Manufacturing method of laminate

Abstract

The present invention provides a laminate manufacturing method including: providing, on a support sheet, a film-like firing material that contains sinterable metal particles and a binder component and that has the same shape or substantially the same shape as a semiconductor chip and has the same size as the semiconductor chip; sticking the film-like firing material on the support sheet to a substrate; peeling the support sheet from the substrate and the film-like firing material; sticking the back side of the semiconductor chip to the film-like firing material on the substrate face to face; and heating the film-like firing material to 200°C or higher to subject the semiconductor chip and the substrate to sinter bonding.

Description

[Technical field]

[0001] The present invention relates to a method for producing a laminate. This application claims priority based on Japanese Patent Application No. 2019-153524, filed on August 26, 2019, the contents of which are incorporated herein by reference. [Background technology]

[0002] In recent years, the demand for power semiconductor elements (power devices) has increased along with the trend toward higher voltages and currents in automobiles, air conditioners, personal computers, etc. Since power semiconductor elements are used under high voltages and currents, the generation of heat from the semiconductor elements can easily become a problem. Conventionally, a heat sink is sometimes attached around a semiconductor element to dissipate heat generated from the semiconductor element, but if the thermal conductivity at the joint between the heat sink and the semiconductor element is not good, efficient heat dissipation is hindered.

[0003] As a joining material capable of forming the above-mentioned joint having excellent thermal conductivity, for example, a paste-like metal microparticle composition obtained by mixing heat-sinterable metal particles, a polymeric dispersant, and a volatile dispersion medium is known. This composition is a sintered material that forms a solid metal by sintering, and this solid metal is said to be capable of forming the above-mentioned joint. However, when using such a paste-like sintering material, the joint is formed by applying it to the objects to be sintered and then sintering it, but it is difficult to make the thickness of the applied material uniform, and it is difficult to form the joint with high thickness stability.

[0004] These problems can be solved by using a film-like sintered material, which is formed in advance with a highly stable thickness, and is then attached to the object to be sintered (e.g., a semiconductor wafer) and sintered to form a highly stable joint. As such a film-like sintered material, for example, one containing sinterable metal particles and a binder component has been disclosed. This film-like sintered material is used as a film-like sintered material with a support sheet, in which a support sheet is temporarily attached releasably to one side and a release film is provided on the other side. The support sheet is provided with an adhesive layer on the entire surface or the outer periphery of the base film, and is configured so that the average thickness of the end of the film-like sintered material, the area of ​​the release film, and the presence or absence of cuts in the release film satisfy specific conditions (see Patent Document 1). This film-like sintered material is used after peeling off the release film, and can form the above-mentioned joint with excellent thickness stability and thermal conductivity. In this film-like sintered material, damage such as cohesive failure, which is usually likely to occur when peeling off the release film, is suppressed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent No. 6327630 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the film-shaped sintered material described in Patent Document 1 is intended to be attached to the entire back surface of a semiconductor wafer when it is used. Therefore, after being attached to a semiconductor wafer, this film-shaped sintered material is cut to match the shape and size of the semiconductor chip when the semiconductor wafer is divided into semiconductor chips. The film-shaped sintered material after cutting is finally sintered to form a joint that joins the semiconductor chip and the substrate. However, since the film-shaped sintered material containing a large amount of sinterable metal particles is relatively brittle, there is a problem that cutting waste is easily generated when cutting, and depending on the cutting method, it is easily broken. Furthermore, if there is a defect in the semiconductor chip, the semiconductor chip cannot be used, so the film-shaped sintered material attached to the semiconductor chip is wasted, and there is a problem that the yield of the film-shaped sintered material is reduced.

[0007] The present invention aims to provide a method for manufacturing a laminate in which a semiconductor chip and a substrate are stacked together via a joint, the joint being formed by sintering a film-shaped sintered material, which has excellent thickness stability and thermal conductivity, can suppress damage to the film-shaped sintered material, and has a good yield of the film-shaped sintered material. [Means for solving the problem]

[0008] The present invention provides a method for manufacturing a laminate, the method including the steps of: providing a film-shaped sintered material, which contains sinterable metal particles and a binder component and has the same shape or approximately the same shape and size as a semiconductor chip to be affixed, on a support sheet; affixing the film-shaped sintered material on the support sheet to a substrate; peeling the support sheet from the substrate and the film-shaped sintered material; affixing the back side of the semiconductor chip to the film-shaped sintered material on the substrate with the back side facing each other; and heating the film-shaped sintered material to 200°C or higher to sinter-bond the semiconductor chip and the substrate.

[0009] In the method for producing a laminate of the present invention, the film-shaped sintered material may be heated to 200° C. or higher and pressurized at 5 MPa or higher to sinter-bond the semiconductor chip and the substrate. In the method for producing a laminate of the present invention, the substrate may be a ceramic substrate. In the method for manufacturing a laminate of the present invention, the support sheet comprises a base film and an adhesive layer provided on the entire surface of the base film, and the film-shaped sintered material may be provided on the adhesive layer of the support sheet. In the method for manufacturing a laminate of the present invention, the support sheet comprises a base film and an adhesive layer provided on the peripheral portion of the base film, and the film-shaped sintered material may be provided on an area of ​​the base film of the support sheet where the adhesive layer is not provided. In the method for producing a laminate of the present invention, the pressure-sensitive adhesive layer may be energy ray-curable. In the method for producing a laminate of the present invention, the pressure-sensitive adhesive layer having energy ray curability may be irradiated with energy rays, and the support sheet may be peeled off from the film-shaped sintered material.

[0010] In the method for producing a laminate of the present invention, the film-shaped sintered material formed on a release film may be transferred onto the support sheet, thereby providing the film-shaped sintered material on the support sheet. In the method for producing a laminate of the present invention, the film-shaped sintered material may be formed by printing on the release film. In the method for manufacturing the laminate of the present invention, the film-shaped sintered material may be formed on the release film by punching using a mold that has the same shape or approximately the same shape and size as the semiconductor chip to be attached. In the method for producing a laminate of the present invention, the film-shaped sintered material may be provided on the support sheet by printing. In the method for producing a laminate of the present invention, the support sheet may be circular. In the method for producing a laminate of the present invention, the support sheet may be capable of being wound into a reel, and the film-shaped sintered material may be provided on the support sheet so as to be arranged at regular intervals. Effect of the Invention

[0011] According to the present invention, there is provided a method for manufacturing a laminate in which a semiconductor chip and a substrate are stacked together via a joint, the joint being formed by sintering a film-shaped sintered material, which has excellent thickness stability and thermal conductivity, can suppress damage to the film-shaped sintered material, and has a good yield of the film-shaped sintered material. [Brief description of the drawings]

