Manufacturing method for semiconductor devices

Abstract

To provide a semiconductor device and a method of manufacturing the semiconductor device capable of comparatively suppressing adhesion unevenness in attaching a plurality of semiconductor chips to a substrate in a state interposing an adhesion sheet.SOLUTION: A method of manufacturing a semiconductor device implements a semiconductor chip attaching step for sequentially pressing a plurality of semiconductor chips by a first pressing member so as to adhere them to a plurality of mounting areas by using a plurality of semiconductor chips B1 and B2, a lead frame substrate D having a plurality of mounting areas on which the plurality of semiconductor chips are mounted, a plurality of adhesion sheets 2 containing sinterable metal particles which can be sintered by heating to a temperature not higher than 400°C, and the first pressing member (collet A) which presses the semiconductor chips to the substrate in a state interposing the adhesion sheet so as to adhere the plurality of semiconductor chips to the plurality of mounting areas. In the semiconductor chip attaching step, the pressing of the semiconductor chips is implemented by using the first pressing member heated to a temperature at which the sinterable metal particles can be sintered.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] This invention relates to a semiconductor device and a method for manufacturing a semiconductor device. [Background technology]

[0002] Conventionally, in the manufacture of semiconductor devices, a method is known in which a semiconductor chip (hereinafter also referred to as a die) is bonded to a substrate (such as a lead frame substrate) with a film containing sinterable particles interposed therebetween (for example, Patent Document 1 below).

[0003] Patent Document 1 below describes forming a dried film (hereinafter also referred to as a sheet) using a paste-like composition containing sinterable particles, and adhering the die to the substrate via the film. Furthermore, Patent Document 1 below describes a method in which at least one die is placed on the substrate with the film interposed therebetween to form an assembly, and then a pressure of less than 40 MPa is applied to the assembly, and a temperature of 175°C to 400°C is applied to the assembly to mount at least one die onto the substrate. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2014-503936 [Overview of the project] [Problems that the invention aims to solve]

[0005] By the way, when the plurality of semiconductor chips are attached to the substrate at once by pressing them while heating, with a sheet containing sinterable particles interposed between them, as described in Patent Document 1 above, uneven adhesion of the plurality of semiconductor chips to the substrate may occur (uneven adhesion may occur). However, in the attachment of the multiple semiconductor chips to the substrate with the aforementioned sheet (adhesive sheet) in between, it is still difficult to say that sufficient research has been conducted on suppressing uneven adhesion.

[0006] Therefore, the object of the present invention is to provide a method for manufacturing a semiconductor device that can relatively suppress uneven adhesion when attaching multiple semiconductor chips to a substrate with an adhesive sheet interposed therebetween, and a semiconductor device manufactured by this method. [Means for solving the problem]

[0007] The method for manufacturing a semiconductor device according to the present invention is: Multiple semiconductor chips, A substrate having multiple mounting areas on which the multiple semiconductor chips are mounted, Multiple adhesive sheets containing sinterable metal particles that can be sintered by heating at a temperature of 400°C or lower, A first pressing member is used to press the semiconductor chip toward the substrate with the adhesive sheet interposed between them, thereby bonding the plurality of semiconductor chips to the plurality of mounting areas. A semiconductor chip mounting process is performed in which the plurality of semiconductor chips are sequentially pressed with the first pressing member and bonded to the plurality of mounting areas. In the semiconductor chip mounting process, the semiconductor chip is pressed using the first pressing member, which has been heated to a temperature at which the sinterable metal particles can be sintered.

[0008] With this configuration, in the semiconductor chip mounting process, in addition to sequentially pressing the plurality of semiconductor chips with the first pressing member to adhere them to the plurality of mounting areas, the pressing of the semiconductor chips is performed using the first pressing member which has been heated to a temperature at which the sinterable metal particles can be sintered. As a result, each of the plurality of semiconductor chips can be attached to the mounting area relatively uniformly with the adhesive sheet in between. As a result, in the attachment of a plurality of semiconductor chips to a substrate with an adhesive sheet interposed therebetween, uneven adhesion can be relatively suppressed.

[0009] Also, in the method of manufacturing the semiconductor device, after the semiconductor chip attachment step, a secondary heating step of heating the substrate to which the plurality of semiconductor chips are attached at a temperature at which the sinterable metal particles can be sintered is further performed, in the secondary heating step, it is preferable that the heating is performed without pressing some or all of the plurality of semiconductor chips toward the substrate.

[0010] According to such a configuration, some or all of the plurality of semiconductor chips can be firmly attached to the substrate with an adhesive sheet interposed therebetween. That is, the connection reliability of some or all of the plurality of semiconductor chips with respect to the substrate can be improved. Also, the equipment used in the second heating step can be made simple without including a pressing member for pressing some or all of the plurality of semiconductor chips.

[0011] Also, in the method of manufacturing the semiconductor device, in the secondary heating step, it is preferable that the heating is performed without pressing all of the plurality of semiconductor chips toward the substrate.

[0012] According to such a configuration, all of the plurality of semiconductor chips can be firmly attached to the substrate with an adhesive sheet interposed therebetween. That is, the connection reliability of all of the plurality of semiconductor chips with respect to the substrate can be improved.

[0013] Also, in the method of manufacturing the semiconductor device, after the semiconductor chip attachment step, Further perform a secondary heating step of heating the substrate to which the plurality of semiconductor chips are attached at a temperature at which the sinterable metal particles can be sintered. In the secondary heating step, it is preferable that the heating is performed while pressing some or all of the plurality of semiconductor chips toward the substrate.

[0014] According to such a configuration, in the secondary heating step, since the heating is performed while pressing some or all of the plurality of semiconductor chips toward the substrate, some or all of the plurality of semiconductor chips can be more firmly attached to the substrate with an adhesive sheet interposed therebetween. That is, the connection reliability of some or all of the plurality of semiconductor chips with respect to the substrate can be further improved.

[0015] Also, in the method of manufacturing the semiconductor device, In the secondary heating step, it is preferable that the heating is performed while pressing all of the plurality of semiconductor chips toward the substrate.

[0016] According to such a configuration, all of the plurality of semiconductor chips can be more firmly attached to the substrate with an adhesive sheet interposed therebetween. That is, the connection reliability of all of the plurality of semiconductor chips with respect to the substrate can be further improved.

[0017] Also, in the method of manufacturing the semiconductor device, In the semiconductor chip mounting step, it is preferable to heat the first pressing member to a temperature of 250°C or higher.

[0018] According to such a configuration, each of the plurality of semiconductor chips can be firmly attached to the substrate with an adhesive sheet interposed therebetween. That is, the connection reliability of each of the plurality of semiconductor chips with respect to the substrate can be improved.

[0019] The semiconductor device according to the present invention is A semiconductor device manufactured by the semiconductor device manufacturing method described in any of the above, The shear strength between one of the aforementioned semiconductor chips and the mounting area at 25°C is 2 MPa or more.

[0020] With this configuration, the semiconductor device has improved connectivity reliability between each of the multiple semiconductor chips and the substrate. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a method for manufacturing a semiconductor device that can relatively suppress uneven adhesion when attaching multiple semiconductor chips to a substrate with an adhesive sheet interposed therebetween, and a semiconductor device manufactured by this method. [Brief explanation of the drawing]

[0022] [Figure 1] A schematic cross-sectional view showing the structure of a laminate according to one embodiment of the present invention. [Figure 2] (a) is a schematic cross-sectional view showing how the collet lifts the first semiconductor chip from the dicing tape. (b) is a schematic cross-sectional view showing how the collet lifts the second semiconductor chip from the dicing tape. [Figure 3] (a) is a schematic cross-sectional view showing the process of transferring a portion of the adhesive sheet of the laminate to the first semiconductor chip. (b) is a schematic cross-sectional view showing the process of transferring a portion of the adhesive sheet of the laminate to the second semiconductor chip. [Figure 4] (a) is a schematic cross-sectional view showing how the collet lifts the first semiconductor chip with the adhesive sheet attached from the laminate. (b) is a schematic cross-sectional view showing how the collet lifts the second semiconductor chip with the adhesive sheet attached from the laminate. [Figure 5](a) is a schematic cross-sectional view showing how the first semiconductor chip with adhesive sheet is attached to the first die pad of the lead frame. (b) is a schematic cross-sectional view showing how the second semiconductor chip with adhesive sheet is attached to the second die pad of the lead frame. [Figure 6] (a) is a schematic cross-sectional view showing an example of a secondary heating process. (b) is a schematic cross-sectional view showing another example of a secondary heating process. [Modes for carrying out the invention]

[0023] The following describes one embodiment of the present invention.

