, S,oreach R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

2. A kit for forming a laminate body including a light-to-heat conversion layer, comprising:a free radical polymerizable liquid adhesive containing at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radically polymerizable compound; and a light-to-heat conversion layer ink composition containing a thermally decomposable light absorbing agent, a binder or a precursor thereof, and a P-dicarbonyl compound expressed by the following formula or a salt thereof(where X1and X2independently represent a covalent bond, O, S,oreach R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

3. The kit according to claim 1 or 2, wherein the at least one polyvalent metal compound contains at least one metal selected from the group consisting of copper (II), vanadium (IV), iron (II), iron (III), cobalt (II), cobalt (III), manganese (II), and manganese (III).

4. The kit according to claim 1 or 2, wherein the free radical polymerizable liquid adhesive also contains a quaternary ammonium halide.

5. The kit according to claim 1 or 2, wherein the P-dicarbonyl compound is a barbituric acid or a derivative thereof.

6. The kit according to claim 1 or 2, wherein the at least one free radical polymerizable compound contains a free radical polymerizable (meth)acrylate oligomer.

7. The kit according to claim 1 or 2, wherein the at least one free radical polymerizable compound contains a free radical polymerizable (meth)acrylate.

8. The kit according to claim 1 or 2, wherein the kit is essentially free of organic peroxides and photoinitiators.

9. A laminate body, comprising: a light-transmitting supporting body; a light-to-heat conversion layer provided on the light-transmitting supporting body; and a curing accelerator layer provided on the light-to-heat conversion layer; wherein the light-to-heat conversion layer contains a thermally decomposable light absorbing agent and a binder, and the curing accelerator layer is a P-dicarbonyl compound or salt thereof expressed by the following formula:(where X1and X2independently represent a covalent bond, O, S,oreach R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

10. A laminate body, comprising: a light-transmitting supporting body; and a light-to-heat conversion layer provided on the light-transmitting supporting body; wherein the light-to-heat conversion layer contains a thermally decomposable light absorbing agent, a binder, and a P-dicarbonyl compound or a salt thereof expressed by the following formula:(where X1and X2independently represent a covalent bond, O, S,oreach R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

11. The laminate body according to claim 9 or 10, wherein the light-transmitting supporting body is glass.

12. A method for producing a laminate body containing a light-to-heat conversion layer, comprising: applying a free radical polymerizable liquid adhesive to a base material to form a bonding precursor layer on the base material; applying the light-to-heat conversion layer ink composition to a light-transmitting supporting body to form a light-to-heat conversion layer on the light-transmitting supporting body; applying a curing accelerator onto the light-to-heat conversion layer to form a curing accelerator layer on the light-to-heat conversion layer; and bonding the base material and the light-transmitting supporting body so that the bonding precursor layer and the curing accelerator layer are in mutual contact, and at least partially curing the bonding precursor layer to form a bonding layer; wherein the free radical polymerizable liquid adhesive contains at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound; the light-to-heat conversion layer ink composition contains a thermally decomposable light absorbing agent and a binder or a precursor thereof; and the curing accelerator contains a P-dicarbonyl compound expressed by the following formula or salt thereof(where X1and X2independently represent a covalent bond, O, S,oreach R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

13. A method for producing a laminate body containing a light-to-heat conversion layer, comprising: applying a free radical polymerizable liquid adhesive to a base material to form a bonding precursor layer on the base material; applying the light-to-heat conversion layer ink composition to a light-transmitting supporting body to form a light-to-heat conversion layer on the light-transmitting supporting body; and bonding the base material and the light-transmitting supporting body so that the bonding precursor layer and the light-to-heat conversion layer are in mutual contact, and at least partially curing the bonding precursor layer to form a bonding layer; wherein the free radical polymerizable liquid adhesive contains at least one free radical polymerizable compound and at least one polyvalent metal compound for polymerizing the at least one free radical polymerizable compound; and the light-to-heat conversion layer ink composition contains a thermally decomposable light absorbing agent, a binder or a precursor thereof, and a P-dicarbonyl compound or salt thereof expressed by the following formula:(where X1and X2independently represent a covalent bond, O, S,RI4— N — oreach R4independently represents H or a hydrocarbyl group having 1 to 18 carbon atoms;R1and R2independently represent a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms;R3represents hydrogen or a hydrocarbyl or substituted hydrocarbyl group having 1 to 18 carbon atoms; or any two of R1, R2, or R3join in forming a 5- or 6-membered ring).

14. The method according to claim 12 or 13, wherein the light-transmitting supporting body is glass.

15. A method for producing a thinned base material, comprising: preparing a laminate body obtained by the method according to claim 12 or 13, the base material being a base material for grinding; grinding the base material to be base material with a desired thickness; irradiating the light-to-heat conversion layer with radiant energy through the lighttransmitting supporting body to decompose the light-to-heat conversion layer, thereby separating the ground base material having the bonding layer from the light-transmitting supporting body; and optionally removing the bonding layer from the base material after the grinding.

16. A method for producing a semiconductor substrate laminate body, comprising: providing a laminate body obtained by the method according to claim 12 or 13, the base material being a semiconductor substrate, the semiconductor substrate having an insulating layer provided on a surface of the semiconductor substrate opposite the bonding layer, and one or a plurality of conductive connections penetrating the insulating layer and electrically connecting to the semiconductor substrate; providing a second semiconductor substrate having a second insulating layer provided on a surface of the second semiconductor substrate and one or a plurality of second conductive connections passing through the second insulating layer and electrically connecting to the second semiconductor substrate; forming a semiconductor substrate laminate body in which the conductive connections of the semiconductor substrate and the second conductive connections of the second semiconductor substrate are opposing each other, by heating and pressing together the semiconductor substrate and the second semiconductor substrate so that the conductiveconnections and the second conductive connections are bonded together, and the insulating layer and the second insulating layer are bonded together; irradiating the light-to-heat conversion layer with radiant energy through the lighttransmitting supporting body to decompose the light-to-heat conversion layer, thereby separating the semiconductor substrate laminate body having the bonding layer from the light-transmitting supporting body; and optionally removing the bonding layer from the surface of the semiconductor substrate laminate body.

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