[0012] [Figure 1A] FIG. 2 is a plan view illustrating an example of a support sheet used in the manufacturing method of the present embodiment. [Figure 1B] 1B is a cross-sectional view of the support sheet shown in FIG. 1A taken along line II in FIG. 1A. [Figure 2A] FIG. 4 is a plan view illustrating another example of a support sheet used in the manufacturing method of the present embodiment. [Figure 2B] 2B is a cross-sectional view of the support sheet shown in FIG. 2A taken along line II-II in FIG. 2A. [Figure 3A] FIG. 11 is a plan view illustrating a schematic diagram of still another example of a support sheet used in the manufacturing method of the present embodiment. [Figure 3B] 3B is a cross-sectional view of the support sheet shown in FIG. 3A taken along line III-III in FIG. 3A. [Figure 4A] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the first embodiment. [Figure 4B] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the first embodiment. [Figure 4C] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the first embodiment. [Figure 4D] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the first embodiment. [Figure 4E] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the first embodiment. [Diagram 5] FIG. 1 is a plan view showing a schematic example of a film-shaped sintered material with a support sheet obtained by the manufacturing method of the first embodiment. [Figure 6] FIG. 4 is a plan view showing a schematic diagram of another example of a film-shaped sintered material with a support sheet obtained by the manufacturing method of the first embodiment. [Figure 7] FIG. 4 is a plan view showing a schematic diagram of still another example of a film-shaped sintered material with a support sheet, obtained by the manufacturing method of the first embodiment. [Figure 8] FIG. 1 is a cross-sectional view showing a schematic example of a film-shaped sintered material with a support sheet, which is provided with a protective film and obtained by the manufacturing method of the first embodiment. [Figure 9] FIG. 2 is a cross-sectional view showing a schematic example of a film-shaped sintered material with a support sheet, the film having a protective film, being unwound from a reel. [Figure 10A] FIG. 11 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the second embodiment. [Figure 10B] FIG. 11 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the second embodiment. [Figure 10C] FIG. 11 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the second embodiment. [Figure 10D] FIG. 11 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the second embodiment. [Figure 10E] FIG. 11 is a cross-sectional view for illustrating a schematic example of a method for producing the laminate of the second embodiment. [Figure 11] FIG. 11 is a plan view showing a schematic example of a film-shaped sintered material with a support sheet obtained by the manufacturing method of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] <<Laminate manufacturing method>> A method for manufacturing a laminate according to one embodiment of the present invention includes the steps of: providing a film-shaped sintered material containing sinterable metal particles and a binder component and having the same or approximately the same shape and size as the semiconductor chip to be attached on a support sheet (sometimes referred to as "step A" in this specification); attaching the film-shaped sintered material on the support sheet to a substrate (sometimes referred to as "step B" in this specification); peeling the support sheet from the substrate and the film-shaped sintered material (sometimes referred to as "step C" in this specification); attaching the back side of the semiconductor chip to the film-shaped sintered material on the substrate with the back side facing each other (sometimes referred to as "step D" in this specification); and heating the film-shaped sintered material to 200°C or higher to sinter-bond the semiconductor chip and the substrate (sometimes referred to as "step E" in this specification).

[0014] In the manufacturing method of the laminate of this embodiment, in step A, a film-shaped sintered material of the same shape or approximately the same shape and size as the semiconductor chip to be attached is provided on the support sheet, so there is no need to cut the film-shaped sintered material to match the shape and size of the semiconductor chip. Therefore, even if the film-shaped sintered material is brittle, no cutting waste is generated from the film-shaped sintered material, and damage to the film-shaped sintered material is suppressed. In addition, in step D, a semiconductor chip is attached to the film-shaped sintered material, so that by avoiding the use of a defective semiconductor chip, a semiconductor chip without a defect can be attached to the film-shaped sintered material. Therefore, the film-shaped sintered material is not wasted, and the yield of the film-shaped sintered material is good. First, the support sheet, film-shaped sintered material, semiconductor chip, and substrate used in this embodiment will be described below.

[0015] <Support sheet> The support sheet is not particularly limited as long as it is capable of providing the film-shaped fired material and capable of carrying out steps B to C described below.

[0016] The shape of the support sheet is not particularly limited, and examples thereof include a quadrangle, a circle, etc. A quadrangle includes, for example, a square and a rectangle, and a rectangle further includes a strip-like shape (in other words, a long rectangle). In this specification, unless otherwise specified, the "shape of the support sheet" means the shape (i.e., the planar shape) of the support sheet when viewed from above its main surface (e.g., the first surface described below) in a planar view.

[0017] The support sheet may, for example, be one that includes a base film and a pressure-sensitive adhesive layer provided on the entire surface of the base film. FIG. 1A is a plan view that illustrates an example of such a support sheet, and FIG. 1B is a cross-sectional view of the support sheet illustrated in FIG. 1A taken along line II in FIG. 1A. The support sheet 11 shown here is rectangular in shape and is composed of a base film 111 and an adhesive layer 112 provided over the entire surface of one side 111a of the base film 111 (sometimes referred to as the "first side" in this specification).

[0018] The adhesive layer 112 is suitable for making it easy to peel the support sheet 11 from the film-shaped fired material, for example, in step C described below.

[0019] When the support sheet 11 is used, the surface 112a of the adhesive layer 112 opposite the base film 111 (sometimes referred to as the "first surface" in this specification) becomes the surface facing the film-shaped sintered material in step A described below. One surface 11a of the support sheet 11 (sometimes referred to as the "first surface" in this specification) is the same as the first surface 112a of the adhesive layer 112.

[0020] FIG. 2A is a plan view that illustrates a schematic diagram of another example of the support sheet, and FIG. 2B is a cross-sectional view of the support sheet illustrated in FIG. 2A taken along line II-II in FIG. 2A. In FIG. 2A and subsequent figures, the same components as those shown in the figures already described are given the same reference numerals as in the figures already described, and detailed description thereof will be omitted.

[0021] The support sheet 31 shown here is strip-shaped and is composed of a base film 311 and an adhesive layer 312 provided over the entire surface of one side 311a of the base film 311 (sometimes referred to as the "first side" in this specification). Base film 311 is the same as base film 111 shown in FIG. 1B except for its different shape, and adhesive layer 312 is the same as adhesive layer 112 shown in FIGS. 1A and 1B except for its different shape.

[0022] The adhesive layer 312 is suitable for making it easy to peel the support sheet 31 from the film-shaped fired material in, for example, step C described below.

[0023] When the support sheet 31 is used, the surface (sometimes referred to as the "first surface" in this specification) 312a of the adhesive layer 312 opposite to the base film 311 becomes the surface facing the film-shaped sintered material in the step A described below. One surface (sometimes referred to as the "first surface" in this specification) 31a of the support sheet 31 is the same as the first surface 312a of the adhesive layer 312.

[0024] The support sheet may, for example, be one that includes a base film and a pressure-sensitive adhesive layer provided on the peripheral portion of the base film. FIG. 3A is a plan view that illustrates an example of such a support sheet, and FIG. 3B is a cross-sectional view of the support sheet illustrated in FIG. 3A taken along line III-III in FIG. 3A.

[0025] The support sheet 19 shown here is configured to include a base film 111 and an adhesive layer 192 provided on a peripheral portion 1110a of one surface (first surface) 111a of the base film 111. Peripheral edge 1110a of first surface 111a of base film 111 is a narrow region along the outer periphery of base film 111, and adhesive layer 192 has a band-like shape along the outer periphery. Adhesive layer 192 is provided continuously in a square ring shape on peripheral edge 1110a. The first surface 19 a of the support sheet 19 is the same as the first surface 111 a of the base film 111 .

[0026] The adhesive layer 192 is thus suitable for use, for example, in adhering the support sheet 19 to a support frame to temporarily fix the support sheet 19, and then peeling it off from the support frame in a subsequent process.

[0027] The support sheet preferably has an adhesive layer provided on the entire surface or peripheral portion of the base film, in other words, it is preferable that an adhesive layer is provided at least on the peripheral portion of the base film.

[0028] [Base film] The material constituting the base film may be a resin. Examples of the resin include polyethylenes such as low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, and polymethylpentene; ethylene-based copolymers (copolymers having structural units derived from ethylene) such as ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-methyl (meth)acrylate copolymers, and ethylene-ethyl (meth)acrylate copolymers; polyvinyl chloride; vinyl chloride-vinyl acetate copolymers; polyurethanes; ionomers; heat-resistant polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; and crosslinked products of these resins.

[0029] In this specification, the term "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid". The same applies to terms similar to (meth)acrylic acid, for example, "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate".

[0030] The base film may be a weakly adhesive one made of an adhesive resin. Such a base film is suitable for directly contacting the film-shaped sintered material with the base film in step A described below.

[0031] The substrate film may be modified by radiation treatment, discharge treatment, or the like.