[0024] [Adhesive Sheet] Before describing the method for manufacturing a semiconductor device according to this embodiment, we will first describe the adhesive sheet used in the method for manufacturing a semiconductor device according to this embodiment.

[0025] The adhesive sheet has two sides, one on which it adheres to the substrate. The adhesive sheet contains sinterable metal particles that can be sintered by heating at a temperature of 400°C or lower. Thus, because the adhesive sheet contains the sinterable metal particles described above, when the adhesive sheet is heated to a temperature at which the sinterable metal particles can be sintered, a sintered layer is formed, ensuring adhesion to the adherend on one side and adhesion to the adherend on the other side. Furthermore, the formation of the sintered layer electrically connects the adherend bonded to one side of the adhesive sheet with the adherend bonded to the other side of the adhesive sheet. In this specification, sinterable metal particles that can be sintered by heating at a temperature of 400°C or lower mean particles that exhibit necking on the outer surface of the particles when heated at a temperature of 400°C or lower. The sintering temperature of sinterable metal particles can be measured using a thermogravimetric differential thermal analyzer. Specifically, by performing measurements under the following conditions using a thermogravimetric differential thermal analyzer (for example, a differential thermal balance TG8120 manufactured by Rigaku), a Tg curve and a DTA curve can be obtained, and the temperature of the largest peak on the DTA curve observed near the beginning of the Tg curve's decline can be determined. <Measurement conditions> • Heating rate: 10℃ / min • Measurement atmosphere: Air • Measurement temperature range: Room temperature (23±2℃) to 500℃

[0026] Examples of sinterable metal particles that can be sintered by heating at temperatures below 400°C include gold, silver, copper, palladium, tin, nickel, and alloys thereof. Furthermore, metal oxides can also be used as sinterable metal particles. Examples of such metal oxides include silver oxide, copper oxide, palladium oxide, and tin oxide. The sinterable metal particles may also be particles having a core-shell structure. Examples of particles having a core-shell structure include particles comprising a core made of copper and a shell made of gold, silver, or the like that covers the core. From the viewpoint that the adhesive sheet can become a sintered layer that is firmly adhered to the adherend after sintering, it is preferable that the sinterable metal particles include at least one particle selected from the group consisting of silver, copper, silver oxide, and copper oxide. Furthermore, from the viewpoint that the adhesive sheet may have excellent electrical and thermal conductivity after sintering, it is preferable that the sinterable metal particles include at least one particle selected from the group consisting of silver and copper. Furthermore, from the viewpoint of improving oxidation resistance, it is preferable that the sinterable metal particles contain silver particles. By containing silver particles, oxidation of the sinterable metal particles can be suppressed when the sinterable metal particles are sintered in an air atmosphere. Furthermore, the sinterable metal particles may also include particles comprising a copper core and a silver shell covering the core (hereinafter also referred to as silver-coated copper particles), and combinations of silver particles. The sinterable metal particles are contained in the adhesive sheet in either the form of primary particles or secondary particles formed by aggregation of primary particles.

[0027] The sintered metal particles have a volume-average particle diameter D 50 However, it is preferable that the particle size be 0.01 μm or larger, and more preferably 0.1 μm or larger. Furthermore, the sinterable metal particles have a volume-average particle diameter D 50 However, it is preferable that the particle size be 10 μm or less, more preferably 5 μm or less, and particularly preferable that it be 1 μm or less. Furthermore, if the sinterable metal particles are composed of two or more types of particles, the volume average particle diameter D 50 This refers to a value measured when two or more types of particles are mixed together.

[0028] The volume-average particle diameter D of the sintered metal particles 50 and D 90 For example, this can be measured on a volume basis using a laser diffraction / scattering particle size analyzer (Microtrac MT3000II series, manufactured by Microtrac-Bell).

[0029] The adhesive sheet contains a binder in addition to sinterable metal particles that can be sintered by heating at a temperature of 400°C or lower. The adhesive sheet may contain, in addition to the sinterable metal particles and binder, a plasticizer or the like. The aforementioned binder comprises a polymer binder and a non-polymer binder (hereinafter also referred to as a low-molecular-weight binder).

[0030] The polymer binder is preferably a pyrolytic polymer binder. The thermally decomposable polymer binder is a binder in which the sinterable metal particles are thermally decomposed at a temperature at which they can be sintered. Furthermore, the pyrolytic polymer binder maintains the shape of the adhesive sheet until the sinterable metal particles are sintered. In this embodiment, from the viewpoint of making it easier to maintain the shape of the adhesive sheet, it is preferable that the pyrolytic polymer binder is solid at room temperature (23±2℃). Examples of such pyrolytic polymer binders include polycarbonate resin and acrylic resin.

[0031] Examples of the polycarbonate resin include aliphatic polycarbonate and aromatic polycarbonate. The aforementioned aromatic polycarbonate contains benzene rings between the carbonate ester groups (-O-CO-O-) of the main chain. The aliphatic polycarbonate contains aliphatic chains without benzene rings between the carbonate ester groups (-O-CO-O-) of the main chain. Examples of the aliphatic polycarbonate include polyethylene carbonate and polypropylene carbonate. Examples of the aforementioned aromatic polycarbonate include polycarbonates containing a bisphenol A structure in the main chain.

[0032] The aforementioned acrylic resin contains (meth)acrylic acid ester as a constituent unit. Examples of the (meth)acrylic acid ester include (meth)acrylic acid esters having a linear or branched alkyl group with 4 to 18 carbon atoms. Examples of the alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, amyl, isoamyl, hexyl, heptyl, cyclohexyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, and octadecyl groups.

[0033] The acrylic resin may contain monomers other than (meth)acrylic acid esters as constituent units. Examples of monomers other than (meth)acrylic acid esters include carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, sulfonic acid group-containing monomers, and phosphate group-containing monomers.

[0034] Examples of the carboxyl group-containing monomers include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acid anhydride monomers include maleic anhydride and itaconic anhydride. Examples of the hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and 4-(hydroxymethyl)cyclohexylmethyl (meth)acrylate. Examples of the sulfonic acid group-containing monomers include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid. Examples of the above-mentioned phosphate group-containing monomers include 2-hydroxyethyl acryloyl phosphate.

[0035] In this specification, "(meth)acrylic" is a concept that includes acrylic and methacrylic. Furthermore, "(meth)acrylate" is a concept that includes both acrylate and methacrylate.

[0036] The mass average molecular weight of the polymer binder is preferably 10,000 or more. The mass average molecular weight is measured by gel permeation chromatography (GPC) and means the value in terms of polystyrene. For example, for the mass average molecular weight, using GPC "HLC-8320GPC" manufactured by Tosoh Corporation as the apparatus, and columns "TSK guardcolumn H HR (S)" manufactured by Tosoh Corporation, and column "TSK GMH HR -H(S)" manufactured by Tosoh Corporation, and column "TSK GMH HR -H(S)" manufactured by Tosoh Corporation, a total of three columns connected in series are used, "TSK gel SuperH-RC" is used as the reference column, tetrahydrofuran (THF) is used as the eluent, and GPC measurement is performed at a column temperature of 40 °C and a flow rate of 0.5 mL / min. It can be obtained as a value in terms of polystyrene by calculation from the measurement results.

