Production method of adhesive sheet with metal sheet and adhesive sheet with metal sheet

Abstract

To provide a production method etc. of an adhesive sheet with a metal sheet capable of handling with ease.SOLUTION: Provided is a production method of an adhesive sheet with a metal sheet in which an adhesive sheet with a metal sheet including a metal layer and an adhesive layer is produced by cutting a laminated sheet including a metal layer constituted of a metal sheet and an adhesive layer constituted of a thermosetting adhesive sheet. In the laminated sheet, the metal sheet has a first face and a second face being an opposite face of the first face, and the thermosetting adhesive sheet has a first adhesive face and a second adhesive face being an opposite face of the first adhesive face, the first face of the metal sheet and the second adhesive face of the thermosetting adhesive sheet are bonded to each other. The thermosetting adhesive sheet is constituted of an epoxy resin composition containing an epoxy resin and an inorganic filler. The adhesive sheet with the metal sheet in which at least a part of one end face of the metal layer is a taper face and the angle between the taper face and the second face is an obtuse angle is produced.SELECTED DRAWING: Figure 1c

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an adhesive sheet with a metal sheet, and an adhesive sheet with a metal sheet.

Background Art

[0002] Conventionally, semiconductor modules in which semiconductor elements are molded with a molding resin have been widely used. Since such a semiconductor module generates heat when energized, various heat dissipation means have been taken to suppress the junction temperature in the semiconductor module from exceeding a predetermined value. As one of the heat dissipation means for a heat generating body that requires heat dissipation such as this semiconductor module, a method of using an adhesive sheet with a metal sheet is known. In this method, the heat generating body is used as an adherend, a metal sheet is adhered to the adherend via an adhesive sheet, and heat dissipation is performed through the metal sheet.

[0003] As the adhesive sheet, a thermosetting adhesive sheet containing an epoxy resin is known because it exhibits good adhesiveness to various adherends and has excellent heat resistance. Further, as the thermosetting adhesive sheet, a sheet composed of an epoxy resin composition containing an epoxy resin and an inorganic filler is known in terms of exhibiting good thermal conductivity from the heat generating body to the metal sheet.

[0004] Such an adhesive sheet with a metal sheet is produced, for example, by cutting a laminated sheet including a metal layer composed of a metal sheet and an adhesive layer composed of a thermosetting adhesive sheet into individual pieces. Since the epoxy resin composition before being completely cured is usually in a brittle state, the adhesive sheet with a metal sheet has a problem that the adhesive layer is likely to peel off from the metal sheet.

[0005] The peeling of the adhesive layer is likely to occur when a strong bending stress or the like is applied to the adhesive sheet with a metal sheet. And Patent Document 1 below discloses that in order to easily remove one by one the adhesive sheets with metal sheets from a stack of multiple adhesive sheets with metal sheets, a part or all of the outer peripheral end faces of the metal sheets are made to flare outward in a direction away from the thermosetting adhesive sheet.

Prior Art Document

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] When the outer peripheral end face of the metal sheet flares outward in a direction away from the thermosetting adhesive sheet, the edge of the metal sheet becomes an acute angle, and it is easy to damage the mating material in contact with the edge. Therefore, for example, an operator handling the adhesive sheet with a metal sheet is required to handle it carefully so as not to damage fingertips or the like. Thus, an object of the present invention is to provide an adhesive sheet with a metal sheet that is easy to handle. Another object of the present invention is to provide a method for manufacturing an adhesive sheet with a metal sheet that is easy to handle.

Means for Solving the Problems

[0008] In order to solve the above problems, the present invention is a method for manufacturing an adhesive sheet with a metal sheet, which cuts a laminated sheet including a metal layer composed of a metal sheet and an adhesive layer composed of a thermosetting adhesive sheet to manufacture an adhesive sheet with a metal sheet including the metal layer and the adhesive layer, wherein in the laminated sheet, the metal sheet has a first surface and a second surface which is the opposite surface of the first surface, the thermosetting adhesive sheet has a first adhesive surface and a second adhesive surface which is the opposite surface of the first adhesive surface, The first surface of the metal sheet is adhered to the second adhesive surface of the thermosetting adhesive sheet. The thermosetting adhesive sheet is composed of an epoxy resin composition containing an epoxy resin and an inorganic filler. Provided is a method for manufacturing an adhesive sheet with a metal sheet, wherein at least a part of the end face of the metal layer is a tapered surface, and the angle formed between the tapered surface and the second surface is an obtuse angle, for manufacturing the adhesive sheet with a metal sheet.

[0009] In order to solve the above problems, the present invention An adhesive sheet with a metal sheet, comprising a metal layer composed of a metal sheet and an adhesive layer composed of a thermosetting adhesive sheet, The metal sheet has a first surface and a second surface which is the opposite surface of the first surface, The thermosetting adhesive sheet has a first adhesive surface and a second adhesive surface which is the opposite surface of the first adhesive surface, The first surface of the metal sheet is adhered to the second adhesive surface of the thermosetting adhesive sheet, The thermosetting adhesive sheet is composed of an epoxy resin composition containing an epoxy resin and an inorganic filler, Provided is an adhesive sheet with a metal sheet, wherein at least a part of the end face of the metal layer is a tapered surface, and the angle formed between the tapered surface and the second surface is an obtuse angle.

Advantages of the Invention

[0010] According to the present invention, at least a part of the end face of the metal layer is a tapered surface, and the angle formed between the tapered surface and the second surface is an obtuse angle, so it is difficult to damage the mating material in contact with the metal layer. Therefore, according to the present invention, an adhesive sheet with a metal sheet that is easy to handle can be provided.

Brief Description of the Drawings

[0011]

Fig. 1a

Fig. 1b

Fig. 1c

Mode for Carrying Out the Invention

[0012] Hereinafter, an embodiment of the present invention will be described.

