Sintered bonding sheets, compositions and varnishes, and dicing tapes with sintered bonding sheets

Abstract

The present invention provides a sintered bonding sheet, composition, and varnish that are less prone to particle irregularities, cracks, and chipping during processing, as well as a dicing tape with a sintered bonding sheet. [Solution] A dicing tape 1 with a sintered bonding sheet comprises a dicing tape 20 having a base material 21 and an adhesive 22, and including a sintered bonding sheet 10 attached to the adhesive 22, wherein the sintered bonding sheet 10 includes sinterable particles containing a conductive metal and a binder, and the distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.0.

Description

[Technical Field]

[0001] The present invention relates to a sintering bonding sheet, a composition and a varnish, and a dicing tape with a sintering bonding sheet. [Background technology]

[0002] There is a growing demand for power semiconductors that can handle high currents and high voltages, using materials such as silicon carbide (SiC) and gallium nitride (GaN). Power semiconductors are required to be stable and usable even during operation when they generate heat and reach high temperatures due to high currents.

[0003] In addition to conventional methods such as solder and paste (Patent Document 1) for die bonding these power semiconductors and other semiconductor chips to a support substrate, a method has been proposed that uses sinterable particles containing conductive metals such as silver and copper to ensure electrical connection and mechanical bonding. In bonding using sinterable particles, a semiconductor chip is placed on a support substrate coated with a composition containing sinterable particles and a solvent, and the substrate is heated to volatilize the solvent and promote the sintering of the sinterable particles, thereby forming a sintered layer between the support substrate and the semiconductor chip.

[0004] In the bonding method using the sinterable particles described above, it was difficult to form a bonding layer of uniform thickness when applying the composition containing the sinterable particles to the support substrate, and it tended to be difficult to ensure uniform sintering of the sinterable particles. From this perspective, sheet-like bonding materials that can maintain a predetermined shape at room temperature have been proposed, such as the sheet-like bonding agent containing sinterable particles described in Patent Document 2. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-010136 [Patent Document 2] International Publication No. 2008 / 065728 Brochure [Overview of the project] [Problems that the invention aims to solve]

[0006] Sheet-shaped sintered bonding sheets containing sinterable particles sometimes exhibited particle unevenness before sintering, or cracks and chips during sheet processing.

[0007] Therefore, the present invention aims to provide a sintered bonding sheet comprising sinterable particles and a binder, which is less prone to particle unevenness and cracking or chipping during sheet processing. [Means for solving the problem]

[0008] The inventors of the present invention conducted diligent research to solve the above problems and, as a result, found that they could solve the above problems, and completed the present invention having the following gist. In other words, the present invention encompasses the following: [1] comprising sinterable particles containing a conductive metal and a binder, A sintered bonding sheet in which the distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.0. [2] The sintering bonding sheet according to [1], which does not contain any binders other than a pyrolytic polymer binder, wherein the distance Db is less than 15.0. [3] The sintered bonding sheet according to [1] or [2], wherein the distance Db is 10.0 or less. [4] The binder comprises at least one selected from the group consisting of polypropylene carbonate and polyethylene carbonate. [1] to [3] The sintered bonding sheet according to any one of these. [5] Dicing tape having a base material and an adhesive, A dicing tape with a sintered bonding sheet, comprising: a sintered bonding sheet according to any one of [1] to [4] attached to the adhesive of the dicing tape. [6] comprising sinterable particles containing a conductive metal and a binder, A composition for sintering bonding, wherein the distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.0. [7] A varnish for sintering bonding, comprising sinterable particles containing a conductive metal, a binder, and a dispersion solvent, wherein the distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.0, and the distance Ds between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the dispersion solvent is less than 15.0. [Advantages of the Invention]

[0009] According to the present invention, it is possible to provide a sintering bonding sheet in which particle unevenness, cracks, and chipping during processing are less likely to occur. [Brief Description of the Drawings]

[0010] [Figure 1] Schematic cross-sectional view showing an example of a dicing tape with a sintering bonding sheet in an embodiment [Figure 2A] Schematic cross-sectional view showing a part of the process of a semiconductor manufacturing method using a dicing tape with a sintering bonding sheet in an embodiment [Figure 2B] Schematic cross-sectional view showing another part of the process of a semiconductor manufacturing method using a dicing tape with a sintering bonding sheet in an embodiment [Figure 2C] Schematic cross-sectional view showing another part of the process of a semiconductor manufacturing method using a dicing tape with a sintering bonding sheet in an embodiment [Figure 2D] Schematic cross-sectional view showing another part of the process of a semiconductor manufacturing method using a dicing tape with a sintering bonding sheet in an embodiment [Embodiments for Carrying Out the Invention]

[0011] (Sintering Bonding Sheet) The sintering bonding sheet can be used to sinter-bond semiconductor chips and other objects to be bonded, such as support substrates, and comprises sinterable particles containing conductive metal and a binder. The sintering bonding sheet maintains a predetermined thickness, making it easier to create a uniform sintered layer between the objects to be bonded, thus enabling uniform sintering and achieving highly reliable bonding.

[0012] The sintered bonding sheet of the present invention comprises sinterable particles and a binder, wherein the distance Dd between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.0. A sintered bonding sheet containing such sinterable particles and a binder tends to have uniformly dispersed sinterable particles within the sheet. This is thought to be because the compatibility between the sinterable particles and the binder becomes better than predetermined due to the distance Dd being within the above range. Therefore, this sintered bonding sheet is less prone to particle unevenness, and less prone to cracking or chipping during sheet processing. Furthermore, when this sintered bonding sheet is used for sintered bonding, the sheet is less likely to leak out from the semiconductor chip or other object to be bonded even under heating and pressurization during bonding, and the sintered layer tends to maintain its original sheet shape after bonding.

[0013] Furthermore, the size and planar shape of the sintering bonding sheet are not particularly limited. The planar shape may be any shape and size, such as rectangular or circular, to suit each process and device of the semiconductor manufacturing equipment.

[0014] <Hansen solubility parameters> The distance Dd between the Hansen solubility parameters (δDx, δPx, δHx) of the sinterable particles and the Hansen solubility parameters (δDy, δPy, δHy) of the binder is less than 15.0. From the viewpoint of forming a sheet in which the sinterable particles are more uniformly dispersed, the distance Db is preferably 13.0 or less, and more preferably 10.0 or less. There is no particular lower limit to the distance Dd between the Hansen solubility parameters of the sinterable particles and the Hansen solubility parameters of the binder. From the viewpoint of promoting the thermal decomposition of the binder during sintering, the distance Db may be 3.0 or more, or 5.0 or more.