[0032] The base film may consist of one layer (single layer) or may consist of two or more layers. When the base film consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0033] In this specification, not only in the case of a base film, "multiple layers may be the same or different" means "all layers may be the same, all layers may be different, or only some layers may be the same", and further, "multiple layers are different" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

[0034] The thickness of the substrate film is not particularly limited and may be, for example, 30 to 300 μm. Here, the "thickness of the base film" means the thickness of the entire base film. For example, the thickness of a base film consisting of multiple layers means the total thickness of all layers constituting the base film.

[0035] [Adhesive layer] Examples of the pressure-sensitive adhesive layer include an energy ray-curable pressure-sensitive adhesive layer and a non-curable weakly adhesive layer. The energy ray-curable adhesive layer is cured by irradiation with energy rays, and its adhesive strength decreases.

[0036] In this specification, the term "energy rays" refers to electromagnetic waves or charged particle beams having an energy quantum, examples of which include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated, for example, by using a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, an LED lamp, or the like as an ultraviolet ray source. Electron beams can be irradiated by generating them using an electron beam accelerator, or the like. Further, "energy ray curable" means a property that is cured by irradiation with energy rays, and "non-curable" means a property that is not cured by any means such as heating or irradiation with energy rays.

[0037] Examples of materials constituting the energy ray-curable pressure-sensitive adhesive layer include known energy ray-curable pressure-sensitive adhesives.

[0038] Examples of materials constituting the non-curable, weakly adhesive adhesive layer include general-purpose adhesives such as rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl ether-based adhesives, and adhesives containing thermal expansion components. A pressure-sensitive adhesive layer having an uneven adhesive surface can be used as a weakly adhesive pressure-sensitive adhesive layer. The non-curable weakly adhesive adhesive layer may have an adhesive strength of 30 to 120 mN / 25 mm to a SUS plate (stainless steel plate) at 23°C, for example.

[0039] The pressure-sensitive adhesive layer may consist of one layer (single layer) or may consist of two or more layers. When consisting of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0040] The thickness of the pressure-sensitive adhesive layer is not particularly limited and may be, for example, 1 to 100 μm. Here, "the thickness of the adhesive layer" means the thickness of the entire adhesive layer, and for example, the thickness of an adhesive layer consisting of multiple layers means the total thickness of all layers that make up the adhesive layer.

[0041] <Film-shaped baking material> The shape of the film-shaped sintered material is the same or approximately the same as the semiconductor chip to which it is attached, and may be, for example, a square or a rectangle. In this specification, unless otherwise specified, the "shape of the film-shaped sintered material" means the shape (i.e., the planar shape) of the film-shaped sintered material when viewed from above its main surface (e.g., the first surface described below) in a plan view.

[0042] The size of the film-shaped fired material is the same as the size of the semiconductor chip to which it is to be attached.

[0043] The film-shaped sintered material contains sinterable metal particles and a binder component, and may or may not contain other components in addition to these.

[0044] [Sinterable metal particles] The sinterable metal particles bond to each other to form a sintered body when the film-shaped sintered material is sintered, and the members that were arranged in contact with the film-shaped sintered material are bonded to each other via the sintered body of the film-shaped sintered material by sintering.

[0045] The sinterable metal particles are particles containing at least a metal element, and may be particles consisting of only a metal element, or may be particles consisting of a metal element and a nonmetal element. Examples of particles consisting of a metal element and a nonmetal element include metal oxide particles.

[0046] Examples of metal species constituting the sinterable metal particles include silver, gold, copper, iron, nickel, aluminum, silicon, palladium, platinum, titanium, etc., and may be a single metal or an alloy of two or more metals.

[0047] The metal species constituting one sinterable metal particle may be only one type, or may be two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily. For example, the metal oxide may be a composite oxide containing two or more metal elements, and an example of such a composite oxide is barium titanate.

[0048] The particle size of the sinterable metal particles is not particularly limited as long as the metal particles exhibit sinterability, and may be, for example, any one of 100 nm or less, 50 nm or less, and 30 nm or less in terms of excellent sinterability. In this specification, the "particle diameter of a metal particle" means the diameter of a circle having the same area as the projected area of ​​a metal particle observed using an electron microscope (diameter equivalent to a projected area circle). The particle diameter of the sinterable metal particles may be such that the number average particle diameter of the particles having a projected area circle equivalent diameter of 100 nm or less is any one of 0.1 to 95 nm, 0.3 to 50 nm, and 0.5 to 30 nm, provided that the metal particles to be observed are 100 or more randomly selected from one film-shaped sintered material.

[0049] The sinterable metal particles are preferably nano-sized particles, preferably silver particles, and more preferably nano-sized silver particles (silver nanoparticles). As used herein, "nano-sized particles" refers to particles having a particle size of 100 nm or less.

[0050] [Binder components] The binder component is a component for imparting formability and adhesiveness to the film-shaped fired material. The binder component may be thermally decomposable so as to be thermally decomposed when the film-shaped fired material is fired.

[0051] The binder component is not particularly limited, but is preferably a resin. Examples of the resin include acrylic resins, polycarbonates, polylactic acids, and polymers of cellulose derivatives, with acrylic resins being preferred. Examples of the acrylic resin include a homopolymer of a (meth)acrylate compound, a copolymer of two or more kinds of (meth)acrylate compounds, and a copolymer of a (meth)acrylate compound and another monomer.

[0052] In the acrylic resin, the content of the structural unit derived from a (meth)acrylate compound may be, for example, 50 to 100% by mass relative to the total amount of the structural units.

[0053] Specific examples of the (meth)acrylate compound include alkyl (meth)acrylate, hydroxyalkyl (meth)acrylate, phenoxyalkyl (meth)acrylate, alkoxyalkyl (meth)acrylate, polyalkylene glycol (meth)acrylate, cycloalkyl (meth)acrylate, benzyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0054] The acrylic resin is preferably a methacrylate. When the binder component contains a structural unit derived from a methacrylate, the film-shaped sintered material can be sintered at a relatively low temperature, and a higher bonding strength can be obtained after sintering.

[0055] In the acrylic resin, the content of the methacrylate-derived structural unit may be, for example, 50 to 100% by mass relative to the total amount of the structural units.

[0056] The other monomer is not particularly limited as long as it is a compound that can be copolymerized with the (meth)acrylate compound. Examples of the other monomers include unsaturated carboxylic acids such as (meth)acrylic acid, vinylbenzoic acid, maleic acid, and vinylphthalic acid; and vinyl group-containing radical polymerizable compounds such as vinylbenzyl methyl ether, vinyl glycidyl ether, styrene, α-methylstyrene, butadiene, and isoprene.

[0057] The weight average molecular weight (Mw) of the resin may be, for example, 1000 to 1000000. When the weight average molecular weight of the resin is within such a range, the film-shaped fired material has higher strength and better flexibility. In this specification, unless otherwise specified, the "weight average molecular weight" is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0058] The glass transition temperature (Tg) of the resin may be, for example, −60 to 50° C. When the Tg of the resin is equal to or higher than the lower limit, the support sheet can be more easily peeled off from the film-shaped sintered material described below. When the Tg of the resin is equal to or lower than the upper limit, the adhesive strength between the film-shaped sintered material and a semiconductor chip or the like is further improved.

[0059] When the binder component is a thermally decomposable component that is thermally decomposed during firing of the film-shaped fired material, the thermal decomposition of the binder component can be confirmed by a mass reduction of the binder component during firing. In this embodiment, when the film-shaped fired material is fired, the binder component may be almost or completely pyrolyzed in its entirety, or a part of the binder component may not be pyrolyzed. The mass of the binder component after firing may be, for example, 10 mass % or less relative to the mass of the binder component before firing.

