Film-shaped sintered material for heating and pressurizing, and method for manufacturing semiconductor devices

Abstract

This film-shaped sintering material for heating and pressurization contains metal particles and a binder component that contains a resin having a decomposition initiation temperature of 200 °C or lower.

Description

Technical Field

[0001] The present disclosure relates to a film-shaped firing material for heating and pressurization, and a method for manufacturing a semiconductor device.

Background Art

[0002] In recent years, with the increase in voltage and current of automobiles, air conditioners, personal computers, etc., the demand for semiconductor elements (for example, power devices) mounted on these has been increasing. In applications such as power devices, semiconductor elements are likely to generate a large amount of heat from the semiconductor elements because they are used under high voltage and high current. Therefore, it is necessary to efficiently release the heat generated from the semiconductor elements.

[0003] Conventionally, in order to release the heat generated from a semiconductor element to the outside, a heat dissipation member (for example, a heat sink) may be attached around the semiconductor element. And a film-shaped firing material may be used to join the heat dissipation member and the semiconductor element. Also, there is a desire to form a bonding material between a power semiconductor element and a substrate from a metal having high thermal conductivity and high heat resistance.

[0004] For example, Patent Document 1 proposes "a film-shaped firing material containing sinterable metal particles and a binder component, in which, in a thermogravimetric curve (TG curve) measured at a heating rate of 10 °C / min in a nitrogen atmosphere, the temperature (A) at which the negative slope is the largest, and the maximum peak temperature (B) in the differential thermal analysis curve (DTA curve) measured at a heating rate of 10 °C / min in a nitrogen atmosphere with alumina particles as a reference sample in the temperature range from 25 °C to 400 °C, satisfy the relationship of A < B < A + 60 °C, a film-shaped firing material." Patent Document 2 proposes a method for manufacturing a bonded body, comprising: step A of preparing a laminate in which two objects to be bonded are temporarily bonded via a heat bonding sheet having a pre-sintering layer containing a heat-decomposable binder that is solid at 23°C; step B of heating the laminate from a first temperature or lower to a second temperature, as defined below; and step C of maintaining the temperature of the laminate within a predetermined range after step B, wherein the laminate is pressurized during at least a portion of step B and at least a portion of step C. The first temperature is the temperature at which an organic component contained in the pre-sintering layer is reduced by 10% by weight when thermogravimetric measurement of the pre-sintering layer is performed. When steps B and C are performed in the atmosphere, the thermogravimetric measurement is performed in the atmosphere. When steps B and C are performed in a nitrogen atmosphere, a reducing gas atmosphere, or a vacuum atmosphere, the thermogravimetric measurement is performed in a nitrogen atmosphere.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-188723 Patent Document 2: Patent No. 6796937 Summary of the Invention [Problem to be solved by the invention]

[0006] It is desirable to sinter such sintered materials for bonding under as mild a temperature as possible. In the examples of Patent Document 2, the sintered materials are heated and pressurized at 200°C or 300°C for sintering. However, when the sintered materials are sintered by heating and pressurizing them, voids tend to form inside the sintered body. Furthermore, the presence of voids inside the sintered body can cause a decrease in thermal conductivity, a decrease in thickness uniformity, etc.

[0007] The problem to be solved by one embodiment of the present disclosure is to provide a film-shaped sintering material for heating and pressing that can produce a sintered body with few voids, and a method for manufacturing a semiconductor device that uses the film-shaped sintering material for heating and pressing according to the present disclosure. [Means for solving the problem]

[0008] The present disclosure includes the following embodiments. <1> A film-shaped sintered material for heating and pressurizing, comprising metal particles and a binder component containing a resin whose decomposition temperature is 200°C or lower. <2> The resin having a decomposition starting temperature of 200°C or less is an aliphatic polycarbonate. <1> The film-shaped sintered material for heating and pressing according to claim 1. <3> The resin having a decomposition starting temperature of 200°C or less is an aliphatic polycarbonate containing an organic acid group. <1> or <2> The film-shaped sintered material for heating and pressing according to claim 1. <4> The metal particles contain silver. <1> ~ <3> 10. A film-shaped sintered material for heating and pressing according to any one of the above items. <5> The metal particles contain metal particles having a particle size of 100 nm or less. <1> ~ <4> 10. A film-shaped sintered material for heating and pressurizing according to any one of the above items. <6> The film-shaped sintered material for heating and pressing is used to bond a semiconductor element to another component. <1> ~ <5> 10. A film-shaped sintered material for heating and pressing according to any one of the above items. <7> The semiconductor element is a power semiconductor element. <6> The film-shaped sintered material for heating and pressing according to claim 1. <8> <6> or <7> 1. A method for manufacturing a semiconductor device using the film-shaped sintering material for heating and pressing described in claim 1, comprising the steps of: obtaining a laminate precursor by sandwiching the film-shaped sintering material for heating and pressing between the semiconductor element and the other component; and applying heat and pressure to the laminate precursor. <9> The step of heating and pressurizing the laminate precursor includes a first process of heating and pressurizing the laminate precursor at a temperature equal to or higher than the decomposition starting temperature of a resin having a decomposition starting temperature of 200° C. or lower and lower than the melting point of the metal particles to obtain a second laminate precursor, and a second process of heating the second laminate precursor at a temperature equal to or higher than the melting point of the metal particles. <8> 2. A method for manufacturing a semiconductor device according to claim 1 . <10> The step of heating and pressurizing the laminate precursor includes a first process of heating and pressurizing the laminate precursor at a temperature equal to or higher than the decomposition starting temperature of a resin having a decomposition starting temperature of 200°C or lower and lower than 250°C to obtain a second laminate precursor, and a second process of heating the second laminate precursor at a temperature of 250°C or higher. <8> 2. A method for manufacturing a semiconductor device according to claim 1 . [Effects of the Invention]

[0009] According to one embodiment of the present disclosure, there is provided a film-shaped sintering material for heating and pressing, which can produce a sintered body with few voids. According to another embodiment of the present disclosure, there is provided a method for manufacturing a semiconductor device using a film-shaped sintering material for heating and pressing according to the present disclosure. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a process for obtaining a sintered body from a film-shaped sintering material for heating and pressing according to the present disclosure. [Figure 2] 1 is a schematic cross-sectional view of a film-shaped sintered material with a support sheet according to one embodiment of the present disclosure. [Figure 3] FIG. 10 is a schematic cross-sectional view of a film-shaped sintered material with a support sheet according to another embodiment of the present disclosure. [Figure 4] FIG. 10 is a schematic perspective view of a film-shaped sintered material with a support sheet according to another embodiment of the present disclosure. [Figure 5] FIG. 1 is a schematic cross-sectional view showing an example of a conventional process for obtaining a sintered body from a film-shaped sintered material. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described. These descriptions and examples are intended to illustrate the embodiment and are not intended to limit the scope of the invention. In the present specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. In addition, in the present specification, the upper or lower limit of a numerical range may be replaced with a value shown in the examples. In this disclosure, the use of "to" to represent a range of values ​​indicates a range that includes the values ​​stated as the upper and lower limits. Furthermore, when a unit is stated for only the upper limit of a range of values ​​expressed as "to," this means that the lower limit is also expressed in the same unit. In this specification, "(meth)acrylic" includes both acrylic and methacrylic.

[0012] Each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, the amount refers to the total amount of those multiple substances present in the composition, unless otherwise specified.

[0013] <Film-shaped baking material for heating and pressurizing> The film-shaped sintered material for heating and pressing according to the present disclosure contains metal particles and a binder component containing a resin having a decomposition starting temperature of 200° C. or lower (hereinafter also referred to as "specific resin"). Here, the film-shaped sintering material for heating and pressing refers to a film-shaped material for obtaining a sintered body by heating and pressing (for example, at 100° C. or higher and 0.15 MPa or higher).

[0014] The film-shaped sintering material for heating and pressing according to the present disclosure has the above-described configuration, which allows a sintered body with few voids to be obtained. The reason for this will be explained with reference to Fig. 5. Fig. 5 shows an example of the process for obtaining a sintered body from a conventional film-shaped sintering material.