[0015] The Hansen solubility parameter (HSP) is obtained by dividing the Hildebrand solubility parameter δ into a dispersion term D, a polarity term P, and a hydrogen bonding term H. The distance Dd between the Hansen solubility parameters of the sinterable particles (δDx, δPx, δHx) and the Hansen solubility parameters of the binder (δDy, δPy, δHy) is given by the following equation (1). When expressed in three-dimensional coordinates, the closer the distance D of the Hansen solubility parameters, the more easily the substances in question dissolve (higher compatibility).

number

[0016] For binders, such as isobornylcyclohexanol (MTPH), whose chemical structure is known, Hansen solubility parameters can be referenced based on publicly available information sources such as databases. Therefore, for substances with a known chemical structure, the Hansen solubility parameter can be calculated, for example, by inputting the chemical structural formula in Smiles format into HSP calculation software. Similarly, for other solvents and substances with a known chemical structure, the Hansen solubility parameter can also be calculated using Smiles format.

[0017] For sinterable particles, such as those containing surface-treated conductive metals (described later) and binders, the Hansen solubility parameter of substances for which parameters are not registered in the database can be calculated, for example, by the following Hansen sphere method (Hansen dissolution sphere method). The Hansen sphere method involves dissolving (dispersing) the substance to be measured in a solvent for which the Hansen solubility parameter is known, plotting the results on a three-dimensional coordinate system, and calculating the parameter from the range of spheres that include the coordinates of the solvent in which the sample dissolved and correspond to the coordinates of the solvent in which the sample did not dissolve. The Hansen solubility parameter calculated by the above-described Hansen sphere method may be measured, for example, at an environment of 25°C.

[0018] <Sinterable particles> The sinterable particles contain conductive metals. Sinterable particles are particles that can be sintered when heated to a sintering temperature (e.g., around 300°C), and examples include gold (Au), silver (Ag), copper (Cu), palladium (Pd), tin (Sn), and nickel (Ni), alloys of two or more of these metals, and metal oxides thereof. It is preferable that the sinterable particles contain one or more of the following: silver particles, copper particles, silver oxide particles, and copper oxide particles. This is because it facilitates the formation of a strong sintered layer during sintering. Furthermore, from the viewpoint of easily forming a sintered layer with high electrical and thermal conductivity during sintering, it is more preferable that the sinterable particles contain silver particles or copper particles. From the viewpoint of easily suppressing ion migration and insulation failures due to ion migration, and improving the reliability of the semiconductor substrate, it is particularly preferable that the sinterable particles be copper particles.

[0019] As sinterable particles, it is also preferable to use particles whose conductive metal surface has been treated with an organic coating or polymer. When sinterable particles are surface-treated, it is easier to maintain uniform dispersion of the sinterable particles in the sintering bonding sheet and to suppress deterioration of the conductive metal due to surface oxidation, etc. The surface treatment agent for the conductive metal is not particularly limited and may be selected appropriately depending on the type of metal. Examples of surface treatment agents for conductive metals include polymers having carboxyl groups, sulfonic acid groups, phosphate groups, amino groups, imino groups, ammonium groups, etc., various nonionic surfactants, and polymer protective colloids. The purpose of surface treatment for conductive metals is not particularly limited, and it is preferable to apply a surface treatment agent that is appropriate to the purpose according to the type of conductive metal. For example, when the conductive metal is silver, a wide range of materials can be used as surface treatment agents, as long as the material is easily detached (disappears) during the sintering process. On the other hand, when the conductive metal is copper, copper is easily oxidized, and once oxidized, it tends to be difficult to remove copper oxide. For this reason, when choosing a surface treatment agent for copper, coverage is often emphasized to ensure that the oxidation of copper is reliably suppressed.

[0020] The Hansen solubility parameters (δDx, δPx, δHx) of sinterable particles will differ depending on the type of surface treatment agent used, etc., if the surface of the conductive metal in the sinterable particles is surface-treated. As mentioned above, the Hansen solubility parameters of sinterable particles can be calculated, for example, by the Hansen sphere method, and are measured by dissolving (dispersing) them in a solvent for which the Hansen solubility parameters are known. In this case, the dispersion of surface-treated conductive metals in the solvent using the Hansen sphere method is affected by the surface treatment agent. From the above, the distance Db between the Hansen solubility parameter of the sinterable particles in the sintering bonding sheet and the Hansen solubility parameter of the binder will also be different depending on the type of surface treatment agent for the conductive metal in the sinterable particles.

[0021] The average particle diameter D50 of the sinterable particles is preferably 10,000 nm or less, more preferably 3,000 nm or less, and particularly preferably 1,000 nm or less. This is because a particle diameter below the above average makes it easier to ensure the smoothness of the surface of the sintered bonding sheet. Furthermore, the average particle diameter D50 of the sinterable particles is preferably 1 nm or more, more preferably 10 nm or more, and particularly preferably 50 nm or more. This is because a particle diameter above the above average makes it easier to maintain a state in which the sinterable particles are uniformly dispersed in the sintered bonding sheet or the composition for forming the sheet. In this specification, the average particle diameter D50 is the average particle diameter based on volume.

[0022] The average particle size of sinterable particles can be measured by observation using a scanning electron microscope (SEM). Specifically, a sheet containing sinterable particles is cooled and cut, and the exposed cross-section is imaged using a field emission scanning electron microscope SU8020 (manufactured by Hitachi High-Technologies Corporation). Image conditions include, for example, an acceleration voltage of 5kV and a magnification of 50,000x. The image data can be binarized using the image analysis software ImageJ and used to calculate the average particle size.

[0023] The content of sinterable particles in the sintering bonding sheet is preferably 85 to 98% by mass, more preferably 87 to 98% by mass, and particularly preferably 88 to 98% by mass. Within this range, the bonded portion after sintering tends to maintain high thermal conductivity, and the sinterable particles are less likely to leak out from between the adherends (e.g., semiconductor chips or substrates) during sintering bonding (the sinterable particles tend to maintain a predetermined shape during sintering bonding, and are less likely to deform or protrude from between the adherends). In this regard, the higher the content of sinterable particles, the easier it is to maintain a high viscosity of the sintering bonding sheet when heated, the less likely the sinterable particles are to leak out from between the adherends, and the more likely the sintered body is to have a dense structure after sintering bonding, thus ensuring high bonding strength and reliability. On the other hand, if there are too few sintered particles, the viscosity tends to decrease due to heating and pressurizing during sintering bonding, which is due to other organic components, making it easier for the particles to leak out from between the adherends, and the sintered body after sintering bonding tends to have many voids, which may lead to weakening.

[0024] <Binder> The binder included in the sintering bonding sheet is one in which the distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.0. The binder only needs to contain binders with a distance Db of less than 15.0, and may also contain binders with a distance Db of 15.0 or more. It is preferable that the sheet does not contain any binders other than the pyrolytic polymer binder with a distance Db of less than 15.0 (it contains only the pyrolytic polymer binder with a distance Db of less than 15.0).

