Semiconductor device manufacturing method

Abstract

The manufacturing method includes the following steps: a step of pasting the sintering bonding sheet (10) side of a sheet body (X) having a laminated structure of a substrate (B) and a sintering bonding sheet (10) to a plurality of chips (C) arranged on a processing tape (T1), and then peeling the substrate B from the sintering bonding sheet (10); a step of picking up the chip (C) on the processing tape (T1) together with the portion of the sintering bonding sheet (10) that is in close contact with the chip (C) to obtain a chip (C) with a sintering bonding material layer; a step of temporarily fixing the chip (C) with the sintering bonding material layer to a substrate with the aid of the sintering bonding material layer (11); and a step of forming a sintered layer by heating the sintering bonding material layer (11) sandwiched between the temporarily fixed chip (C) and the substrate, and bonding the chip (C) to the substrate. The semiconductor device manufacturing method is suitable for efficiently supplying sintering bonding materials to semiconductor chips while reducing the loss of sintering bonding materials.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a semiconductor device, such as a so-called power semiconductor device. Background Art

[0002] In the manufacture of semiconductor devices, the following methods are known as methods for electrically connecting a semiconductor chip to a supporting substrate such as a lead frame or an insulating circuit substrate while bonding the chip to the supporting substrate: a method of forming an Au-Si eutectic alloy layer between the supporting substrate and the chip to achieve a bonding state; and a method of using solder or a resin containing conductive particles as bonding materials.

[0003] On the other hand, in recent years, the popularity of power semiconductor devices that are responsible for controlling the supply of electricity has increased significantly. In power semiconductor devices, in most cases, a large amount of heat is released due to the large amount of current flowing during operation. Therefore, in the manufacture of power semiconductor devices, a method of bonding the chip to the support substrate while allowing the semiconductor chip to be electrically connected to the support substrate side is required to achieve a highly reliable bonding state even during high-temperature operation. Such a requirement is particularly strong in power semiconductor devices that use SiC and GaN as semiconductor materials to achieve high-temperature operation. In addition, in order to meet such requirements, a technology using a sintering bonding composition containing sinterable particles and a solvent has been proposed as a chip bonding method accompanied by electrical connection.

[0004] In chip bonding using a sintering bonding material containing sinterable particles, first, a semiconductor chip is placed under specified temperature / load conditions relative to a predetermined chip bonding position of a support substrate with the aid of the sintering bonding material. Afterwards, a heating process is performed under specified temperature / pressure conditions in a manner such that the solvent in the sintering bonding material evaporates between the support substrate and the semiconductor chip thereon and sintering is performed between the sinterable particles. Thus, a sintering layer is formed between the support substrate and the semiconductor chip, the semiconductor chip is electrically connected to the support substrate, and the bonding is performed mechanically. Such a technology is described in, for example, the following patent documents 1 and 2.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2008 / 065728

[0008] Patent Document 2: Japanese Patent Application Publication No. 2013-039580 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] In the process of manufacturing semiconductor devices by performing chip bonding by sinter bonding, a paste composition containing sinterable particles is conventionally applied to each semiconductor chip. However, this method is inefficient.

[0011] On the other hand, in the manufacturing process of semiconductor devices that perform chip bonding by sintering bonding, it can be considered to paste a sintering bonding material sheet containing sinterable particles on a semiconductor wafer that has already produced a plurality of semiconductor elements, and then singulate the semiconductor wafer with the sheet by blade cutting. However, this method causes a large loss of sintering bonding materials depending on the yield of the elements produced in the semiconductor wafer. In the manufacture of power semiconductor devices using SiC and GaN as semiconductor materials, for example, the semiconductor elements produced in the wafer of such semiconductor materials sometimes do not achieve a sufficiently high yield. In this case, the loss of sintering bonding materials is large in the method of pasting a sintering bonding material sheet on the semiconductor wafer before singulation into semiconductor chips. This is because the sintering bonding material is also supplied to defective chips. There is a tendency that the lower the yield of the elements produced in the semiconductor wafer, the greater the loss of sintering bonding materials.

[0012] The present invention has been conceived based on the above circumstances, and an object of the present invention is to provide a method for manufacturing a semiconductor device having a sinter-bonding portion for a semiconductor chip suitable for efficiently supplying a sinter-bonding material to a semiconductor chip while reducing loss of the sinter-bonding material.

[0013] Solutions for solving problems

[0014] The semiconductor device manufacturing method provided by the first aspect of the present invention includes the following steps: arranging step, transferring step, picking up step, temporarily fixing step and sintering step. This method is suitable for manufacturing semiconductor devices such as power semiconductor devices having sintered bonding parts of semiconductor chips.

[0015] In the arrangement step, a plurality of semiconductor chips are arranged on the adhesive surface of the processing tape having an adhesive surface. The distance between adjacent semiconductor chips is, for example, 50 to 2000 μm, preferably 50 to 1000 μm, and more preferably 50 to 700 μm, depending on the viscosity and thickness of the sintering bonding sheet used in the present manufacturing method.