[0015] As shown in FIG. 5, a conventional film-shaped sintered material 10 includes metal particles 11 and a binder component 12 containing a resin whose decomposition temperature exceeds 200°C. When the conventional film-shaped sintered material 10 is heated, the binder component 12 decomposes and vaporizes, the metal particles 11 melt, and the metal particles bond together, ultimately forming a sintered body 14. Here, a high melting point of the metal particles 11 necessitates a high sintering temperature for the film-shaped sintered material 10, so a low melting point of the metal particles 11 is desirable. For example, metal particles 11 have a characteristic in which their melting point gradually decreases as their size decreases to the nano-level (melting point depression). Therefore, selecting metal particles 11 with small sizes can result in metal particles 11 with a low melting point. However, in conventional film-shaped sintered materials 10, the decomposition temperature of the resin contained in the binder component exceeds 200°C, which can reduce the difference between the melting point of the metal particles 11 and the decomposition temperature of the resin. In this case, the decomposition of the binder component 12 and the melting of the metal particles 11 may proceed simultaneously. As a result, before the binder component 12 is largely decomposed to form a sintered body 14, it is easy to form a sintered body precursor 13 in which the metal particles 11 melt and bond together around the binder component 12. Furthermore, when the sintered body precursor 13 is formed, the metal particles 11 melt together and bond together, so they do not maintain their particle shape and their melting point increases. Therefore, the sintered body 14 obtained by decomposing the binder component 12 in the sintered body precursor 13 may be incomplete, with voids 15 formed in the area where the binder component was previously present. Furthermore, it is difficult to remelt such an incomplete sintered body 14 to eliminate the voids 15 and aggregate the metals due to the increase in the melting point of the metals.

[0016] On the other hand, the film-shaped sintered material for heating and pressing 20 according to the present disclosure contains metal particles 21 and a binder component 22 containing a specific resin, as shown in FIG. 1. The binder component 22 contains a specific resin. The decomposition temperature of the specific resin is 200°C or lower. Therefore, the metal The difference between the melting point of the particles 21 and the decomposition temperature of the specific resin becomes large. Therefore, by applying heat and pressure, the decomposition and vaporization of the binder component 22 proceeds first. As a result, the metal particles 21 are densely aggregated, and an aggregate 23 of metal particles is obtained. By further heating the aggregate 23, the metal particles melt and bond to each other, and a sintered body 24 is obtained. As described above, the film-shaped sintered material for heating and pressing according to the present disclosure provides an aggregate 23 in which metal particles are densely packed, making it difficult for the metal particles to fuse together and form bonds around the binder component. Furthermore, because the metal particles 21 contained in the aggregate 23 maintain their particle shape, the melting point of the metal particles 21 is unlikely to rise above its initial value. Therefore, the metal particles 21 contained in the aggregate 23 melt easily when heated, resulting in a sintered body 24 with few voids. Here, the film-shaped sintering material 20 for heating and pressurizing according to the present disclosure is heated and pressurized to obtain a sintered body 24, which further promotes the decomposition and vaporization of the binder component 22. Furthermore, by applying heat and pressure, the voids contained in the aggregate 23 tend to disappear due to the pressure. In other words, if the film-shaped sintering material is sintered by heating only without applying pressure, voids remain in the sintered body. For example, even if it is possible to increase the electrical conductivity of the sintered body because the metal particles 21 bond together due to heating, the voids hinder the transfer of heat, making it difficult to obtain high thermal conductivity.

[0017] From the above, the film-shaped sintering material for heating and pressing according to the present disclosure is a film-shaped sintering material for heating and pressing that can produce a sintered body with few voids. Furthermore, the film-shaped sintering material for heating and pressing according to the present disclosure is suitable for obtaining a sintered body by heating and pressing (preferably at 100° C. or higher and 0.15 MPa or higher).

[0018] Hereinafter, each component contained in the film-shaped sintering material for heating and pressing according to the present disclosure will be described.

[0019] (metal particles) The film-shaped sintering material for heating and pressing according to the present disclosure contains metal particles. By including metal particles, the film-shaped sintering material for heating and pressing can be heated and pressurized to fuse and bond the metal particles together, thereby obtaining a sintered body. The formation of this sintered body bonds the adherend that was in contact with the film-shaped sintering material for heating and pressing.

[0020] Examples of materials for the metal particles include metals such as silver, gold, copper, iron, nickel, aluminum, silicon, palladium, platinum, and titanium; oxides of these metals; alloys containing at least two of these metals; and barium titanate. From the viewpoint of easily adjusting the melting point of the metal particles so that they can be melted at a relatively low temperature, it is preferable that the metal particles contain silver. The silver content of the metal particles is preferably 20% by mass or more, more preferably 30% by mass or more, of the metal particles. The metal particles may be silver particles made of at least one type selected from the group consisting of silver and silver oxides.

[0021] From the viewpoint of improving dispersibility in the binder component, the surfaces of the metal particles may be coated with an organic substance. Examples of organic substances include alcohol molecule derivatives derived from alcohol molecules having 1 to 12 carbon atoms, and amine molecule derivatives.

[0022] The shape of the metal particles may be any of spherical, plate-like, etc., and is preferably spherical. The spherical metal particles may be either cubic or ellipsoidal.

[0023] The particle size of the metal particles varies depending on the ratio of the content of sinterable metal particles to non-sinterable metal particles described below, but may be 0.1 nm or more and 10,000 nm or less, 0.3 nm or more and 3,000 nm or less, or 0.5 nm or more and 1,000 nm or less.

[0024] The particle size of the metal particles is measured using an electron microscope. The particle size of the metal particles is measured by the following procedure. The film-shaped sintered material for heating and pressing is observed under an electron microscope, and 100 or more metal particles are randomly selected. The projected area of ​​the selected metal particles is calculated, and the equivalent circle diameter corresponding to the projected area is calculated for each. The number average of the calculated equivalent circle diameters is taken as the particle size of the metal particles.

[0025] The metal particles may contain two or more types of metal particles having different particle sizes. Specifically, it may contain metal particles with a particle size of 100 nm or less, and metal particles with a particle size of more than 100 nm. Here, metal particles with a particle size of 100 nm or less are referred to as "sinterable metal particles." Metal particles with a particle size exceeding 100 nm are referred to as "non-sinterable metal particles." From the viewpoint of sintering the film-shaped sintered material for heating and pressing at a low temperature, it is preferable that at least some of the metal particles are sinterable metal particles with a large melting point depression. Furthermore, from the viewpoint of efficiently obtaining a sintered body by bonding the non-sinterable metal particles with the molten sinterable metal particles after sintering the film-shaped sintered material for heating and pressing, it is preferable that the metal particles include both sinterable metal particles and non-sinterable metal particles.

[0026] The particle size of the sinterable metal particles may be selected so as to cause an appropriate melting point depression depending on the temperature at which the film-shaped sintered material for heating and pressing is sintered, and may be 0.1 nm or more and 100 nm or less, 0.3 nm or more and 50 nm or less, or 0.5 nm or more and 30 nm or less. The particle size of the non-sinterable metal particles may be greater than 150 nm and not greater than 50,000 nm, may be 150 nm or greater and 10,000 nm, or may be 180 nm or greater and not greater than 5,000 nm.

[0027] The particle size of the sinterable metal particles is measured in the same manner as the procedure for measuring the particle size of metal particles described above. In measuring the particle size of sinterable metal particles, the selected metal particles are limited to those having a circle-equivalent diameter corresponding to the projected area of ​​100 nm or less.

[0028] The particle size of the non-sinterable metal particles is measured in the same manner as the procedure for measuring the particle size of metal particles described above. In measuring the particle size of non-sinterable metal particles, the selected metal particles are limited to those having a circle-equivalent diameter, which corresponds to the projected area, of more than 100 nm.