[0013] (Raw material sheet) The adhesive sheet with a metal sheet according to the present embodiment is cut out from a laminated sheet including a metal layer composed of a metal sheet and an adhesive layer composed of a thermosetting adhesive sheet. That is, in the present embodiment, the laminated sheet is used as a raw material sheet for the adhesive sheet with a metal sheet. FIGS. 1a and 1b are a perspective view and a cross-sectional view showing the state of the laminated sheet (raw material sheet S) immediately before the adhesive sheet with a metal sheet is separated into individual pieces. FIG. 1c is a cross-sectional view showing the cross-sectional structure of the adhesive sheet 10 with a metal sheet after being cut out from the raw material sheet S.

[0014] The raw material sheet S according to the present embodiment includes a first surface Sx and a second surface Sy that is the opposite surface of the first surface Sx. The raw material sheet S according to the present embodiment has a rectangular shape in plan view. All four corners of the rectangle are right angles. The raw material sheet S has a first direction (hereinafter also referred to as the longitudinal direction D1) parallel to two of the four sides defining the rectangle and a second direction (hereinafter also referred to as the lateral direction D2) parallel to the remaining two sides. In the raw material sheet S according to the present embodiment, the first direction and the second direction are orthogonal to each other. The raw material sheet S further has a third direction (hereinafter also referred to as the thickness direction D3) orthogonal to each of the first direction and the second direction.

[0015] The raw material sheet S according to this embodiment is a laminated sheet including a metal layer 1 composed of a metal sheet Sa and an adhesive layer 2 composed of a thermosetting adhesive sheet Sb. The metal sheet Sa according to this embodiment has a first surface 1a and a second surface 1b which is the opposite surface of the first surface 1a. The first surface 1a of the metal sheet Sa is located on the side of the first surface Sx of the raw material sheet S, and the second surface 1b of the metal sheet Sa is located on the side of the second surface Sy of the raw material sheet S.

[0016] The thermosetting adhesive sheet Sb according to this embodiment is composed of an epoxy resin composition containing an epoxy resin and an inorganic filler, and has a first adhesive surface 2a and a second adhesive surface 2b which is the opposite surface of the first adhesive surface 2a. The first adhesive surface 2a of the thermosetting adhesive sheet Sb is located on the side of the first surface Sx of the raw material sheet S, and the second adhesive surface 2b of the thermosetting adhesive sheet Sb is located on the side of the second surface Sy of the raw material sheet S.

[0017] In the raw material sheet S (laminated sheet) according to this embodiment, the first surface 1a of the metal sheet Sa and the second adhesive surface 2b of the thermosetting adhesive sheet Sb are adhered. The raw material sheet S according to this embodiment includes a protective sheet Sc detachably adhered to the second surface 1b of the metal sheet Sa. In the raw material sheet S according to this embodiment, the first adhesive surface 2a of the thermosetting adhesive sheet Sb is an adhesive surface used for adhesion to an adherend. Therefore, the raw material sheet S according to this embodiment further includes a separator sheet Sd adhered to the first adhesive surface 2a to protect the first adhesive surface 2a of the thermosetting adhesive sheet Sb. That is, the raw material sheet S according to this embodiment has a four-layer structure.

[0018] In the raw material sheet S according to the present embodiment, the metal sheet Sa and the protective sheet Sc are laminated with their outer peripheral edges aligned, and the thermosetting adhesive sheet Sb and the separator sheet Sd are laminated with their outer peripheral edges aligned. In the raw material sheet S according to the present embodiment, the thermosetting adhesive sheet Sb is slightly smaller than the metal sheet Sa. Therefore, in the raw material sheet S according to the present embodiment, the first surface Sx is slightly smaller than the second surface Sy. And in the raw material sheet S according to the present embodiment, the metal sheet Sa extends outward beyond the thermosetting adhesive sheet Sb. The raw material sheet S is not limited to such a mode. In the raw material sheet S, the metal sheet Sa and the thermosetting adhesive sheet Sb may have the same size and be laminated with their outer peripheral edges aligned.

[0019] The raw material sheet S is larger than the adhesive sheet 10 with a metal sheet and has a size capable of cutting out a plurality of adhesive sheets 10 with metal sheets. In the present embodiment, the shape of the adhesive sheet 10 with a metal sheet is a quadrilateral. Similar to the raw material sheet S, all four corners of the adhesive sheet 10 with a metal sheet are right angles. And in the present embodiment, the adhesive sheet 10 with a metal sheet is cut out from the raw material sheet S so that each side of the quadrilateral is parallel to each side of the raw material sheet S.

[0020] The raw material sheet S has a size capable of arranging a plurality of adhesive sheets 10 with metal sheets side by side in either the longitudinal direction D1 or the transverse direction D2. The raw material sheet S of the present embodiment has a size capable of arranging a plurality of adhesive sheets 10 with metal sheets both longitudinally and transversely. That is, the raw material sheet S of the present embodiment has a size that is 4 times (2×2) or more of the adhesive sheet 10 with a metal sheet.

[0021] In this embodiment, a V-groove is formed in the raw material sheet S, and the raw material sheet S is cut along the V-groove to fragment the adhesive sheet 10 with a metal sheet. The raw material sheet S includes a product area S' used for the adhesive sheet 10 with a metal sheet and a non-product area S'' not used for the production of the adhesive sheet 10 with a metal sheet. In the raw material sheet S of this embodiment, the product area S' is a square that is slightly smaller than the raw material sheet S and is also slightly smaller than the thermosetting adhesive sheet Sb. In this embodiment, the non-product area S'' is provided so as to surround the product area S'. That is, the non-product area S'' in this embodiment has a rectangular frame shape that constitutes the outer peripheral portion of the raw material sheet S.

[0022] The raw material sheet S of this embodiment is used to form the adhesive sheet 10 with a metal sheet having a specific shape. In the adhesive sheet 10 with a metal sheet produced using the raw material sheet S, at least a part of the end face of the metal layer 1 is a tapered surface, and the angle θ1 formed between the tapered surface and the second surface 1b is an obtuse angle.