[0016] In the transfer process, first, the sintering bonding sheet side of the sheet body having a laminated structure including a substrate and a sintering bonding sheet is pressed and pasted to the plurality of semiconductor chips on the processing tape. The sintering bonding sheet preferably contains at least a binder component and sinterable particles containing a conductive metal. Next, the sintering bonding sheet is left on the semiconductor chip side, and the substrate is peeled off from the sintering bonding sheet.

[0017] In the picking-up process, the semiconductor chip on the processing tape is picked up together with the portion of the sintering bonding sheet that is in close contact with the semiconductor chip, thereby obtaining a semiconductor chip with a sintering bonding material layer. If a process for cutting the sintering bonding sheet into small pieces is not performed before the picking-up process, the sintering bonding sheet will be cut into small pieces into the sintering bonding material layer together with the semiconductor chip in the picking-up process.

[0018] In the temporary fixing step, the semiconductor chip with the sinter bonding material layer is pressure-bonded and temporarily fixed to the substrate via the sinter bonding material layer.

[0019] In the sinter bonding step, the sinter bonding material layer interposed between the temporarily fixed semiconductor chip and the substrate is subjected to a heating process to form a sintered layer, and the semiconductor chip is sinter-bonded to the substrate.

[0020] The present semiconductor device manufacturing method includes an arrangement process as described above. In the arrangement process, for semiconductor chips, chips that have undergone various inspections and have been identified as qualified products after the manufacturing process, namely KGD (Known Good Die, known qualified chips) can be selected and arranged on a processing tape. Therefore, in the present manufacturing method, a transfer process can be performed on a processing tape that only holds a plurality of KGDs as semiconductor chips, and a sintering bonding sheet as a sintering bonding material can be transferred to these semiconductor chips (KGD) together through the transfer process. Such a present manufacturing method is suitable for avoiding the supply of sintering bonding materials to semiconductor chips that have not been identified as qualified products when supplying sintering bonding materials to a plurality of semiconductor chips together, and is therefore suitable for reducing the loss of sintering bonding materials.

[0021] Furthermore, in the transfer process of the manufacturing method, as described above, the plurality of semiconductor chips on the processing tape are attached with the sintering bonding sheet (sintering bonding material) side of the sheet body, and the sheet body substrate is peeled off while the sintering bonding sheet remains on the processing tape and / or the plurality of semiconductor chips. This configuration is suitable for efficiently supplying the sintering bonding material to the plurality of semiconductor chips at once.

[0022] Furthermore, in the present manufacturing method, the chip-to-chip distance of the semiconductor chips arranged on the processing tape in the above-mentioned arrangement process, that is, the distance between adjacent semiconductor chips, is set to be shorter so that the sintering bonding sheet remains on the plurality of semiconductor chips when the substrate is peeled off in the transfer process. As described above, the chip-to-chip distance is, for example, 50 to 2000 μm, preferably 50 to 1000 μm, and more preferably 50 to 700 μm. When the chip-to-chip distance is too long, the sintering bonding sheet side of the sheet body having a laminated structure including a substrate and a sintering bonding sheet is pasted to the plurality of semiconductor chips on the processing tape, and then the process of peeling off the sheet body substrate is performed, when the sheet body substrate is peeled off, a part of the sintering bonding sheet will be removed along with the substrate. The removed part of the sintering bonding sheet becomes the loss of the sintering bonding material. In the present manufacturing method, the chip-to-chip distance of the semiconductor chips arranged on the processing tape in the arrangement process is set according to the viscosity, thickness, etc. of the sintering bonding sheet used, so that such removal of the sintering bonding sheet does not occur in the transfer process. This structure is suitable for reducing the loss of sintering bonding material.

[0023] As described above, the semiconductor device manufacturing method according to the present invention is suitable for efficiently supplying the sinter bonding material to each semiconductor chip while reducing the loss of the sinter bonding material.

[0024] The manufacturing method preferably further includes an expansion process between the transfer process and the pick-up process. In the expansion process, the processing tape holding the plurality of semiconductor chips to which the sintering bonding sheets are attached is temporarily expanded, thereby cutting the sintering bonding sheets on the plurality of semiconductor chips into small pieces into the sintering bonding material layers of each semiconductor chip. This configuration is preferred for properly picking up a semiconductor chip with a sintering bonding material layer that has been separated from an adjacent sintering bonding material layer in the pick-up process.

[0025] The manufacturing method preferably further includes a blade cutting step between the transfer step and the pick-up step. In the blade cutting step, the sintered bonding sheet that is closely attached to a plurality of semiconductor chips held by a processing tape is cut by a blade, thereby breaking the sintered bonding sheet into pieces for each semiconductor chip. This configuration is preferred for properly picking up a semiconductor chip with a sintered bonding material layer that has been separated from an adjacent sintered bonding material layer in the pick-up step.

[0026] The manufacturing method preferably further includes a bending process between the transfer process and the picking process. In the bending process, the processing tape holding a plurality of semiconductor chips to which sintering bonding sheets are attached is bent, thereby cutting the sintering bonding sheets on the plurality of semiconductor chips into small pieces into respective sintering bonding material layers for each semiconductor chip. Bending the processing tape includes bending and folding the processing tape. This configuration is preferred for properly picking up a semiconductor chip with a sintering bonding material layer that has been separated from an adjacent sintering bonding material layer in the picking process.