[0029] In order to obtain a sintered body with few voids while improving adhesion before sintering to a semiconductor element or other component when the film-shaped sintered material for heating and pressing is used for joining a semiconductor element, as described below, the content of metal particles (total content of sinterable metal particles and non-sinterable metal particles; the same applies hereinafter) is preferably 50% by mass or more and 98% by mass or less, more preferably 70% by mass or more and 97% by mass or less, even more preferably 80% by mass or more and 95% by mass or less, and even more preferably 80% by mass or more and 90% by mass or less, based on the entire film-shaped sintered material for heating and pressing.

[0030] From the viewpoint that the film-shaped sintered material for heating and pressing contains a certain amount of metal particles with a large melting point depression and that a sintered body can be easily formed even at low sintering temperatures, if the metal particles contain sinterable metal particles, the content of the sinterable metal particles is preferably 20% by mass or more and 100% by mass or less, and more preferably 30% by mass or more and 95% by mass or less, of the total content of the metal particles.

[0031] (binder component) -Specific resin- The binder component contains a resin (specific resin) whose decomposition temperature starts at 200° C. or lower. Since the specific resin has a decomposition starting temperature of 200°C or lower, the difference between the melting point of the metal particles and the decomposition temperature of the specific resin becomes large. Therefore, by applying heat and pressure, the decomposition and vaporization of the binder component tends to proceed first.

[0032] The decomposition starting temperature of the resin is a value measured using a differential scanning thermogravimeter. Using a differential thermal / thermogravimetric simultaneous analyzer (e.g., Shimadzu DTG-60), the decomposition behavior is measured by heating from room temperature to 400°C at a rate of 20°C / min in a nitrogen atmosphere. The decomposition onset temperature is defined as the temperature at the intersection of a line parallel to the horizontal axis passing through the mass before the start of test heating and a tangent drawn so that the gradient between the inflection points on the decomposition curve is maximized.

[0033] From the viewpoint of facilitating the production of a resin with a low decomposition starting temperature, the specific resin is preferably an aliphatic polycarbonate. Aliphatic polycarbonate is a polycarbonate whose main chain is composed of an aliphatic hydrocarbon group and a carbonate group (which in this specification means a group represented by -O-CO-O-). The aliphatic polycarbonate may have side chains. The main chain refers to the relatively longest bond chain in the molecule of a compound. The side chain refers to a linking chain branching from the main chain.

[0034] The aliphatic hydrocarbon group contained in the main chain preferably has 1 or more and 6 or less, more preferably 2 or more and 4 or less, and even more preferably 2 or 3 carbon atoms.

[0035] From the viewpoint that it is easier to obtain a resin having a low decomposition starting temperature, the specific resin is preferably an aliphatic polycarbonate containing an organic acid group. The organic acid group includes a carboxy group and a sulfo group. From the viewpoint of simplifying the synthesis procedure of the aliphatic polycarbonate and improving the handling properties, the organic acid group is preferably a carboxy group.

[0036] When the specific resin contains an organic acid group, the acidity derived from the organic acid group accelerates the decomposition of the specific resin, thereby lowering the decomposition initiation temperature.

[0037] From the viewpoint of simplifying the synthesis procedure of the aliphatic polycarbonate, the aliphatic polycarbonate containing an organic acid group is preferably an aliphatic polycarbonate containing a group represented by the following formula (0). Formula (0) *-(CH2) m -COOH In formula (0), m represents an integer of 1 or more, and * represents a bond.

[0038] From the viewpoint of reducing the influence of the side chains on the physical properties of the aliphatic polycarbonate, m is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and even more preferably 1 or 2.

[0039] More specifically, the aliphatic polycarbonate containing an organic acid group preferably contains a structural unit represented by the following formula (1).

[0040] [ka]

[0041] In formula (1), R 1 , R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms; and n is 1 or 2.

[0042] In formula (1), the alkyl group has 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. The alkyl group may be a straight-chain or branched, substituted or unsubstituted alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, and an n-decyl group. The alkyl group may be substituted with a substituent selected from an alkoxy group, an ester group, a silyl group, a sulfanyl group, a cyano group, a nitro group, a sulfo group, a formyl group, an aryl group, a halogen atom, and the like.

[0043] In formula (1), the aryl group has 6 to 20 carbon atoms, and preferably 6 to 14 carbon atoms. Examples of the aryl group include a phenyl group, an indenyl group, a naphthyl group, and a tetrahydronaphthyl group. The aryl group may be substituted with a substituent such as an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group; another aryl group such as a phenyl group or a naphthyl group; an alkoxy group, an ester group, a silyl group, a sulfanyl group, a cyano group, a nitro group, a sulfo group, a formyl group, or a halogen atom.

[0044] From the viewpoint of adjusting the number of organic acid groups present in the molecule, the aliphatic polycarbonate containing organic acid groups preferably contains a structural unit represented by the following formula (2) in addition to the structural unit represented by the above formula (1).

[0045] [ka]

[0046] In formula (2), R 4 , R 5 and R 6 are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and X is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 10 carbon atoms, an ether bond-containing group, an ester bond-containing group, or an allyl group.

[0047] In formula (2), the alkyl group has 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. The alkyl group may be a straight-chain or branched, substituted or unsubstituted alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, and an n-decyl group. The alkyl group may be substituted with, for example, an alkoxy group, an ester group, a silyl group, a sulfanyl group, a cyano group, a nitro group, a sulfo group, a formyl group, an aryl group, a halogen atom, or the like.

[0048] In formula (2), the aryl group has 6 to 20 carbon atoms, and preferably 6 to 14 carbon atoms. Examples of the aryl group include a phenyl group, an indenyl group, a naphthyl group, and a tetrahydronaphthyl group. The aryl group may be substituted with a substituent such as an alkyl group, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group; another aryl group, such as a phenyl group or a naphthyl group; an alkoxy group, an ester group, a silyl group, a sulfanyl group, a cyano group, a nitro group, a sulfo group, a formyl group, or a halogen atom.

[0049] In formula (2), X is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 10 carbon atoms, an ether bond-containing group, an ester bond-containing group, or an allyl group, and X is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, more preferably a hydrogen atom or a methyl group.

[0050] The alkyl group having 1 to 10 carbon atoms represented by X is preferably an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, and an n-propyl group.

[0051] The number of carbon atoms in the haloalkyl group is 1 to 10, and preferably 1 to 4. Examples of the haloalkyl group include a fluoromethyl group, a chloromethyl group, a bromomethyl group, and an iodomethyl group.

[0052] The ether bond-containing group is preferably an alkyl group having 1 to 4 carbon atoms substituted with an alkoxy group having 1 to 4 carbon atoms, an allyloxy group, or the like, and examples thereof include a methoxymethyl group, an ethoxymethyl group, and an allyloxymethyl group.

[0053] The ester bond-containing group is preferably an acyloxy group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms substituted with a benzyloxycarboxy group, or the like, and examples thereof include an acetoxymethyl group and a butylyloxymethyl group.

[0054] The content of the structural unit represented by formula (1) in the aliphatic polycarbonate is preferably 0.001 mol% to 30 mol% of all structural units constituting the aliphatic polycarbonate, from the viewpoint of easily lowering the decomposition onset temperature of the aliphatic polycarbonate, more preferably 0.1 mol% to 20 mol% or less, even more preferably 0.5 mol% to 20 mol% or less, and particularly preferably 1.0 mol% to 20 mol% or less. From the viewpoint of reducing the influence of acid on articles to which the film-shaped sintered material for heating and pressing according to the present disclosure is applied, such as semiconductor elements, the content of the structural unit represented by formula (1) in the aliphatic polycarbonate may be 0.1 mol% to 5.0 mol% or 0.5 mol% to 3.0 mol% of all structural units constituting the aliphatic polycarbonate.

[0055] The content of the structural unit represented by formula (2) in the aliphatic polycarbonate is preferably 70 mol% or more and 99.999 mol% or less, more preferably 80 mol% or more and 99.9 mol% or less, still more preferably 80 mol% or more and 99.5 mol% or less, and particularly preferably 90 mol% or more and 99.0 mol% or less, of all the structural units constituting the aliphatic polycarbonate.