[0060] <Semiconductor chip> The semiconductor chip may be a known one. The size of the semiconductor chip (for example, the area when the semiconductor chip is viewed from above the circuit formation surface) is, for example, 0.01 to 25 cm 2 It may be 0.25 to 9 cm 2 may be also possible.

[0061] <Substrate> The substrate is not particularly limited as long as it can be bonded to a semiconductor chip. A preferred example of the substrate is a ceramic substrate.

[0062] Next, the method for producing the laminate of this embodiment will be described in detail with reference to the drawings. In addition, the figures used in the following explanation may show key parts enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as the actual ones. First, the method for producing the laminate (sometimes referred to as "first embodiment" in this specification) will be described using an example in which the support sheet 31 shown in Figs. 2A and 2B is used. 4A to 4E are cross-sectional views for illustrating a schematic example of a method for producing the laminate of this embodiment.

[0063] First embodiment <Process A> In step A, as shown in Fig. 4A, a film-shaped sintered material 12 is provided on a support sheet 31. In this embodiment, the support sheet on which the film-shaped sintered material is provided may be referred to as a "film-shaped sintered material with a support sheet." In Fig. 4A, the film-shaped sintered material with a support sheet is denoted by the reference symbol 3.

[0064] As described above, since the support sheet 31 has an adhesive layer 312, in step A, more specifically, the film-shaped sintered material 12 is provided on the adhesive layer 312 of the support sheet 31 (the first surface 312a of the adhesive layer 312).

[0065] In step A, it is preferable to bring the film-shaped sintered material 12 into direct contact with the first surface 31a of the support sheet 31 as shown here.

[0066] In step A, as shown here, it is preferable to provide a plurality (two or more) of film-shaped sintered materials 12 on one support sheet 31. In this case, the number of film-shaped sintered materials 12 provided on one support sheet 31 is preferably 10 to 10,000, and more preferably 25 to 1,000. When the number is equal to or greater than the lower limit, the production efficiency of the laminate is improved. When the number is equal to or less than the upper limit, a support sheet 31 of a more appropriate size can be used, and the workability of step A is improved.

[0067] FIG. 5 is a plan view that illustrates an example of a film-shaped sintered material with a support sheet obtained by the manufacturing method of this embodiment. The support sheet 31 and the film-shaped sintered material 3 with support sheet shown here are strip-shaped, and two or more film-shaped sintered materials 12 are provided in a row in the longitudinal direction of the support sheet 31 on the first surface 31a of the support sheet 31.

[0068] On the support sheet 31, the orientation of all the film-shaped sintered materials 12 is the same, and the film-shaped sintered materials 12 are arranged side by side at regular intervals in the longitudinal direction. In addition, in the direction perpendicular to the longitudinal direction, the positions of all the film-shaped sintered materials 12 are the same. In this way, the film-shaped sintered materials 12 are arranged in a line on the support sheet 31. In FIG. 5, the reference symbol 12a indicates the surface of the film-shaped sintered material 12 opposite the support sheet 31 side (sometimes referred to as the "first surface" in this specification). Thus, the step A of providing the film-shaped sintered material 12 at regular intervals on the support sheet 31 is an example of a preferred embodiment. In particular, the support sheet 31 can be wound into a reel as described below, and such a support sheet is suitable for providing the film-shaped sintered material 12 at regular intervals.

[0069] The film-shaped sintered material with support sheet 3 shown in Figure 5 is an example of a film-shaped sintered material with support sheet when the support sheet is strip-shaped, and the film-shaped sintered material with support sheet produced in this embodiment is not limited to what is shown here. For example, the orientation of one or more film-shaped sintered materials 12 may not be the same on the support sheet 31. In addition, in the longitudinal direction, one or more film-shaped sintered materials 12 may not be arranged side by side at regular intervals, and in the direction perpendicular to the longitudinal direction, the arrangement positions of one or more film-shaped sintered materials 12 may not be the same.

[0070] The number of rows of the film-shaped sintered material 12 on the support sheet 31 may be other than 1 (i.e., 2 or more). When the number of rows is 2 or more, the film-shaped sintered material 12 may be arranged in a lattice pattern on the support sheet 31.

[0071] In step A, preferred methods for providing the film-like sintered material 12 on the support sheet 31 include, for example, a method in which the film-like sintered material 12 is printed on the support sheet 31 (sometimes referred to as "method (A-1)" in this specification); and a method in which the film-like sintered material 12 formed on a release film is transferred onto the support sheet 31 to provide the film-like sintered material 12 on the support sheet 31 (sometimes referred to as "method (A-2)" in this specification).

[0072] As is conventionally known, when a paste-like composition serving as the raw material for a film-shaped sintered material 12 is applied to a support sheet 11 using a syringe and then sintered to form a joint, it is difficult to uniformize the thickness of the applied composition by controlling the amount of the composition applied, and it is difficult to form a joint with high thickness stability. In contrast, when the above-mentioned method (A-1) or (A-2) is adopted, a film-shaped sintered material 12 with high thickness stability can be provided on the support sheet 31 (more specifically, on the first surface 31a of the support sheet 31), and as a result, in the step E described below, the joint formed from the film-shaped sintered material 12 also maintains high thickness stability. In particular, when the method (A-2) is adopted, the film-shaped sintered material 12 with high thickness stability can be formed in advance on a release film, and by transferring this in its current state, a film-shaped sintered material 12 with higher thickness stability can be provided on the support sheet 31. In this specification, the term "high thickness stability" for a film-shaped sintered material and a joint formed from a film-shaped sintered material means that the thickness thereof is highly uniform.

[0073] In method (A-2), examples of the method for forming the film-like sintered material 12 on the release film include a method in which the film-like sintered material 12 is printed on the release film; and a method in which the film-like sintered material 12 is punched onto the release film using a die that is the same or approximately the same shape and size as the semiconductor chip to be attached.

[0074] In the method (A-1), the film-shaped sintered material 12 is printed on the support sheet 31, and in the method (A-2), the film-shaped sintered material 12 is printed on the release film, and examples of the printing method include known printing methods. More specifically, examples of the printing method include relief printing methods such as flexographic printing, intaglio printing methods such as gravure printing, lithographic printing methods such as offset printing, screen printing methods such as silk screen printing and rotary screen printing, and printing methods using various printers such as inkjet printing.

[0075] <Process B> Step B is carried out after step A. In step B, as shown in FIG. 4B, the film-shaped sintered material 12 on the support sheet 31 is attached to the substrate 8. The film-shaped sintered material 12 can be attached to the substrate 8 by contacting the first surface 12a with the substrate 8.

[0076] An arrow G in FIG. 4B indicates the direction of movement of the film-shaped fired material 12 when it is attached to the substrate 8. Here, the state of step B is shown at a stage where attachment of some of the film-shaped fired material 12 to the substrate 8 has not been completed.

[0077] The belt-shaped support sheet 31 is suitable for storage in a reel shape by winding up one sheet (one piece) of the film-shaped sintered material 12 with a protective film further provided on the first surface 12a of the film-shaped sintered material 12, as described below. When using the reel-shaped support sheet 31 in this manner, after unwinding the support sheet 31 from the reel, the protective film is peeled off from the first surface 12a of the film-shaped sintered material 12, and the first surface 12a is brought into contact with the substrate 8, so that the film-shaped sintered material 12 on the support sheet 31 is attached to the substrate 8. The method of storing the support sheet will be explained in detail later.