[0027] The thickness of the sintered layer formed by the sintering bonding process is preferably in the range of 60 to 140% of the average thickness of the sintered layer, more preferably in the range of 80 to 120%, and more preferably in the range of 90 to 110%. The more uniform the thickness of the sintered layer, the easier it is to obtain high bonding reliability in the sintered layer. In addition, the average thickness of the sintered layer formed by the sintering bonding process is preferably 5 to 200 μm, more preferably 10 to 150 μm. This structure is preferred for alleviating the internal stress caused by thermal stress in the sintered layer and ensuring sufficient thermal shock reliability, while suppressing the cost associated with sintering bonding and thus the manufacturing cost of the semiconductor device.

[0028] The sinterable particles in the sintered bonding sheet used in the present manufacturing method preferably contain at least one selected from the group consisting of silver, copper, silver oxide and copper oxide. This configuration is suitable for forming a strong sintered layer between the substrate to be sintered and bonded and the semiconductor chip. In addition, the binder component in the sintered bonding sheet is preferably a thermally decomposable polymer binder. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0030] Figure 2 express Figure 1 The subsequent process of the indicated process.

[0031] Figure 3 express Figure 2 The subsequent process of the indicated process.

[0032] Figure 4 express Figure 3 The subsequent process of the indicated process.

[0033] Figure 5 express Figure 4 The subsequent process of the indicated process.

[0034] Figure 6 express Figure 5 The subsequent process of the indicated process.

[0035] Figure 7 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0036] Figure 8 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0037] Fig. 9 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0038] Fig.10 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0039] Fig.11 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown. DETAILED DESCRIPTION

[0040] Figure 1 to Figure 6 A semiconductor device manufacturing method according to an embodiment of the present invention is shown. The semiconductor device manufacturing method of this embodiment is a method for manufacturing a semiconductor device such as a power semiconductor device having a sintered bonding portion of a semiconductor chip, and includes the following arrangement step, transfer step, pickup step, temporary fixing step and sintering bonding step.

[0041] In the arrangement process, Figure 1 As shown in the figure, a plurality of chips C are arranged on the processing tape T1. The processing tape T1 has a laminated structure of, for example, a base material and an adhesive layer, and has an adhesive surface T1a formed by an adhesive layer on one side. An annular frame R is adhered to the peripheral portion of the adhesive surface T1a of the processing tape T1. The annular frame R is a component that a conveying mechanism such as a conveying arm mechanically abuts when conveying a workpiece in a state adhered to the processing tape T1. The chip C is a semiconductor chip of KGD that has been confirmed as a qualified product after various inspections and is adhered to the adhesive surface T1a of the processing tape T1, and has one main surface ( Figure 1 The lower surface in the figure) and the opposite back surface ( Figure 1 The upper surface in the chip C is formed on the back side with a planar electrode (not shown) as an external electrode. As constituent materials for forming the chip body of the chip C, semiconductor materials for power semiconductor devices such as silicon carbide (SiC) and gallium nitride (GaN) can be listed. The thickness of the chip C is, for example, 20 to 1000 μm.

[0042] In the arrangement process, specifically, on the adhesive surface Ta of the processing tape T1, a plurality of chips C are arranged with spaces between adjacent chips. From the viewpoint of avoiding or suppressing the contact between the chip C to be picked up and the adjacent chip C in the later-described pickup process, the distance between adjacent chips C, that is, the distance between chips is preferably 50 μm or more, more preferably 100 μm or more. From the viewpoint of avoiding the loss caused by the removal of the sintering bonding material in the later-described transfer process, the distance between chips is, for example, 2000 μm or less, preferably 1000 μm or less, and more preferably 700 μm or less, depending on the viscosity and thickness of the later-described sintering bonding sheet.

[0043] In the semiconductor device manufacturing method, next, Figure 2 In this process, first, as shown in Figure 2 (a) and Figure 2 As shown in (b), a sheet body X is pasted to multiple chips C on the processing tape T1. The sheet body X has a stacked structure including a substrate B and a sintering bonding sheet 10. The substrate B is, for example, a plastic film. The sintering bonding sheet 10 is a sheet-like sintering bonding composition that contains at least a binder component and sinterable particles containing a conductive metal. In this process, the sintering bonding sheet 10 side of the sheet body X is crimped and pasted to multiple chips C. As a pressing means for pasting, for example, a crimping roller can be cited. The pasting temperature is, for example, in the range of room temperature to 200°C, and the load for pasting is, for example, 0.01 to 10 MPa. After pasting, as Figure 2 As shown in (c), the substrate B is peeled off from the sinter-bonding sheet 10 while the sinter-bonding sheet 10 remains on the chip C side. In this step, the sinter-bonding material can be supplied to each chip C at once.

[0044] The sinter-bonding sheet 10 is a sheet used for sinter-bonding objects to be bonded, and is a sheet-shaped sinter-bonding composition containing at least a binder component and sinterable particles containing a conductive metal, as described above.