[0037] The low molecular weight binder preferably contains a low boiling point binder having a boiling point lower than the thermal decomposition start temperature of the thermally decomposable polymer binder. Moreover, the low molecular weight binder is preferably liquid at 23 °C. Furthermore, the low molecular weight binder preferably has a viscosity at 23 °C of 1 × 10 5 Pa·s or less. The viscosity can be measured with a dynamic viscoelasticity measuring apparatus (trade name "HAAKE MARS III", manufactured by Thermo Fisher Scientific). In this measurement, a 20 mmφ parallel plate is used as the jig, the gap between the plates is 100 μm, and the shear rate in rotational shear is 1 s -1 is used.

[0038] Examples of the low molecular weight binder include alcohols and ethers. Examples of the alcohols include terpene alcohols. Examples of the aforementioned terpene alcohols include isobornylcyclohexanol, citronellol, geraniol, nerol, carveol, and α-terpionel. Examples of alcohols other than terpene alcohols include pentanol, hexanol, heptanol, octanol, 1-decanol, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, and 2,4-diethyl-1,5-pentanediol. Examples of the aforementioned ethers include alkylene glycol alkyl ethers. 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. Examples of ethers other than the alkylene glycol alkyl ethers mentioned above include 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.

[0039] The low molecular weight binder is preferably a terpene alcohol, and more preferably isobornylcyclohexanol. Here, isobornylcyclohexanol is an organic compound with a boiling point of 308-318°C. Under a nitrogen gas flow of 200 mL / min and a heating rate of 10°C / min, when heated from room temperature to 600°C, it exhibits a significant mass decrease above 100°C and volatilizes at 245°C (no further mass decrease is observed). It also exhibits an extremely high viscosity of 1,000,000 mPa·s at 25°C. As described above, isobornylcyclohexanol exhibits extremely high viscosity at 25°C, and therefore, when included in the adhesive sheet, it can maintain its sheet shape at room temperature. Furthermore, in this embodiment, the sinterable metal particles contained in the adhesive sheet are metal particles that can be sintered by heating at a temperature of 400°C or lower, and such sinterable metal particles are usually sintered at a temperature of about 200 to 300°C. In other words, a temperature of 200 to 300°C is adopted as the sintering temperature. Therefore, when isobornylcyclohexanol is included in the adhesive sheet, when the above-mentioned sintering temperature is used, the isobornylcyclohexanol will volatilize to the outside of the adhesive sheet during sintering, causing the sinterable metal particles to be in close proximity to each other within the adhesive sheet. This allows the sintering of the sinterable metal particles within the adhesive sheet to proceed even further. Note that the above mass loss is the value when the mass loss rate at the measurement start temperature (room temperature) is set to 0%.

[0040] The content ratio (particle filling rate) of the sinterable metal particles in the adhesive sheet is preferably 85% by mass or more and 97% by mass or less, and more preferably 88% by mass or more and 96% by mass or less. The adhesive sheet contains 85% by mass or more of the sinterable metal particles, which makes it easier for the sheet to exhibit sufficient conductivity after sintering. Furthermore, by containing 97% by mass or less of the sinterable metal particles in the adhesive sheet, the shape of the adhesive sheet is more easily maintained. The content ratio of the sinterable metal particles in the adhesive sheet is the content ratio before the sintering of the sinterable metal particles.

[0041] The content of the polymer binder in the adhesive sheet is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.5% by mass or more and 5% by mass or less. The adhesive sheet contains 0.1% by mass or more of a polymer binder, which makes it easier to maintain the shape of the adhesive sheet. Furthermore, by having the pre-adhesive sheet contain 10% by mass or less of a polymer binder, the amount of residual components derived from the polymer binder after sintering can be reduced.

[0042] The content of the low molecular weight binder in the adhesive sheet is preferably 1% by mass or more and 20% by mass or less, and more preferably 2% by mass or more and 15% by mass or less. By containing 1% by mass or more of a low-molecular-weight binder in the adhesive sheet, the adhesive sheet exhibits excellent transferability to the adherend. Furthermore, by including 20% ​​by mass or less of a low-molecular-weight binder in the adhesive sheet, the amount of residual components derived from the low-molecular-weight binder after sintering can be reduced.

[0043] The thickness of the adhesive sheet is preferably 5 μm or more, and more preferably 10 μm or more. Furthermore, the thickness of the adhesive sheet is preferably 300 μm or less, and more preferably 150 μm or less. The thickness of the adhesive sheet can be determined, for example, by measuring the thickness of five randomly selected points using a dial gauge (PEACOCK, model R-205) and taking the arithmetic mean of these thicknesses.

[0044] As shown in Figure 1, the adhesive sheet 2 configured as described above is used in the manufacture of semiconductor devices in the form of a laminate 10 laminated on the base sheet 1. In the laminate 10, the adhesive sheet 2 is laminated to the base sheet 1 in a peelable manner.

[0045] The base sheet 1 is a resin layer containing resin. Examples of resins included in the resin layer include polyolefin resin, polyester resin, polyurethane resin, polycarbonate resin, polyetheretherketone resin, polyimide resin, polyetherimide resin, polyamide resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyphenyl sulfide resin, fluororesin, cellulose resin, and silicone resin.

[0046] The thickness of the base sheet 1 is preferably 10 μm or more and 5000 μm or less, more preferably 20 μm or more and 4000 μm or less, and even more preferably 30 μm or more and 3000 μm or less. The thickness of the base sheet 1 can be determined, for example, by measuring the thickness of five randomly selected points using a dial gauge (PEACOCK, model R-205) and taking the arithmetic mean of these thicknesses.

[0047] [Manufacturing method for semiconductor devices] A method for manufacturing a semiconductor device according to one embodiment of the present invention (hereinafter also referred to as this embodiment) is: Multiple semiconductor chips, A substrate having multiple mounting areas on which the multiple semiconductor chips are mounted, Multiple adhesive sheets containing sinterable metal particles that can be sintered by heating at a temperature of 400°C or lower, A first pressing member is used to press the semiconductor chip toward the substrate with the adhesive sheet interposed between them, thereby bonding the plurality of semiconductor chips to the plurality of mounting areas. A semiconductor chip mounting process is performed in which the plurality of semiconductor chips are sequentially pressed with the first pressing member and bonded to the plurality of mounting areas. Furthermore, in the semiconductor device manufacturing method according to this embodiment, in the semiconductor chip mounting step, the semiconductor chip is pressed using the first pressing member which has been heated to a temperature at which the sinterable metal particles can be sintered.

[0048] Below, an example of a semiconductor device manufacturing method using the laminate 10 will be described with reference to Figures 2 to 5. In the following description, we will explain the case where the substrate is a lead frame substrate, the mounting area is a die pad, and the first pressing member is a collet.

[0049] First, multiple semiconductor chips are obtained by cutting a semiconductor wafer on a dicing tape. Next, as shown in Figure 2(a), collet A lifts one of the multiple semiconductor chips, semiconductor chip B1 (hereinafter also referred to as the first semiconductor chip B1), from the dicing tape C. Semiconductor chips typically have a rectangular shape when viewed from above, and more specifically, a square shape when viewed from above. Furthermore, the thickness of the semiconductor chip is, for example, between 10 μm and 500 μm, and more specifically, between 20 μm and 400 μm. Furthermore, the area of ​​a semiconductor chip in a planar view is, for example, 0.01 mm². 2 Above 1000mm 2 The following, and more specifically, 0.04 mm 2 500mm or more 2 The following applies: Furthermore, the dimensions of the collet A that contacts the semiconductor chip are equivalent to the size of the chip. That is, the area S1 of the surface of the collet A that contacts the semiconductor chip in a plan view (hereinafter also referred to as the collet area S1) is equivalent to the area S2 of the semiconductor chip in a plan view (hereinafter also referred to as the chip area S2). More specifically, the collet area S1 is between 0.9 and 1.1 times the size of the chip area S2.