[0078] In step B, as shown here, it is preferable to attach some or all of the film-shaped sintered materials 12 on the support sheet 31 to the substrate 8 with a time difference between them. For example, the film-shaped sintered materials 12 may be attached to the substrate 8 in sequence from the film-shaped sintered material 12 located closest to one end of the support sheet 31 (i.e., the film-shaped sintered material 12 located on the left side in FIG. 4B) to the film-shaped sintered material 12 located closest to the other end of the support sheet 31 (i.e., from the film-shaped sintered material 12 located on the left side in FIG. 4B to the film-shaped sintered material 12 located farthest on the support sheet 31). In step B, all of the film-shaped sintered materials 12 on the support sheet 31 may be attached to the substrate 8 simultaneously or almost simultaneously, but the method of attaching the film-shaped sintered materials 12 to the substrate 8 with a time difference as described above is advantageous in that the strip-shaped support sheet-attached film-shaped sintered material 3 is easier to handle.

[0079] <Process C> Step C is carried out after step B. In step C, as shown in FIG. 4C, the support sheet 31 is peeled off from the substrate 8 and the film-shaped sintering material 12. When the support sheet 31 is peeled off, the film-shaped sintering material 12 and the substrate 8 remain in a state of being bonded to each other and integrated. In this embodiment, a substrate and a film-shaped sintering material provided on the surface (circuit-forming surface) of the substrate in this manner may be referred to as a "substrate with film-shaped sintering material". In FIG. 4C, the substrate with film-shaped sintering material is denoted by the reference symbol 80. The arrow P in FIG. 4C indicates the direction in which the support sheet 31 is peeled off. Here, the state of step C is shown at a stage where peeling of a part of the support sheet 31 from the substrate 80 with the film-shaped firing material is not yet complete.

[0080] The support sheet 31 can be peeled off from the substrate 80 with the film-shaped sintering material by applying a force to the support sheet 31 in a direction away from the film-shaped sintering material 12 .

[0081] In step C, as shown here, it is preferable to peel off a part or all of the regions of the support sheet 31 from the substrate 80 with the film-shaped sintering material with a time difference between each other. For example, the support sheet 31 may be peeled off from the substrate 80 with the film-shaped sintering material in sequence from one end of the support sheet 31 (i.e., the end on the left side of the support sheet 31 in FIG. 4C) to the other end of the support sheet 31 (i.e., the end on the side other than the left side of the support sheet 31 in FIG. 4C). In step C, the entire region of the support sheet 31 may be peeled off from the substrate 80 with the film-shaped sintering material at the same time or almost at the same time, but the method of peeling the support sheet 31 from the substrate 80 with the film-shaped sintering material with a time difference as described above is advantageous in that the belt-shaped support sheet 31 is easier to handle.

[0082] As described above, when the support sheet 31 includes the base film 311 and the adhesive layer 312, and the adhesive layer 312 has energy ray curing properties, it is preferable to irradiate the adhesive layer 312 with energy rays in step C to peel the support sheet 31 (more specifically, the cured product of the adhesive layer 312) from the film-shaped sintering material 12. In this case, by curing the adhesive layer 312 by irradiation with energy rays, the adhesive force between the cured product of the adhesive layer 312 and the film-shaped sintering material 12 is reduced, so that the support sheet 31 can be more easily peeled off from the substrate 80 with the film-shaped sintering material.

[0083] In this embodiment, the peeling of the support sheet 31 from the substrate 80 with the film-like sintered material in step C may be started after the attachment of the film-like sintered material 12 on the support sheet 31 to the substrate 8 in step B is completed for all of the film-like sintered materials 12, or the peeling of the support sheet 31 from the substrate 80 with the film-like sintered material in step C may be started before the attachment of the film-like sintered material 12 on the support sheet 31 to the substrate 8 in step B is completed for all of the film-like sintered materials 12. In the latter case, it is possible to shorten the manufacturing time of the laminate, which is the target product.

[0084] <Process D> Step D is carried out after step C. In step D, as shown in Fig. 4D, the back surface 9b of the semiconductor chip 9 is attached to the film-shaped sintering material 12 on the substrate 8 (in other words, the film-shaped sintering material 12 in the substrate 80 with the film-shaped sintering material). The arrow M in Fig. 4D indicates the direction of movement of the semiconductor chip 9 when it is attached to the film-shaped sintering material 12 (substrate 80 with the film-shaped sintering material). Here, the state of step D is shown at a stage where attachment of some of the semiconductor chips 9 to the substrate 80 with the film-shaped sinterable material has not been completed.

[0085] 4D, reference numeral 12b indicates the surface opposite to the first surface 12a of the film-shaped sintered material 12 (sometimes referred to as the "second surface" in this specification), which is also the attachment surface of the semiconductor chip 9. Here, the second surface 12b of the film-shaped sintered material 12 and the back surface 9b of the semiconductor chip 9 are attached to each other.

[0086] The semiconductor chip 9 can be attached to the substrate 80 with the film-shaped sintering material by using a known method for fixing and moving a semiconductor chip, such as a method using a collet.

[0087] In the process D, the semiconductor chip 9 is attached to the substrate 80 with the film-shaped firing material, and by avoiding the use of defective semiconductor chips, a semiconductor chip 9 without defects can be attached to the substrate 80 with the film-shaped firing material. Therefore, the film-shaped firing material 12 and the substrate 80 with the film-shaped firing material are not wasted, and the yield of the film-shaped firing material 12 and the substrate 80 with the film-shaped firing material is improved.

[0088] <Process E> Step E is carried out after step D. In step E, the film-shaped sintered material 12 is heated to 200° C. or higher to sinter-bond the semiconductor chip 9 and the substrate 8 together, as shown in FIG. 4E. By carrying out step E, a joint 12' is formed from the film-shaped sintered material 12 by sintering the film-shaped sintered material 12, and a laminate 801 is obtained in which the semiconductor chip 9 and the substrate 8 are stacked together via the joint 12'.

[0089] In step E, there is no particular upper limit to the heating temperature of the film-shaped sintering material 12. For example, in terms of suppressing damage caused by heating to the wiring formed on the surface of the semiconductor chip 9, the heating temperature of the film-shaped sintering material 12 is preferably 500° C. or lower. On the other hand, by setting the heating temperature to the lower limit or higher, the degree of sintering of the film-shaped sintering material 12 is further improved.

[0090] In step E, the heating time of the film-shaped sintered material 12 can be appropriately selected taking into consideration the type of the film-shaped sintered material 12 and the heating temperature, but is preferably 1 to 60 minutes. When the heating time is equal to or more than the lower limit, the degree of sintering of the film-shaped sintered material 12 is further improved. When the heating time is equal to or less than the upper limit, excessive heating is suppressed.

[0091] In step E, the film-shaped sintered material 12 may be heated and pressurized. In this way, the bonding strength between the semiconductor chip 9 and the substrate 8 and the strength of the bonding portion 12' itself can be further improved. At this time, the film-shaped sintered material 12 may be pressed from the substrate 8 side, from the semiconductor chip 9 side, or from both the substrate 8 side and the semiconductor chip 9 side.

[0092] Although there are no particular limitations on the pressure applied to the film-shaped sintered material 12, it is preferable that the pressure be 5 MPa or more. By setting the pressure within this range, the effect obtained by applying pressure is enhanced. That is, in step E, the film-shaped sintered material 12 may be heated to 200° C. or higher and pressurized at 5 MPa or higher to sinter-bond the semiconductor chip 9 and the substrate 8.

[0093] In step E, there is no particular upper limit to the pressure when the film-shaped sintered material 12 is heated and pressurized. For example, in order to prevent damage to the substrate 8, particularly the substrate 8 that is a ceramic substrate, the pressure is preferably 50 MPa or less.

[0094] In this embodiment, the joint 12' is formed from the film-shaped sintered material 12, and therefore has excellent thickness stability and thermal conductivity. In addition, since the film-shaped sintered material 12 has the same shape or approximately the same shape and size as the semiconductor chip 9, there is no need to cut the film-shaped sintered material 12 to match the shape and size of the semiconductor chip 9. Even if the film-shaped sintered material 12 is brittle, no cutting waste is generated from the film-shaped sintered material 12, damage to the film-shaped sintered material 12 is suppressed, and a joint 12' without damage is formed. The laminate 801 is suitable for forming a power semiconductor element (power device).