[0045] The sinterable particles in the sintered bonding sheet 10 are particles containing conductive metal elements and capable of sintering. As conductive metal elements, for example, gold, silver, copper, palladium, tin and nickel can be cited. As the constituent materials of such sinterable particles, for example, gold, silver, copper, palladium, tin, nickel and alloys of two or more metals selected from their groups can be cited. As the constituent materials of sinterable particles, metal oxides such as silver oxide, copper oxide, palladium oxide, and tin oxide can also be cited. In addition, the sinterable particles can be particles with a core-shell structure. For example, the sinterable particles can be particles of the following core-shell structure, that is, the particles of the core-shell structure have a core with copper as the main component and a shell with gold, silver, etc. as the main component and covering the core. In the present embodiment, the sinterable particles preferably include at least one selected from the group consisting of silver particles, copper particles, silver oxide particles and copper oxide particles. From the viewpoint that the formed sintered layer realizes high electrical conductivity and high thermal conductivity, as sinterable particles, silver particles and copper particles are preferably used. And, from the viewpoint of oxidation resistance, silver particles are easy to handle and are preferred. For example, in the sintering bonding of a semiconductor chip to a copper substrate with a silver plated layer, when a sintering material containing copper particles as sinterable particles is used, the sintering process needs to be performed in an inactive environment such as a nitrogen atmosphere. However, when a sintering material containing silver particles as sinterable particles is used, the sintering process can be properly performed even in an air atmosphere.

[0046] From the viewpoint of achieving a low sintering temperature for the sinterable particles and ensuring good sinterability, the average particle size of the sinterable particles used is preferably 2000nm or less, more preferably 800nm ​​or less, and more preferably 500nm or less. From the viewpoint of achieving good dispersibility for the sinterable particles in the sintering bonding sheet 10 and / or the composition used to form it, the average particle size of the sinterable particles is preferably 1nm or more, more preferably 10nm or more, and more preferably 50nm or more. The average particle size of the sinterable particles can be measured by observation using a scanning electron microscope (SEM).

[0047] From the viewpoint of achieving highly reliable sintered bonding, the content of the sinterable particles in the sinter-bonding sheet 10 is preferably 60 to 99 mass %, more preferably 65 to 98 mass %, more preferably 70 to 97 mass %, and even more preferably 70 to 95 mass %.

[0048] In the present embodiment, the binder component in the sintering bonding sheet 10 includes at least a thermally decomposable polymer binder and a low boiling point binder, and may further include other components such as a plasticizer. The thermally decomposable polymer binder is a binder component that can be thermally decomposed during the high-temperature heating process for sintering bonding, and is an element that helps to maintain the sheet shape of the sintering bonding sheet 10 until the heating process. In the present embodiment, from the perspective of guaranteeing the sheet shape retention function, the thermally decomposable polymer binder is a material that is solid at room temperature (23°C). Examples of such thermally decomposable polymer binders include polycarbonate resins and acrylic resins.

[0049] Regarding the polycarbonate resin as a thermally decomposable polymer binder, for example, there can be mentioned: aliphatic polycarbonates that do not contain aromatic compounds such as benzene rings between the carbonate groups (-O-CO-O-) of the main chain and contain aliphatic chains; and aromatic polycarbonates that contain aromatic compounds between the carbonate groups (-O-CO-O-) of the main chain. Examples of aliphatic polycarbonates include polyethylene carbonate and polypropylene carbonate. Examples of aromatic polycarbonates include polycarbonates containing a bisphenol A structure in the main chain.

[0050] Regarding the acrylic resin as a thermally decomposable polymer binder, for example, there can be mentioned polymers of acrylic acid esters and / or methacrylic acid esters having a linear or branched alkyl group with 4 to 18 carbon atoms. In the following, "(meth)acrylic acid" means "acrylic acid" and / or "methacrylic acid", and "(meth)acrylate" means "acrylate" and / or "methacrylate". As for the alkyl group of (meth)acrylate used to form the acrylic resin as a thermally decomposable polymer binder, for example, there can be mentioned methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl, amyl, isopentyl, hexyl, heptyl, cyclohexyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, and octadecyl.

[0051] The acrylic resin of the thermally decomposable polymer binder can be a polymer containing monomer units derived from other monomers other than the above-mentioned (meth) acrylic acid ester. As such other monomers, for example, carboxyl-containing monomers, anhydride monomers, hydroxyl-containing monomers, sulfonic acid-containing monomers, and phosphoric acid-containing monomers can be cited. Specifically, as carboxyl-containing monomers, for example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid can be cited. As anhydride monomers, for example, maleic anhydride and itaconic anhydride can be cited. As hydroxyl-containing monomers, for example, 2-hydroxyethyl (meth) acrylic acid, 2-hydroxypropyl (meth) acrylic acid, 4-hydroxybutyl (meth) acrylic acid, 6-hydroxyhexyl (meth) acrylic acid, 8-hydroxyoctyl (meth) acrylic acid, 10-hydroxydecyl (meth) acrylic acid, 12-hydroxylauryl (meth) acrylic acid, and 4-(hydroxymethyl)cyclohexylmethyl (meth) acrylic acid can be cited. Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, (meth)acrylate sulfopropyl ester, and (meth)acryloyloxynaphthalenesulfonic acid. Examples of the phosphoric acid group-containing monomer include 2-hydroxyethylacryloyl phosphate.

