Manufacturing method of laminate

Abstract

Provided is a laminate manufacturing method with which it is possible to maintain a stable bonding property between an electronic component and a circuit pattern even when an electronic component that generates a large amount of heat is used, and to mitigate problems that may occur in the insulation layer.　A method for manufacturing a laminate (1) in which a base substrate (2), an insulation layer (3), a circuit pattern (4), and an electronic component (5) are laminated in this order comprises: a step for providing the insulation layer (3) on an upper surface side of the base substrate (2); a step for providing the electronic component (5) on an upper surface side of the circuit pattern (4); and a step for laminating the insulation layer (3) provided on the base substrate (2) with the circuit pattern (4) having the electronic component (5) provided thereon.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a laminate. [Background technology]

[0002] A laminate is known in which a circuit pattern is laminated on the front side of an insulating layer and electronic components are mounted on this circuit pattern. In this laminate, a base substrate such as a heat sink or heat sink is laminated on the back side of the insulating layer to dissipate heat generated by the electronic components. Conventionally, solder has been widely used as a bonding material for mounting electronic components on the circuit pattern.

[0003] In recent years, as electronic devices have become more powerful and smaller, the amount of heat generated by electronic components has been increasing. For example, semiconductor chips using silicon carbide (SiC) (e.g., SiC power devices) can conduct large currents and can reach high temperatures (e.g., 300°C or higher) during operation. However, because the melting point of solder is relatively low, if solder is used as a bonding material for electronic components that operate at such high temperatures, the solder may remelt when the semiconductor chip is operated, leading to problems such as peeling of the semiconductor chip and short circuits in the circuit pattern.

[0004] One known technique for solving these problems is to use a paste containing metal nanoparticles such as Ag nanoparticles or Cu nanoparticles as a bonding material (see, for example, Patent Document 1). In this method, a conductive pattern (circuit pattern) is formed on an insulating substrate (insulating layer), and then a paste containing metal nanoparticles is interposed between the circuit pattern and an electronic component. The electronic component is then heated at a predetermined temperature while being pressurized, thereby sintering the metal nanoparticles and bonding the circuit pattern to the electronic component. This technique of sintering metal nanoparticles provides higher heat resistance than when solder is used. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-10703 Summary of the Invention [Problem to be solved by the invention]

[0006] When sintering metal nanoparticles, electronic components are subjected to high-temperature and high-load pressure. This means that the insulating layer is also subjected to high-temperature and high-load pressure, which can lead to cracks or peeling. Furthermore, when a ceramic substrate is used as the insulating layer, there is a risk that the ceramic substrate may crack or warp, resulting in poor bonding between the electronic component and the circuit pattern or even cracking of the electronic component. Furthermore, warping of the ceramic substrate can cause abnormalities in the parallelism and flatness of the mounted electronic components, potentially resulting in problems in downstream processes such as wire bonding.

[0007] In view of these conventional problems, the present invention aims to provide a method for manufacturing a laminate that can maintain stable bonding between electronic components and circuit patterns and suppress defects that occur in the insulating layer, even when electronic components that generate a large amount of heat are used. [Means for solving the problem]

[0008] The present invention provides a method for manufacturing a laminate in which a base substrate, an insulating layer, a circuit pattern, and an electronic component are laminated in this order, the method comprising the steps of: providing the insulating layer on a front surface side of the base substrate; The method for manufacturing a laminate includes a step of providing the electronic components on the surface side of the circuit pattern, and a step of laminating the insulating layer provided on the base substrate and the circuit pattern provided with the electronic components.

[0009] In the method for manufacturing the above-mentioned laminate, it is preferable that in the step of providing the insulating layer on the surface side of the base substrate, the insulating layer is in a semi-cured state, and in the step of laminating the insulating layer provided on the base substrate and the circuit pattern on which the electronic components are provided, the insulating layer is in a fully cured state.