[0023] In this embodiment, the product area S' is divided into a plurality of divided pieces by a disk cutter, and the divided pieces are used as the adhesive sheet 10 with a metal sheet. The disk cutter has a blade tip that tapers radially outward when viewed in a direction perpendicular to the axis. That is, the disk cutter in this embodiment can form a groove (V-groove) having a V-shaped cross-section with respect to the workpiece when the blade tip is brought into contact with the workpiece while rotating.

[0024] Before the fragmentation of the product area S', the raw material sheet S has V-grooves formed by a disk cutter on both the first surface Sx, which is the side where the thermosetting adhesive sheet Sb is provided, and the second surface Sy, which is the opposite surface of the first surface, among the metal sheet Sa and the thermosetting adhesive sheet Sb.

[0025] The raw material sheet S has a first-side V-groove V1 provided on the side of the first surface and a second-side V-groove V2 provided on the side of the second surface. The first-side V-groove V1 includes a plurality of vertical grooves V11 provided so as to extend in the vertical direction D1 and a plurality of horizontal grooves V12 provided so as to extend in the horizontal direction. In the case where there are a plurality of vertical grooves and horizontal grooves, the same applies to the second-side V-groove V2.

[0026] The plurality of vertical grooves V11 are provided so as to be parallel to each other with a predetermined distance in the horizontal direction D2. The plurality of horizontal grooves V12 are provided so as to be parallel to each other with a predetermined distance in the vertical direction D1.

[0027] The positions of the vertical grooves of the first-side V-groove V1 and the second-side V-groove V2 are common. The positions of the horizontal grooves of the first-side V-groove V1 and the second-side V-groove V2 are common.

[0028] The first-side V-groove V1 and the second-side V-groove V2 may be connected or separated at the deepest part of the grooves. When the first-side V-groove V1 and the second-side V-groove V2 are connected, the adhesive sheet 10 with a metal sheet can be collected from the raw material sheet S immediately. When the first-side V-groove V1 and the second-side V-groove V2 are separated, the adjacent adhesive sheets with metal sheets are connected at the central part in the thickness direction D3, so that a plurality of adhesive sheets with metal sheets can be handled as if they were a single sheet. In addition, when the adjacent adhesive sheets with metal sheets are connected, the connected part can be broken to individualize the adhesive sheets with metal sheets.

[0029] When connecting the adjacent adhesive sheets with metal sheets, they may be connected by the metal layer 1 or the adhesive layer 2. When connecting with the metal layer 1, there is a possibility that burrs are likely to occur during breakage. On the other hand, when connecting with the adhesive layer 2, such a possibility is reduced, so it is easy to obtain the adhesive sheet 10 with a metal sheet that is less likely to damage the mating material in contact with the end face. On the other hand, when connecting with the metal layer 1, it is difficult for dust or the like to be generated during breakage. If the adhesive sheets with metal sheets are connected with the adhesive layer 2 and the adhesive layer 2 is heated to be softened slightly during breakage, the generation of dust can be prevented.

[0030] The raw material sheet S may be in a connected state in one of the vertical grooves and the horizontal grooves, and in a state where the adhesive sheets with metal sheets are separated from each other in the other. In that case, the V-groove in one of the vertical groove and the horizontal groove may be only the second surface side V-groove V2. That is, in one of the vertical groove and the horizontal groove, the second surface side V-groove V2 may reach near the first adhesive surface 2a of the thermosetting adhesive sheet Sb, and only the other V-groove may be provided for the first surface side V-groove V1. When the raw material sheet S has the separator sheet Sd, in one of the vertical groove and the horizontal groove, the second surface side V-groove V2 may reach the middle of the separator sheet Sd, and the separator sheet Sd may not be completely cut. In that case, since the separator sheet Sd is connected in either the vertical direction D1 or the horizontal direction D2, it is possible to prevent the adhesive sheet 10 with a metal sheet from being scattered. Conversely, only the first surface side V-groove V1 may be provided in one of the vertical groove and the horizontal groove. In that case, in one of the vertical groove and the horizontal groove, the first surface side V-groove V1 may reach a position close to the second surface 1b of the metal sheet Sa, or may reach the middle of the protective sheet Sc. Also in that case, it is possible to prevent the adhesive sheet 10 with a metal sheet from being scattered.

[0031] In the above case, in any case, an adhesive sheet 10 with a metal sheet having a tapered surface where the angle θ1 formed with the second surface 1b is an obtuse angle on two opposing sides of the quadrilateral can be obtained. In this case, as shown in FIG. 1c, a tapered surface IS1 continuous with the edge of the second surface 1b is formed at the corner 10c so as to flare outward from the second surface 1b toward the first surface 1a, and the tapered surface IS1 is formed so as to flare outward from both ends of the second surface 1b, respectively. Then, it becomes easy to scoop up the adhesive sheet 10 with a metal sheet by a pair of members X provided with claws that can abut against the tapered surface IS1 from the side, and it becomes easy to collect the adhesive sheets 10 with a metal sheet one by one from a plurality of adhesive sheets 10 with a metal sheet stacked in the thickness direction. In the present embodiment, since it is easy to collect the adhesive sheets 10 with a metal sheet one by one using the tapered surface IS1, interfacial peeling between the metal layer 1 and the adhesive layer 2 hardly occurs when handling the adhesive sheets 10 with a metal sheet.

[0032] The adhesive sheet 10 with a metal sheet of the present embodiment is easy to pick up from the workbench by having the tapered surface IS1 even when, for example, the second surface 1b of the metal sheet Sa is placed directly in contact with the top surface of the workbench. Since the central portion in the thickness direction of the adhesive sheet 10 with a metal sheet of the present embodiment protrudes outward, it is easy to pick up from the workbench not only when the metal sheet Sa is placed on the workbench so as to face downward but also when the metal sheet Sa is placed on the workbench so as to face upward. As described above, the raw material sheet S of the present embodiment can be advantageous for forming an adhesive sheet 10 with a metal sheet that is easy to handle.