[0052] The weight average molecular weight of the thermally decomposable polymer binder is preferably not less than 10000. The weight average molecular weight of the thermally decomposable polymer binder is a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene.

[0053] From the viewpoint of appropriately exhibiting the sheet shape-retaining function, the content of the thermally decomposable polymer binder in the sinter-bonding sheet 10 is preferably 0.5 to 10% by mass, more preferably 0.8 to 8% by mass, and even more preferably 1 to 6% by mass.

[0054] The low boiling point binder in the sinter bonding sheet 10 has a viscosity of 1×10 5 Liquid or semi-liquid adhesive with a viscosity of less than Pa·s. In this viscosity measurement, parallel plates with a diameter of 20 mm were used as a jig, the gap between the plates was set to 100 μm, and the shear rate in the rotational shear was set to 1 s. -1 .

[0055] As the above-mentioned low boiling point binder, for example, terpene alcohols, alcohols other than terpene alcohols, alkylene glycol alkyl ethers, and ethers other than alkylene glycol alkyl ethers can be cited. As terpene alcohols, for example, isobornyl cyclohexanol, citronellol, geraniol, nerol, carveol, and α-terpineol can be cited. As alcohols other than terpene alcohols, for example, amyl alcohol, hexanol, heptanol, octanol, 1-decanol, ethylene glycol, diethylene glycol, propylene glycol, butanediol, and 2,4-diethyl-1,5-pentanediol can be cited. Examples of the alkylene glycol alkyl ethers include ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, diethylene glycol isobutyl ether, diethylene glycol hexyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, diethylene glycol isopropyl methyl ether, triethylene glycol methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, propylene glycol propyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, dipropylene glycol butyl ether, dipropylene glycol dimethyl ether, tripropylene glycol methyl ether, and tripropylene glycol dimethyl ether. As ethers other than alkylene glycol alkyl ethers, for example, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, and dipropylene glycol methyl ether acetate can be cited. As a component in the sintering bonding sheet 10, one low boiling point binder can be used, or two or more low boiling point binders can be used. As the low boiling point binder in the sintering bonding sheet 10, from the viewpoint of stability at room temperature, terpene alcohols are preferred, and isobornyl cyclohexanol is more preferred.

[0056] The thickness of the sintered bonding sheet 10 at 23°C is preferably 5 μm or more, more preferably 10 μm or more, and preferably 300 μm or less, more preferably 150 μm or less. The viscosity of the sintered bonding sheet 10 and / or the sintered bonding composition forming the sintered bonding sheet 10 at 70°C is, for example, 5×10 3 ~1×10 7 Pa·s, preferably 1×10 4 ~1×10 6 Pa·s.

[0057] The sintered bonding sheet 10 may be provided with a cut along its predetermined separation line. The cut depth (the depth from the surface of the sintered bonding sheet 10 on the side opposite to the substrate B) is, for example, 20 to 100% of the thickness of the sintered bonding sheet 10. Such a configuration related to the cut of the sintered bonding sheet 10 is preferred for appropriately fragmenting the sintered bonding sheet 10 into the sintered bonding material layer described later.

[0058] The sintered bonding sheet 10 can be produced, for example, by mixing the above components in a solvent to prepare a varnish, applying the varnish to form a coating film on the substrate B, and drying the coating film. As the solvent for preparing the varnish, an organic solvent or an alcohol solvent can be used.

[0059] In the semiconductor device manufacturing method, next, Figure 3 As shown, the chip C and the portion of the sintering bonding sheet 10 that is in close contact with the chip C are picked up from the processing tape T1 to obtain a chip C with a sintering bonding material layer (picking up process). In the picking up process of the present embodiment, specifically, with respect to the chip C to be picked up, the pin member 21 of the picking up mechanism is raised on the lower side of the processing tape T1 in the figure and lifted up through the processing tape T1. At this time, on the chip C to be picked up, the sintering bonding sheet 10 is partially fragmented to form a sintering bonding material layer 11. After such lifting, the chip C is held by suction by a suction collet 22 through the effect of adsorption toward the sintering bonding material layer 11. In this way, the chip C with the sintering bonding material layer can be picked up.

[0060] In this embodiment, then, Figure 4 As shown, the chip C with the sintering material layer is transferred from the suction collet 22 that has picked up the chip C to another suction collet 23 (reversal step). The suction collet 23 holds the chip C with the sintering material layer by sucking it toward the chip side.

[0061] Then, if Figure 5 As shown in (a), the chip C with a sintered bonding material layer is temporarily fixed by pressing the sintered bonding material layer 11 onto the supporting substrate S (temporary fixing process). Specifically, for example, using a chip mounter, the chip C with a sintered bonding material layer is temporarily fixed by pressing the sintered bonding material layer 11 onto the supporting substrate S. As the supporting substrate S, for example, lead frames and insulating circuit substrates with wiring such as copper wiring on the surface can be cited. The chip mounting part in the supporting substrate S can be a substrate surface of copper wiring, lead frame, etc., or a plated surface formed on the substrate surface. As the plating, for example, gold plating, silver plating, nickel plating, palladium plating and platinum plating can be cited. In this process, the temperature conditions for temporary fixing are, for example, in the range of room temperature to 300°C, the pressing load is, for example, 0.01 to 50 MPa, and the bonding time is, for example, 0.01 to 300 seconds.