[0050] Next, as shown in Figure 3(a), the laminate 10 is placed on the stage G so that the adhesive sheet 2 of the laminate 10 is on the upper side. Then, by pressing the first semiconductor chip B1 onto the adhesive sheet 2 of the laminate 10 with a collet A, a portion of the adhesive sheet 2 is transferred to the first semiconductor chip B1. This results in the first semiconductor chip B1 with the adhesive sheet 2 attached. The pressure applied to press the first semiconductor chip B1 onto the adhesive sheet 2 is preferably 0.01 MPa or more and 10 MPa or less, and more preferably 0.1 MPa or more and 5 MPa or less. Furthermore, the temperature of the collet A or stage G when pressing the first semiconductor chip B1 onto the adhesive sheet 2 is preferably 40°C to 150°C, and more preferably 50°C to 120°C.

[0051] Next, as shown in Figure 4(a), the first semiconductor chip B1 with the adhesive sheet 2 attached is lifted from the laminate 10 using collet A.

[0052] Next, as shown in Figure 5(a), the lead frame substrate D is placed on the stage H. Next, while holding collet A at a temperature within the range of 25°C to 100°C, collet A is lowered vertically downwards, bringing the first semiconductor chip B1 with adhesive sheet 2 attached into contact with one die pad E1 (first die pad E1) on the lead frame substrate D from the adhesive sheet 2 side. Next, with the adhesive sheet 2 attached to the first semiconductor chip B1 in contact with the first die pad E1 of the lead frame substrate D, the first semiconductor chip B1 with the adhesive sheet 2 attached is pressed down with the collet A, and the collet A is heated to a temperature at which the sinterable metal particles (sinterable metal particles contained in the adhesive sheet 2) can be sintered, thereby causing the sinterable metal particles in the adhesive sheet 2 to undergo primary sintering (see Figure 5(a)). The pressure applied when pressing the first semiconductor chip B1 with the adhesive sheet 2 attached against the first die pad E1 of the lead frame substrate D from the adhesive sheet 2 side is preferably 0.01 MPa or more and 50 MPa or less, and more preferably 0.1 MPa or more and 30 MPa or less. It is preferable that collet A be heated to a temperature of 250°C or higher. By heating collet A to a temperature of 250°C or higher, the sinterable metal particles can be sintered more thoroughly, allowing the semiconductor chip to be more firmly attached to the substrate with the adhesive sheet in between. In other words, the reliability of the connection of the semiconductor chip to the substrate can be improved. Furthermore, it is preferable that collet A is rapidly heated (in about 5 seconds) to a temperature at which the sinterable metal particles can be sintered. Collet A is preferably heated at a temperature of 30°C / sec or higher, and more preferably at a temperature of 45°C / sec or higher, until the sinterable metal particles become sinterable. Furthermore, the primary sintering may be carried out by heating the stage H to a temperature above the temperature at which the sinterable metal particles can be sintered, in addition to the collet A. This allows heating from both sides of the adhesive sheet 2, enabling more thorough sintering of the sinterable metal particles. As a result, the semiconductor chip can be attached to the substrate more firmly with the adhesive sheet in between. In other words, the reliability of the connection of the semiconductor chip to the substrate can be further improved. Furthermore, the temperature at which the stage H is heated is preferably below the temperature at which oxidation of the lead frame substrate D is suppressed. For example, if the lead frame substrate D is made of a Cu alloy (such as Cu-Cr-Zr, Cu-Cr-Sn-Zn, or Cu-Ni-Si-Mg), the temperature at which the stage H is heated is preferably 150°C or lower.

[0053] After the sinterable metal particles are sintered together, the collet A is lifted to separate it from the first semiconductor chip B1 with the adhesive sheet 2 attached, thereby lowering the temperature of the collet A to a temperature at which the sinterable metal particles become less likely to sinter (for example, 50°C).

[0054] After lowering the temperature of collet A as described above, collet A lifts another semiconductor chip B2 (hereinafter also referred to as the second semiconductor chip B2) from the dicing tape C, as shown in Figure 2(b). Next, as shown in Figure 3(b), the second semiconductor chip B2 is pressed onto the adhesive sheet 2 of the laminate 10 with a collet A, thereby transferring a portion of the adhesive sheet 2 to the second semiconductor chip B2. This results in a second semiconductor chip B2 with the adhesive sheet 2 attached. Next, as shown in Figure 4(b), the collet A lifts the second semiconductor chip B2, which has the adhesive sheet 2 attached, from the dicing tape C. Next, while holding collet A at a temperature within the range of 25°C to 100°C, the second semiconductor chip B2 with adhesive sheet 2 attached is brought into contact with another die pad E2 (second die pad E2) on the lead frame substrate D from the adhesive sheet 2 side. Next, with the adhesive sheet 2 attached to the second semiconductor chip B2 in contact with the second die pad E2 of the lead frame substrate D, the second semiconductor chip B2 with the adhesive sheet 2 attached is pressed down with the collet A, causing the sinterable metal particles contained in the adhesive sheet 2 to undergo primary sintering (see Figure 5(b)). The heating temperature of collet A and the pressure applied when pressing the first semiconductor chip B1 with adhesive sheet 2 attached against the die pad E2 of lead frame substrate D from the adhesive sheet 2 side should be selected as described above. After the sinterable metal particles are sintered together, the collet A is lifted to separate it from the second semiconductor chip B2 attached to the adhesive sheet 2, thereby lowering the temperature of the collet A to a temperature at which the sinterable metal particles no longer sinter (for example, 50°C). The above steps are repeated sequentially until semiconductor chips are attached to all die pads on the lead frame substrate D. In this way, the semiconductor chip mounting process is carried out. Furthermore, after semiconductor chips have been attached to all die pads of the lead frame substrate D (after the semiconductor chip attachment process), bonding wires may be bonded to the necessary locations.

[0055] In the semiconductor device manufacturing method according to this embodiment, as described above, in addition to pressing a plurality of semiconductor chips sequentially with a first pressing member (collet A) to adhere them to a plurality of mounting areas (first die pad E1, second die pad E2) on a substrate (lead frame substrate D), the semiconductor chips (first semiconductor chip B1, second semiconductor chip B2) are pressed using a first pressing member (collet A) that has been heated to a temperature at which the sinterable metal particles contained in the adhesive sheet 2 can be sintered. Therefore, with the adhesive sheet 2 in between, each of the multiple semiconductor chips (first semiconductor chip B1, second semiconductor chip B2) can be attached relatively uniformly to the mounting area (first die pad E1, second die pad E2) of the substrate (lead frame substrate D). This makes it possible to relatively suppress uneven adhesion when attaching multiple semiconductor chips (first semiconductor chip B1, second semiconductor chip B2) to a substrate (lead frame substrate D) with the adhesive sheet 2 interposed.

[0056] Furthermore, in the method for manufacturing a semiconductor device according to this embodiment, After the semiconductor chip mounting process, A secondary heating step is further performed on the substrate to which the plurality of semiconductor chips are attached, in which the substrate is heated to a temperature at which the sinterable metal particles can be sintered. In the secondary heating step, it is preferable that the heating is performed without pressing some or all of the plurality of semiconductor chips toward the substrate. Furthermore, in the method for manufacturing a semiconductor device according to this embodiment, In the secondary heating step, it is preferable that the heating is performed without pressing all of the plurality of semiconductor chips toward the substrate.