[0010] Furthermore, in the above-mentioned method for manufacturing a laminate, the step of providing the insulating layer on the surface side of the base substrate preferably includes the steps of heating a resin composition applied to a base sheet to form the insulating layer in a semi-cured state on the base sheet, and heating and pressurizing the insulating layer in a semi-cured state placed on the base substrate, and then peeling off the base sheet to transfer the insulating layer in a semi-cured state to the surface side of the base substrate, and the step of laminating the insulating layer provided on the base substrate and the circuit pattern provided with the electronic components preferably includes the steps of placing the circuit pattern provided with the electronic components on the insulating layer in a semi-cured state transferred to the surface side of the base substrate, and heating and pressurizing the circuit pattern to temporarily adhere it to the insulating layer, and heating and pressurizing the insulating layer to which the circuit pattern has been temporarily adhered to bring the insulating layer to a fully cured state.

[0011] In the method for producing the laminate described above, in the step of transferring the insulating layer in a semi-cured state onto the surface side of the base substrate, the insulating layer is preferably pressed at a temperature of 30 to 180° C. and a pressure of 1 to 25 MPa.

[0012] In the method for producing the laminate described above, in the step of temporarily adhering the circuit pattern to the insulating layer, the insulating layer and the circuit pattern are pressurized at a temperature of 30 to 180°C and a pressure of 0.1 to 25 MPa to temporarily adhere the circuit pattern to the insulating layer, and further the insulating layer and the circuit pattern are pressurized at a temperature of 130 to 200°C and a pressure of 0.1 to 25 MPa to temporarily cure the insulating layer, and in the step of bringing the insulating layer into a fully cured state, the insulating layer is preferably pressurized at a temperature of 150 to 300°C and a pressure of 0 to 25 MPa.

[0013] The insulating layer is preferably a cured film of a latent curable resin composition. An example of the latent curable resin composition is an epoxy resin composition containing an epoxy resin, an aromatic amine compound represented by the following general formula (1), a boron-phosphorus complex represented by the following general formula (2), and a phosphorus compound represented by the following general formula (3).

[0014] [ka]

[0015] In general formula (1), R1 represents an alkyl group, m represents an integer of 2 or more, n represents an integer of 0 or more, and m and n satisfy m+n≦6. When n is an integer of 2 or more, multiple R1s may be the same or different.

[0016] [ka]

[0017] In general formula (2), R2 and R3 each independently represent an alkyl group, r represents an integer of 0 to 5, and s represents an integer of 0 to 5. When r is an integer of 2 or greater, multiple R2s may be the same or different. When s is an integer of 2 or greater, multiple R3s may be the same or different.

[0018] [ka]

[0019] In general formula (3), R4 represents an alkyl group or an alkoxy group, and t represents an integer of 0 to 5. When t is an integer of 2 or more, multiple R4s may be the same or different. [Effects of the Invention]

[0020] According to the present invention, even when an electronic component that generates a large amount of heat is used, it is possible to suppress defects occurring in the insulating layer while maintaining stable bonding between the electronic component and the circuit pattern. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a diagram showing a laminate manufactured by a method for manufacturing a laminate according to one embodiment of the present invention; [Figure 2] FIG. 2 is a diagram showing a first step to a second step of a method for producing a laminate according to one embodiment of the present invention. [Figure 3] FIG. 4 is a diagram showing a third step of the method for producing a laminate according to one embodiment of the present invention. [Figure 4] FIG. 3 is a diagram showing fourth to sixth steps of a method for producing a laminate according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, a method for manufacturing a laminate according to one embodiment of the present invention will be described with reference to the accompanying drawings. Note that the drawings are schematic, and the thickness, width, and ratio of each part may differ from those actually implemented.

[0023] 1 is a diagram showing a laminate 1 manufactured by the manufacturing method of this embodiment. The laminate 1 includes a heat sink 2, an insulating layer 3, a circuit pattern 4, an electronic component 5, and a bonding layer 6.

[0024] The heat sink 2 has a plate-shaped base 2a and comb-shaped fins 2b protruding from the base 2a, and has the function of dissipating heat transferred to the base 2a to the outside through the fins 2b. The heat sink 2 is preferably made of a material with high thermal conductivity, such as copper, aluminum, iron, or other metals (which may be simple metals or alloys).

[0025] The heat sink 2 corresponds to the "base substrate" in this specification. The shape of the "base substrate" is not limited to one having fins 2b as shown in the figure, and may be, for example, a plate-like substrate formed only of a base portion 2a. The "base substrate" is not limited to one made of a single member, and may be one made by combining multiple members. The "base substrate" may also include a configuration that further improves the effect of releasing heat to the outside, and may be, for example, a metal plate with a vapor chamber or heat pipe embedded in it.