[0025] Here, the pyrolytic polymer binder is a binder made of a polymer material (molecular weight approximately 1000 or more) that is at least partially pyrolytically decomposed by heating at a typical sintering temperature (e.g., approximately 300°C or higher). Preferably, the pyrolytic polymer binder is made of a polymer material that is 50% or more pyrolytically decomposed at 300°C. Preferably, the pyrolytic polymer binder does not pyrolytically decompose before heating to the above sintering temperature so as to maintain the sheet shape of the sintering bonding sheet. For this reason, the pyrolytic polymer binder is preferably a solid material at room temperature (23°C). Examples of pyrolytic polymer binders include one or more of either polycarbonate resin or acrylic resin. When these materials are used, it is easier to reduce the amount of organic residue derived from the binder remaining in the layer after sintering.

[0026] With the pyrolytic polymer binder described above, when temporarily fixing the objects to be joined before sintering, it is easy to ensure adhesion to the objects by utilizing the viscoelasticity of the binder at the temporary fixing temperature (e.g., about 70°C). Furthermore, by using a sintered bonding sheet to which this pyrolytic polymer binder is applied, it is easier to prevent misalignment of the objects to be joined when pressing them together or after pressing them together.

[0027] When the binder of a sintered bonding sheet contains one or more of either polycarbonate resin or acrylic resin, the binder tends to decompose and disappear during sintering. Therefore, using these binders makes it easier to reduce organic residue in the layer after sintering. Less organic residue remaining after sintering allows for stronger bonding of the objects to be bonded and makes it easier to obtain high bonding reliability.

[0028] Examples of polycarbonate resins include aliphatic polycarbonates and aromatic polycarbonates. Here, aliphatic polycarbonates consist of aliphatic chains that do not contain aromatic compounds in the main chain. Aromatic polycarbonates contain aromatic compounds in the main chain. The main chain of polycarbonate as used here refers to a chain having carbonate ester groups. Examples of aliphatic polycarbonates include polyethylene carbonate and polypropylene carbonate. Examples of aromatic polycarbonates include polycarbonates containing a bisphenol A structure in the main chain.

[0029] Examples of acrylic resins include polymers of acrylic acid esters and methacrylic acid esters. These polymers may have linear or branched alkyl groups, and preferably have 4 to 18 hydrocarbons. In this specification, "(meth)acrylic" refers to both or either "acrylic" and "methacrylic". Examples of alkyl groups in (meth)acrylic acid esters include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, heptyl group, cyclohexyl group, 2-ethylhexyl group, octyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, lauryl group, tridecyl group, tetradecyl group, stearyl group, octadecyl group, and the like.

[0030] Acrylic resins may be polymers containing monomer units derived from monomers other than (meth)acrylic acid esters. Examples of such other monomers include carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, sulfonic acid group-containing monomers, and phosphate group-containing monomers. Examples of carboxyl group-containing monomers include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of acid anhydride monomers include maleic anhydride and itaconic anhydride. Examples of 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 monomers containing sulfonic acid groups 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 monomers containing phosphate groups include 2-hydroxyethylacryloyl phosphate.

[0031] The binder preferably contains a polyalkylene carbonate, and the polyalkylene carbonate is -OC(=O)-OC n H 2nThe polymer has repeating units of -(n is an integer from 2 to 12). The binder more preferably contains at least one selected from the group consisting of polypropylene carbonate (PPC) and polyethylene carbonate (PEC). When a binder contains these, the above-mentioned distance Dd of the Hansen solubility parameter tends to be 15.0 or less, and the distance Dd tends to be 15.0 or less in particular when sinterable particles containing copper particles as a conductive metal are used. Furthermore, PPC and PEC are suitable as binders because their thermal decomposition temperatures are relatively low (about 300°C).

[0032] It is preferable to use a binder of an appropriate type depending on the constituent metal of the sinterable particles and the surface treatment of the sinterable particle surface. This is because it is easier to form a sintered bonding sheet that falls within the distance Dd range described above. For example, the binder to be applied may be determined by using values ​​such as δDx and δPx in the Hansen solubility parameter (HSP) of the sinterable particles as a guideline. For instance, if the δDx of the sinterable particles is less than 20.0, the application of PPC as described above may be considered, while if δDx is 20.0 or greater, the application of PEC as the binder may be considered. Similarly, if δPx is less than 10.0, the application of PEC as the binder may be considered, while if δPx is 10.0 or greater, the application of PPC as the binder may be considered.

[0033] The weight-average molecular weight of the binder is preferably 10,000 or higher. Within this range, the viscoelasticity of the binder makes it easier to ensure the cohesive force (e.g., the ease with which it can form a tough sheet by encapsulating sinterable particles) and adhesive strength of the sintering bonding sheet. The weight-average molecular weight of the binder can be measured by gel permeation chromatography (GPC) and calculated in polystyrene equivalent.

[0034] The binder content in the sintered bonding sheet is preferably 0.5 to 10.0% by mass, more preferably 0.8 to 8.0% by mass, and particularly preferably 1.0 to 6.0% by mass. When the binder content is within the above range, it is easier to maintain an appropriate shape for the sintered bonding sheet.

[0035] The binder may further contain a low molecular weight binder (molecular weight less than 1000). The low molecular weight binder preferably has a distance Db of less than 15.0. Furthermore, the low molecular weight binder is preferably a low boiling point binder. A low boiling point binder is a binder component that begins thermal decomposition (weight loss) at a temperature lower than the thermal decomposition initiation temperature of a polymer binder, such as a thermally decomposable polymer binder (for example, around 200°C).

[0036] The low molecular weight binder had a viscosity of 1 × 10⁻⁶ at 23°C, as measured using a dynamic viscoelasticity analyzer (product name "HAAKE MARS III", manufactured by Thermo Fisher Scientific). 5 It is preferable that the substance be liquid or semi-liquid, exhibiting a Pa·s or less. The above measurement was performed using a 20 mmφ parallel plate with a plate gap of 100 μm and a shear rate of 1 s in rotational shear. -1 It can be measured as follows.

[0037] Examples of low molecular weight binders include terpene alcohols, alcohols other than terpene alcohols, alkylene glycol alkyl ethers, and ethers other than alkylene glycol alkyl ethers. Examples of terpene alcohols include isobornylcyclohexanol, citronellol, geraniol, nerol, carveol, and α-terpineol. 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 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, triethylene glycol methyl 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 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 alkylene glycol alkyl ethers include ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, and ethylene glycol phenyl ether. The low-molecular-weight binder may be one type or two or more types.For the low molecular weight binder, terpene alcohols are preferred due to their stability at room temperature, and isobornylcyclohexanol is more preferred.

[0038] The content of the low-molecular-weight binder in the sintered bonding sheet is preferably 1.0 to 50.0% by mass. This is because within this range, it is easier to ensure tackiness on the surface of the sintered bonding sheet, which is effective in the bonding process with the objects to be bonded.