[0033] The metal sheet Sa constituting the metal layer 1 in the raw material sheet S can be, for example, a sheet made of a metal such as copper, aluminum, iron, nickel, tin, magnesium, gold, silver, or an alloy based on the metal. Further, the metal sheet Sa may be a clad material having a plurality of metal layers.

[0034] The thickness of the metal sheet Sa is not particularly limited. The thickness of the metal sheet Sa can be, for example, 0.1 mm or more. The thickness of the metal sheet Sa may be 0.2 mm or more, 0.3 mm or more, or 0.4 mm or more. The thickness of the metal sheet Sa may be 0.5 mm or more, or 0.8 mm or more. The thickness of the metal sheet Sa can be, for example, 10 mm or less. The thickness of the metal sheet Sa may be 8 mm or less, 6 mm or less, or 4 mm or less. The thickness of the metal sheet Sa may be 3 mm or less, or 2 mm or less.

[0035] The metal sheet Sa may be subjected to surface treatment such as plating treatment, oxidation treatment, matte treatment, hairline treatment, rust prevention treatment (antioxidation treatment) on either one or both of the first surface 1a and the second surface 1b. In terms of excellent thermal conductivity, the metal sheet Sa of the present embodiment is preferably a copper plate or an aluminum plate. The copper plate may be subjected to oxidation treatment such as blackening treatment, or may be subjected to matte treatment (roughening treatment) such as blasting treatment. The aluminum plate may be subjected to anodizing treatment such as phosphoric acid anodizing treatment or sulfuric acid anodizing treatment, or may be subjected to sealing treatment or the like.

[0036] In the present embodiment, since the interfacial peeling between the metal layer 1 and the adhesive layer 2 is suppressed, the metal sheet Sa may not be subjected to any special surface treatment. In the present embodiment, an untreated product which is a rolled material of copper or aluminum (rolled copper plate, rolled aluminum plate) and has not been subjected to surface treatment can be used as the metal sheet Sa. Such a metal sheet Sa is suitable in that it can be obtained at low cost.

[0037] In this embodiment, the epoxy resin contained in the epoxy resin composition is not particularly limited either. Examples of the epoxy resin contained in the epoxy resin composition include various known epoxy resins such as triphenylmethane type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, modified bisphenol A type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, modified bisphenol F type epoxy resin, dicyclohexadiene type epoxy resin, phenol novolak type epoxy resin, and phenoxy resin. These various epoxy resins may be used alone or in combination of two or more. Among these, as the epoxy resin to be contained in the epoxy resin composition, a triphenylmethane type epoxy resin is preferable, and it is preferable that 80% by mass or more of the epoxy resin contained in the thermosetting adhesive sheet is a triphenylmethane type epoxy resin.

[0038] With respect to 100 parts by mass of the epoxy resin composition, the content of the epoxy resin is preferably 5 parts by mass or more and 25 parts by mass or less, more preferably 10 parts by mass or more and 25 parts by mass or less, and still more preferably 15 parts by mass or more and 20 parts by mass or less.

[0039] The epoxy resin composition may contain a curing agent. Examples of the curing agent include phenolic curing agents, amine curing agents, and acid anhydride curing agents. Examples of the phenolic curing agent include phenol novolak resin, aralkyl type phenol resin, dicyclopentadiene modified phenol resin, naphthalene type phenol resin, and bisphenol type phenol resin. Examples of the amine curing agent include diaminodiphenyl sulfone, dicyandiamide, diaminodiphenyl methane, and triethylenetetramine. Among these, as the curing agent to be contained in the epoxy resin composition, the phenolic curing agent is preferable, and among the phenolic curing agents, the aralkyl type phenolic resin is preferably used. Examples of the aralkyl type phenolic resin include xylylene novolak phenol and bisphenol novolak phenol.

[0040] With respect to 100 parts by mass of the epoxy resin composition, the content of the curing agent is preferably 4 parts by mass or more and 25 parts by mass or less, more preferably 7 parts by mass or more and 20 parts by mass or less, and still more preferably 10 parts by mass or more and 15 parts by mass or less.

[0041] The epoxy resin composition may contain a curing accelerator. From the viewpoint of storage stability, it is preferable to use an imidazole-based curing accelerator or an amine-based curing accelerator as the curing accelerator. Examples of the amine-based curing accelerator include triphenyl phosphate (TPP) and boron trifluoride monoethylamine.

[0042] With respect to 100 parts by mass of the epoxy resin composition, the content of the curing accelerator is preferably 0.10 part by mass or more and 0.40 part by mass or less, more preferably 0.15 part by mass or more and 0.35 part by mass or less, and still more preferably 0.20 part by mass or more and 0.30 part by mass or less.

[0043] Examples of the inorganic filler contained in the epoxy resin composition include inorganic nitride fillers, inorganic oxide fillers, diamond, talc, clay, and calcium carbonate. Examples of the inorganic nitride filler include boron nitride, aluminum nitride, and silicon nitride. Examples of the inorganic oxide filler include silicon oxide (silica), aluminum oxide (alumina), titanium oxide (titania), zirconium oxide (zirconia), and the like. Among these, as the inorganic filler to be contained in the epoxy resin composition, it is preferable that it is at least 1 sort (s) chosen from the group which consists of boron nitride, aluminum oxide, and silicon oxide. Moreover, it is more preferable that the said epoxy resin composition contains the mixture containing boron nitride and aluminum oxide, or the mixture containing boron nitride and silicon oxide as the said inorganic filler. In the said mixture, it is preferable that the content of boron nitride is 50 mass % or more and 95 mass % or less.

[0044] Since the said inorganic filler has a higher thermal conductivity than the epoxy resin, it is advantageous for the thermosetting adhesive sheet Sb to be highly filled in order to exhibit excellent thermal conductivity in the adhesive sheet 10 with a metal sheet. When the said thermosetting adhesive sheet Sb contains boron nitride as the said inorganic filler, the content of boron nitride in the said thermosetting adhesive sheet is preferably 30 volume % or more, more preferably 40 volume % or more, and still more preferably 50 volume % or more. When the content of boron nitride in the said thermosetting adhesive sheet is 30 volume % or more, the said thermosetting adhesive sheet Sb becomes excellent in thermal conductivity. On the other hand, from a viewpoint of exhibiting excellent adhesiveness, mechanical strength, and electrical insulation in the said thermosetting adhesive sheet Sb, the content of boron nitride in the said thermosetting adhesive sheet is preferably 65 volume % or less. In addition, the content of boron nitride in the said thermosetting adhesive sheet Sb means the value at 20 degreeC.