[0026] The insulating layer 3 is formed of an insulating material and is provided so as to cover the surface of the base 2a of the heat sink 2. The insulating layer 3 may cover the entire surface of the base 2a, or may cover only a part of the surface.

[0027] An example of the material for the insulating layer 3 is a resin composition containing a thermosetting resin. Examples of the thermosetting resin include epoxy resin, phenol resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, and cyanate resin. One type of thermosetting resin may be used alone, or two or more types may be used in combination.

[0028] As the epoxy resin, any monomer, oligomer, or polymer having two or more epoxy groups per molecule can be used, regardless of its molecular weight or molecular structure. Specific examples of such epoxy resins include bisphenol-type epoxy resins such as bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol E-type epoxy resin, bisphenol S-type epoxy resin, hydrogenated bisphenol A-type epoxy resin, bisphenol M-type epoxy resin (4,4'-(1,3-phenylenediisopridiene)bisphenol-type epoxy resin), bisphenol P-type epoxy resin (4,4'-(1,4-phenylenediisopridiene)bisphenol-type epoxy resin), and bisphenol Z-type epoxy resin (4,4'-cyclohexydienebisphenol-type epoxy resin); novolac-type epoxy resins such as phenol novolac-type epoxy resin, brominated phenol novolac-type epoxy resin, cresol novolac-type epoxy resin, tetraphenol-group ethane novolac-type epoxy resin, and novolac-type epoxy resin having a condensed ring aromatic hydrocarbon structure; biphenyl-type epoxy resin; and xylylene. aralkyl-type epoxy resins such as aralkyl-type epoxy resins, such as naphthylene ether-type epoxy resins, naphthol-type epoxy resins, naphthalene-type epoxy resins, naphthalenediol-type epoxy resins, difunctional to tetrafunctional epoxy-type naphthalene resins, binaphthyl-type epoxy resins, and naphthalenearalkyl-type epoxy resins; epoxy resins having a naphthalene skeleton, such as anthracene-type epoxy resins; phenoxy-type epoxy resins; dicyclopentadiene-type epoxy resins; norbornene-type epoxy resins; adamantane-type epoxy resins; fluorene-type epoxy resins, phosphorus-containing epoxy resins, alicyclic epoxy resins, aliphatic linear epoxy resins, bisphenol A novolac-type epoxy resins, bixylenol-type epoxy resins, triphenolmethane-type epoxy resins, trihydroxyphenylmethane-type epoxy resins, tetraphenylolethane-type epoxy resins, and heterocyclic epoxy resins such as triglycidyl isocyanurate;Examples include glycidyl amines such as N,N,N',N'-tetraglycidyl meta-xylenediamine, N,N,N',N'-tetraglycidyl bisaminomethylcyclohexane, and N,N-diglycidylaniline; copolymers of glycidyl (meth)acrylate and compounds having an ethylenically unsaturated double bond; epoxy resins having a butadiene structure; diglycidyl ethers of bisphenols; diglycidyl ethers of naphthalenediol; and glycidyl ethers of phenols. The resin composition according to this embodiment may contain one or more epoxy resins selected from these.

[0029] In addition to the thermosetting resin, the resin composition may contain, for example, a curing agent. The curing agent is selected depending on the type of thermosetting resin, and is not particularly limited as long as it reacts with the thermosetting resin. For example, when an epoxy resin is used, examples of the curing agent include an amine-based curing agent, an imidazole-based curing agent, and a phenol-based curing agent.

[0030] An example of the curing agent is one containing an aromatic amine compound represented by the following general formula (1).

[0031] [ka]

[0032] In general formula (1), R1 represents an alkyl group, m represents an integer of 2 or more, n represents an integer of 0 or more, and m and n satisfy m+n≦6. When n is an integer of 2 or more, multiple R1s may be the same or different.

[0033] m, which represents the number of amino groups substituted on the benzene ring, is from 2 to 6, and may be from 2 to 5, or may be 2 or 3, or may be 2. When m is 2, the arrangement of the two amino groups on the benzene ring is preferably meta or ortho relative to one of the amino groups.