[0039] The binder described above preferably contains only binders with a distance Db of less than 15.0. Furthermore, it is preferable that the distance of the Hansen solubility parameters between organic components contained in the sintering bonding sheet is less than 15.0 for each component. With such a sintering bonding sheet, sinterable particles are less likely to protrude from between the adherends even when heated and pressurized during sintering.

[0040] The sintered bonding sheet may contain other components besides those mentioned above. For example, the sintered bonding sheet may contain plasticizers.

[0041] <Physical properties> The thickness of the sintering bonding sheet is preferably 5 μm or more, and more preferably 10 μm or more. The thickness of the sintering bonding sheet is preferably 300 μm or less, and more preferably 150 μm or less. A thickness within the above range makes it easier to maintain handling during semiconductor manufacturing and prevents sinterable particles from protruding from between the adherends during sintering.

[0042] The porosity of the sintered bonding sheet is preferably 10% or less, more preferably 8% or less, and particularly preferably 6% or less. The porosity may be 0%, but it is preferable to be 1% or more from the viewpoint of maintaining appropriate flexibility of the sheet. Within the above range of porosity, sinterable particles are present at a high density after sintering, making it easier to achieve reliable bonding. The porosity of the sintered bonding sheet can be measured in the sintered layer after sintering by heating the sintered bonding sheet at 300°C for 2.5 minutes under a pressure of 10 MPa.

[0043] Each component contained in the sintered bonding sheet can be measured using the following analytical methods. The sintered bonding sheet is solvent-extracted with solvents such as methanol, acetone, ethyl acetate, methylene chloride, chloroform, and hexane to dissolve and remove organic components derived from the binder. After solvent extraction, the sinterable particles remaining as solid matter are isolated. The binder's components can be measured by qualitative analysis of the solvent after solvent extraction using methods such as infrared absorption spectroscopy (IR), gas chromatography-mass spectrometry (GC / MAS), and liquid chromatography-mass spectrometry (LC / MS). Sinterable particles can be identified by methods such as pyrolysis gas chromatography (GC / MAS) to identify organic decomposition products derived from the surface treatment agent, or by high-temperature methanol decomposition to break the bonds between the conductive metal and components such as carboxylic acids in the surface treatment agent, after which the components of the surface treatment agent can be measured by LC / MS or GC / MAS.

[0044] (Composition for sintering and bonding) Sintered bonding sheets can be manufactured using sintered bonding compositions or sintered bonding varnishes. The sintering bonding composition comprises sinterable particles containing a conductive metal and a binder, wherein the distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.0. The sinterable particles and binder contained in the sintering bonding composition can be the same as those used in the sintering bonding sheet described above.

[0045] The content of sinterable particles in the sintering bonding composition is preferably 85 to 98% by mass, more preferably 87 to 98% by mass, and particularly preferably 88 to 98% by mass. When the content of sinterable particles is within the above range, the bonded joint after sintering tends to maintain high thermal conductivity, and the sinterable particles are less likely to leak out from between the adherends during sintering bonding. Furthermore, increasing the content of sinterable particles tends to result in a denser structure for the sintered body after sintering bonding, making it easier to ensure high bonding strength and reliability.

[0046] (Varnish for sintering and bonding) The sintering varnish comprises sinterable particles containing a conductive metal, a binder, and a dispersion solvent. The distance Db between the Hansen solubility parameters (δDx, δPx, δHx) of the sinterable particles and the Hansen solubility parameters (δDy, δPy, δHy) of the binder is less than 15.0, and the distance Ds between the Hansen solubility parameters (δDx, δPx, δHx) of the sinterable particles and the Hansen solubility parameters (δDz, δPz, δHz) of the dispersion solvent is less than 15.0. The sinterable particles and binder contained in the sintering varnish can be the same as those used in the sintering sheet described above. Furthermore, the formula for distance Db is the same as in formula (1) above.

[0047] The distance Ds between the Hansen solubility parameters (δDx, δPx, δHx) of the sinterable particles and the Hansen solubility parameters (δDz, δPz, δHz) of the dispersion solvent is given by the following equation (2).

number

[0048] Preferably, the distance between the Hansen solubility parameters of the organic components contained in the sintering varnish is less than 15.0 for each component. With such a sintering varnish, the raw materials are easily dispersed uniformly in the varnish, and it is easy to form a sintering sheet in which sinterable particles are less likely to protrude from between the adherends even when heated and pressurized during sintering. As a result, a sintering sheet can be obtained in which particle unevenness and cracking or chipping during processing are less likely to occur.

[0049] <Dispersed solvent> Organic solvents or alcoholic solvents can be used as the dispersion solvent in the sintering varnish. Examples of organic solvents include dimethylformamide, dimethylacetamide, N-methylpyrrolidone, acetone, methyl ethyl ketone, cyclohexanone, toluene, and xylene. Examples of alcoholic solvents include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-butene-1,4-diol, 1,2,6-hexanetriol, glycerin, octanediol, 2-methyl-2,4-pentanediol, and terpineol.

[0050] (Dicing tape) The sintering bonding sheet is also preferably used in the semiconductor manufacturing process together with the dicing tape. A dicing tape comprises a base material and an adhesive. A dicing tape with a sintering bonding sheet, in which the sintering bonding sheet of the present invention is attached to the adhesive of the dicing tape, is suitably used in semiconductor manufacturing processes.

[0051] Figure 1 is a schematic cross-sectional view showing an example of a dicing tape with a sintering bonding sheet. The following explanation will follow Figure 1. The sintered bonding sheet-attached dicing tape 1 comprises a dicing tape 20 having a base material 21 and an adhesive 22. The sintered bonding sheet-attached dicing tape 1 also comprises a sintered bonding sheet 10 attached to the adhesive 22. The sintering bonding sheet 10 may have the same shape as the dicing tape 20, or it may have a different shape. The sintering bonding sheet 10 may have any shape in plan view, for example, it may be rectangular or circular. Furthermore, a single dicing tape 20 may have multiple sintering bonding sheets 10. The dicing tape 1 with a sintering bonding sheet may have any other layers besides those described above.

[0052] <Adhesive> The adhesive 22 should be provided in such a way that it adheres the base material 21 and the sintering bonding sheet 10. The adhesive 22 does not necessarily have to be provided over the entire surface of the base material 21, and may be present only in the positions corresponding to the sintering bonding sheet 10. Furthermore, the adhesive 22 does not necessarily have to be formed in layers, and may be provided in a discontinuous shape, for example, as dots or stripes when viewed from above on the base material 21.