[0056] The weight average molecular weight of the aliphatic polycarbonate is preferably 3,000 or more and 1,000,000 or less, more preferably 10,000 or more and 500,000 or less, and even more preferably 10,000 or more and 300,000 or less, from the viewpoint of easily maintaining the film shape of the film-shaped fired material for heating and pressing according to the present disclosure and adjusting the viscosity of the film-forming composition.

[0057] The weight average molecular weight of the aliphatic polycarbonate is a value measured by gel permeation chromatography (GPC). The weight average molecular weight of the aliphatic polycarbonate is measured as follows. A chloroform solution containing 0.5% by mass of aliphatic polycarbonate is prepared and measured using GPC. After the measurement, the weight average molecular weight is calculated by comparing it with that of polystyrene whose weight average molecular weight is known and measured under the same conditions. The measurement conditions are as follows: Column: GPC column (Shodex K-804L, product name of Showa Denko K.K.) Column temperature: 40℃ Eluent: chloroform Flow rate: 1.0mL / min

[0058] Specific examples of aliphatic polycarbonates include those represented by the formula (1) R 1 , R 2 , R 3 , and n, respectively, R 1 , R 2 , and R 3 are all hydrogen atoms, n is 1, and R 4 , R 5 , R 6 , and X, respectively, R 4 , R 5 , and R 6 are all hydrogen atoms, X is a methyl group, and the structural units include only those represented by formula (1) and those represented by formula (2).

[0059] When such an aliphatic polycarbonate is synthesized by adjusting the content of the structural unit represented by formula (1) in the aliphatic polycarbonate within the range of 1.0 mol % to 20 mol % of all the structural units constituting the aliphatic polycarbonate, it is possible to achieve a mass loss rate (described below) within a predetermined range and a decomposition onset temperature of 200° C. or lower. For example, even when the content of the structural unit represented by formula (1) in the aliphatic polycarbonate is as low as 3.0 mol % by mass or lower of all the structural units constituting the aliphatic polycarbonate, an aliphatic polycarbonate having a mass loss rate of about 95% by mass and a decomposition onset temperature of about 150° C. can be obtained.

[0060] From the viewpoint of facilitating a decrease in the decomposition initiation temperature of the aliphatic polycarbonate, specifically, the aliphatic polycarbonate is preferably a compound represented by the following formula (3).

[0061] [ka]

[0062] In formula (3), m and l represent the content (unit: mol %) of the structural unit relative to all structural units constituting the aliphatic polycarbonate.

[0063] The decomposition starting temperature of the aliphatic polycarbonate is preferably 80°C or higher and 185°C or lower, more preferably 100°C or higher and 170°C or lower, and even more preferably 120°C or higher and 160°C or lower, from the viewpoint of preventing decomposition of the binder component before heating and from the viewpoint of obtaining a sintered body with few voids.

[0064] Since the aliphatic polycarbonate has a low decomposition onset temperature, it is preferable that most of the weight of the aliphatic polycarbonate is lost by decomposition when heated for a certain period of time even at a low temperature. Therefore, the mass loss rate after being held at 160°C for 1 hour in thermogravimetric analysis is preferably 90% or more, more preferably 95% or more. From the viewpoint of preventing decomposition of the binder component before heating, the mass loss rate after holding at 100°C for 1 hour is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less. The decomposition initiation temperature can be adjusted by the content of the structural unit represented by formula (1).

[0065] The mass loss rate is measured by a thermogravimetric analyzer. As the thermogravimetric analyzer, for example, a DTG-60 manufactured by Shimadzu Corporation, which is a differential thermal-thermogravimetric simultaneous analyzer, can be used. The sample is placed in a thermogravimetric analyzer and heated from room temperature to a specified temperature (160°C or 100°C) at a rate of 50°C / min under a nitrogen atmosphere, then held at that temperature for one hour to measure thermal decomposition behavior. The mass loss rate is calculated from the ratio of the mass (W1) after one hour of heating from the decomposition curve to the initial mass (W0) [i.e., (W0-W1) / W0×100].

[0066] The decomposition initiation temperature of the aliphatic polycarbonate is measured as described above.

[0067] The glass transition temperature of the aliphatic polycarbonate is preferably 0°C or higher and 50°C or lower, more preferably 10°C or higher and 40°C or lower, and even more preferably 15°C or higher and 30°C or lower, from the viewpoints of the strength of the film-shaped sintered material for heating and pressing and the flexibility of the film-shaped sintered material for heating and pressing.

[0068] The glass transition temperature of an aliphatic polycarbonate is the temperature at the peak of the differential heat curve measured by a differential scanning calorimeter for the aliphatic polycarbonate.

[0069] From the viewpoint of obtaining a sintered body with few voids, the content of the specific resin relative to the total binder components is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, and even more preferably 80% by mass or more and 100% by mass or less.

[0070] -Other resins- The binder component may contain a resin other than the specific resin. Examples of resins other than the specific resin include acrylic resins, polylactic acid, and cellulose derivatives. The content of other resins other than the specific resin is, for example, preferably 0% by mass or more and 50% by mass or less, more preferably 0% by mass or more and 30% by mass or less, even more preferably 0% by mass or more and 20% by mass or less, and particularly preferably 0% by mass, relative to the entire binder component.

[0071] -Binder component content- From the viewpoint of obtaining a sintered body with few voids, the content of the binder component is preferably 2% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 30% by mass or less, even more preferably 5% by mass or more and 20% by mass or less, and even more preferably 10% by mass or more and 20% by mass or less, based on the entire film-shaped sintered material for heating and pressing.

[0072] (Other ingredients) The film-shaped sintered material for heating and pressing according to the present disclosure may contain components other than the metal particles and binder component. Other components include solvents, dispersants, plasticizers, tackifiers, storage stabilizers, antifoaming agents, thermal decomposition accelerators, and antioxidants.

[0073] (Thickness of film-shaped baking material for heating and pressing) The thickness of the film-shaped sintered material for heating and pressing according to the present disclosure is not particularly limited, but is preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less, and even more preferably 30 μm or more and 90 μm or less.

[0074] The thickness of the film-shaped sintered material for heating and pressing is measured in accordance with JIS K7130 (1999). According to JIS K7130 (1999), the thickness is measured at any five points on the object to be measured, and the arithmetic mean value of the obtained values ​​is taken as the thickness of the film-shaped sintered material for heating and pressing. A constant pressure thickness gauge can be used as the thickness gauge.

[0075] (Method for producing a film-shaped fired material for heating and pressurizing) The method for producing the film-shaped sintered material for heating and pressing is not particularly limited, and the material can be obtained by appropriately mixing metal particles, a binder component, and, if necessary, other components to obtain a mixture (hereinafter, the mixture is also referred to as a "raw material mixture"), and molding the mixture into a film. The molding can be performed, for example, by applying the raw material mixture onto a substrate to form a film, and then separating the film from the substrate.

[0076] From the viewpoint of improving film-forming properties, the raw material mixture preferably contains a solvent. The solvent preferably has a boiling point of less than 200°C. Examples of the solvent include n-hexane (boiling point: 68°C), ethyl acetate (boiling point: 77°C), 2-butanone (boiling point: 80°C), n-heptane (boiling point: 98°C), methylcyclohexane (boiling point: 101°C), toluene (boiling point: 111°C), acetylacetone (boiling point: 138°C), n-xylene (boiling point: 139°C), and dimethylformamide (boiling point: 153°C). These may be used alone or in combination.

[0077] Examples of methods for applying the raw material mixture include methods using various coaters such as an air knife coater, blade coater, bar coater, gravure coater, comma coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, Mayer bar coater, and kiss coater.

[0078] When the raw material mixture contains a solvent, it is preferable to apply the raw material mixture in the form of a film and then heat-dry the film-like raw material mixture. The temperature during heat drying is preferably equal to or lower than the decomposition starting temperature of the specific resin contained in the binder component and equal to or higher than the boiling point of the solvent contained in the film-shaped raw material mixture. The heating and drying time is not particularly limited, and is preferably, for example, 10 seconds to 10 minutes.