[0034] R1 is an arbitrary substituent for the benzene ring. The number of carbon atoms in the alkyl group represented by R1 may be 1 to 4, or may be 1 or 2. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. n, which represents the number of R1 substituted on the benzene ring, is 0 or more and 4 or less, or may be 0 or more and 3 or less, or may be 1 or more and 3 or less.

[0035] The aromatic amine compound represented by the general formula (1) has a small steric hindrance and is therefore excellent in improving the curability, and can exhibit sufficient performance even in a short curing time.

[0036] The resin composition may contain a filler (inorganic filler). The filler preferably has excellent insulating properties and high thermal conductivity, and examples thereof include aluminum oxide, silica, aluminum nitride, boron nitride, silicon nitride, and magnesium oxide.

[0037] The resin composition may contain a curing accelerator, a stabilizer, an ion scavenger, a solvent, etc. The resin composition may also contain a flexibility-imparting agent.

[0038] An example of the curing accelerator is one containing a boron-phosphorus complex represented by the following general formula (2).

[0039] [ka]

[0040] In general formula (2), R2 and R3 each independently represent an alkyl group, r represents an integer of 0 to 5, and s represents an integer of 0 to 5. When r is an integer of 2 or greater, multiple R2s may be the same or different. When s is an integer of 2 or greater, multiple R3s may be the same or different.

[0041] R2 and R3 are optional substituents for the benzene ring. Specific examples of the alkyl group represented by R2 and R3 include a methyl group and an ethyl group.

[0042] r, which represents the number of R2 substituted on the benzene ring on which the P atom is substituted, is from 0 to 5, may be from 0 to 3, may be from 0 to 2, or may be 0 or 1. When r is 1, the position of the alkyl group represented by R2 may be any of the ortho, meta, and para positions relative to the P atom.

[0043] The number s, which represents the number of R3 substituted on the benzene ring on which the B atom is substituted, is 0 or more and 5 or less, and may be 0 or more and 3 or less, or may be 0 or more and 2 or less.

[0044] When the boron-phosphorus complex represented by the above general formula (2) is contained as the curing accelerator, it is preferable to contain a phosphorus compound represented by the following general formula (3) as a stabilizer.

[0045] [ka]

[0046] In general formula (3), R4 represents an alkyl group or an alkoxy group, and t represents an integer of 0 to 5. When t is an integer of 2 or more, multiple R4s may be the same or different.

[0047] R4 is an optional substituent for the benzene ring. Specific examples of the alkyl group represented by R4 include a methyl group, an ethyl group, and a propyl group. Specific examples of the alkoxy group represented by R4 include a methoxy group and a butoxy group.

[0048] As described below, the insulating layer 3 is preferably a cured film formed from a latent curing resin composition that exhibits latent curing properties, which are slow to cure near room temperature but can be transferred or temporarily bonded to other objects when heated to a predetermined temperature. For example, the insulating layer 3 can exhibit the latent curing properties when it is a cured film of an epoxy resin composition containing an epoxy resin, an aromatic amine compound represented by the general formula (1), a boron-phosphorus complex represented by the general formula (2), and a phosphorus compound represented by the general formula (3). The latent curing resin composition is preferably a system that can be stored for long periods in a mixed state of epoxy resin and curing agent and initiates a curing reaction upon application of stimuli such as heat, light, pressure, or moisture. Furthermore, the rise of the exothermic peak associated with the curing reaction (cure initiation temperature) is preferably 40°C or higher as measured by differential scanning calorimetry. Furthermore, as a curing agent for an epoxy resin or an additive for an epoxy resin and a curing agent, dicyandiamide, a dihydrazide compound, various amine adduct-based latent curing agents, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, onium salts (sulfonium salts, phosphonium salts), boron halide-amine complexes, vinyl ether block carboxylic acids, activated esters of polycarboxylic acids, ketimine compounds, silanol group-containing polymers, and the like may be used.

[0049] t, which represents the number of substitutions of R4 on the benzene ring, is 0 or more and 5 or less, and may be 0 or more and 4 or less, or 0 or more and 2 or less, or may be 0.