[0053] Examples of adhesives include acrylic adhesives based on acrylic polymers, rubber adhesives, and the like. The adhesive may also be one whose adhesive strength can be reduced by external action such as heating or radiation (adhesive strength reduction type). Alternatively, the adhesive may be one whose adhesive strength is not reduced at all (or almost) by external action (adhesive strength non-reduction type). Examples of adhesive strength reduction type adhesives include radiation-curable adhesives (adhesives with radiation-curing properties) and heat-foaming adhesives. An example of an adhesive strength non-reduction type adhesive is a pressure-sensitive adhesive.

[0054] When the adhesive includes an acrylic adhesive, the acrylic polymer that forms the base of the acrylic adhesive preferably contains monomer units derived from alkyl acrylates and / or alkyl methacrylates. Furthermore, it is preferable that these monomer units are included as the most abundant monomer units by mass in the adhesive.

[0055] Examples of alkyl (meth)acrylates include alkyl (meth)acrylates having linear or branched alkyl groups, and cycloalkyl (meth)acrylates. Examples of alkyl (meth)acrylates include methyl esters, ethyl esters, propyl esters, isopropyl esters, butyl esters, isobutyl esters, s-butyl esters, t-butyl esters, pentyl esters, isopentyl esters, hexyl esters, heptyl esters, octyl esters, 2-ethylhexyl esters, isooctyl esters, nonyl esters, decyl esters, isodecyl esters, undecyl esters, dodecyl esters, tridecyl esters, tetradecyl esters, hexadecyl esters, octadecyl esters, and eicosyl esters. Examples of cycloalkyl (meth)acrylates include cyclopentyl esters and cyclohexyl esters of (meth)acrylate. Only one alkyl (meth)acrylate may be used, or two or more may be used. The proportion of alkyl (meth)acrylate in the total monomer components is preferably 50% by mass or more. This is because the basic properties of the adhesive, such as its adhesive strength, are more easily exhibited within this range.

[0056] Acrylic polymers may further contain monomer units derived from other monomers copolymerizable with alkyl (meth)acrylate esters. The inclusion of these monomer units facilitates modification of properties such as cohesiveness and heat resistance. Examples of such monomers include carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, sulfonic acid group-containing monomers, phosphate group-containing monomers, acrylamide, and acrylonitrile. Examples of 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 acid anhydride monomers include maleic anhydride and itaconic anhydride. Examples of monomers containing a hydroxyl group 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 monomers containing a sulfonic acid group 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 monomers containing a phosphate group include 2-hydroxyethyl acryloyl phosphate. The other monomers may be one type of monomer or two or more types of monomers. The proportion of monomers other than alkyl (meth)acrylate in the total monomer components forming the acrylic polymer is preferably 50% by mass or less. This is because the basic properties such as the adhesive strength of the adhesive are more easily exhibited within this range.

[0057] The acrylic polymer may further contain monomer units derived from polyfunctional monomers copolymerizable with alkyl (meth)acrylates to form crosslinked structures within the polymer backbone. Examples of polyfunctional monomers include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy(meth)acrylate, glycidyl(meth)acrylate, polyester(meth)acrylate, and urethane(meth)acrylate. The polyfunctional monomer may be one monomer or two or more monomers. The proportion of polyfunctional monomers in the total monomer components is preferably 40% by mass or less. This is because the basic properties of the adhesive, such as its adhesive strength, are more easily exhibited within this range.

[0058] The adhesive may contain, for example, an external crosslinking agent to increase the number-average molecular weight of the base polymer, such as an acrylic polymer. Examples of external crosslinking agents include polyisocyanate compounds, epoxy compounds, aziridine compounds, and melamine-based crosslinking agents. The content of the external crosslinking agent in the adhesive is preferably 5% by mass or less per 100% by mass of the base polymer. This is because the adhesive is more likely to exhibit its basic properties, such as adhesive strength, appropriately within this range.

[0059] The adhesive may be a radiation-curable adhesive that reduces adhesive strength by increasing the degree of polymer crosslinking at the irradiated area with radiation such as ultraviolet light. Examples of radiation-curable adhesives include additive-type radiation-curable adhesives. This additive-type radiation-curable adhesive contains a base polymer such as an acrylic polymer and radiation-polymerizable monomer components or oligomer components having functional groups such as radiation-polymerizable carbon-carbon double bonds.

[0060] Examples of radiation-polymerizable monomer components include urethane (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4-butanediol di(meth)acrylate. Examples of radiation-polymerizable oligomer components include urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based oligomers. The oligomer component preferably has a molecular weight of about 100 to 30,000. The content of monomer components and oligomer components in the radiation-curable adhesive may be appropriately determined within a range that can reduce the adhesive strength. For example, the content of monomer components and oligomer components is preferably 40 to 150% by mass relative to 100% by mass of the base polymer. As an additive-type radiation-curing adhesive, for example, the adhesive disclosed in Japanese Patent Publication No. 60-196956 may be used.

[0061] Examples of adhesives include intrinsically induced radiation-curable adhesives. Intrinsically induced radiation-curable adhesives contain a base polymer having radiation-polymerizable functional groups such as carbon-carbon double bonds in the polymer side chains, polymer main chains, or polymer main chain ends. Intrinsically induced radiation-curable adhesives make it easier to suppress unintended changes in adhesive properties over time due to the migration of low molecular weight components in the adhesive.

[0062] The base polymer contained in the intrinsically modified radiation-curable adhesive is preferably an acrylic polymer with an acrylic polymer as its basic skeleton. The acrylic polymers described above can be used as this acrylic polymer. As an example of a method for introducing a radiation-polymerizable carbon-carbon double bond to an acrylic polymer, the following method can be used. First, an acrylic polymer is obtained by copolymerizing raw material monomers containing a monomer having a predetermined functional group (first functional group). Then, a compound having a predetermined functional group (second functional group) that can react and bond with the first functional group, and a radiation-polymerizable carbon-carbon double bond, is subjected to a condensation or addition reaction with the acrylic polymer. This condensation or addition reaction is carried out in such a way that the radiation polymerizability of the carbon-carbon double bond is maintained.

[0063] Examples of the combinations of the first and second functional groups described above include carboxyl group and epoxy group, epoxy group and carboxyl group, carboxyl group and aziridyl group, aziridyl group and carboxyl group, hydroxyl group and isocyanate group, and isocyanate group and hydroxyl group. Of these combinations, the combination of hydroxyl group and isocyanate group, and the combination of isocyanate group and hydroxyl group are preferred from the viewpoint of ease of reaction tracking. Here, it is technically difficult to produce polymers having highly reactive isocyanate groups. Therefore, from the viewpoint of ease of production or availability, it is more preferable for the acrylic polymer to have a hydroxyl group as its first functional group and an isocyanate group as its second functional group. Examples of isocyanate compounds having both a radiation-polymerizable carbon-carbon double bond and an isocyanate group as the second functional group include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, and m-isopropenyl-α,α-dimethylbenzyl isocyanate. As for the acrylic polymer with the first functional group, it is preferable to include monomer units derived from hydroxyl group-containing monomers, and it is preferable to include monomer units derived from ether compounds such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether.