[0095] The manufacturing method of this embodiment is not limited to the one described above, and may have some of the configurations changed or deleted, or may have other configurations added to those described above, without departing from the spirit of the present invention. More specifically, the manufacturing method is as follows.

[0096] So far, the method for producing a laminate when the support sheet has a strip shape has been described, but the shape of the support sheet used in this embodiment may be a rectangle other than a strip. Fig. 6 is a plan view showing a schematic example of a film-shaped sintered material with a support sheet in that case.

[0097] The support sheet 11 and the film-shaped sintered material 1 with support sheet shown here are rectangular in shape, and the first surface 11a of the support sheet 11 has a total of 35 film-shaped sintered materials 12 provided in five rows and seven rows in two perpendicular directions. Furthermore, on the support sheet 11, all the film-shaped sintered materials 12 are aligned so that the orientations of the films are the same and the positions of adjacent film-shaped sintered materials 12 are the same in the two perpendicular directions. That is, the film-shaped sintered materials 12 are arranged in a lattice pattern on the support sheet 11. Thus, the process A in which the film-shaped sintered material 12 is arranged in a lattice pattern on the support sheet 11 is an example of a preferred embodiment.

[0098] The arrangement of the film-shaped sintered material 12 on the support sheet 11 shown in Figure 6 is the same as the arrangement of the film-shaped sintered material 12 on the support sheet 31, except that the number of rows of the film-shaped sintered material 12, the number of film-shaped sintered materials 12 per row, and the total number of film-shaped sintered materials 12 may differ.

[0099] 6, the film-shaped sintered materials 12 are arranged in a lattice pattern on the support sheet 11, but the arrangement of the film-shaped sintered materials 12 on the support sheet 11 is not limited to this. For example, the orientations of one or more film-shaped sintered materials 12 do not have to be the same, and the arrangement positions of adjacent film-shaped sintered materials 12 in the two orthogonal directions described above do not have to be the same.

[0100] 6, the number of the film-shaped sintered materials 12 provided on the support sheet 11 is 35, but the number is not limited to this. For example, the number may be 5 to 10,000.

[0101] When the support sheet 11 is used, the method for producing the laminate is the same as the method for producing the laminate described above, except that the support sheet 11 is used instead of the support sheet 31.

[0102] The support sheet used in this embodiment may have a circular shape. Fig. 7 is a plan view showing a schematic example of a film-shaped sintered material with a support sheet in this case.

[0103] The support sheet 21 and the film-shaped sintered material 2 with support sheet shown here have a circular shape, and a total of 56 film-shaped sintered materials 12 are provided on the first surface 21a of the support sheet 21, in 4 to 8 rows and 3 to 9 rows in two perpendicular directions.

[0104] The arrangement of the film-shaped sintered material 12 on the support sheet 21 shown in Figure 7 is the same as the arrangement of the film-shaped sintered material 12 on the support sheet 11, except for the number of rows of the film-shaped sintered material 12, the number of film-shaped sintered materials 12 per row, and the total number of film-shaped sintered materials 12.

[0105] The adhesive layer 212 in the support sheet 21 is the same as the adhesive layer 112 in the support sheet 11 except for its circular shape, and the base film (not shown) in the support sheet 21 is the same as the base film 111 in the support sheet 11 except for its circular shape. The surface 212a of the pressure-sensitive adhesive layer 212 opposite the base film side (sometimes referred to as the “first surface” in this specification) is the same as the first surface 21a of the support sheet 21.

[0106] The film-shaped sintered material with support sheet 2 shown in Figure 7 is an example of a film-shaped sintered material with support sheet when the support sheet is circular, and the film-shaped sintered material with circular support sheet produced in this embodiment is not limited to what is shown here. For example, in the case of a film-shaped sintered material with a circular support sheet, the orientation, arrangement position and number of rows of the film-shaped sintered material on the support sheet, the number of film-shaped sintered materials per row, and the total number of film-shaped sintered materials can be arbitrarily set depending on the purpose.

[0107] When the support sheet 21 is used, the manufacturing method of the laminate is the same as the manufacturing method of the laminate described above, except that the support sheet 21 is used instead of the support sheet 31.

[0108] In this embodiment, when the support sheet 11 is used, in either one or both of the steps A and B, the peripheral portion of the adhesive layer 112 (more specifically, the first surface 112a of the adhesive layer 112) in the support sheet 11 is bonded to the support frame (not shown), thereby temporarily fixing the support sheet 11 to the support frame. In this case, the upper portion of the peripheral portion of the first surface 112a of the adhesive layer 112 is left open so as not to hinder the bonding of the adhesive layer 112 to the support frame. Here, the peripheral portion of the first surface 112a of the adhesive layer 112 is a narrow region along the outer periphery of the adhesive layer 112, in the first surface 112a of the adhesive layer 112, similar to the peripheral portion 1110a of the first surface 111a of the base film 111 described above.

[0109] The same applies to the case where the support sheet 21 is used. That is, in the present embodiment, when the support sheet 21 is used, in either one or both of the steps A and B, the peripheral portion of the adhesive layer 212 (more specifically, the first surface 212a of the adhesive layer 212) in the support sheet 21 is bonded to a support frame (not shown), thereby temporarily fixing the support sheet 21 to the support frame. In this case, the upper portion of the peripheral portion of the first surface 212a of the adhesive layer 212 is left open so as not to hinder the bonding of the adhesive layer 212 to the support frame. Here, the peripheral portion of the first surface 212a of the adhesive layer 212 is the same as in the case of the adhesive layer 112 described above, and is a narrow region along the outer periphery of the adhesive layer 212 of the first surface 212a of the adhesive layer 212.

[0110] In this embodiment, the film-shaped sintered material with a support sheet obtained by carrying out step A is suitable for storage. For example, a film-shaped sintered material with a support sheet, which further has a protective film on the first surface of the film-shaped sintered material, is particularly suitable for storage.

[0111] That is, the manufacturing method of this embodiment may include, between step A and step B, a step of attaching a protective film to the side (first side) of the film-shaped sintered material opposite the support sheet side (sometimes referred to in this specification as "step F1"), a step of storing the support sheet and film-shaped sintered material (film-shaped sintered material with support sheet) after the protective film has been attached (sometimes referred to in this specification as "step F2"), and a step of peeling off the protective film from the film-shaped sintered material on the support sheet after storage to which the protective film has been attached (film-shaped sintered material with support sheet after storage) (sometimes referred to in this specification as "step F3").

[0112] The protective film is for protecting the film-shaped sintered material in the film-shaped sintered material with the support sheet. Examples of the protective film include the same films as the release films mentioned above.

[0113] FIG. 8 is a cross-sectional view that shows a schematic example of a film-shaped fired material with a support sheet, which is provided with a protective film when a support sheet 31 is used. The film-shaped sintered material 3 with a support sheet shown here has a protective film 7 on the first surface 12a of the film-shaped sintered material 12. The shape and size of the protective film 7 are not particularly limited as long as it can cover the first surface 12a of all the film-shaped sintered materials 12 in the film-shaped sintered material 3 with a support sheet. For example, the shape (planar shape) of the protective film 7 may be the same as the shape (planar shape) of the support sheet 31, in terms of improving the handleability of the film-shaped sintered material 3 with a support sheet in the state in which the protective film 7 is provided.

[0114] Even when the shape of the support sheet is not strip-shaped as in the case of support sheet 31, but is, for example, rectangular as in the case of support sheet 11, or circular as in the case of support sheet 21, the film-shaped sintered material with a support sheet and a protective film has a structure similar to that of the film-shaped sintered material with a support sheet and a protective film 3, except for its shape.