[0057] More specifically, after semiconductor chips have been attached to all die pads of the lead frame substrate D (after the semiconductor chip attachment process), as shown in Figure 6(a), the stage H may be heated to a temperature at which the sinterable metal particles contained in the adhesive sheet 2 can be sintered (for example, any temperature in the range of 200°C to 400°C) without pressing down on some or all of the semiconductor chips attached to all die pads of the lead frame substrate D (a secondary heating step may be performed). Figure 6(a) shows an example where the lead frame substrate D is heated without pressing down on all of the semiconductor chips (first semiconductor chip B1 and second semiconductor chip B2) to which all die pads (first die pad E1 and second die pad E2) are attached. By performing this secondary heating process, the sinterable metal particles can be further sintered (secondary sintering), allowing the semiconductor chip to be more firmly attached to the substrate (lead frame substrate D) with the adhesive sheet in between. In other words, the reliability of the connection of the semiconductor chip to the substrate can be improved. Furthermore, the equipment used in the secondary heating process can be simplified and may not include a pressing member that presses some or all of the aforementioned semiconductor chips. Even when performing such a secondary heating process, bonding wires may be bonded to the necessary locations after the secondary heating process.

[0058] Furthermore, in the method for manufacturing a semiconductor device according to this embodiment, After the semiconductor chip mounting process, A secondary heating step is further performed on the substrate to which the plurality of semiconductor chips are attached, in which the substrate is heated to a temperature at which the sinterable metal particles can be sintered. In the secondary heating step, the heating may be performed while pressing some or all of the plurality of semiconductor chips toward the substrate. Furthermore, in the method for manufacturing a semiconductor device according to this embodiment, In the secondary heating step, the heating may be performed while pressing all of the plurality of semiconductor chips toward the substrate.

[0059] More specifically, after semiconductor chips have been attached to all die pads of the lead frame substrate D (after the semiconductor chip attachment process), as shown in Figure 6(b), a heating and pressing device F may be used to heat some or all of the semiconductor chips attached to all die pads of the lead frame substrate D to a temperature at which they can be sintered while being pressed (a secondary heating process may be performed). This device has two flat plates (parallel plates) positioned to sandwich some or all of the semiconductor chips attached to all die pads of the lead frame substrate D from above and below, and is configured to be heatable. Figure 6(b) shows an example in which all semiconductor chips (first semiconductor chip B1 and second semiconductor chip B2) attached to all die pads (first die pad E1 and second die pad E2) of the lead frame substrate D are heated while being pressed. By performing this secondary heating process, some or all of the semiconductor chips can be heated while being pressed toward the substrate (lead frame substrate D), allowing some or all of the semiconductor chips to be more firmly attached to the substrate (lead frame substrate D) with the adhesive sheet 2 in between. In other words, the reliability of the connection of the semiconductor chips to the substrate can be further improved. Even when performing such a secondary heating process, bonding wires may be bonded to the necessary locations after the secondary heating process.

[0060] Various known lead frame substrates can be used as the lead frame substrate D. Examples of various known lead frame substrates include lead frame substrates in which a Cu lead frame substrate has been subjected to Ag plating, and lead frame substrates in which Ni, Pd, and Au are plated on a Cu lead frame substrate in that order (Palladium Pre-Plated Lead Frame (Pd-PPF)).

[0061] [Semiconductor device] The semiconductor device according to this embodiment is a semiconductor device manufactured by the method for manufacturing a semiconductor device according to this embodiment. Furthermore, the semiconductor device according to this embodiment has a shear strength of 2 MPa or more at 25°C between one semiconductor chip and the substrate of the plurality of semiconductor chips. By having a shear strength of 2 MPa or more at 25°C, the semiconductor device according to this embodiment has improved reliability in connecting the semiconductor chip to the substrate. The shear strength at 25°C may be 200 MPa or less.

[0062] The shear intensity at 25°C can be measured as follows: Specifically, a test specimen is obtained by attaching a bare chip with an adhesive sheet to the die pad of a lead frame substrate. The shear strength of this test specimen is measured at 25°C using a Nordson Advanced Technology Series 4000 universal bond tester under the following conditions. <Shear strength measurement conditions> • Load cell: DS100kg • Measurement range: 100kg • Test type: Destructive test • Test speed: 100 μm / s • Descent speed: 100 μm / s • Test height: 100 μm Tool movement: 2000 μm • Destruction detection point: Low (10%)

[0063] Furthermore, the semiconductor device and method for manufacturing the semiconductor device according to the present invention are not limited to the embodiments described above. Also, the semiconductor device and method for manufacturing the semiconductor device according to the present invention are not limited by the effects described above. Various modifications are possible to the semiconductor device and method for manufacturing the semiconductor device according to the present invention without departing from the spirit of the present invention.

[0064] For example, in the semiconductor device manufacturing method according to the embodiment described above, an example was described in which multiple semiconductor chips are sequentially attached to the die pad of a lead frame substrate with an adhesive sheet in between, while heating and cooling one collet. However, the example of attaching multiple semiconductor chips to a lead frame substrate is not limited to this. For example, multiple semiconductor chips may be sequentially attached to the die pads of a lead frame substrate with an adhesive sheet in between, while alternately heating and cooling two or more collets. In this way, after attaching one semiconductor chip from among multiple semiconductor chips to one die pad of the lead frame substrate with one collet, other semiconductor chips from among multiple semiconductor chips can be attached to other die pads of the lead frame substrate with other collets without waiting for the first collet to cool to a predetermined temperature or below. This makes it possible to shorten the cycle time in the manufacturing of semiconductor devices.

[0065] Furthermore, although the above-described method for manufacturing a semiconductor device according to the embodiment described above uses a collet as the first pressing member, the first pressing member is not limited to a collet. Any member that can sequentially press multiple semiconductor chips onto multiple die pads of a lead frame substrate while heating them (for example, any member whose pressing surface area in a plan view is 0.9 times or more and 1.1 times or less the area of ​​the semiconductor chip in a plan view) can be used. [Examples]

[0066] Next, the present invention will be described in more detail with reference to examples. The following examples are provided to further illustrate the present invention and do not limit its scope.

[0067] <Laminate> Using a hybrid mixer (product name "HM-500", manufactured by Keyence Corporation), a composition containing the following materials in the following mass ratios was mixed for 3 minutes in the stirring mode of the hybrid mixer to prepare a varnish. • Sinterable metal particles: 93.2 parts by mass The sinterable metal particles are first silver particles (product name "DF-SNI-003", manufactured by DOWA Corporation, volume average particle size D 50 (60nm) and second silver particles (SPQ05S, manufactured by Mitsui Mining & Smelting Co., Ltd., volume average particle size D 50 The mixture consists of particles with a diameter of 1.1 μm, with the mass percentage of the first silver particle being 83.9% and the mass percentage of the second silver particle being 9.3%. ·Polymer binder: 1.4 parts by mass The polymer binder is a pyrolytic polymer binder, specifically polycarbonate resin (product name "QPAC40," manufactured by Empower Materials, with a mass-average molecular weight of 150,000, and solid at room temperature). ·Low molecular binder: 5.4 parts by mass The low molecular weight binder used is isobornylcyclohexanol (trade name "Tersolve MTPH", manufactured by Nippon Terpene Chemical Industry Co., Ltd., liquid at room temperature), which is a low boiling point binder. Methyl ethyl ketone (MEK): appropriate amount Methyl ethyl ketone is used to adjust the viscosity of the varnish. The varnish prepared as described above was applied to a porous polyethylene sheet (porous PE sheet) (thickness: 300 μm) as a base sheet and then dried to form an adhesive layer (adhesive sheet) with a thickness of 54 μm, thereby obtaining a laminate. The drying temperature was 110°C and the drying time was 3 minutes. The content ratio (particle filling rate) of the sinterable metal particles in the adhesive layer (adhesive sheet) was 93.2% by mass.