[0064] Radiation-curing adhesives may also preferably contain a photopolymerization initiator. Examples of photopolymerization initiators include α-ketol compounds, acetophenone compounds, benzoin ether compounds, ketal compounds, aromatic sulfonyl chloride compounds, photoactive oxime compounds, benzophenone compounds, thioxanthone compounds, camphorquinone, halogenated ketones, acylphosphinoxides, and acylphosphonates. Examples of α-ketol compounds include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenyl ketone. Examples of acetophenone compounds include methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1. Examples of benzoin ether compounds include benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether. Examples of ketal compounds include benzyldimethyl ketal. Examples of aromatic sulfonyl chloride compounds include 2-naphthalenesulfonyl chloride. Examples of photoactive oxime compounds include 1-phenone-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. Examples of benzophenone compounds include benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone. Examples of thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone. The photopolymerization initiator content in radiation-curable adhesives is preferably 0.05 to 20% by mass relative to 100% by mass of the base polymer.

[0065] In addition to the components mentioned above, the adhesive may optionally contain additives such as crosslinking accelerators, tackifiers, antioxidants, and colorants. The colorant may be a compound that becomes colored by irradiation (e.g., leuco dyes).

[0066] Furthermore, the acrylic polymer described above can be obtained by polymerizing the raw material monomers. Examples of polymerization methods include solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. It is preferable that the amount of low molecular weight components in the adhesive is small, and it is preferable that the number average molecular weight of the acrylic polymer is 100,000 or more. If it is within this range, it is easier to ensure good cleanability when used in semiconductor manufacturing as a dicing tape with a sintering bonding sheet.

[0067] The viscosity of adhesive 22 is 5 × 10 3 ~1 × 10 7 It is preferable that it be Pa·s, which is 1 × 10 4 ~1 × 10 6 A viscosity of Pa·s is even more preferable. When the viscosity is within the above range, it is easier to maintain adhesion between the sintering bonding sheet 10 and the substrate 21 during the semiconductor manufacturing process. The viscosity of the adhesive 22 can be measured in the same manner as the sintering bonding composition described above.

[0068] The thickness of the adhesive 22 in the cross-sectional direction is preferably 5 μm or more, and more preferably 10 μm or more. The thickness is preferably 100 μm or less, and more preferably 80 μm or less. This is because, within the above thickness range, the adhesive tends to decompose and disappear after sintering while maintaining adhesion between the sintering bonding sheet 10 and the substrate 21 during the semiconductor manufacturing process. The thickness of the adhesive 22 can be measured by electron microscope observation of the cross-section of the dicing tape at 23°C.

[0069] <Base material> The substrate 21 functions as a support in the dicing tape 20. Examples of base material 21 include plastic base materials. It is preferable to use a plastic film as the plastic base material. Examples of plastic base materials include polyolefins, polyesters, polyurethanes, polycarbonates, polyether ether ketones, polyimides, polyetherimides, polyamides, fully aromatic polyamides, polyvinyl chloride, polyvinylidene chloride, polyphenyl sulfide, aramids, fluororesins, cellulose resins, and silicone resins. Examples of polyolefins include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, ethylene-butene copolymer, and ethylene-hexene copolymer. Examples of polyesters include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. The forming material of the base material 21 may be one type or two or more types.

[0070] The base material 21 may be composed of a single layer or a multilayer structure. If the base material 21 is made of a plastic film, the base material 21 may be an unoriented film, a uniaxially oriented film, or a biaxially oriented film.

[0071] The main surface of the substrate 21 facing the adhesive 22 may be surface-treated to improve adhesion with the adhesive 22. Examples of surface treatments include physical treatments such as corona discharge treatment, plasma treatment, sandblasting, ozone exposure treatment, flame exposure treatment, high-voltage electric shock exposure treatment, and ionization radiation treatment; chemical treatments such as chromic acid treatment; and primer treatments.

[0072] The thickness of the substrate 21 is preferably 40 μm or more, more preferably 50 μm or more, and particularly preferably 55 μm or more. Within this range, the substrate 21 can easily ensure strength as a support. Furthermore, the thickness of the substrate 21 is preferably 200 μm or less, more preferably 180 μm or less, and particularly preferably 150 μm or less. Within this range, the substrate 21 has appropriate flexibility, making it easier to improve handling properties such as tackiness in semiconductor manufacturing.

[0073] Dicing tape with a sintering bonding sheet can be manufactured, for example, as follows: First, a dicing tape 20 is prepared by applying an adhesive 22 to a base material 21. For example, a resin base material 21 can be prepared by calendering, casting in an organic solvent, inflation extrusion in a closed system, T-die extrusion, co-extrusion, dry lamination, etc. To provide the adhesive 22, first prepare an adhesive composition for forming the adhesive 22. Apply this adhesive composition to the substrate 21 or a predetermined separator (release liner) to form an adhesive composition layer. Dry the adhesive composition layer as needed (heat crosslinking as needed). Examples of application methods for the adhesive composition include roll coating, screen coating, gravure coating, etc. The temperature for drying the adhesive composition layer may be, for example, 80 to 150°C. The drying time may be, for example, 0.5 to 5 minutes. When forming the adhesive 22 on a separator, the adhesive 22 with the separator is bonded to the substrate 21.

[0074] The sintered bonding sheet 10 can be prepared, for example, by applying the above-mentioned sintered bonding varnish onto a separator. Specifically, the prepared varnish can be applied to a predetermined separator to form a coating, and the coating can be dried to obtain the sintered bonding sheet 10 made on the separator.

[0075] The sintering bonding sheet 10 can be attached to the dicing tape by the following method. For example, the sintering bonding sheet 10 is pressure-bonded and laminated on the adhesive 22 side of the dicing tape 20. The temperature during lamination is preferably 30 to 50°C. The pressure (linear pressure) is preferably 0.1 to 20 kgf / cm. When the adhesive 22 is a radiation-curable adhesive, radiation such as ultraviolet rays may be irradiated onto the adhesive 22 from the side of the base material 21. The irradiation dose is preferably 50 to 500 mJ / cm 2 and more preferably 100 to 300 mJ / cm 2 . The irradiation region (irradiation region D) may be, for example, the adhesive 22 in a region excluding the peripheral portion where the sintering bonding sheet is laminated (for example, the central portion of the sintering bonding sheet, etc.).

[0076] The dicing tape with a sintering bonding sheet may have a separator (for protection before use) on the sintering bonding sheet 10 (the main surface opposite to the adhesive 22). Having this separator can protect the sintering bonding sheet 10 and the adhesive 22 from being exposed. The separator can be peeled off before use in semiconductor manufacturing, etc. Examples of the separator include polyethylene terephthalate (PET) films, polyethylene films, polypropylene films, and various plastic films surface-coated with a release agent (for example, a fluorine-based release agent or a long-chain alkyl acrylate-based release agent), paper, etc.