[0115] A film-shaped sintered material with a support sheet (e.g., film-shaped sintered material with a support sheet 1 or film-shaped sintered material with a support sheet 2) having a protective film and in which the shape of the support sheet is square or circular can be stored, for example, by stacking multiple sheets in the thickness direction. In addition, such a film-shaped sintered material with a support sheet can be stored in a roll shape, for example, by rolling up one sheet of the film.

[0116] For example, a film-shaped sintered material with a support sheet (e.g., film-shaped sintered material with a support sheet 3) that has a protective film and in which the support sheet is in the shape of a strip is particularly suitable for storage in the form of a reel by winding up one piece (single piece). That is, when the support sheet has a belt-like shape, the step F2 may be a step of winding up the support sheet and the film-like sintered material (the film-like sintered material with the support sheet) after the protective film is attached into a reel shape and storing it. The step F3 may be a step of unwinding the support sheet and the film-like sintered material (the film-like sintered material with the support sheet after storage) after the storage with the protective film attached from the reel shape, and then peeling off the protective film from the film-like sintered material.

[0117] 9 is a cross-sectional view showing an example of a film-shaped sintered material with a support sheet having a protective film being unwound from a reel. Here, the reel-shaped film-shaped sintered material with a support sheet having a protective film 3 is shown being unwound. The film-shaped sintered material 3 with support sheet is wound into a reel with the exposed surface of the protective film 7 facing radially inward of the reel and the exposed surface (second surface 11b) of the support sheet 11 facing radially outward of the reel, with the support sheet 11 wound outward (in other words, the protective film 7 wound inward).

[0118] A film-shaped sintered material with a support sheet in which the shape of the support sheet is rectangular or circular (for example, film-shaped sintered material with a support sheet 1 or film-shaped sintered material with a support sheet 2) is laminated in the longitudinal direction to a strip-shaped protective film (for example, protective film 7) (hereinafter referred to as a "strip-shaped composite film"), similar to the case of the film-shaped sintered material with a support sheet in which the shape of the support sheet is strip-shaped, is particularly suitable for storage in a reel by winding up one of the films. In this case, too, the strip-shaped composite film is wound into a reel with the exposed surface of the protective film facing the radially inward direction of the reel and the exposed surface (second surface) of the support sheet facing the radially outward direction of the reel, with the support sheet wound outward (in other words, the protective film wound inward). The film-like sintered material with support sheet, in which multiple sheets are bonded to a single strip-shaped protective film in the longitudinal direction, may be arranged in a single row or in two or more rows in the longitudinal direction of the single protective film. In addition, it is preferable that the multiple sheets of film-shaped sintered material with support sheet arranged in a row in this manner are arranged at a distance from each other.

[0119] When a strip-shaped composite film is used, the step F1 may be a step of attaching a plurality of support sheets (i.e., a film-shaped sintered material with a plurality of support sheets) on which the film-shaped sintered material is provided, in a row, to a strip-shaped protective film by using the surface (first surface) of the film-shaped sintered material opposite to the support sheet side. The step F2 may be a step of winding up the strip-shaped protective film on which the plurality of support sheets (film-shaped sintered material with a plurality of support sheets) on which the film-shaped sintered material is provided are attached, into a reel shape, and storing the film-shaped protective film. The step F3 may be a step of unwinding the strip-shaped protective film on which the plurality of support sheets (film-shaped sintered material with a plurality of support sheets) on which the film-shaped sintered material is provided, after storage, from the reel shape, and then peeling off the strip-shaped protective film from the plurality of film-shaped sintered materials.

[0120] Regardless of the shape of the support sheet, steps F1, F2, and F3 are performed in this order. In step F1, the application of a protective film to the film-shaped sintered material (application of the film-shaped sintered material to the protective film), in step F2, the storage of the film-shaped sintered material with support sheet, and in step F3, the peeling of the protective film from the film-shaped sintered material with support sheet after storage can all be carried out by known methods.

[0121] Next, a method for producing the laminate (sometimes referred to as "second embodiment" in this specification) will be described using an example in which the support sheet 19 shown in Figs. 3A and 3B is used. 10A to 10E are cross-sectional views for illustrating a schematic example of a method for producing the laminate of the present embodiment.

[0122] Second embodiment <Process A> In step A, as shown in FIG. 10A, a film-shaped sintered material 12 is provided on a support sheet 19 to produce a film-shaped sintered material 6 with a support sheet.

[0123] As described above, in the support sheet 19, the adhesive layer 192 is provided on the peripheral portion 1110a of the first surface 111a of the base film 111. More specifically, in step A, the film-shaped sintering material 12 is provided on the base film 111 of the support sheet 19 (the first surface 111a of the base film 111) in an area where the adhesive layer 192 is not provided.

[0124] As described above, step A in the second embodiment is the same as step A in the first embodiment, except that the target on which the film-shaped sintered material 12 is provided is different. For example, in step A of the second embodiment, it is preferable to bring the film-shaped sintered material 12 into direct contact with the first surface 19a of the support sheet 19 as shown here.

[0125] FIG. 11 is a plan view that illustrates an example of a film-shaped sintered material 6 with a support sheet obtained by the manufacturing method according to the second embodiment. The support sheet 19 shown here has a rectangular shape, and the film-shaped sintered materials 12 are arranged in a lattice pattern on the first surface 19a of the support sheet 19 in the same arrangement as in the case of the film-shaped sintered material 1 with support sheet. However, all of the film-shaped sintered materials 12 are provided on the support sheet 19 on the inside of the adhesive layer 192 (in other words, on the center of gravity side of the support sheet 19). The first surface 19 a of the support sheet 19 is the same as the first surface 111 a of the base film 111 .

[0126] <Process B> Step B is carried out after step A. In step B, the film-shaped sintered material 12 on the support sheet 19 is attached to the substrate 8, as shown in FIG. 10B. Step B in the second embodiment is the same as step B in the first embodiment, except that the film-shaped sintered material with a support sheet is different as described above.

[0127] However, unlike the support sheet 31, the support sheet 19 may or may not be suitable for storage in a reel shape. Therefore, unlike the case where the film-shaped sintered material 3 with a support sheet is used, when the film-shaped sintered material 6 with a support sheet is used, for example, it may be preferable to attach some or all of the film-shaped sintered materials 12 on the support sheet 19 to the substrate 8 with a time difference, or it may be preferable to attach all of the film-shaped sintered materials 12 on the support sheet 19 to the substrate 8 simultaneously or almost simultaneously. The method of attaching the film-shaped sintered materials 12 can be selected depending on, for example, the arrangement form of the film-shaped sintered materials 12 on the support sheet 19.

[0128] In the second embodiment, the support sheet 19 can be temporarily fixed to a support frame (not shown) by bonding the adhesive layer 192 in the support sheet 19 to the support frame in either one or both of step A and step B. In this case, the first surface 192a of the adhesive layer 192 is left open so as not to impede bonding of the adhesive layer 192 to the support frame.

[0129] When the adhesive layer 192 has energy ray curing properties, it is preferable to irradiate the adhesive layer 192 with energy rays before peeling off the support sheet 19 fixed to the support frame from the support frame. In this case, by curing the adhesive layer 192 by irradiation with energy rays, the adhesive force between the cured product of the adhesive layer 192 and the support frame is reduced, so that the support sheet 19 can be peeled off from the support frame more easily.

[0130] <Process C> Step C is carried out after step B. In step C, as shown in Fig. 10C, the support sheet 19 is peeled off from the substrate 8 and the film-shaped sintered material 12 (i.e., the substrate 80 with the film-shaped sintered material). When the support sheet 19 is peeled off, the film-shaped sintered material 12 and the substrate 8 remain bonded to each other and integrated. Here, the state of step C is shown at a stage where peeling of a portion of the support sheet 19 from the substrate 80 with the film-shaped firing material is not yet complete.