[0045] The said thermosetting adhesive sheet preferably has a thermal conductivity of 5 W / mK or more, more preferably 7 W / mK or more, and still more preferably 10 W / mK or more. In the thermosetting adhesive sheet, the content of the inorganic filler is limited from the viewpoint of exhibiting excellent adhesiveness and mechanical strength. Therefore, the thermal conductivity of the thermosetting adhesive sheet is usually 20 W / m·K or less.

[0046] The thermosetting adhesive sheet preferably has a volume resistivity of 1×10 12 Ω·cm or more. Further, it is preferable that the thermosetting sheet exhibits more sufficient electrical insulation by having a volume resistivity of 1×10 13 Ω·cm or more. Note that since the thermosetting adhesive sheet is highly filled with an inorganic filler, it is difficult to expect excessive electrical insulation in the thermosetting adhesive sheet. Therefore, in the thermosetting adhesive sheet, the volume resistivity is usually 1×10 18 Ω·cm or less.

[0047] The epoxy resin composition may contain various additives. Examples of the additives include those generally used as plastic compounding chemicals such as dispersants, tackifiers, anti-aging agents, antioxidants, processing aids, stabilizers, defoamers, flame retardants, thickeners, and pigments.

[0048] In the raw material sheet S of the present embodiment, the thickness of the adhesive layer 2 composed of the thermosetting adhesive sheet Sb is not particularly limited. The thickness of the adhesive layer 2 can be, for example, 100 μm or more. The thickness of the adhesive layer 2 may be 150 μm or more, 200 μm or more, or 250 μm or more. The thickness of the adhesive layer 2 can be, for example, 1000 μm or less. The thickness of the adhesive layer 2 may be 750 μm or less, 600 μm or less, or 450 μm or less.

[0049] For the protective sheet Sc, for example, an adhesive sheet having a base material such as a polyvinyl chloride resin film, a polyethylene resin film, or a polyethylene terephthalate resin film can be used. That is, the protective sheet Sc may be an adhesive sheet including a base material layer and an adhesive layer. The protective sheet Sc preferably has flexibility so as to exhibit excellent followability with respect to the second surface 1b of the metal sheet Sa. The protective sheet Sc can be left in a state of being adhered without being peeled off from the metal sheet Sa when forming a V-groove in the metal sheet Sa. In that case, it is desirable to have appropriate rigidity in order to exhibit good grindability. From such a viewpoint, the protective sheet Sc is preferably an adhesive sheet having a polyethylene resin film as a base material.

[0050] The thickness of the polyethylene resin film is not particularly limited. The thickness of the polyethylene resin film can be, for example, 10 μm or more. The thickness of the polyethylene resin film may be 20 μm or more, or may be 30 μm or more. The thickness of the polyethylene resin film can be, for example, 200 μm or less. The thickness of the polyethylene resin film may be 150 μm or less, or may be 100 μm or less.

[0051] The separator sheet Sd may be an adhesive sheet having an adhesive layer like the protective sheet Sc, but is preferably a simple resin sheet without an adhesive layer in order to suppress the possibility of excessive adhesion with the adhesive layer 2. The separator sheet Sd can be, for example, a polyvinyl chloride resin film, a polyethylene resin film, a polyethylene terephthalate resin film, or the like. The separator sheet Sd may be, for example, kraft paper subjected to a release treatment.

[0052] The separator sheet Sd is preferably a polyethylene terephthalate resin film having a matte treatment on the surface in contact with the adhesive layer 2 in order to exhibit appropriate adhesiveness with the adhesive layer 2 and good peelability.

[0053] The thickness of the polyethylene terephthalate resin film is not particularly limited. The thickness of the polyethylene terephthalate resin film can be, for example, 25 μm or more. The thickness of the polyethylene terephthalate resin film may be 50 μm or more, or may be 75 μm or more. The thickness of the polyethylene terephthalate resin film can be, for example, 500 μm or less. The thickness of the polyethylene terephthalate resin film may be 250 μm or less, or may be 200 μm or less.

[0054] The thicknesses of the metal sheet Sa constituting the metal layer 1, the thermosetting adhesive sheet Sb constituting the adhesive layer 2, the base material of the protective sheet Sc, and the separator sheet Sd can be measured by a micrometer or the like, and can be obtained as the arithmetic mean value when measuring the thicknesses at 10 randomly selected locations.

[0055] In addition, the raw material sheet S may have a two-layer structure of the metal sheet Sa and the thermosetting adhesive sheet Sb, or may have a three-layer structure or a four-layer structure. That is, in addition to the two-layer structure of the metal sheet Sa and the thermosetting adhesive sheet Sb, the raw material sheet S may further include at least one of the protective sheet Sc and the separator sheet Sd.

[0056] (Adhesive sheet with metal sheet) Since the adhesive sheet 10 with a metal sheet according to the present embodiment is common to the raw material sheet S in terms of its configuration and the thickness of each part, detailed description will not be repeated here.

[0057] In the adhesive sheet 10 with a metal sheet according to this embodiment, a part or all of the end face that defines the outer peripheral portion of the metal layer 1 is a first tapered surface I that expands outward from the second surface 1b toward the first surface 1a. S1 It is like this. In the adhesive sheet 10 with a metal sheet according to this embodiment, the portion of the end face close to the second surface 1b is the first tapered surface I. S1 It is like this.

[0058] In the adhesive sheet 10 with a metal sheet according to this embodiment, it expands outward from the first surface 1a toward the second surface 1b and further has a second tapered surface I that intersects the first tapered surface I. S1 A second tapered surface I S2 is further provided. In the adhesive sheet 10 with a metal sheet according to this embodiment, the portion of the end face close to the first surface 1a is the second tapered surface I. S2 It is like this.