[0062] Then, if Figure 5As shown in (b), the sintering layer 12 is formed by the sintering bonding material layer 11 sandwiched between the temporarily fixed chip C and the supporting substrate S through a heating process, and the chip C is sintered and bonded to the supporting substrate S (sintering bonding process). Specifically, by undergoing a prescribed high-temperature heating process, the low-boiling point binder in the sintering bonding material layer 11 is volatilized, the thermally decomposable polymer binder is thermally decomposed and volatilized, and the conductive metal of the sinterable particles is sintered. As a result, a sintering layer 12 is formed between the supporting substrate S and each chip C, and the chip C is electrically connected to the supporting substrate S side and bonded to the supporting substrate S. In this process, the temperature conditions for sintering bonding are, for example, in the range of 150 to 400°C, and preferably in the range of 250 to 350°C. The pressure used for sintering bonding is, for example, below 60 MPa, and preferably below 40 MPa. In addition, the bonding time of the sintering bond is, for example, 0.3 to 300 minutes, preferably 0.5 to 240 minutes. For example, within the range of these conditions, the temperature curve and pressure curve for implementing the sintering bond process are appropriately set. The sintering bond process as above can be carried out using a device that can heat and pressurize at the same time. As such a device, for example, a flip chip bonding machine and a parallel plate press can be cited. In addition, from the viewpoint of preventing oxidation of the metal involved in the sintering bond, this process is preferably carried out under a nitrogen atmosphere, under reduced pressure or under a reducing gas atmosphere.

[0063] In the present embodiment, the thickness of the sintered layer 12 formed by the sintering bonding process is preferably in the range of 60 to 140% of the average thickness of the sintered layer 12, more preferably in the range of 80 to 120%, and more preferably in the range of 90 to 110%. The more uniform the thickness of the sintered layer 12 is, the easier it is to obtain high bonding reliability in the sintered layer 12. In addition, the average thickness of the sintered layer 12 is preferably 5 to 200 μm, more preferably 10 to 150 μm. This configuration is preferred for alleviating the internal stress caused by thermal stress in the sintered layer 12 and ensuring sufficient thermal shock reliability, while suppressing the cost associated with sintering bonding and thus the manufacturing cost of the semiconductor device.

[0064] In the semiconductor device manufacturing method, next, Figure 6 As shown in (a), the terminal portion of the chip C (not shown) and the terminal portion of the supporting substrate S (not shown) are electrically connected by means of a bonding wire W as needed (wire bonding process). The connection between the terminal portion of the chip C, the terminal portion of the supporting substrate S and the bonding wire W is achieved by, for example, ultrasonic welding accompanied by heating. As the bonding wire W, for example, a gold wire, an aluminum wire or a copper wire can be used. The wire heating temperature in the wire bonding is, for example, 80 to 250°C, preferably 80 to 220°C. In addition, the heating time is several seconds to several minutes.

[0065] Then, if Figure 6 As shown in (b), a sealing resin M for protecting the chip C and the bonding wire W on the supporting substrate S is formed (sealing process). In this process, the sealing resin M is formed, for example, by a transfer molding technique using a mold. As a constituent material of the sealing resin M, for example, an epoxy resin can be used. In this process, the heating temperature for forming the sealing resin M is, for example, 165 to 185°C, and the heating time is, for example, 60 seconds to several minutes. In the case where the sealing resin M is not fully cured in this sealing process, a post-curing process for completely curing the sealing resin M is performed after this process.

[0066] As described above, a semiconductor device including a sintered bonded portion of a semiconductor chip can be manufactured.

[0067] In the semiconductor device manufacturing method, referring to Figure 2 After the transfer process described above and before the pickup process, a reversal process may be performed as follows. Figure 7 As shown in (a), a processing tape T2 having an adhesive surface T2a is attached to the workpiece (a plurality of chips C, sintering bonding sheet 10) after the transfer process, and the processing tape T1 is peeled off from the workpiece. The adhesive force of the adhesive surface T2a of the processing tape T2 is equal to or greater than the adhesive force of the adhesive surface T1a of the processing tape T1. In this process, for example, after the processing tape T2 is attached to the sintering bonding sheet 10 side of the workpiece after the transfer process with its adhesive surface T2a side, the processing tape T1 is peeled off from the workpiece.

[0068] When performing this reversal process, use Figure 7 The picking process is performed as shown in (b). Specifically, with respect to the chip C to be picked up, on the lower side of the processing tape T2 in the figure, the pin member 21 of the picking mechanism is raised and lifted up through the processing tape T2. At this time, the portion of the sintering bonding sheet 10 that is in close contact with the chip C to be picked up is fragmented to form a sintering bonding material layer 11. After such lifting, the chip C is held by adsorption with the adsorption barrel clamp 22. In this manner, the chip C with the sintering bonding material layer is provided to the reference Figure 5 (a) and the temporary fixing process as described above.