[0079] (Application) The film-shaped sintered material for heating and pressing according to the present disclosure is used, for example, to bond two adherends together to obtain a laminate. Examples of the adherend to be joined include semiconductor wafers, semiconductor elements, substrates, lead frames, and heat dissipators (heat sinks, etc.).

[0080] The film-shaped sintered material for heating and pressing according to the present disclosure is preferably used to bond a semiconductor element to another component. Examples of other components bonded to a semiconductor element using the film-shaped sintered material for heating and pressing according to the present disclosure include substrates. Furthermore, the other components may also be semiconductor elements, and the film-shaped sintered material for heating and pressing may be used to bond two semiconductor elements together. In particular, it is preferable that the semiconductor element to be joined is a power semiconductor element, which has a rated current of 1 A or more. The film-shaped sintering material for heating and pressing according to the present disclosure produces a sintered body with few voids. Therefore, the sintered body obtained by sintering the film-shaped sintering material for heating and pressing according to the present disclosure has high thermal conductivity. This allows for more efficient dissipation of heat generated by semiconductor elements. A technology called the die-top system is also known as a technology related to power semiconductors. In this technology, a copper foil with a special shape is attached to the die (chip) via a sintering paste. Specifically, the copper foil is roughly rectangular, but one side is In some cases, a substrate having a shape with a notch is used. In this case, the first adherend is a semiconductor element, and the second adherend is copper foil.

[0081] (Method of manufacturing laminate) An example of a method for producing a laminate using the film-shaped sintering material for heating and pressing according to the present disclosure will be described below.

[0082] A laminate can be produced by joining two adherends using the film-shaped sintered material for heating and pressing according to the present disclosure. Any method can be used to produce a laminate, as long as the two adherends can be joined via the film-shaped sintered material for heating and pressing according to the present disclosure. For example, it is also suitable to produce a laminate by the laminate production method described below. The method for producing the laminate includes: A step (1) of obtaining a laminate precursor by sandwiching a film-shaped sintered material for heating and pressing between a first adherend and a second adherend; a step (2) of heating and pressurizing the laminate precursor; It is preferred that the compound contains:

[0083] (Process (1)) Step (1) is a step of obtaining a laminate precursor by sandwiching a film-shaped calcined material for heating and pressing between a first adherend and a second adherend. The method for sandwiching the film-shaped sintered material for heating and pressing between the first adherend and the second adherend is, for example, as follows. One side of a film-like sintered material for heating and pressing is attached to the surface of a first adherend, and then a second adherend is attached to the other side of the film-like sintered material for heating and pressing so that the second adherend faces the first adherend via the film-like sintered material for heating and pressing.

[0084] (Process (2)) Step (2) is a step of applying heat and pressure to the laminate precursor. The heating temperature is preferably 150°C or higher and 600°C or lower, more preferably 165°C or higher and 500°C or lower, and even more preferably 180°C or higher and 400°C or lower. The pressure is preferably 0.15 MPa or more and 50 MPa or less. When this process is carried out in a single treatment at a temperature equal to or higher than the melting point of the metal particles without carrying out the first and second treatments described below, the heating and pressurizing time is, for example, preferably 5 seconds to 180 minutes, more preferably 5 seconds to 150 minutes, and even more preferably 10 seconds to 120 minutes.

[0085] Step (2) may involve applying heat and pressure, and may involve applying heat and pressure simultaneously, or may involve applying heat and pressure sequentially, but it is preferable to apply heat and pressure simultaneously.

[0086] The device that can be used in step (2) is not particularly limited as long as it is capable of applying heat and pressure to the laminate precursor. Examples of the apparatus include a platen press, a flip chip bonder, a die bonder, and an autoclave, and it is preferable to use a platen press or an autoclave that can apply a strong pressure.

[0087] Mechanical pressure means (plate press) can require a large-scale device. From the viewpoint of reducing the frequency of use of mechanical pressure means, it is preferable to use an autoclave as the device in step (2).

[0088] When an autoclave is used in step (2), the procedure is, for example, as follows. First, the laminate precursor is placed in an autoclave. At this time, the method for placing the laminate precursor is not particularly limited, but for example, a method of placing a horizontal table in the autoclave and placing the laminate precursor on the table can be mentioned.

[0089] The autoclave is then sealed and heated and pressurized. The heating method is not particularly limited, and for example, heating may be performed using a heating device attached to the autoclave, or by using an autoclave equipped with a jacket (a steam flow path) and flowing steam through the jacket.

[0090] The method of pressurization is not particularly limited, and examples thereof include a method of pressurizing by supplying a gas into the autoclave. The gas is not particularly limited, and examples thereof include nitrogen and air.

[0091] Step (2) may be carried out by changing the heating and pressurizing conditions in two stages. For example, the step (2) includes a first treatment of heating and pressurizing the laminate precursor at a temperature equal to or higher than the decomposition starting temperature of the specific resin and lower than the melting point of the metal particles to obtain a second laminate precursor; It is preferable that the method further comprises a second treatment of heating the second laminate precursor at a temperature equal to or higher than the melting point of the metal particles.

[0092] -First process- In the first treatment, the laminate precursor is heated and pressurized at a temperature equal to or higher than the decomposition temperature of the specific resin and lower than the melting point of the metal particles to obtain a second laminate precursor. Here, the melting point of the metal particles in step (2) refers to the maximum peak temperature in the temperature range of 25°C to 400°C in a differential thermal analysis (DTA) curve measured for the film-shaped fired material at a heating rate of 10°C / min in a nitrogen atmosphere using alumina particles as a reference sample. Specifically, the differential thermal analysis is performed on the film-shaped fired material using a thermal analysis measuring device (e.g., a simultaneous TG / DTA thermal analyzer DTG-60, manufactured by Shimadzu Corporation) at a heating rate of 10°C / min in a nitrogen atmosphere using approximately the same amount of alumina particles as the measurement sample as a reference sample.

[0093] The first treatment involves heating and pressurizing at a temperature below the melting point of the metal particles, which allows the decomposition and vaporization of the binder component to proceed while suppressing the melting of the metal particles contained in the film-shaped fired material for heating and pressurizing.

[0094] In the first treatment, the heating temperature is preferably at least 15°C higher than the decomposition temperature of the specific resin, and more preferably at least 30°C higher than the decomposition temperature of the specific resin. For example, the heating temperature can be 150°C or higher, preferably 165°C or higher, and more preferably 180°C or higher. If the heating temperature is within this range, for example, when the decomposition starting temperature of the specific resin is 150°C, the heating temperature can be set higher than the decomposition temperature of the specific resin. The upper limit of the heating temperature is preferably 20°C lower than the melting point of the metal particles. For example, in the first treatment, the heating temperature can be less than 250°C, preferably 230°C or less, and more preferably 210°C or less. If the heating temperature is within this range, for example, when the melting point of the metal particles is 250° C., the heating temperature can be set lower than the melting point of the metal particles. Because the decomposition starting temperature of the specific resin is 200° C. or lower, it is easy to set the heating temperature of the first treatment to a value that is far from both the decomposition starting temperature of the specific resin and the melting point of the metal particles. For example, if the decomposition starting temperature of the specific resin is 150°C and the melting point of the metal particles is 250°C, the first treatment can be carried out at a heating temperature of 200°C. As mentioned above, the pressure applied to the laminate precursor may be in the range of 0.15 MPa to 50 MPa. However, when pressurization is performed using an autoclave, the pressure is preferably 0.50 MPa to 3.00 MPa, more preferably 1.00 MPa to 3.00 MPa, and even more preferably 1.50 MPa to 3.00 MPa. In the first treatment, the laminate precursor is heated and pressurized, eliminating voids formed by decomposition of the binder component, and an aggregate in which metal particles are densely packed in the second laminate precursor can be obtained. Therefore, the subsequent second treatment can produce a sintered body with few voids. The time for the first treatment is preferably changed as appropriate depending on the composition of the binder component and metal particles, and is, for example, preferably 5 seconds to 180 minutes, more preferably 5 seconds to 150 minutes, and even more preferably 10 seconds to 120 minutes.