[0059] In the adhesive sheet 10 with a metal sheet according to this embodiment, the angle θ1 between the second surface 1b and the first tapered surface I S1 is an obtuse angle. The first tapered surface I S1 is preferably provided on all four sides of the adhesive sheet 10 with a metal sheet, and is preferably provided on at least two opposite sides. The first tapered surface I S1 When provided at a plurality of locations, the angles formed by each first tapered surface I S1 and the second surface 1b may all be the same or different. The angle θ1 can be, for example, 95 degrees or more. The angle θ1 may be 100 degrees or more, and may be 105 degrees or more. The angle θ1 can be 150 degrees or less. The angle θ1 may be 140 degrees or less, and may be 135 degrees or less.

[0060] In the adhesive sheet 10 with a metal sheet according to this embodiment, the first surface 1a and the second tapered surface I S2The angle θ2 between them is an obtuse angle. Second tapered surface I S2 is preferably provided on all four sides of the adhesive sheet 10 with a metal sheet, and is preferably provided on at least two opposing sides. Second tapered surface I S2 When provided at a plurality of locations, the angles formed by each second tapered surface I S2 and the first surface 1a may all be the same or different. The angle θ2 can be, for example, 95 degrees or more. The angle θ2 may be 100 degrees or more, and may be 105 degrees or more. The angle θ2 can be 150 degrees or less. The angle θ2 may be 140 degrees or less, and may be 135 degrees or less.

[0061] In the adhesive sheet 10 with a metal sheet according to this embodiment, the first tapered surface I is at the central portion in the thickness direction S1 and the second tapered surface I S2 intersect. In this embodiment, the interior angle α of this intersection portion is also an obtuse angle.

[0062] The interior angle α of the intersection portion is usually the supplementary angle (180 - θ1) between the second surface 1b and the first tapered surface I S1 and the sum (360 - (θ1 + θ2)) of the supplementary angle (180 - θ2) between the first surface 1a and the second tapered surface I S2 Therefore, in order to make the interior angle α of the intersection portion an obtuse angle, it is preferable to satisfy the following formula (1a), more preferably to satisfy the following formula (1b), and even more preferably to satisfy the following formula (1c). 190 ≤ (θ1 + θ2) < 270 ···(1a) 190 ≤ (θ1 + θ2) ≤ 265 ···(1b) 200 ≤ (θ1 + θ2) ≤ 260 ···(1c)

[0063] ​These angles (θ1, θ2, α) are parallel to the thickness direction of the adhesive sheet 10 with a metal sheet, and can be measured by observing the cross-section when the adhesive sheet 10 with a metal sheet is cut in a plane orthogonal to the side where the angles are observed, using a microscope or the like. In addition, in the cross-section, the first surface 1a, the second surface 1b, the first tapered surface I S1 , and the second tapered surface I S2 If each of them is not observed as a straight line but has some undulation, etc., an approximate straight line may be obtained by the least squares method to obtain each angle. Also, for each angle, it can be the arithmetic mean value of the measured values in a plurality of randomly selected cross-sections (for example, 10 cross-sections).

[0064] (Manufacturing method of adhesive sheet with metal sheet) In the manufacturing method of the adhesive sheet with a metal sheet according to the present embodiment, as described above, a laminated sheet including a metal layer 1 composed of a metal sheet Sa and an adhesive layer 2 composed of a thermosetting adhesive sheet Sb is used as a raw material sheet S. In the manufacturing method of the present embodiment, the raw material sheet S is cut to manufacture an adhesive sheet 10 with a metal sheet including the metal layer 1 and the adhesive layer 2. In the present embodiment, the thermosetting adhesive sheet Sb is composed of an epoxy resin composition containing an epoxy resin and an inorganic filler, has a first adhesive surface 2a and a second adhesive surface 2b which is the opposite surface of the first adhesive surface 2a, and the metal sheet Sa has a first surface 1a and a second surface 1b which is the opposite surface of the first surface 1a. And in the present embodiment, using the raw material sheet S (laminated sheet) in which the first surface 1a of the metal sheet Sa and the second adhesive surface 2b of the thermosetting adhesive sheet Sb are adhered, at least a part of the end surface of the metal layer 1 is a tapered surface, and an adhesive sheet 10 with a metal sheet in which the angle θ1 formed by the tapered surface and the second surface 1b is an obtuse angle is manufactured.

[0065] In the manufacturing method of the present embodiment, as described above, a disk cutter is used for cutting the raw material sheet S. The disk cutter is usually disk-shaped and has cutting edges provided on its outer peripheral portion. The disk cutter extends in a direction perpendicular to the plate surface and has an axis passing through the center of the disk cutter. The disk cutter is capable of making a cut in the mating material with the cutting edge by bringing the outer peripheral edge into contact with the mating material while rotating around the axis.

[0066] The cutting means for the raw material sheet S in this embodiment is not limited to a disk cutter. For cutting the raw material sheet S, a band saw, a laser cutter, etc. can also be used. Also, if necessary, a slitting cutter or the like may be used for cutting the raw material sheet S. In this embodiment, after cutting the raw material sheet S with a slitting cutter or the like and once producing an adhesive sheet with a metal sheet whose end face is perpendicular to the second face 1b, it may be shaved so that the end face becomes oblique to form a tapered surface.

[0067] The disk cutter has a cutting edge that tapers outward in the radial direction when viewed in a direction perpendicular to the axis. When a V-groove is provided in the raw material sheet S using such a disk cutter, each of one inner wall surface and the other inner wall surface rising from the deepest part of the groove can be made into a tapered surface. Therefore, when using a slitting cutter or the like, cutting and the formation of the tapered surface are divided into two steps, whereas when using a disk cutter, the formation of the tapered surface is also performed in one step. A method of forming the first tapered surface I by making a cut in the raw material sheet S from the side of the metal layer 1 with a disk cutter to form a V-groove in the raw material sheet S S1 can be said to be an efficient method.