[0069] In the semiconductor device manufacturing method as described above, Figure 1In the arrangement process as described above, for the chip C, the chip that has undergone various inspections after the manufacturing process and is recognized as a qualified product, that is, KGD (Known Good Die), can be selected and arranged on the processing tape T1. Therefore, in the present manufacturing method, a transfer process can be performed on the processing tape T1 that only holds a plurality of KGDs as chip C, and the sintering bonding sheet 10 as a sintering bonding material can be transferred to these chips C (KGD) through the transfer process. Such a manufacturing method is suitable for avoiding the supply of sintering bonding materials to chips C that have not been recognized as qualified products when supplying sintering bonding materials to a plurality of chips C at a time, and is therefore suitable for reducing the loss of sintering bonding materials.

[0070] In addition, in the transfer step of the present manufacturing method, as shown in FIG. Figure 2 As described above, the sintering bonding sheet 10 (sintering bonding material) side of the sheet body X is attached to the plurality of chips C on the processing tape T1, and the substrate B is peeled off while the sintering bonding sheet 10 remains on the processing tape T1 and / or the plurality of chips C. This configuration is suitable for efficiently supplying the sintering bonding material to the plurality of chips C at once.

[0071] Furthermore, in the present manufacturing method, the chip-to-chip distance of the chips C arranged on the processing tape T1 in the arrangement process is set shorter so that the sintering bonding sheet 10 remains on the plurality of chips C when the substrate B is peeled off in the transfer process. When the chip-to-chip distance is too long, the plurality of chips on the processing tape are pasted on the side of the sintering bonding sheet in the sheet body having a stacked structure including a substrate and a sintering bonding sheet, and then the process of peeling off the sheet body substrate is performed. When the sheet body substrate is peeled off, a portion of the sintering bonding sheet will be removed along with the substrate. The removed portion of the sintering bonding sheet becomes the loss of the sintering bonding material. In contrast, in the present manufacturing method, the chip-to-chip distance of the chips C arranged on the processing tape T1 in the above-mentioned arrangement process is set according to the viscosity, thickness, etc. of the sintering bonding sheet 10 used, so that such removal of the sintering bonding sheet 10 does not occur in the above-mentioned transfer process. This configuration is suitable for reducing the loss of the sintering bonding material.

[0072] As described above, the present semiconductor device manufacturing method is suitable for efficiently supplying the sinter bonding material to each chip C while reducing the loss of the sinter bonding material.

[0073] In the semiconductor device manufacturing method, referring to Figure 2 Between the transfer process and the pick-up process, Figure 8 As shown in FIG. 1 , a process of temporarily expanding the processing tape T1 holding the workpiece (plurality of chips C, sintering bonding sheet 10) can be performed. Figure 7(a) and in the above-mentioned reversal process, in reference to Figure 2 Between the transfer process and the reversal process, Figure 8 As shown, a step of temporarily expanding the processing tape T1 holding the workpiece can be performed.

[0074] In this expansion process, an expansion device is used. First, Figure 8 As shown in (a) of FIG. 1 , the processing tape T1 with the workpiece (plurality of chips C, sintering bonding sheet 10) and the ring frame R on the bonding surface T1a is fixed to the holding tool 31 of the expansion device. Figure 8 As shown in (b), the hollow cylindrical lifting member 32 of the expansion device abuts against the processing belt T1 from its lower side and rises, and the processing belt T1 holding the workpiece is expanded in a manner of being stretched along two-dimensional directions including the radial and circumferential directions of the workpiece holding area. As a result, the sintering bonding sheet 10 tightly attached to each chip C is cut and broken into small pieces into the sintering bonding material layer 11 of each chip C. The temperature condition during expansion is, for example, -20 to 70°C. Thereafter, as Figure 8 As shown in (c), the lifting member 32 is lowered, and the expanded state in the processing tape T1 is released. After expansion, the portion of the processing tape T1 that is further outside the workpiece holding area can be heated to shrink. The heating temperature is, for example, 100 to 300°C. This structure is preferred for suppressing the narrowing of the spacing distance between the chips C after expansion.

[0075] In this process, as described above, by temporarily expanding the processing tape T1 holding the plurality of chips C to which the sintered bonding sheets 10 are attached, the sintered bonding sheets 10 on the plurality of chips C are cut into small pieces into the sintered bonding material layers 11 of each chip C. This configuration is preferred for properly picking up the chip C with the sintered bonding material layer 11 separated from the adjacent sintered bonding material layer 11 in the subsequent picking-up process.

[0076] In the semiconductor device manufacturing method, referring to Figure 2 Between the transfer process and the pick-up process, Fig. 9 As shown in FIG. 1 , a blade cutting step for cutting the sintered bonding sheet 10 can be performed. Figure 7 (a) and in the above-mentioned reversal process, in reference to Figure 2 Between the transfer process and the reversal process, Fig. 9 As shown, a blade cutting step for cutting the sheet 10 for sinter bonding may be performed.