[0050] The circuit pattern 4 can be obtained by forming a predetermined pattern using a conductive material. Examples of such materials include metal foils such as copper and aluminum. The thickness of the metal foil is, for example, about 0.01 to 2.0 mm. Methods for forming the predetermined pattern include, for example, forming a mask pattern on the metal foil and removing the exposed portions of the metal foil by etching, and punching out the metal foil using a mold.

[0051] The electronic component 5 is, for example, a semiconductor chip. Although there is no limitation on the electronic component 5 used in this embodiment, the method for manufacturing a laminate according to this embodiment is particularly suitable for use with a semiconductor chip (for example, a SiC power device) that becomes hot during operation.

[0052] The bonding layer 6 electrically connects the circuit pattern 4 and the electronic components 5 and also functions to fix the electronic components 5 to the circuit pattern 4. The bonding layer 6 is appropriately selected taking into consideration the material forming the circuit pattern 4, the amount of heat generated by the electronic components 5, the environmental load, etc. Examples of the bonding layer 6 include a solder layer obtained by melting solder (e.g., an Sn-based solder layer or a Zn-Al-based solder layer), and a sintered metal layer obtained by sintering metal nanoparticles (e.g., Ag nanoparticles, Cu nanoparticles, etc.).

[0053] Next, a method for producing the laminate 1 will be described with reference to FIGS. 2 to 4. FIG. 2 illustrates the first and second steps in the method for producing the laminate 1. FIG. 3 illustrates the third step. FIG. 4 illustrates the fourth, fifth, and sixth steps. The first step corresponds to the "step of heating a resin composition applied to a base sheet to form a semi-cured insulating layer on the base sheet" in this specification. The second step corresponds to the "step of heating and pressurizing a semi-cured insulating layer disposed on a base substrate, and then peeling off the base sheet to transfer the semi-cured insulating layer to the surface side of the base substrate" in this specification. The third step corresponds to the "step of providing electronic components on the surface side of a circuit pattern" in this specification. The fourth and fifth steps correspond to the "step of arranging a circuit pattern with electronic components on the semi-cured insulating layer transferred to the surface side of the base substrate, and applying heat and pressure to temporarily bond the circuit pattern to the insulating layer" in this specification. The sixth step corresponds to the "step of heating and pressurizing the insulating layer to which the circuit pattern has been temporarily attached to bring the insulating layer to a fully cured state" in this specification. In the following description, the first step is described in the order of step 1, step 2, etc. However, the present invention is not limited to carrying out the steps in this order, and the order may be reversed as long as each step is effective, or each step may be carried out simultaneously. The temperature, pressure, and time conditions described below are exemplified for the case where an epoxy resin (e.g., bisphenol A epoxy resin) is used as the resin composition.

[0054] In the first step, a base sheet made of, for example, PET is prepared, the above-mentioned resin composition is applied to this base sheet, and the resin composition is heated together with the base sheet to form a semi-cured insulating layer 3 on the base sheet. In the first step, the resin composition together with the base sheet is heated at a temperature of 50 to 200°C for a heating time of 10 to 200 minutes. The heating conditions in the first step are preferably a temperature of 50 to 180°C and a heating time of 10 to 180 minutes, and more preferably a temperature of 50 to 160°C and a heating time of 10 to 160 minutes.

[0055] In the second step, the semi-cured insulating layer 3 formed on the base sheet is placed on the surface side of the heat sink 2 shown in Figure 2, and they are heated and pressed. Then, the base sheet is peeled off and the semi-cured insulating layer 3 is transferred to the surface side of the heat sink 2. The heating and pressing conditions in the second step are a temperature of 30 to 180°C, a pressure of 1 to 25 MPa, and a pressing time of 10 to 300 seconds. The heating and pressing conditions in the second step are more preferably a temperature of 30 to 160°C, a pressure of 3 to 25 MPa, and a pressing time of 10 to 240 seconds, and even more preferably a temperature of 30 to 140°C, a pressure of 5 to 25 MPa, and a pressing time of 10 to 180 seconds.

[0056] Alternatively to the first and second steps, the resin composition may be applied to the surface of the base 2a of the heat sink 2 using a roll coating method, a bar coating method, a screen printing method, or the like, followed by heating and pressure to form a semi-cured insulating layer 3 on the surface of the base 2a.