[0095] -Second Processing- In the second treatment, the second laminate precursor is heated to a temperature equal to or higher than the melting point of the metal particles. From the viewpoint of obtaining a sintered body with fewer voids, it is preferable to pressurize the second laminate precursor in the second treatment as well.

[0096] By carrying out the second treatment, the metal particles are melted and bonded together, thereby obtaining a sintered body. Because the binder components are decomposed and vaporized through the first treatment, the metal particles are densely packed together after the first treatment. Therefore, the metal particles are easily melted and bonded together without the need for physical pressure treatment. As a result, a sintered body can be obtained by heating the second laminate precursor and setting the atmospheric pressure as described above in the second treatment.

[0097] In the second treatment, the heating temperature is preferably 600°C or lower, more preferably 500°C or lower, and even more preferably 400°C or lower. The lower limit of the heating temperature is preferably 20°C higher than the melting point of the metal particles, and more preferably 40°C higher than the melting point of the metal particles. For example, in the second treatment, the heating temperature can be 250°C or higher, preferably 270°C or higher, and more preferably 290°C or higher. If the heating temperature is within this range, for example, when the melting point of the metal particles is 250°C, the heating temperature is higher than the melting point of the metal particles, and the metal particles melt reliably and quickly, allowing a sintered body without voids to be efficiently obtained. For example, if the decomposition starting temperature of the specific resin is 150°C and the melting point of the metal particles is 250°C, the second treatment can be carried out at 350°C. As mentioned above, the pressure to be applied to the second laminate precursor may be set to a value within the range of 0.15 MPa or more and 50 MPa or less. However, if the pressure is applied using an autoclave, the pressure is more preferably set to 0.15 MPa or more and 3.0 MPa or less, and even more preferably set to 0.5 MPa or more and 2.0 MPa or less. The time for the second treatment is preferably varied as appropriate depending on the composition and particle size of the metal particles, but is preferably, for example, from 1 minute to 30 minutes, more preferably from 1 minute to 15 minutes, and even more preferably from 1 minute to 10 minutes.

[0098] It is preferable that the laminate is manufactured through the above steps.

[0099] <Film-shaped baking material with support sheet> An example of an embodiment of a film-shaped sintered material for heating and pressing according to the present disclosure is a film-shaped sintered material with a support sheet, which has a support sheet and a film-shaped sintered material for heating and pressing provided on the support sheet.

[0100] In the film-shaped sintered material with a support sheet according to the present disclosure, the support sheet preferably has a base film and a pressure-sensitive adhesive layer provided on the base film.

[0101] According to the film-shaped sintered material with a support sheet of the present disclosure, a laminate of the first adherend and the film-shaped sintered material with a support sheet is obtained by adhering a first adherend to the surface of the film-shaped sintered material for heating and pressing of the film-shaped sintered material with a support sheet, and then the support sheet is peeled off from the laminate, and the exposed surface of the film-shaped sintered material for heating and pressing (i.e., the surface of the film-shaped sintered material for heating and pressing that faced the support sheet) is adhered to a second adherend, thereby obtaining a laminate in which the first adherend, the film-shaped sintered material for heating and pressing, and the second adherend are laminated in this order. The film-shaped sintered material with support sheet according to the present disclosure is preferably used as a dicing sheet used when obtaining semiconductor elements by cutting a semiconductor wafer into multiple chips (hereinafter also referred to as "dicing").

[0102] The film-shaped sintered material with a support sheet will be described with reference to FIGS. However, the film-shaped sintered material with a support sheet according to the present disclosure is not limited to this.

[0103] 2 and 3 show schematic cross-sectional views of a film-shaped fired material with a support sheet. The film-shaped material to be fired with a support sheet 100a, 100b includes a film-shaped material to be fired with heating and pressurizing 1 and a support sheet 2.

[0104] As shown in FIGS. 2 and 3, the support sheet 2 preferably has a base film 3 and a pressure-sensitive adhesive layer 4. The adhesive layer 4 facilitates laminating the film-like sintered material for heating and pressing onto the support sheet, facilitates dicing as described below, and also serves to fix the ring frame 5. Note that the ring frame 5 is placed on the film-like sintered materials with support sheet 100a, 100b to fix the film-like sintered materials with support sheet 100a, 100b during dicing of the semiconductor wafer, but is not a component constituting the film-like sintered materials with support sheet 100a, 100b. The pressure-sensitive adhesive layer 4 may be provided on the entire surface of the base film 3 as shown in FIG. 2, or may be provided along the outer periphery of the base film 3 as shown in FIG.

[0105] FIG. 4 is a schematic perspective view of a film-shaped fired material 100b with a support sheet. As shown in FIG. 4, the film-shaped sintered material 100b with support sheet may be circular in shape to fit the shape of the semiconductor wafer. Although a schematic perspective view of the film-shaped sintered material 100a with support sheet is not shown, it may be formed in a circular shape that conforms to the shape of a semiconductor wafer.

[0106] Each component of the film-shaped sintered material with a support sheet will be described in detail below. Furthermore, reference numerals will be omitted.

[0107] (support sheet) The support sheet is not particularly limited as long as it is capable of providing a film-like sintered material for heating and pressurizing on the support sheet. The support sheet may have only a base film, or may have a base film and a pressure-sensitive adhesive layer provided on the base film. From the viewpoint of adjusting the adhesiveness between the support sheet and the film-shaped fired material for heating and pressing, and facilitating dicing, the support sheet preferably has a base film and an adhesive layer provided on the base film.

[0108] -Base film- The material of the substrate film is not particularly limited, but examples include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ethylene-propylene copolymer, polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-methyl (meth)acrylate copolymer, ethylene-ethyl (meth)acrylate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyurethane film, ionomer, etc. Furthermore, when higher heat resistance is required for the support sheet, examples of the material for the base film include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polypropylene and polymethylpentene; and the like.

[0109] When the support sheet does not have a pressure-sensitive adhesive layer, the surface of the base film may be treated with a release agent. Examples of the release agent that can be used include alkyd-based release agents, silicone-based release agents, fluorine-based release agents, unsaturated polyester-based release agents, polyolefin-based release agents, wax-based release agents, etc. From the viewpoint of heat resistance, the release agent is preferably at least one selected from the group consisting of alkyd-based release agents, silicone-based release agents, and fluorine-based release agents.

[0110] The thickness of the substrate film is not particularly limited, and is, for example, preferably 30 μm or more and 300 μm or less, and more preferably 50 μm or more and 200 μm or less. By setting the thickness of the base film within the above range, the base film is less likely to tear even when cut by dicing. In addition, the film-shaped sintered material with support sheet is given sufficient flexibility, so it exhibits good adhesion to the adherend (e.g., semiconductor wafer, etc.).

[0111] The shape of the substrate film is preferably adjusted appropriately in accordance with the shape of the adherend. For example, when the adherend is a semiconductor wafer, the shape of the film-shaped sintered material for heating and pressing is preferably circular. When the substrate film has a circular shape, the diameter is preferably 10 mm or more and 500 mm or less.

[0112] The substrate film may be one type of substrate film, or two or more types of substrate films may be laminated together.

[0113] -Adhesive layer- The adhesive layer is a layer having adhesiveness capable of fixing the film-shaped sintered material on the support sheet. Furthermore, for example, when the film-shaped sintered material with a support sheet is used as a dicing sheet, the adhesive layer in the present disclosure can fix a device (e.g., a ring frame) that fixes the film-shaped sintered material with a support sheet during dicing. It is preferable that the adhesive layer allows the ring frame to be peeled off after dicing.

[0114] Examples of materials for the adhesive layer include rubber-based, acrylic-based, silicone-based, urethane-based, and vinyl ether-based adhesives. Focusing on the functions that can be imparted to the adhesive layer, the adhesive layer can be formed from an adhesive with an uneven surface, an energy ray-curable adhesive, an adhesive containing a thermal expansion component, etc.