[0068] (Fabrication of semiconductor chips with adhesive sheets) The semiconductor chips with adhesive sheets were fabricated using the FC3000W manufactured by Toray Engineering Co., Ltd. First, the collet of the FC3000W was heated to 90°C. Then, one side of a Si mirror chip (planar dimensions 5mm x 5mm, thickness 200μm), whose entire surface was plated with silver, was pressed against the adhesive layer (adhesive sheet) of the laminate using the collet (the adhesive layer of the laminate was pressed with one side of the chip). The pressing was performed by applying a load of 50N for 5 seconds. Next, the collet was separated from the laminate at a speed of 0.3 mm / sec to obtain a semiconductor chip with an adhesive sheet attached to the collet.

[0069] [Example 1] (Fabrication of substrates with semiconductor chips) A substrate with semiconductor chips was fabricated by attaching three semiconductor chips with adhesive sheets to three die pads on a Cu lead frame substrate plated with Ag (hereinafter also referred to as Ag-plated Cu lead frame substrate; 3 mm thick). The attachment of semiconductor chips with adhesive sheets to die pads on Ag-plated Cu lead frame substrates was primarily performed using the FC3000W manufactured by Toray Engineering Co., Ltd. Specifically, the process was carried out as follows: The Ag-plated Cu lead frame substrate was placed on the FC3000W stage and heated to 150°C. (1) With the semiconductor chip with adhesive sheet attached (hereinafter referred to as the first semiconductor chip with adhesive sheet) attached to the collet, the collet is heated to 100°C. (2) With the collet heated to 100°C, the collet is lowered vertically downward so that the adhesive sheet of the first semiconductor chip with the adhesive sheet attached comes into contact with the first die pad of the Ag-plated Cu lead frame substrate. (3) With the adhesive sheet of the first semiconductor chip with the adhesive sheet in contact with the first die pad of the Ag-plated Cu lead frame substrate, the first semiconductor chip with the adhesive sheet is pressed (applied pressure) with the collet, and the collet is heated to 250°C, thereby sintering (primary sintering) the sinterable metal particles in the adhesive sheet and attaching the first semiconductor chip with the adhesive sheet to the first die pad. The pressing (pressure) with the collet is performed at 10 MPa. The pressurizing and heating time is 100 sec. (4) After lifting the collet to separate it from the first semiconductor chip with the adhesive sheet attached, the temperature of the collet is lowered to a temperature (50°C) at which the sinterable metal particles become difficult to sinter. (5) Using the collet, obtain a semiconductor chip with the second adhesive sheet attached to the collet in the same manner as described above, and heat the collet to 100°C. (6) The second semiconductor chip with the adhesive sheet is attached to the second die pad of the Ag-plated Cu lead frame substrate in the same manner as in (2) and (3) above. (7) In the same manner as in (4) above, the collet is lifted to separate it from the second semiconductor chip with the adhesive sheet, and then the temperature of the collet is lowered to a temperature (50°C) at which the sinterable metal particles become difficult to sinter. (8) The third semiconductor chip with the adhesive sheet is attached to the third die pad of the Ag-plated Cu lead frame substrate by the collet in the same manner as described above. In this manner, an Ag-plated Cu lead frame substrate with semiconductor chips attached was obtained according to Example 1, in which three semiconductor chips were attached to the Ag-plated Cu lead frame substrate with an adhesive sheet interposed between them.