[0057] When the insulating layer 3 is semi-cured by applying a resin composition to the surface of the base 2a by, for example, roll coating, the resin composition is applied to the surface of the base 2a and then heated. In this method, when an epoxy resin (e.g., bisphenol A epoxy resin) is used as the thermosetting resin, the resin composition is applied and then heated at a temperature of 80°C for 60 minutes, and then heated at a temperature of 90°C while being pressurized at a pressure of 23 MPa.

[0058] In the third step shown in FIG. 3 , electronic components 5 are mounted on the surface side of the circuit pattern 4. To mount the electronic components 5 on the circuit pattern 4, for example, solder paste is applied to predetermined positions on the circuit pattern 4, the electronic components 5 are placed on top of the solder paste, and the two are joined by heating at a predetermined temperature to melt the solder. A paste containing metal nanoparticles may be used instead of the solder paste. In this case, a paste containing metal nanoparticles is applied to the circuit pattern 4, the electronic components 5 are placed on top of the paste, and the electronic components 5 are heated at a predetermined temperature while being pressurized, thereby sintering the metal nanoparticles and joining the circuit pattern 4 and the electronic components 5. Various methods can be used to apply the solder paste or paste containing metal nanoparticles, including roll coating, bar coating, and screen printing.

[0059] After the first to third steps are performed, the fourth to sixth steps shown in FIG. 4 are performed. In the fourth step, the semi-cured insulating layer 3 provided on the heat sink 2 is temporarily bonded to the circuit pattern 4 on which the electronic components 5 are mounted. In the fifth step, the insulating layer 3 to which the circuit pattern 4 is temporarily bonded is temporarily cured, thereby temporarily attaching the circuit pattern 4 to the insulating layer 3. In the sixth step performed thereafter, the temporarily cured insulating layer 3 is permanently cured. Note that the device used to perform the fourth to sixth steps may be any device that can apply pressure while heating, and may be a heat press or an autoclave.

[0060] In the fourth step, the electronic component 5 and / or the circuit pattern 4 are heated at a temperature of 30 to 180°C and pressed at a pressure of 0.1 to 25 MPa for a pressurizing time of 10 to 300 seconds. The temperature and pressure conditions in the fourth step are more preferably heated at a temperature of 30 to 160°C and pressed at a pressure of 0.1 to 20 MPa for a pressurizing time of 10 to 240 seconds, and even more preferably heated at a temperature of 30 to 140°C and pressed at a pressure of 0.1 to 15 MPa for a pressurizing time of 10 to 180 seconds.

[0061] In the fifth step, the electronic component 5 and / or the circuit pattern 4 are pressed at a pressure of 0.1 to 25 MPa while being heated at a temperature of 130 to 200°C. The pressing time is 1 to 30 minutes. The temperature and pressure conditions in the fifth step are more preferably a temperature of 130 to 200°C while being pressed at a pressure of 0.1 to 20 MPa for a pressing time of 1 to 30 minutes, and even more preferably a temperature of 130 to 200°C while being pressed at a pressure of 0.1 to 15 MPa for a pressing time of 1 to 30 minutes.

[0062] In the sixth step, the electronic component 5 and / or the circuit pattern 4 are heated at a temperature of 150 to 300°C and pressed at a pressure of 0 to 25 MPa for a period of 30 to 180 minutes. The temperature and pressure conditions in the sixth step are more preferably a temperature of 150 to 300°C, a pressure of 0 to 20 MPa, and a period of 30 to 180 minutes, and even more preferably a temperature of 150 to 300°C, a pressure of 0 to 15 MPa, and a period of 30 to 180 minutes.

[0063] In the above-mentioned pressure range, a pressure of 0 MPa during application of pressure refers to a non-pressurized state. Furthermore, the temporary bonding of the circuit pattern 4 to the insulating layer 3 may be performed in one step rather than being divided into two steps, the fourth and fifth steps, or may be performed in three or more steps. Furthermore, the final curing of the insulating layer 3 is not limited to being performed in the above-mentioned one step, but may be performed in two or more steps.