[0115] The adhesive strength of the adhesive layer to a SUS plate at 23°C is preferably 30 mN / 25 mm to 120 mN / 25 mm, more preferably 50 mN / 25 mm to 100 mN / 25 mm, and even more preferably 60 mN / 25 mm to 90 mN / 25 mm, from the viewpoint of the peelability of the film-shaped baked material for heating and pressing.

[0116] The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is, for example, preferably from 1 μm to 100 μm, more preferably from 2 μm to 80 μm, and even more preferably from 3 μm to 50 μm.

[0117] The pressure-sensitive adhesive layer may be disposed over the entire surface of the base film, or may be disposed over only a portion of the base film. When the pressure-sensitive adhesive layer is disposed on a portion of the base film, it is preferable that the pressure-sensitive adhesive layer be disposed along the contour of the shape of the base film in a plan view.

[0118] When the pressure-sensitive adhesive layer is disposed over the entire surface of the base film, the shape of the pressure-sensitive adhesive layer is the same as the shape of the base film. When the pressure-sensitive adhesive layer is disposed on a portion of the base film, the pressure-sensitive adhesive layer is preferably ring-shaped.

[0119] (Film-shaped baking material for heating and pressurizing) The film-shaped material for heating and pressing to be fired contained in the film-shaped material for firing with a support sheet is the film-shaped material for heating and pressing to be fired according to the present disclosure, and the preferred aspects of the composition and thickness are as described above.

[0120] The shape of the film-shaped sintered material for heating and pressing is not particularly limited, but may be a sheet, a long film, etc., and a long film-shaped sintered material for heating and pressing is preferably a wound roll. Furthermore, from the viewpoint of reducing the amount of relatively expensive metal particles discarded, it is preferable to appropriately adjust the shape of the film-shaped sintered material for heating and pressing to match the shape of the adherend. For example, when the adherend is a semiconductor wafer, the shape of the film-shaped sintered material for heating and pressing is preferably circular. When the film-shaped sintered material for heating and pressing is circular, it preferably has a diameter of 10 mm or more and 500 mm or less.

[0121] (Other parts) The film-shaped sintering material with a support sheet according to the present disclosure may have other components in addition to the support sheet and the film-shaped sintering material for heating and pressing. The other members include, for example, a protective sheet. The protective sheet is a sheet for preventing the surfaces of the film-like sintered material and the pressure-sensitive adhesive layer from coming into contact with the outside until the film-like sintered material with a support sheet is used. The protective sheet is not particularly limited, and examples thereof include sheets made of polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, and the like.

[0122] -Method for manufacturing film-shaped fired material with support sheet- The method for producing the film-shaped sintered material with a support sheet is not particularly limited. There are no particular limitations as long as the pressure-applied film-shaped fired material and the pressure-applied film-shaped fired material can be laminated in this order. An example of a method for producing a film-shaped sintered material with a support sheet will be shown below, but the method is not limited to this.

[0123] --Specific Example 1 of a Method for Producing a Film-Shaped Sintered Material with a Support Sheet-- A method for producing a film-like sintered material with a support sheet 100a in which a base film 3, an adhesive layer 4, and a film-like sintered material for heating and pressing 1 are laminated in this order as shown in FIG. 2 will be described. In the following, reference numerals will be omitted.

[0124] A mixture containing materials constituting a film-shaped sintered material for heating and pressing and a solvent (hereinafter also referred to as "sintered material raw material mixture") is applied (e.g., coated) in the form of a film onto a protective sheet (or other component), and if necessary, the film-shaped sintered material raw material mixture is heated and dried to form a film-shaped sintered material for heating and pressing on the protective sheet. On the other hand, a mixture containing materials constituting the adhesive layer and a solvent (hereinafter also referred to as "adhesive layer raw material mixture") is applied (e.g., coated) in the form of a film onto a base film, and if necessary, the film-like adhesive layer raw material mixture is heated and dried to form an adhesive layer on the base film. Then, the exposed surface of the film-like sintered material for heating and pressing formed on the protective sheet is bonded to the exposed surface of the adhesive layer formed on the base film to obtain a film-like sintered material with a support sheet.

[0125] --Specific Example 2 of a Manufacturing Method for a Film-Shaped Sintered Material with a Support Sheet-- As shown in Figure 3, a method for producing a film-shaped sintered material with support sheet 100b is described below, which has an adhesive layer 4 on a base film 3 along the outer periphery of the base film 3, and a film-shaped sintered material for heating and pressing 1 inside the adhesive layer 4. In the following, reference numerals will be omitted.

[0126] The adhesive layer raw material mixture is applied (e.g., coated) onto a protective sheet (or other member) so as to form a shape that follows the periphery of the base film. Then, the firing material raw material mixture is applied (e.g., coated) in the form of a film inside the area on the protective sheet (or other member) where the adhesive layer raw material mixture is applied (e.g., coated). Then, if necessary, the firing material raw material mixture and the adhesive layer raw material mixture applied (e.g., coated) onto the protective sheet are heated and dried to form an adhesive layer and a film-like firing material for heating and pressing on the base film. The adhesive layer formed on the protective sheet and the exposed surface of the film-like sintered material for heating and pressing are then bonded to the base film to obtain a film-like sintered material with a support sheet.

[0127] (Applications for film-shaped fired materials with support sheets) Examples of uses for the film-shaped sintered material with support sheet include, as already mentioned, a bonding material for bonding semiconductor elements to other parts (adherends), and further examples include film-shaped sintered materials with support sheet that also serve as dicing sheets.

[0128] (Method of manufacturing semiconductor devices) A method for manufacturing a semiconductor device using a film-shaped sintering material for heating and pressurizing will be described. In the following description of the method for manufacturing a semiconductor device, the term "semiconductor device" refers to a laminate including an adherend, a sintered body obtained by sintering a film-shaped sintering material for heating and pressing, and a semiconductor element, as described below. Furthermore, the semiconductor element refers to a chip obtained by dicing a semiconductor wafer.

[0129] A method for manufacturing a semiconductor device using a film-shaped sintering material for heating and pressing includes: It is preferable to have a step of obtaining a laminate precursor by sandwiching the film-shaped fired material for heating and pressing between other parts, and a step of heating and pressing the laminate precursor.

[0130] In a method for manufacturing a semiconductor device using a film-shaped sintered material for heating and pressing, the step of heating and pressurizing the laminate precursor preferably includes a first process in which the laminate precursor is heated and pressurized at a temperature equal to or higher than the decomposition onset temperature of the resin, which has a decomposition onset temperature of 200°C or lower, and lower than the melting point of the metal particles, to obtain a second laminate precursor, and a second process in which the second laminate precursor is heated at a temperature equal to or higher than the melting point of the metal particles.

[0131] As an example of a method for using the film-shaped sintering material for heating and pressing, a method for manufacturing a semiconductor device using the film-shaped sintering material with a support sheet that also serves as a dicing sheet will be described.

[0132] A method for manufacturing a semiconductor device using a film-shaped sintered material with a support sheet (for example, 100a in FIG. 2 or 100b in FIG. 3) includes the steps of: A step (1-1) of attaching a film-shaped sintered material with a support sheet (for example, 100a in FIG. 2 or 100b in FIG. 3) to the back surface of a semiconductor wafer (hereinafter simply referred to as a "semiconductor wafer") having a circuit formed on its front surface (front surface); A step (1-2) of dicing the semiconductor wafer to obtain semiconductor elements; A step (1-3) of peeling off the semiconductor element and the film-shaped sintering material for heating and pressing (e.g., reference numeral 1 in FIG. 2 or FIG. 3) from the support sheet (e.g., reference numeral 2 in FIG. 2 or FIG. 3) to obtain an element with the film-shaped sintering material; A step (1-4) of attaching a film-shaped sintered material-attached element to the surface of an adherend; The method may also include a step (2-1) of baking a film-shaped baking material for heating and pressing (for example, reference numeral 1 in FIG. 2 or FIG. 3) to bond the semiconductor element and the adherend. The steps (1-1) to (1-4) correspond to the step (1) in the above-described method for producing a laminate, and the step (2-1) corresponds to the step (2) in the above-described method for producing a laminate.