[0077] <Example of a semiconductor device manufacturing method> FIG. 2 shows some of the steps of an example of a semiconductor device manufacturing method using a dicing tape with a sintering bonding sheet.

[0078] First, as shown in Figure 2A, the semiconductor wafer 30 is bonded to the sintering bonding sheet 10 of the dicing tape with a sintering bonding sheet. Specifically, the semiconductor wafer 30 is pressed against the sintering bonding sheet 10 using a pressure roll or the like to bond it to the sintering bonding sheet 10. Multiple semiconductor elements may be fabricated on the semiconductor wafer 30, and planar electrodes may be formed as external electrodes on the main surface of the semiconductor wafer 30 that is bonded to the sintering bonding sheet 10. The thickness of the planar electrodes is, for example, 10 to 1000 nm. For example, silver can be used as the planar electrodes. The planar electrodes may be laminated on a titanium thin film formed on the semiconductor wafer. The thickness of the titanium thin film is preferably 10 to 1000 nm. The planar electrodes and titanium thin film can be formed, for example, by a vapor deposition method. On the main surface of the semiconductor wafer 30 opposite to the sintering bonding sheet 10, other electrode pads, etc., may be formed for each semiconductor element.

[0079] The temperature during bonding of the semiconductor wafer 30 is preferably 50 to 90°C, and the load is preferably 0.01 to 10 MPa. When the adhesive 22 of the dicing tape is a radiation-curing adhesive, instead of radiation irradiation during the manufacturing of the dicing tape, the adhesive 22 may be irradiated with radiation from the substrate 21 side after bonding the semiconductor wafer 30. The irradiation dose is 50 to 500 mJ / cm². 2 Preferably, 100-300 mJ / cm² 2 That is even more preferable.

[0080] Next, as shown in Figure 2B, the semiconductor wafer 30 is diced. Specifically, with the semiconductor wafer 30 bonded together, the semiconductor wafer 30 is diced using a rotating blade of a dicing device or the like, dividing it into individual semiconductor chips (in the figure, the cutting points are schematically represented by thick lines). Through dicing, a semiconductor chip is formed with a chip-sized sintering bonding sheet 10.

[0081] After dicing, a cleaning process is performed as needed, in which the semiconductor chip is cleaned using a cleaning solution such as water. Then, the semiconductor chip with the sintering bonding sheet attached is picked up from the dicing tape (pickup process). The semiconductor chip to be picked up can be picked up by, for example, using a pin member of a pickup mechanism and then holding it with a suction jig.

[0082] As shown in Figure 2C, the semiconductor chip picked up above is temporarily fixed to the support substrate 40 (temporary fixing step). Examples of the support substrate 40 include an insulating circuit board with wiring such as copper wiring on its surface, a lead frame, etc. The area on the support substrate 40 where the semiconductor chip is mounted may be the bare surface of copper wiring or a lead frame, or the surface of a plating film formed on the bare surface. Examples of the plating film include a gold (Au) plating film, a silver (Ag) plating film, a nickel (Ni) plating film, a palladium (Pd) plating film, a platinum (Pt) plating film, etc. The temperature conditions for temporary fixing are preferably in the temperature range of 50 to 90°C, including 70°C and its vicinity. The pressing load conditions for temporary fixing are preferably 0.01 to 5 MPa, and the bonding time is preferably 0.01 to 5 seconds.

[0083] Subsequently, the semiconductor chips are bonded to the support substrate 40 by high-temperature heating for sintering (sintering bonding process). High-temperature heating causes thermal decomposition and volatilization of the binder between the support substrate 40 and the semiconductor chips, and sintering of the conductive metal sinterable particles. This forms a sintered layer between the support substrate 40 and each semiconductor chip, establishing an electrical connection between the support substrate 40 and the semiconductor chips. The temperature conditions for sintering bonding are preferably 200 to 400°C, including 300°C and its vicinity, and more preferably 330 to 350°C. The pressure conditions for sintering bonding are preferably 40 MPa or less, more preferably 20 MPa or less, and particularly preferably 15 MPa or less. The bonding time for sintering bonding is preferably 0.3 to 300 minutes, and particularly preferably 0.5 to 240 minutes. The sintering bonding process is preferably carried out using an apparatus that can perform heating and pressurizing simultaneously. Examples include a flip-chip bonder and a parallel plate press. From the viewpoint of preventing metal oxidation, the sintering bonding process is preferably carried out under a nitrogen atmosphere, under reduced pressure, or under a reducing gas atmosphere.

[0084] As shown in Figure 2D, the electrode pads of the semiconductor chip are electrically connected to the terminal portion of the support substrate 41 via bonding wires 41 as needed (wire bonding process). Additionally, a sealing resin may be formed on the support substrate 41 to protect the semiconductor chip and bonding wires (sealing process). As described above, semiconductor devices can be manufactured using dicing tape with a sintering bonding sheet. However, the above is just one example of a manufacturing method, and other manufacturing methods can be applied. [Examples]

[0085] [Example 1] A sintering varnish was prepared by mixing 5.0 parts by mass of commercially available copper nanoparticles (a-1), which are sinterable particles; 0.5 parts by mass of polypropylene carbonate (PPC) (b-1, weight-average molecular weight 1,200,000, product name QPAC40, manufactured by Empower Materials), which is a binder, and 2.0 parts by mass of methyl ethyl ketone (MEK) (c-1), which is a dispersion solvent, in a hybrid mixer (ARE-310, manufactured by Thinky Co., Ltd.) at 2000 rpm for 120 seconds.

[0086] The obtained varnish was applied to a release film (MRA50, manufactured by Mitsubishi Plastics, Inc.) and dried to form a sheet with a thickness of 40 μm, thereby obtaining the sintered bonding sheet of Example 1. The drying temperature was 110°C and the drying time was 3 minutes. The content of sinterable particles in the sintered bonding sheet of Example 1 was 90.9% by mass.

[0087] [Examples 2-6, Comparative Examples 1-5] In the preparation of the sintering varnish, the sintering sheets for Examples 2-6 and Comparative Examples 1-5 were obtained under the same conditions as in Example 1, except that the materials shown in Table 1 were used in the parts by mass shown in Table 3. [Table 1]

[0088] [evaluation] For each example and comparative example, the Hansen solubility parameter was measured under the following conditions, and the varnish appearance, sheet appearance, and sinterability were evaluated. The results are shown in Tables 2 and 3.