[0068] In terms of manufacturing the adhesive sheet 10 with an easy-to-handle metal sheet, the shape of the adhesive sheet 10 with a metal sheet to be manufactured may be square, the tapered surface may be formed on at least two of the four sides of the square, and the tapered surface may be formed on two opposite sides of the square.

[0069] In this embodiment, V-grooves are formed on both the first surface Sx of the raw material sheet S and the second surface Sy which is the opposite surface of the first surface Sx by a disk cutter, and a first surface side V-groove V1 provided on the side of the first surface Sx and a second surface side V-groove V2 provided on the side of the second surface Sy are formed along a line segment defining at least a part of the outer periphery of the adhesive sheet 10 with a metal sheet. The second surface side V-groove V2 forms the first tapered surface I S1 while the first surface side V-groove V1 forms the first tapered surface I S1 and a second tapered surface I which is a reverse taper to the first tapered surface I S2 on the first surface Sx side of the raw material sheet S, and an adhesive sheet 10 with a metal sheet in which the central portion in the thickness direction protrudes outwardly at a location corresponding to the line segment may be manufactured. In this case, an adhesive sheet 10 with an easy-to-handle metal sheet can be efficiently manufactured.

[0070] In the formation of the V-groove along the line segment, the first surface side V-groove V1 may be formed after the second surface side V-groove V2 is formed. When forming the V-groove from the metal layer side, there is a possibility that the adhesive layer 2 peels near the V-groove. However, by forming the first surface side V-groove V1 provided from the adhesive layer side later, it becomes easier to remove the peeled portion. When peeling of the adhesive layer occurs in the formation of the second surface side V-groove V2, the peeling mainly occurs near the deepest part of the second surface side V-groove V2.

[0071] The peeled portion appears whiter than the surrounding area in the appearance of the first adhesive surface 2a. Therefore, when peeling of the adhesive layer 2 occurs near the deepest part of the second surface side V-groove V2, it appears as a white line on the first adhesive surface 2a, and the degree of peeling can be grasped by the width of the white line. Therefore, for example, when almost no peeling is observed, the raw material sheet S is cut such that the cutting depth of the disk cutter when forming the V-groove V1 on the first surface side reaches the deepest part of the V-groove V2 on the second surface side. When a certain amount of peeling occurs during the formation of the V-groove V2 on the second surface side, if the cutting depth of the disk cutter when forming the V-groove V1 on the first surface side is made to exceed the deepest part of the V-groove V2 on the second surface side to some extent, the peeled part can be selectively removed.

[0072] The V-groove V2 on the second surface side may be provided such that its deepest part is located in the metal layer 1 or may be provided such that it is located in the adhesive layer 2. The V-groove V2 on the second surface side may be provided such that its deepest part passes through the adhesive layer 2 and reaches the separator sheet Sd. In addition, providing the V-groove V1 on the first surface side later is also effective for removing burrs that may occur at the edge of the first surface 1a of the metal layer 1.

[0073] The V-groove provided in the raw material sheet S using a disk cutter usually has a groove width in a direction orthogonal to the extending direction of the V-groove that becomes narrower from the surface side of the raw material sheet S toward the deepest part of the groove. The degree to which this groove width becomes narrower toward the deepest part is usually determined by the shape of the cutting edge of the disk cutter. Therefore, in this embodiment, a plurality of disk cutters with different cutting edge angles may be used so as to form V-grooves with different cross-sectional shapes.

[0074] The disk cutter in this embodiment may be a chip saw or a disk grinder. In this embodiment, a plurality of disk cutters including one or more chip saws and one or more disk grinders may be used for cutting the raw material sheet S. When forming a plurality of V-grooves parallel to each other in the raw material sheet S, the V-grooves may be formed one by one with one disk cutter, or a plurality of V-grooves may be formed at once with a plurality of disk cutters.

[0075] The adhesive sheet 10 with a metal sheet formed by forming V-grooves from both sides on the raw material sheet S can be used for heat dissipation from the adherend by removing foreign substances adhering to the end faces, then removing the protective sheet Sc and the separator sheet Sd, exposing the first adhesive surface 2a, and adhering the first adhesive surface 2a to the adherend. Adhesion to the adherend can be carried out by heating the adhesive layer to a temperature equal to or higher than the curing temperature of the epoxy resin and pressing the first adhesive surface 2a against the adherend.

[0076] Note that the manufacturing method of the adhesive sheet with a metal sheet and the adhesive sheet with a metal sheet according to the present invention are not limited to the above-described embodiment. Also, the manufacturing method of the adhesive sheet with a metal sheet and the adhesive sheet with a metal sheet according to the present invention are not limited by the above-described effects. The manufacturing method of the adhesive sheet with a metal sheet and the adhesive sheet with a metal sheet according to the present invention can be variously modified without departing from the gist of the present invention.