[0133] -Process (1-1)- Step (1-1) is a step of attaching a film-shaped sintered material with a support sheet to the back surface of a semiconductor wafer. The film-shaped sintering material for heating and pressing in the film-shaped sintering material with support sheet is attached to the back surface of the semiconductor wafer so that it adheres to the back surface of the semiconductor wafer, thereby obtaining a laminate A in which the support sheet, the film-shaped sintering material for heating and pressing, and the semiconductor wafer are stacked in this order.

[0134] The diameter of the semiconductor wafer is not particularly limited, but is preferably smaller than the inner diameter of the ring frame (for example, reference numeral 5 in FIG. 2 or 3). Examples of semiconductor wafers include silicon wafers and compound semiconductor wafers such as silicon carbide, gallium arsenide, and gallium nitride. When a semiconductor element is used as a power semiconductor, the semiconductor wafer may be a silicon wafer as long as it operates at a relatively low temperature, but when operation at a higher temperature is envisaged, the semiconductor wafer is preferably a compound semiconductor wafer, and silicon carbide or gallium nitride is preferred as the compound semiconductor. It is preferable that a circuit be formed on the surface of the semiconductor wafer in advance. Formation of a circuit on the semiconductor wafer can be carried out by a conventional method such as etching or lift-off. The surface (back surface) of the semiconductor wafer opposite to the circuit surface is preferably ground in advance. There are no particular limitations on the grinding method, and known means using a grinder or the like can be used.

[0135] -Process (1-2)- The step (1-2) is a step of dicing the semiconductor wafer to obtain semiconductor elements. More specifically, this is a process in which the above-mentioned laminate A is diced into individual circuits formed on the surface of the semiconductor wafer, and laminate B is obtained in which a support sheet, a film-shaped sintering material for heating and pressing, and a semiconductor element are laminated in this order. The dicing is preferably performed so as to cut both the semiconductor wafer and the film-shaped sintered material for heating and pressing. The dicing depth may be such that the film-shaped sintered material for heating and pressing is completely cut, but is preferably set to cut partway through the layer of the film-shaped sintered material for heating and pressing. The dicing method is not particularly limited, and examples include a method in which the peripheral portion of the support sheet (the outer periphery of the support) is fixed with a ring frame (e.g., reference numeral 5 in Figure 2 or Figure 3), and then the wafer is divided into individual pieces with a rotating circular blade such as a dicing blade. The means for cutting the semiconductor wafer is not limited to using a cutting blade, and laser dicing, dicing by plasma treatment, etc. can also be used. Laser dicing may be a dicing method in which a modified region that serves as the fracture initiation point is formed in the semiconductor wafer by a laser, and the semiconductor wafer is fractured at the modified region by a mechanical action such as expanding the support sheet.

[0136] -Process (1-3)- Step (1-3) is a step of peeling the semiconductor chip and the film-like sintering material for heating and pressing from the support sheet to obtain an element with the film-like sintering material attached. The method for peeling off the semiconductor element and the film-like sintering material for heating and pressing, and the support sheet from the laminate B is not particularly limited, and examples thereof include a method using a collet or the like. By peeling off the semiconductor element and the film-shaped sintering material for heating and pressing from the support sheet, a laminate C (element with film-shaped sintering material) is obtained in which the film-shaped sintering material for heating and pressing and the semiconductor element are laminated in this order.

[0137] -Process (1-4)- Step (1-4) is a step of attaching the film-shaped sintered material-attached element to the surface of the adherend. Specifically, this is a process of attaching an element with a film-like sintering material to the surface of an adherend by contacting the surface of the adherend with the side of the chip with a film-like sintering material that has the film-like sintering material for heating and pressurizing. This step yields a laminate D in which the adherend, the film-like sintered material for heating and pressing, and the semiconductor element are laminated in this order.

[0138] The adherend is not particularly limited, but examples thereof include a substrate, another semiconductor element, a lead frame, a heat sink, a heat pipe, etc., made of a metal plate such as a copper plate, can also be used as the heat sink.

[0139] -Process (2-1)- The step (2-1) is a step of baking the film-shaped baking material for heating and pressing to bond the semiconductor element and the adherend. By firing the film-shaped sintering material for heating and pressing, the binder components contained in the film-shaped sintering material for heating and pressing are decomposed and vaporized, and the metal particles are melted to form a sintered body. The sintered body then bonds the semiconductor element and the adherend, thereby obtaining a semiconductor device.

[0140] The conditions for firing the film-shaped fired material for heating and pressing may be the conditions described in step (2) of the method for producing a laminate, and the first and second treatments may be carried out in this step (2-1).

[0141] -Variations- In this example, in step (1-1), a film-shaped sintering material with a support sheet is attached to the back surface of the semiconductor wafer, but the method for manufacturing a semiconductor device according to the present disclosure may also be such that a film-shaped sintering material for heating and pressing is attached to a diced semiconductor element, and then steps (1-4) and (2-1) are performed. In this case, it is preferable to previously manufacture the film-shaped sintering material for heating and pressing into approximately the same shape as the semiconductor element. [Explanation of symbols]

[0142] 100a, 100b Film-shaped sintered material with support sheet, 1 Film-shaped sintered material for heating and pressing, 2 Support sheet, 3 Base film, 4 Adhesive layer, 5 Ring frame, 10 Film-shaped sintered material, 11 Metal particles, 12 Binder component, 13 Sintered body precursor, 14 Sintered body, 15 Void, 20 Film-shaped sintered material for heating and pressing, 21 Metal particles, 22 Binder components, 23 aggregates, 24 sintered bodies

[0143] The disclosure of Japanese Patent Application No. 2022-061105, filed on March 31, 2022, is incorporated herein by reference in its entirety. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. Metal particles containing metal particles having a particle size of 100 nm or less; a binder component containing a resin having a decomposition starting temperature of 200°C or less; A film-like sintered material for heating and pressurizing, used for joining semiconductor elements to other parts, comprising:

2. 2. The film-shaped sintered material for heating and pressing according to claim 1, wherein the resin having a decomposition starting temperature of 200[deg.] C. or less is an aliphatic polycarbonate.

3. 3. The film-shaped sintered material for heating and pressing according to claim 1, wherein the resin having a decomposition starting temperature of 200° C. or less is an aliphatic polycarbonate containing an organic acid group.

4. The film-shaped sintering material for heating and pressing according to claim 1 , wherein the metal particles contain silver.

5. 2. The film-shaped sintering material for heating and pressing according to claim 1, wherein the semiconductor element is a power semiconductor element.

6. 10. A method for manufacturing a semiconductor device using the film-shaped sintering material for heating and pressing according to claim 1 or 5, comprising: a step of obtaining a laminate precursor by sandwiching the film-shaped sintering material for heating and pressing between the semiconductor element and the other component; and a step of heating and pressing the laminate precursor.

7. 7. The method for manufacturing a semiconductor device according to claim 6, wherein the step of heating and pressurizing the laminate precursor comprises a first process of heating and pressurizing the laminate precursor at a temperature equal to or higher than the decomposition starting temperature of a resin having a decomposition starting temperature of 200°C or lower and lower than the melting point of the metal particles to obtain a second laminate precursor, and a second process of heating the second laminate precursor at a temperature equal to or higher than the melting point of the metal particles.

8. 7. The method for manufacturing a semiconductor device according to claim 6, wherein the step of heating and pressurizing the laminate precursor comprises: a first process of heating and pressurizing the laminate precursor at a temperature equal to or higher than the decomposition onset temperature of a resin having a decomposition onset temperature of 200°C or lower and lower than 250°C to obtain a second laminate precursor; and a second process of heating the second laminate precursor at a temperature of 250°C or higher.

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