[0064] In the method for manufacturing the laminate 1 described above, even when a paste containing metal nanoparticles is used to bond the circuit pattern 4 and the electronic components 5, the insulating layer 3 is not laminated with the circuit pattern 4 or the electronic components 5 in the step of sintering the metal nanoparticles. In other words, the insulating layer 3 is not affected by the high-load pressure in a high-temperature environment that is required to sinter the metal nanoparticles, and therefore defects that may have occurred in the past, such as cracking of the insulating layer 3, can be suppressed. Furthermore, when the circuit pattern 4 on which the electronic components 5 are mounted is laminated on the insulating layer 3 in a semi-cured state, the insulating layer 3 in the semi-cured state is not excessively crushed when pressure is applied to the electronic components 5, and the predetermined thickness can be maintained, so the insulating properties of the insulating layer 3 can be stably ensured.

[0065] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0066] <Example> As a material for the insulating layer 3, a resin composition was prepared. The resin composition used was a blend of 100 parts by mass of bisphenol A epoxy resin (trade name EXA-850CRP; manufactured by DIC Corporation), 28 parts by mass of curing agent ("DETDA-80"; manufactured by Lonza), 0.9 parts by mass of curing accelerator ("TTP-S"; manufactured by Hokko Chemical Industry Co., Ltd.), 0.3 parts by mass of stabilizer ("TPP"; manufactured by Hokko Chemical Industry Co., Ltd.), 24 parts by mass of flexibility imparting agent, 3 parts by mass of ion scavenger, 210 parts by mass of aluminum oxide (trade name AS40; manufactured by Showa Denko K.K.) as fillers, 339 parts by mass of boron nitride (BN) aggregates (trade name HP40MF100; manufactured by Mizushima Ferroalloy Co., Ltd.), 60 parts by mass of boron nitride (BN) fine powder (trade name NX1; manufactured by Momentive Corporation), and 248 parts by mass of ethyl 3-ethoxypropionate (EEP) as a solvent.

[0067] This resin composition was then applied to a base sheet and heated to form a semi-cured insulating layer 3 on the base sheet.

[0068] The insulating layer 3 was then placed on the heat sink 2 together with the base sheet so that the surface of the heat sink 2 and the semi-cured insulating layer 3 were in contact with each other, and this was then pressed in a vacuum press at a temperature of 90°C and a pressure of 23 MPa for 30 seconds. The base sheet was then peeled off, allowing the semi-cured insulating layer 3 to be transferred to the heat sink 2.

[0069] Furthermore, electronic component 5 was placed on circuit pattern 4 coated with paste containing metal nanoparticles, and then electronic component 5 was mounted on circuit pattern 4 by heating at a predetermined temperature while applying pressure.

[0070] Thereafter, the circuit pattern 4 on which the electronic components 5 were mounted was placed at a predetermined position on the semi-cured insulating layer 3. Then, the circuit pattern 4 was temporarily bonded to the insulating layer 3 by applying pressure of 4 MPa at a temperature of 75°C for 40 seconds in a vacuum press.

[0071] Next, the vacuum press was placed in a vacuum exhaust state (open to the atmosphere), and the insulating layer 3 was temporarily cured by applying pressure at a temperature of 180° C. and a pressure of 4 MPa for 780 seconds.

[0072] Thereafter, the insulating layer 3 was allowed to stand for 60 minutes at a temperature of 185° C. and a pressure of 0 MPa (non-pressurized state), thereby completely curing the insulating layer 3.

[0073] When the laminate 1 manufactured by the above method was checked, no cracks or peeling were found in the insulating layer 3, even when the electronic component 5 was operating at high temperatures. The parallelism and flatness of the electronic component 5 were also normal.

[0074] Although one embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and unless otherwise limited in the above description, various modifications and changes are possible within the scope of the spirit of the present invention as set forth in the claims. Furthermore, the effects of the above embodiment are merely examples of the effects that can be obtained from the present invention, and do not mean that the effects of the present invention are limited to the above effects.