[0077] The matters disclosed by this specification include the following. (1) A manufacturing method of an adhesive sheet with a metal sheet for manufacturing an adhesive sheet with a metal sheet having a metal layer composed of a metal sheet and an adhesive layer composed of a thermosetting adhesive sheet, In the laminated sheet, the metal sheet has a first surface and a second surface which is the opposite surface of the first surface, the thermosetting adhesive sheet has a first adhesive surface and a second adhesive surface which is the opposite surface of the first adhesive surface, the first surface of the metal sheet is adhered to the second adhesive surface of the thermosetting adhesive sheet, the thermosetting adhesive sheet is composed of an epoxy resin composition containing an epoxy resin and an inorganic filler, manufacturing the adhesive sheet with a metal sheet in which at least a part of the end face of the metal layer is a tapered surface and the angle formed by the tapered surface and the second surface is an obtuse angle Method for manufacturing an adhesive sheet with a metal sheet. (2) The shape of the adhesive sheet with a metal sheet to be manufactured is rectangular, The tapered surfaces are formed on two sides that are in a positional relationship of facing each other in the rectangle. The method for manufacturing an adhesive sheet with a metal sheet according to (1) above. (3) The tapered surface is formed by cutting into the laminated sheet from the side of the metal layer with a disk cutter to form a V-groove in the laminated sheet. The method for manufacturing an adhesive sheet with a metal sheet according to (1) or (2) above. (4) V-grooves are formed on both the first surface of the laminated sheet and the second surface which is the opposite surface of the first surface with a disk cutter, The first-surface-side V-groove provided on the side of the first surface and the second-surface-side V-groove provided on the side of the second surface are formed along a line segment that defines at least a part of the outer periphery of the adhesive sheet with a metal sheet, The tapered surface is formed by the second-surface-side V-groove, and a tapered surface that is an inverse taper to the tapered surface is formed on the first surface side of the laminated sheet by the first-surface-side V-groove, An adhesive sheet with a metal sheet is manufactured in which the central portion in the thickness direction protrudes outward at a location corresponding to the line segment. The method for manufacturing an adhesive sheet with a metal sheet according to (3) above. (5) In the formation of the V-groove along the line segment, the first-surface-side V-groove is formed after the second-surface-side V-groove is formed. The method for manufacturing an adhesive sheet with a metal sheet according to (4) above. (6) An adhesive sheet with a metal sheet including a metal layer composed of a metal sheet and an adhesive layer composed of a thermosetting adhesive sheet, The metal sheet has a first surface and a second surface which is the opposite surface of the first surface, The thermosetting adhesive sheet has a first adhesive surface and a second adhesive surface which is the opposite surface of the first adhesive surface, The first surface of the metal sheet is adhered to the second adhesive surface of the thermosetting adhesive sheet. The thermosetting adhesive sheet is composed of an epoxy resin composition containing an epoxy resin and an inorganic filler. At least a part of the end face of the metal layer is a tapered surface, and the angle formed by the tapered surface and the second surface is an obtuse angle. Adhesive sheet with a metal sheet. (7) The shape is a quadrilateral, and the tapered surfaces are provided on two sides that are in a positional relationship of facing each other in the quadrilateral. The adhesive sheet with a metal sheet according to the above (6). (8) At the location where the tapered surface is formed, the central portion in the thickness direction protrudes outward. The adhesive sheet with a metal sheet according to the above (6) or (7).

Explanation of reference numerals

[0078] 1 Metal layer, 1a First surface, 1b Second surface, 2 Adhesive layer, 2a First adhesive surface, 2b Second adhesive surface, 10 Adhesive sheet with a metal sheet, I S1 First tapered surface, I S2 Second tapered surface S Raw material sheet (laminated sheet), Sa Metal sheet, Sb Thermosetting adhesive sheet, V1 First surface side V-groove, V2 Second surface side V-groove

Claims

1. A method for manufacturing an adhesive sheet with a metal sheet, which cuts a laminated sheet including a metal layer composed of a metal sheet and an adhesive layer composed of a thermosetting adhesive sheet to manufacture an adhesive sheet with a metal sheet including the metal layer and the adhesive layer, in the laminated sheet, the metal sheet has a first surface and a second surface opposite to the first surface, the thermosetting adhesive sheet has a first adhesive surface and a second adhesive surface opposite to the first adhesive surface, the first surface of the metal sheet is adhered to the second adhesive surface of the thermosetting adhesive sheet, the thermosetting adhesive sheet is composed of an epoxy resin composition containing an epoxy resin and an inorganic filler, at least a part of the end face of the metal layer is a tapered surface, and an adhesive sheet with a metal sheet is manufactured, in which the angle formed by the tapered surface and the second surface is an obtuse angle A method for manufacturing an adhesive sheet with a metal sheet.

2. The shape of the adhesive sheet with a metal sheet to be manufactured is a quadrilateral, the tapered surfaces are formed on two sides that are in a positional relationship of facing each other in the quadrilateral The method for manufacturing an adhesive sheet with a metal sheet according to claim 1.

3. The tapered surface is formed by making a cut into the laminated sheet from the side of the metal layer with a disk cutter to form a V-groove in the laminated sheet The method for manufacturing an adhesive sheet with a metal sheet according to claim 1 or 2.

4. V-grooves are formed on both the first surface of the laminated sheet and the second surface opposite to the first surface with a disk cutter, a first surface side V-groove provided on the side of the first surface and a second surface side V-groove provided on the side of the second surface are formed along a line segment that defines at least a part of the outer periphery of the adhesive sheet with a metal sheet, the tapered surface is formed by the second surface side V-groove, and a tapered surface that is an inverse taper to the tapered surface is formed on the first surface side of the laminated sheet by the first surface side V-groove, An adhesive sheet with a metal sheet is manufactured, in which the central part in the thickness direction protrudes outward at a location corresponding to the line segment The method for manufacturing an adhesive sheet with a metal sheet according to claim 3.

5. In the formation of the V-groove along the line segment, the first surface side V-groove is formed after the second surface side V-groove is formed The method for manufacturing an adhesive sheet with a metal sheet according to claim 4.

6. An adhesive sheet with a metal sheet including a metal layer composed of a metal sheet and an adhesive layer composed of a thermosetting adhesive sheet, The metal sheet has a first surface and a second surface opposite to the first surface. The thermosetting adhesive sheet has a first adhesive surface and a second adhesive surface opposite to the first adhesive surface. The first surface of the metal sheet is adhered to the second adhesive surface of the thermosetting adhesive sheet. The thermosetting adhesive sheet is composed of an epoxy resin composition containing an epoxy resin and an inorganic filler. At least a part of the end face of the metal layer is a tapered surface, and the angle formed by the tapered surface and the second surface is an obtuse angle. Adhesive sheet with a metal sheet.

7. The shape is a quadrilateral, and the tapered surfaces are provided on two sides that are in a positional relationship of facing each other in the quadrilateral. The adhesive sheet with a metal sheet according to claim 6.

8. At the location where the tapered surface is formed, the central portion in the thickness direction protrudes outward. The adhesive sheet with a metal sheet according to claim 6 or 7.

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