[0089] (Hansen solubility parameter) The HSP distance is the distance between the HSPs of two substances, for example, in this embodiment, it is the distance between the HSPs of the sinterable particles and the HSPs of the organic binder or dispersion solvent. HSP is the Hansen solubility parameter (δ), defined by the three-dimensional parameter (δD, δP, δH), and is given by equation (X):δ 2 =(δD) 2 +(δP) 2 +(δH) 2...(X) [wherein equation (X) represents the London dispersion force term, δP represents the molecular polarization term (inter-dipole force term), and δH represents the hydrogen bonding term].

[0090] The Hansen solubility parameters for copper nanoparticles a-1 to a-4, PPC b-1, and PEC b-2 were measured using the Hansen sphere method. Furthermore, for MTPH b-3, MEK c-1, and dioxane c-2, whose chemical structures are known, the Hansen solubility parameters were measured using Smiles notation based on database information.

[0091] In the Hansen sphere method (Hansen solubility sphere method), the Hansen solubility parameters were measured as follows. The target sample was mixed with a solvent whose solubility parameter was known, and it was determined whether or not it dissolved. The solvents used were water, formic acid, acetic acid, methanol, ethanol, 1-propanol, 2-butanol, 1-pentanol, acetone, methyl ethyl ketone, tetrahydrofuran, N-methylpyrrolidone, N-methylformamide, N,N-dimethylformamide, ethyl acetate, cyclohexanone, xylene, toluene, hexane, and 1,4-dioxane.

[0092] The results of the solubility test were plotted in a three-dimensional space of solubility parameters using HSPiP (HansenSolubilityParametersinPractice) Ver.5, and the HSP value was determined.

[0093] Furthermore, for MTPH b-3, MEK c-1, and dioxane c-2, whose chemical structures are known, Smiles notation was created, and the HSP values ​​were calculated using HSPiP (HansenSolubilityParametersinPractice) Ver.5.

[0094] The distance between HSP values ​​is calculated by setting the Hansen solubility parameters δA and δB of two substances A and B, respectively, as δA=(δDA,δPA,δHA) and δB=(δDB,δPB,δHB), where the distance between HSP values ​​is [4 × (δDA - δDB)]. 2 +(δPA‐δPB) 2 +(δHA‐δHB) 2 ] 0.5 It can be calculated using the following formula.

[0095] The dispersion term, polarity term, and hydrogen bonding term of the Hansen solubility parameters for each material measured as described above are shown in Table 2 below. [Table 2]

[0096] (Varnished exterior) During the preparation of the varnish, the appearance of the varnish after mixing with a hybrid mixer was observed and evaluated according to the following criteria. ○: No color unevenness or sedimentation of sinterable particles was observed in the varnish. ×: Uneven coloring, sedimentation of sinterable particles, or separation of sinterable particles from the binder was observed in the varnish.

[0097] (Seat appearance) The appearance of the sintered bonding sheets was observed and evaluated according to the following criteria. ○: No particle unevenness (color unevenness) was observed in the sheet. △: Particle irregularities were observed in the sheet, but no cracks or chips occurred during sheet processing. ×: Cracks or chips occurred during sheet processing, or the resulting sheet was brittle and could not maintain its shape.

[0098] (Sinterability) Using the sintering bonding sheets of each example and comparative example, sintering bonding was performed as follows, and the appearance after sintering was observed. First, a silicon chip (5 mm square, 350 μm thick) with a planar electrode (5 mm square) on one side was prepared. As the planar electrode, a silicon chip with a Ti layer (100 nm thick) and an Ag layer (750 nm thick) was used. Next, a sintering bonding sheet was bonded to the planar electrode of the silicon chip using a laminator equipped with a pressure roll. The bonding temperature was 70°C, the load (pressure from the pressure roll) was 0.3 MPa, and the pressure roll speed was 10 mm / second. As a result, a silicon chip with a 5 mm square sintering bonding sheet was obtained.

[0099] A silicon chip with a sintering bonding sheet was sintered onto a copper plate (3 mm thick) that was entirely covered with an Ag film (5 μm thick). Specifically, the sintering was performed using a sintering apparatus (HTM-3000, manufactured by Hakuto Co., Ltd.) so that the sintering bonding sheet was positioned between the copper plate and the silicon chip. During sintering, the pressure applied in the thickness direction was 20 MPa, the heating temperature was 275°C, and the heating time was 5 minutes. Furthermore, with the composition of Comparative Example 5, it was not possible to produce a sheet-like sintered bonding sheet, and therefore, a test on sinterability could not be performed.

[0100] The silicon chips sintered under the above conditions were observed for their appearance and evaluated according to the following criteria. ○: In a front view of the sintered silicon chip, no sintering bonding sheet is observed (the shape is maintained without protruding from the silicon chip). ×: In a front view of the sintered silicon chip, components of the sintering bonding sheet that had leaked out onto the outer circumference of the silicon chip were observed, but the silicon chip and the copper plate were bonded. ××: In a front view of the silicon chip after sintering, components of the sintering bonding sheet leaked significantly to the outer circumference of the silicon chip, preventing the silicon chip from bonding with the copper plate.

[0101] [Table 3] In the table above, Db is the distance between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder. Ds is the distance between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the dispersion solvent.

[0102] Based on the results above, no color unevenness or sedimentation of sinterable particles was observed in any of the sintering bonding varnishes of Examples 1 to 6. Furthermore, no cracks or chips occurred during sheet processing in any of the sintering bonding sheets of Examples 1 to 6, and the shape of the sheet was maintained without protruding from the silicon chip in a plan view of the silicon chip during sintering. [Explanation of symbols]

[0103] 1. Dicing tape with sintering bonding sheet 10 Sintering Bonding Sheet 20 dicing tapes 21 Base material 22 Adhesive 30 semiconductor wafers 40 Support substrate 41 Bonding wire

Claims

1. It comprises sinterable particles containing a conductive metal and a binder. A sintered bonding sheet in which the distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.

0.

2. The sintering bonding sheet according to claim 1, which does not contain any binders other than a pyrolytic polymer binder whose distance Db is less than 15.

0.

3. The sintered bonding sheet according to claim 1 or 2, wherein the distance Db is 10.0 or less.

4. The sintering bonding sheet according to claim 1 or 2, wherein the binder comprises at least one selected from the group consisting of polypropylene carbonate and polyethylene carbonate.

5. A dicing tape having a base material and an adhesive, A dicing tape with a sintered bonding sheet, comprising a sintered bonding sheet according to claim 1 or 2 attached to the adhesive of the dicing tape.

6. It comprises sinterable particles containing a conductive metal and a binder. A sintering bonding composition in which the distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.

0.

7. The material comprises sinterable particles containing a conductive metal, a binder, and a dispersion solvent. The distance Db between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the binder is less than 15.

0. A sintering varnish in which the distance Ds between the Hansen solubility parameter of the sinterable particles and the Hansen solubility parameter of the dispersion solvent is less than 15.0.

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