[0070] (Measurement of shear strength) The shear strength of the Ag-plated Cu lead frame substrate with a semiconductor chip, obtained as described above in Example 1, was measured at 25°C. Specifically, the shear strength at 25°C was measured using a Nordson Advanced Technology Series 4000 universal bond tester under the following conditions. <Shear strength measurement conditions> • Load cell: DS100kg • Measurement range: 100kg • Test type: Destructive test • Test speed: 100 μm / s • Descent speed: 100 μm / s • Test height: 100 μm Tool movement: 2000 μm • Destruction detection point: Low (10%) The shear strength at 25°C was measured for each semiconductor chip, from the first adhesive sheet to the third adhesive sheet, and the arithmetic mean of these measurements was obtained. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0071] [Example 2] (Fabrication of substrates with semiconductor chips) Except for removing the Ag-plated Cu lead frame substrate with the first to third semiconductor chips attached from the FC3000W stage and then placing it in a dryer heated to 250°C and heating it for 10 minutes to further sinter (secondary sinter) the sinterable metal particles contained in the adhesive sheet, an Ag-plated Cu lead frame substrate with semiconductor chips according to Example 2 was obtained in the same manner as in Example 1. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0072] [Example 3] (Fabrication of substrates with semiconductor chips) Except for setting the pressurized heating time to 10 seconds, the semiconductor chips were attached to the Ag-plated Cu lead frame substrate in the same manner as in Example 2, and an Ag-plated Cu lead frame substrate with semiconductor chips attached according to Example 3 was obtained, in which three semiconductor chips were attached to the Ag-plated Cu lead frame substrate with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0073] [Example 4] (Fabrication of substrates with semiconductor chips) Except for pressing (pressing) with the collet at 20 MPa, the semiconductor chips were attached to the Ag-plated Cu lead frame substrate in the same manner as in Example 2, and an Ag-plated Cu lead frame substrate with semiconductor chips attached according to Example 4 was obtained, in which three semiconductor chips were attached to the Ag-plated Cu lead frame substrate with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0074] [Example 5] (Fabrication of substrates with semiconductor chips) Except for performing primary sintering by heating the collet to 300°C, the semiconductor chips were attached to the Ag-plated Cu lead frame substrate in the same manner as in Example 1, and a lead frame substrate with semiconductor chips according to Example 5 was obtained, in which three semiconductor chips were attached to the Ag-plated Cu lead frame substrate with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0075] [Example 6] (Fabrication of substrates with semiconductor chips) Primary sintering was performed by heating the collet to 450°C, and the pressurized heating time was set to 5 seconds. In the same manner as in Example 1, semiconductor chips were attached to the Ag-plated Cu lead frame substrate, and an Ag-plated Cu lead frame substrate with semiconductor chips attached according to Example 6 was obtained, with three semiconductor chips attached to the Ag-plated Cu lead frame substrate with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0076] [Example 7] (Fabrication of substrates with semiconductor chips) A substrate with semiconductor chips was fabricated by attaching three semiconductor chips with adhesive sheets, configured in the same way as in Example 1, to three die pads made of Pd-PPF (Palladium Pre-Plated Lead Frame; a Cu lead frame plated with Ni, Pd, and Au in that order; thickness 0.2 mm). The semiconductor chips with adhesive sheets attached were primarily mounted to the die pads of the Pd-PPF using the FC3000W manufactured by Toray Engineering Co., Ltd. Specifically, the process was carried out as follows: The Pd-PPF was placed on the FC3000W stage without heating (the stage temperature was 25°C). (1) With the semiconductor chip with adhesive sheet attached (hereinafter referred to as the first semiconductor chip with adhesive sheet) attached to the collet, the collet is heated to 100°C. (2) With the collet heated to 100°C, the collet is lowered vertically downward so that the adhesive sheet of the first semiconductor chip with the adhesive sheet attached comes into contact with the first die pad of the Pd-PPF. (3) With the adhesive sheet of the first semiconductor chip with the adhesive sheet in contact with the first die pad of the Pd-PPF, the first semiconductor chip with the adhesive sheet is pressed against the collet, and the collet is heated to 300°C, thereby sintering the sinterable metal particles in the adhesive sheet (primary sintering) and attaching the first semiconductor chip with the adhesive sheet to the first die pad. The pressing with the collet is performed at 10 MPa. The pressurizing and heating time is 5 seconds. (4) After lifting the collet to separate it from the first semiconductor chip with the adhesive sheet attached, the temperature of the collet is lowered to a temperature (50°C) at which the sinterable metal particles become difficult to sinter. (5) Using the collet, obtain a semiconductor chip with the second adhesive sheet attached to the collet in the same manner as described above, and heat the collet to 100°C. (6) The second semiconductor chip with the adhesive sheet is attached to the second die pad of the Pd-PPF in the same manner as in (2) and (3) above. (7) In the same manner as in (4) above, the collet is lifted to separate it from the second semiconductor chip with the adhesive sheet, and then the temperature of the collet is lowered to a temperature (50°C) at which the sinterable metal particles become difficult to sinter. (8) The third semiconductor chip with the adhesive sheet is attached to the third die pad of the Pd-PPF by the collet in the same manner as described above. In this manner, a Pd-PPF with semiconductor chips attached, according to Example 7, was obtained, in which three semiconductor chips were attached to the Pd-PPF with an adhesive sheet interposed between them. In Example 7, secondary sintering was not performed. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0077] [Example 8] (Fabrication of substrates with semiconductor chips) Except for pressing (pressing) with the collet at 5 MPa and removing the Pd-PPF (Pd-PPF after (8) of Example 7 above) with the first to third semiconductor chips attached from the FC3000W stage, and then placing it in a dryer heated to 300°C and heating for 60 mins to further sinter (secondary sinter) the sinterable metal particles contained in the adhesive sheet, the semiconductor chips were attached to the Pd-PPF in the same manner as in Example 7, and a Pd-PPF with semiconductor chips according to Example 8 was obtained, in which three semiconductor chips were attached to the Pd-PPF with the adhesive sheet in between. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0078] [Example 9] (Fabrication of substrates with semiconductor chips) Except for heating the FC3000W stage to 150°C, the semiconductor chips were attached to the Pd-PPF in the same manner as in Example 7, and a Pd-PPF with semiconductor chips attached according to Example 9 was obtained, in which three semiconductor chips were attached to the Pd-PPF with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0079] [Example 10] (Fabrication of substrates with semiconductor chips) Except for performing primary sintering by heating the collet to 400°C, the semiconductor chips were attached to the Pd-PPF in the same manner as in Example 7, and a Pd-PPF with semiconductor chips according to Example 10 was obtained, in which three semiconductor chips were attached to the Pd-PPF with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0080] [Example 11] (Fabrication of substrates with semiconductor chips) Except for removing the Pd-PPF with the first to third semiconductor chips attached (the Pd-PPF after (8) in Example 7 above) from the FC3000W stage and then placing it in a dryer heated to 300°C and heating it for 60 minutes to further sinter (secondary sinter) the sinterable metal particles contained in the adhesive sheet, the semiconductor chips were attached to the Pd-PPF in the same manner as in Example 10, and a Pd-PPF with semiconductor chips attached according to Example 11 was obtained, in which three semiconductor chips were attached to the Pd-PPF with the adhesive sheet in between. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0081] [Example 12] <Laminate> Using a hybrid mixer (product name "HM-500", manufactured by Keyence Corporation), a mixture containing each material in the mass ratios shown in Table 1 below was stirred and mixed in "stirring mode" to prepare the varnish. The mixing using the hybrid mixer was performed in three stages. Specifically, first, a primary mixture containing a thermosetting resin and a thermoplastic resin acting as a polymer binder was mixed for 3 minutes (primary mixing). Next, a secondary mixture obtained by adding conductive particles and a volatile material acting as a low molecular weight binder to the primary mixture was mixed for 6 minutes (secondary mixing). Finally, a tertiary mixture obtained by adding a catalyst and a solvent to the secondary mixture was mixed for 3 minutes (tertiary mixing). This varnish was applied to one side of a release film (product name "MRA38", manufactured by Mitsubishi Chemical Corporation, 38 μm thick), and then dried at 100°C for 2 minutes to form a 30 μm thick adhesive layer (adhesive sheet), thereby obtaining a laminate. The materials used were as follows, as shown in Table 1 below. • Phenolic resin MEHC-7851S (bisphenol-type phenolic resin, phenol equivalent 209 g / eq) manufactured by Meiwa Kasei Co., Ltd. • Solid epoxy resin KI-3000-4 (cresol novolac type polyfunctional epoxy resin, epoxy equivalent 200g / eq) manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd. • Liquid epoxy resin EXA-4816 (aliphatic-modified bisphenol A type epoxy resin (bifunctional), epoxy equivalent 403 g / eq) manufactured by DIC Corporation. ·Silver (Ag) coated copper (Cu) particles DOWA Electronics Co., Ltd. Product name AOP-TCY-16(EN) (Spherical copper particles coated with 20% by mass of silver particles. Particle shape is spherical. Volume average particle diameter D 50 (2.8 μm) ·Silver (Ag) particles DOWA Electronics Co., Ltd. Product name AG-2-47J (Surface-treated silver particles. Particle shape is spherical. Volume average particle diameter D 50 (0.5 μm) • Volatile agent (isobornylcyclohexanol (MTPH)) MTPH manufactured by Nippon Terpene Co., Ltd. • Acrylic resin Teisan Resin SG-70L manufactured by Nagase Chemitex Co., Ltd. (contains MEK and toluene as solvents, solids content 12.5% ​​by mass, glass transition temperature -13°C, mass-average molecular weight 900,000, acid value 5 mg / KOH, carboxyl group-containing acrylic copolymer) • Coupling agent KBE-846 (bis(triethoxysilylpropyl)tetrasulfide) manufactured by Shin-Etsu Chemical Co., Ltd. ·catalyst TPP-MK (tetraphenylphosphonium tetra-p-tolylborate) manufactured by Hokko Chemical Industry Co., Ltd. ·solvent Methyl ethyl ketone (MEK)

[0082] [Table 1]