[0131] Step C in the second embodiment is the same as step C in the first embodiment, except that the film-shaped sintered material with a support sheet is different as described above. However, in the second embodiment, since the film-shaped sintering material 12 is in contact with the base film 111 rather than the adhesive layer 192, even if the adhesive layer 192 has energy ray curing properties, the adhesive layer 192 cannot be cured by irradiating it with energy rays to more easily peel the support sheet 19 from the substrate 80 with the film-shaped sintering material.

[0132] <Process D, Process E> Step D is performed after step C, and step E is performed after step D. In process D, as shown in Fig. 10D, the back surfaces 9b of the semiconductor chips 9 are attached to the film-shaped sintering material 12 on the substrate 8 (in other words, the film-shaped sintering material 12 in the substrate 80 with film-shaped sintering material) so that they face each other. At this time, the second surface 12b of the film-shaped sintering material 12 and the back surface 9b of the semiconductor chip 9 are attached to each other. Here, as in the case of Fig. 4D, process D is shown at a stage where attachment of some of the semiconductor chips 9 to the substrate 80 with film-shaped sintering material has not been completed. Then, in step E, the film-shaped sintered material 12 is heated to 200° C. or higher, thereby sintering and bonding the semiconductor chip 9 and the substrate 8 together, as shown in FIG. 10E. By carrying out step E, a joint 12' is formed from the film-shaped sintered material 12 by sintering the film-shaped sintered material 12, and a laminate 801 is obtained in which the semiconductor chip 9 and the substrate 8 are stacked together via the joint 12'. In the second embodiment, the substrate 80 with the film-shaped sintered material is obtained by the above-mentioned step C, as in the first embodiment. Therefore, the step D of the second embodiment is the same as the step D of the first embodiment, and the step E of the second embodiment is the same as the step E of the first embodiment.

[0133] In the second embodiment, the joint 12' is also excellent in thickness stability and thermal conductivity because it is formed from the film-shaped sintered material 12. Moreover, since the film-shaped sintered material 12 has the same shape or approximately the same shape and size as the semiconductor chip 9, there is no need to cut the film-shaped sintered material 12 to match the shape and size of the semiconductor chip 9, and even if the film-shaped sintered material 12 is brittle, no cutting waste is generated from the film-shaped sintered material 12, damage to the film-shaped sintered material 12 is suppressed, and an undamaged joint 12' is formed.

[0134] The manufacturing method of the second embodiment is not limited to the one described above, and may have some of the configurations changed or removed, or may have other configurations added to those described above, without departing from the spirit of the present invention. More specifically, the manufacturing method is as follows.

[0135] In the second embodiment, as in the first embodiment, the shape of the support sheet may be, for example, a circle or a strip other than a rectangle. However, in either case, as described above, all the film-shaped sintered materials are provided on the support sheet on the inside of the adhesive layer (in other words, on the center of gravity side of the support sheet).

[0136] In the second embodiment as well, the film-shaped sintered material with a support sheet obtained by carrying out step A is suitable for storage. For example, a film-shaped sintered material with a support sheet, which further has a protective film on the first surface of the film-shaped sintered material, is particularly suitable for storage.

[0137] That is, the manufacturing method of the second embodiment may include, between step A and step B, a step (step F1) of attaching a protective film to the side (first side) of the film-shaped sintered material opposite the support sheet, a step (step F2) of storing the support sheet and film-shaped sintered material (film-shaped sintered material with support sheet) after the protective film has been attached, and a step (step F3) of peeling off the protective film from the film-shaped sintered material on the support sheet after storage to which the protective film has been attached (film-shaped sintered material with support sheet after storage).

[0138] Steps F1, F2, and F3 in the second embodiment are the same as steps F1, F2, and F3 in the first embodiment, except that the support sheet used is different. In step F1 of the second embodiment, a protective film may or may not be attached not only to the first surface of the film-shaped sintered material but also to the first surface of the adhesive layer (e.g., first surface 192a of adhesive layer 192).

[0139] In the second embodiment, the film-shaped sintered material with a support sheet and a protective film (e.g., film-shaped sintered material with a support sheet 6) can be stored in the same manner as the film-shaped sintered material with a support sheet and a protective film in the first embodiment (e.g., film-shaped sintered materials with a support sheet 1 to 3). [Industrial Applicability]

[0140] The present invention can be used in the manufacture of power semiconductor elements (power devices). [Explanation of symbols]

[0141] 1,2,3,6...film-shaped sintered material with support sheet, 11,19,21,31...support sheet, 11a,19a,21a,31a...first surface of support sheet, 111,311...base film, 111a,311a...first surface of base film, 112,212,192,312...adhesive layer, 112a,212a,192a,312a...first surface of adhesive layer, 12...film-shaped sintered material, 12a...first surface of film-shaped sintered material, 12b...second surface of film-shaped sintered material 12, 12'...joint, 8...substrate, 9...semiconductor chip, 9b...rear surface of semiconductor chip 9, 80...substrate with film-shaped sintered material, 801...laminated body

Claims

1. A step of providing a film-like sintered material containing sinterable metal particles and a binder component and having the same shape or approximately the same shape and size as the semiconductor chip to be attached on a support sheet; A step of attaching the film-shaped sintered material (excluding those containing a solvent) on the support sheet to a substrate; peeling the support sheet from the substrate and the film-shaped fired material; A step of attaching the back side of the semiconductor chip to the film-shaped sintered material on the substrate so that the back side of the semiconductor chip faces the film-shaped sintered material on the substrate; and heating the film-shaped sintered material to 200° C. or higher to sinter-bond the semiconductor chip and the substrate.

2. The method for producing a laminate according to claim 1 , wherein the film-shaped sintered material is heated to 200° C. or higher and pressurized at 5 MPa or higher to sinter-bond the semiconductor chip and the substrate.

3. The method for producing a laminate according to claim 1 or 2, wherein the substrate is a ceramic substrate.

4. The support sheet comprises a base film and an adhesive layer provided on the entire surface of the base film, and the film-shaped sintered material is provided on the adhesive layer of the support sheet. The method for producing a laminate according to any one of claims 1 to 3.

5. The method for producing a laminate according to any one of claims 1 to 3, wherein the support sheet comprises a base film and an adhesive layer provided on the peripheral portion of the base film, and the film-shaped sintered material is provided on an area of ​​the base film of the support sheet where the adhesive layer is not provided.

6. The method for producing a laminate according to claim 4 or 5, wherein the pressure-sensitive adhesive layer is energy ray curable.

7. The method for producing a laminate according to claim 4 , further comprising irradiating the pressure-sensitive adhesive layer with energy rays to peel the support sheet from the film-shaped sintered material.

8. The method for producing a laminate according to any one of claims 1 to 7, further comprising transferring the film-shaped sintered material formed on a release film onto the support sheet, to provide the film-shaped sintered material on the support sheet.

9. The method for producing a laminate according to claim 8 , wherein the film-like sintered material is formed on the release film by printing.

10. The method for manufacturing a laminate described in claim 8, wherein the film-shaped sintered material is formed on the release film by punching using a mold having the same shape or approximately the same shape and size as the semiconductor chip to be attached.

11. The method for producing a laminate according to any one of claims 1 to 7, wherein the film-shaped sintered material is provided on the support sheet by printing.

12. The method for producing a laminate according to any one of claims 1 to 11, wherein the support sheet is circular.

13. The method for producing a laminate according to any one of claims 1 to 12, wherein the support sheet can be wound into a reel, and the film-shaped sintered material is arranged on the support sheet at regular intervals.

Images