[0075] For example, the layer structure of the laminate 1 is not limited to the above embodiment, and other layers may be interposed between the above layers. One example of a modified layer structure is to interpose an adhesive sheet between the heat sink 2 and the insulating layer 3. Alternatively, a liquid adhesive may be applied to the surface of the insulating layer 3. If voids are formed on the surface of the insulating layer 3, the liquid adhesive is applied to fill the voids. That is, when bonding the insulating layer 3 to a mating object, the adhesive function of the voided portion can be compensated for by the liquid adhesive. The insulating layer 3 may be any material that has insulating properties and is not limited to being formed from a resin composition. An example of an insulating layer 3 other than a resin composition is a ceramic substrate. [Explanation of symbols]

[0076] 1: Laminate 2: Heat sink (base board) 3: Insulation layer 4: Circuit pattern 5: Electronic components

Claims

1. A method for manufacturing a laminate in which a base substrate, an insulating layer, a circuit pattern, and an electronic component are laminated in this order, comprising the steps of: providing the insulating layer on the front surface side of the base substrate; providing the electronic component on the front surface side of the circuit pattern; laminating the insulating layer provided on the base substrate and the circuit pattern provided with the electronic components, The insulating layer is a resin composition, and the resin composition contains a bisphenol A type epoxy resin as a thermoplastic resin, an aromatic amine compound represented by the following general formula (1) as a curing agent, a boron-phosphorus complex represented by the following general formula (2) as a curing accelerator, a phosphorus compound represented by the following general formula (3) as a stabilizer, and a filler. 【Chemistry 1】 In general formula (1), R 1 represents an alkyl group, m represents an integer of 2 or more, n represents an integer of 0 or more, and m and n satisfy m + n ≦ 6. When n is an integer of 2 or more, multiple R 1s may be the same or different. 【Chemistry 2】 In general formula (2), R2 and R3 each independently represent an alkyl group, r represents an integer of 0 to 5, and s represents an integer of 0 to 5. When r is an integer of 2 or greater, multiple R2s may be the same or different. When s is an integer of 2 or greater, multiple R3s may be the same or different. 【Transformation 3】 In general formula (3), R 4 represents an alkyl group or an alkoxy group, and t represents an integer of 0 to 5. When t is an integer of 2 or more, multiple R 4 s may be the same or different.

2. In the step of providing the insulating layer on the front surface side of the base substrate, the insulating layer is in a semi-cured state, The method for producing a laminate according to claim 1 , wherein the insulating layer is fully cured in the step of laminating the insulating layer provided on the base substrate and the circuit pattern provided with the electronic components.

3. The step of providing the insulating layer on the front surface side of the base substrate includes: a step of heating the resin composition applied to the base sheet to form the insulating layer in a semi-cured state on the base sheet; a step of heating and pressurizing the insulating layer in a semi-cured state disposed on the base substrate, and then peeling off the base sheet to transfer the insulating layer in a semi-cured state to the front surface side of the base substrate, The step of laminating the insulating layer provided on the base substrate and the circuit pattern provided with the electronic components includes: a step of placing the circuit pattern provided with the electronic components on the insulating layer in a semi-cured state transferred to the front surface side of the base substrate, and temporarily bonding the circuit pattern to the insulating layer by applying heat and pressure; The method for producing a laminate according to claim 2 , further comprising the step of applying heat and pressure to the insulating layer to which the circuit pattern has been temporarily attached, to bring the insulating layer into a fully cured state.

4. 4. The method for manufacturing a laminate according to claim 3, wherein in the step of transferring the insulating layer in a semi-cured state to the surface side of the base substrate, the insulating layer is pressed at a temperature of 30 to 180°C and a pressure of 1 to 25 MPa.

5. In the step of temporarily bonding the circuit pattern to the insulating layer, the insulating layer and the circuit pattern are pressurized at a temperature of 30 to 180°C and a pressure of 0.1 to 25 MPa to temporarily bond the circuit pattern to the insulating layer, and further the insulating layer and the circuit pattern are pressurized at a temperature of 130 to 200°C and a pressure of 0.1 to 25 MPa to temporarily cure the insulating layer; 5. The method for producing a laminate according to claim 3, wherein in the step of bringing the insulating layer into a fully cured state, the insulating layer is pressed at a temperature of 150 to 300° C. and a pressure of 0 to 25 MPa.

6. The method for producing a laminate according to any one of claims 1 to 5, wherein the insulating layer is a cured film of a latent curing resin composition.

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