[0077] In this blade cutting process, specifically, a cutting device with a rotating blade is used to cut the sintered bonding sheet 10 on multiple chips C held by the processing tape T1 along their predetermined cutting positions, and the sintered bonding sheet 10 is divided into small pieces into sintered bonding material layers 11 for each chip C. Fig. 9 In FIG. 1 , the cut portion by the rotating blade is schematically shown by a thick line. This configuration is preferable for appropriately picking up the chip C with the sintered bonding material layer 11 separated from the adjacent sintered bonding material layer 11 in the subsequent picking-up step.

[0078] In the semiconductor device manufacturing method, reference is made to Figure 7 (a) and in the above-mentioned inversion step, in the inversion step and the reference Figure 7 (b) and between the picking steps as described above, as Fig.10 As shown, a blade cutting step for cutting the sheet 10 for sinter bonding may be performed.

[0079] In this blade cutting process, specifically, a cutting device with a rotating blade is used to cut the sintered bonding sheet 10 held by the processing belt T2 together with multiple chips C along its predetermined cutting position, and the sintered bonding sheet 10 is divided into small pieces into sintered bonding material layers 11 for each chip C. Fig.10 In FIG. 1 , the cut portion by the rotary blade is schematically shown by a thick line. This configuration is preferable for appropriately picking up the chip C with the sintered bonding material layer 11 separated from the adjacent sintered bonding material layer 11 in the subsequent picking-up step.

[0080] In the semiconductor device manufacturing method, referring to Figure 2 Between the transfer process and the pick-up process, Fig.11 As shown in FIG. 1 , a process of temporarily bending the processing tape T1 holding the workpiece (plurality of chips C, sinter-bonding sheet 10 ) can be performed. Figure 7 (a) and in the above-mentioned reversal process, in reference to Figure 2 Between the transfer process and the reversal process as described above, Fig.11 As shown in FIG. 1 , the process of temporarily bending the processing tape T1 holding the workpiece may be performed. Bending the processing tape T1 includes bending or folding the processing tape T1 .

[0081] In this bending process, for example, Fig.11As shown in (a), by bending the processing tape T1 holding the plurality of chips C to which the sintering bonding sheet 10 is attached, the sintering bonding sheet 10 on the plurality of chips C is cut into small pieces into the sintering bonding material layer 11 for each chip C. Fig.11 As shown in (b) of FIG. 1 , the deformed state of the processing tape T1 is released. This configuration is preferable for appropriately picking up the chip C with the sinter-bonding material layer 11 separated from the adjacent sinter-bonding material layer 11 in the subsequent picking-up step.

[0082] Description of Reference Numerals

[0083] X-ray body

[0084] B. Substrate

[0085] 10 Sintering bonding sheet

[0086] 11 Sintering bonding material layer

[0087] 12 Sintering layer

[0088] T1, T2 processing belt

[0089] C chip (semiconductor chip)

[0090] S Support substrate (substrate)

Claims

1. A method for manufacturing a semiconductor device, comprising the following steps: an arranging step of arranging a plurality of semiconductor chips on the adhesive surface of the processing tape having an adhesive surface; A transfer step of attaching the sintered bonding sheet side of a sheet body having a laminated structure including a substrate and a sintered bonding sheet to the plurality of semiconductor chips on the processing tape, and then peeling the substrate of the sheet body from the sintered bonding sheet; A picking-up step of picking up the semiconductor chip on the processing tape together with the portion of the sintering bonding sheet that is in close contact with the semiconductor chip to obtain a semiconductor chip with a sintering bonding material layer; A temporary fixing step of temporarily fixing the semiconductor chip with the sintering bonding material layer to the substrate via the sintering bonding material layer; as well as The bonding step is to form a sintered layer by subjecting the sintered bonding material layer sandwiched between the temporarily fixed semiconductor chip and the substrate to a heating process, and then bonding the semiconductor chip to the substrate. The sintered bonding sheet includes a thermally decomposable polymer binder and sinterable particles containing a conductive metal.

2. The method for manufacturing a semiconductor device according to claim 1, wherein: An expansion process is also included between the transfer process and the pickup process. In this expansion process, the processing tape holding the multiple semiconductor chips is temporarily expanded to cut the sintering bonding sheets on the multiple semiconductor chips into small pieces into respective sintering bonding material layers for each semiconductor chip.

3. The method for manufacturing a semiconductor device according to claim 1, wherein: A blade dicing step is further included between the transfer step and the pickup step. In the blade dicing step, the sinter bonding sheet is diced with a blade to form small pieces into sinter bonding material layers for each semiconductor chip.

4. The method for manufacturing a semiconductor device according to claim 1, wherein: A bending process is also included between the transfer process and the pickup process. In this bending process, the processing belt holding the multiple semiconductor chips is bent, so that the sintering bonding sheets on the multiple semiconductor chips are cut into small pieces into respective sintering bonding material layers for each semiconductor chip.

5. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein: The thickness of the sintered layer is in the range of 60 to 140% of the average thickness of the sintered layer.

6. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein: The average thickness of the sintered layer is 5 to 200 μm.

7. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein: The sinterable particles include at least one selected from the group consisting of silver, copper, silver oxide, and copper oxide.

8. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein: The semiconductor device is a power semiconductor device.

9. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein: The distance between adjacent semiconductor chips in the plurality of semiconductor chips is 50 to 1000 μm.

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