[0083] (Fabrication of semiconductor chips with adhesive sheets) A semiconductor chip with an adhesive sheet was fabricated in the same manner as in Example 1, except that the adhesive sheet was configured as described above. (Fabrication of substrates with semiconductor chips) Except for pressing (pressing) with the collet at 3 MPa, the semiconductor chips were attached to the Pd-PPF in the same manner as in Example 10, and a Pd-PPF with semiconductor chips attached according to Example 12 was obtained, in which three semiconductor chips were attached to the Pd-PPF with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0084] [Example 13] <Laminate> In the same manner as in Example 12, a laminate was obtained in which a 30 μm thick adhesive layer (adhesive sheet) was formed on one side of a release-treated film (product name "MRA38", manufactured by Mitsubishi Chemical Corporation, thickness 38 μm). (Fabrication of semiconductor chips with adhesive sheets) A semiconductor chip with an adhesive sheet was fabricated in the same manner as in Example 1, except that the adhesive sheet was configured as described above. (Fabrication of substrates with semiconductor chips) Using the adhesive sheet configured as described above, primary sintering was performed by heating the collet to 400°C, and pressing (pressing) with the collet was performed at 3 MPa. Except for these steps, three semiconductor chips were attached to the Pd-PPF in the same manner as in Example 8, thereby obtaining a Pd-PPF with semiconductor chips according to Example 13, in which three semiconductor chips were attached to the Pd-PPF with the adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0085] [Example 14] <Laminate> In the same manner as in Example 12, a laminate was obtained in which a 30 μm thick adhesive layer (adhesive sheet) was formed on one side of a release-treated film (product name "MRA38", manufactured by Mitsubishi Chemical Corporation, thickness 38 μm). (Fabrication of semiconductor chips with adhesive sheets) A semiconductor chip with an adhesive sheet was fabricated in the same manner as in Example 1, except that the adhesive sheet was configured as described above. (Fabrication of substrates with semiconductor chips) Except for heating the stage temperature of the FC3000W to 150°C, three semiconductor chips were attached to the Pd-PPF in the same manner as in Example 12, and a Pd-PPF with semiconductor chips attached according to Example 14 was obtained, in which the three semiconductor chips were attached to the Pd-PPF with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0086] [Comparative Example 1] (Fabrication of substrates with semiconductor chips) The semiconductor chip-equipped substrate was fabricated as follows. First, three semiconductor chips with adhesive sheets were temporarily fixed to three die pads on an Ag-plated Cu lead frame substrate. The adhesive sheets used were those described in Example 1. The temporary fixing of semiconductor chips with adhesive sheets to die pads on Ag-plated Cu lead frame substrates was performed using the FC3000W manufactured by Toray Engineering Co., Ltd. Specifically, the procedure was as follows: The Ag-plated Cu lead frame substrate was placed on the FC3000W stage. (1) With the semiconductor chip with adhesive sheet attached (hereinafter referred to as the first semiconductor chip with adhesive sheet) attached to the collet, the collet is heated to 50°C. (2) The semiconductor chip with the first adhesive sheet attached is pressed (applied pressure) onto the first die pad of the Ag-plated Cu lead frame substrate using the collet from the adhesive sheet side, thereby attaching the first semiconductor chip with the adhesive sheet attached to the first die pad. The pressing (applied pressure) with the collet is performed at 0.01 MPa. The pressurizing time is 1 sec. (3) The collet is lifted to separate it from the first semiconductor chip with the adhesive sheet attached. (4) Using the collet, obtain a second semiconductor chip with an adhesive sheet attached to the collet in the same manner as described above, and attach the second semiconductor chip with the adhesive sheet to the second die pad of the Ag-plated Cu lead frame in the same manner as described in (2) above. After attaching the second semiconductor chip with the adhesive sheet to the second die pad of the Ag-plated Cu lead frame, lift the collet to separate it from the second semiconductor chip with the adhesive sheet. (5) Using the collet, obtain a third semiconductor chip with an adhesive sheet attached to the collet in the same manner as described above, and attach the third semiconductor chip with the adhesive sheet to the third die pad of the Ag-plated Cu lead frame in the same manner as described in (2) above. After attaching the third semiconductor chip with the adhesive sheet to the third die pad of the Ag-plated Cu lead frame, lift the collet to separate it from the third semiconductor chip with the adhesive sheet. Based on the above, semiconductor chips with adhesive sheets were temporarily fixed to the Ag-plated Cu lead frame substrate. Next, semiconductor chips with adhesive sheets were attached (fixed) to the Ag-plated Cu lead frame substrate. The semiconductor chips were attached (fixed) to the Ag-plated Cu lead frame substrate using the HTM-3000 manufactured by Hakuto Kiko Co., Ltd. Specifically, the procedure was as follows. The Ag-plated Cu lead frame substrate, with the semiconductor chip attached to the adhesive sheet temporarily fixed, was placed on the HTM-3000 stage. (1') While pressing parallel plates from the top and bottom of the stage from the first semiconductor chip with the adhesive sheet to the third semiconductor chip with the adhesive sheet (pressing with the parallel plates), the stage temperature is raised to 200°C, causing the sinterable metal particles in the adhesive sheet to sinter (primary sintering), thereby attaching (fixing) the third semiconductor chip with the adhesive sheet to the Ag-plated Cu lead frame from the first semiconductor chip with the adhesive sheet. The pressing with the parallel plates is performed at 10 MPa. The pressurizing and heating time is 150 sec. In this manner, an Ag-plated Cu lead frame substrate with semiconductor chips attached was obtained according to Comparative Example 1, in which three semiconductor chips were attached to the Ag-plated Cu lead frame substrate with an adhesive sheet interposed between them.

[0087] (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0088] [Comparative Example 2] (Fabrication of substrates with semiconductor chips) After performing (1') above, the pressing state on the parallel plate was released (to no pressure), and the Ag-plated Cu lead frame substrate with the first to third semiconductor chips attached (fixed) was removed from the HTM-3000 stage. The procedure was then carried out in the same manner as in Comparative Example 1, except that the substrate was placed in a dryer heated to 250°C and heated for 10 minutes to further sinter (secondary sinter) the sinterable metal particles contained in the adhesive sheet. Then, an Ag-plated Cu lead frame substrate with semiconductor chips attached was obtained, according to Comparative Example 2, in which three semiconductor chips were attached to the Ag-plated Cu lead frame substrate with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0089] [Comparative Example 3] (Fabrication of substrates with semiconductor chips) In the mounting (fixing) of semiconductor chips with adhesive sheets onto an Ag-plated Cu lead frame substrate, the procedure was the same as in Comparative Example 1, except that the stage temperature of the HTM-3000 was changed to 300°C. Then, an Ag-plated Cu lead frame substrate with semiconductor chips attached was obtained, according to Comparative Example 3, in which three semiconductor chips were attached to the Ag-plated Cu lead frame substrate with an adhesive sheet interposed between them. (Measurement of shear strength) The shear strength at 25°C was measured in the same manner as in Example 1. The measurement results of shear strength at 25°C are shown in Table 2 below.

[0090] Furthermore, for each example, the standard deviation of the shear strength at 25°C and 250°C was calculated. The standard deviations are also shown in Table 2 below.

[0091] [Table 2]

[0092] Table 2 shows that in Examples 1 to 14, the standard deviation of shear strength at 25°C was 7 or less, indicating relatively small adhesion irregularities between the three semiconductor chips attached to the substrate with the adhesive sheet in between. In contrast, in Comparative Examples 1-3, the standard deviation of shear strength at 25°C was 8 or more, indicating relatively large adhesion irregularities between the three semiconductor chips attached to the substrate with the adhesive sheet in between. [Explanation of Symbols]

[0093] 1 base sheet, 2 adhesive sheets, 10 laminate, A collet, B1 first semiconductor chip, B2 second semiconductor chip, C dicing tape, D lead frame substrate, E1 first die pad, E2 second die pad, F heating and pressurizing device, G stage, H stage.

Claims

1. Multiple semiconductor chips, A substrate having multiple mounting areas on which the multiple semiconductor chips are mounted, Multiple adhesive sheets containing sinterable metal particles that can be sintered by heating at a temperature of 400°C or lower, each adhesive sheet arranged on a base sheet, A method for manufacturing a semiconductor device, comprising: a first pressing member that presses the semiconductor chip toward the substrate with a portion of the adhesive sheet interposed therebetween to bond the plurality of semiconductor chips to the plurality of mounting areas, The semiconductor chip mounting process is performed by lifting each of the plurality of semiconductor chips with the first pressing member, pressing each lifted semiconductor chip against the adhesive sheet on the base sheet with the first pressing member and then lifting it, thereby transferring a portion of the adhesive sheet along the shape of the semiconductor chip, and then sequentially pressing the plurality of semiconductor chips with the first pressing member to bond them to the plurality of mounting areas. In the semiconductor chip mounting process, the semiconductor chip is pressed using the first pressing member, which has been heated to a temperature at which the sinterable metal particles can be sintered, and the first pressing member is heated to 30°C / sec or higher during the pressing process. A method for manufacturing a semiconductor device.

2. After the semiconductor chip mounting process, A secondary heating step is further performed on the substrate to which the plurality of semiconductor chips are attached, in which the substrate is heated to a temperature at which the sinterable metal particles can be sintered. In the secondary heating step, the heating is performed without pressing some or all of the plurality of semiconductor chips toward the substrate. A method for manufacturing a semiconductor device according to claim 1.

3. In the secondary heating step, the heating is performed without pressing all of the plurality of semiconductor chips toward the substrate. The method for manufacturing a semiconductor device according to claim 2.

4. After the semiconductor chip mounting process, A secondary heating step is further performed on the substrate to which the plurality of semiconductor chips are attached, in which the substrate is heated to a temperature at which the sinterable metal particles can be sintered. In the secondary heating step, the heating is performed while pressing some or all of the plurality of semiconductor chips toward the substrate. A method for manufacturing a semiconductor device according to claim 1.

5. In the secondary heating step, the heating is performed while pressing all of the plurality of semiconductor chips toward the substrate. The method for manufacturing a semiconductor device according to claim 4.

6. In the semiconductor chip mounting process, the first pressing member is heated to a temperature of 250°C or higher. A method for manufacturing a semiconductor device according to any one of claims 1 to 5.

Images