Adhesive for semiconductor, method for manufacturing semiconductor device, and semiconductor device

Abstract

The present invention provides an adhesive for a semiconductor, a method for manufacturing a semiconductor device, and a semiconductor device, the adhesive for a semiconductor comprising a resin having a weight-average molecular weight of less than 10,000, a curing agent, an inorganic filler, a silicone rubber filler, a polymer component having a weight-average molecular weight of 10,000 or more, and a flux, the content of the inorganic filler is 20-50% by mass based on the total solid content of the adhesive for semiconductors, and the adhesive for semiconductors is in the form of a film having a thickness of 2.5-20 [mu] m.

Description

[0001] This application is a divisional application with an application date of March 23, 2020, a priority date of March 26, 2019, Chinese patent application number 202080023019.1, and an invention name of “Adhesive for semiconductors, method for manufacturing semiconductor devices, and semiconductor devices”. Technical Field

[0002] The present invention relates to a semiconductor adhesive, a method for manufacturing a semiconductor device, and a semiconductor device. Background Art

[0003] In the past, when connecting a semiconductor chip to a substrate, a wire bonding method using a fine metal wire such as a gold wire was widely used. On the other hand, in response to the requirements for high functionality, high integration, and high speed of semiconductor devices, a flip chip connection method (FC connection method) is being promoted, which forms a conductive protrusion called a bump on a semiconductor chip or substrate to directly connect the semiconductor chip to the substrate.

[0004] As FC connection methods, there are known methods of metal bonding the connection parts using solder, tin, gold, silver, copper, etc.; methods of metal bonding the connection parts by applying ultrasonic vibration; and methods of maintaining mechanical connection by the shrinkage force of resin, etc. However, from the viewpoint of the reliability of the connection parts, the method of metal bonding the connection parts using solder, tin, gold, silver, copper, etc. is generally adopted.

[0005] For example, regarding the connection between a semiconductor chip and a substrate, the COB (Chip On Board) type connection method widely used in BGA (Ball grid Array) and CSP (Chip Size Package) is also equivalent to the FC connection method. In addition, the FC connection method is also widely used in the COC (Chip On Chip) type connection method in which a connection portion (bump or wiring) is formed on a semiconductor chip to connect semiconductor chips (for example, refer to Patent Document 1).

[0006] Furthermore, in the case of packages that are strongly demanded to be further miniaturized, thinned, and highly functional, chip stack packages, POP (Package On Package), TSV (Through-Silicon Via), etc., which are formed by stacking and multi-layering the above-mentioned connection methods, have also begun to become widely popular. Since this stacking and multi-layering technology configures semiconductor chips and the like in three dimensions, it is possible to reduce the package size compared to the method of two-dimensional configuration. Furthermore, since this stacking and multi-layering technology is also effective in improving semiconductor performance, reducing noise, reducing mounting area, and saving power, it has attracted much attention as the next generation of semiconductor wiring technology.

[0007] In addition, from the perspective of improving productivity, COW (Chip On Wafer) in which semiconductor chips are pressed (connected) on a semiconductor wafer and then singulated to produce a semiconductor package, and WOW (Wafer On Wafer) in which semiconductor wafers are pressed (connected) to each other and then singulated to produce a semiconductor package have attracted much attention. Furthermore, from the same perspective, a multi-terminal bonding (Gang bonding) method in which multiple semiconductor chips are aligned on a semiconductor wafer or a mapping substrate and temporarily pressed, and then these multiple semiconductor chips are officially pressed together to ensure connection has also attracted much attention.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Publication No. 2008-294382 Summary of the invention

[0011] Technical issues to be solved by the invention

[0012] In flip chip packaging, the difference in thermal expansion coefficients between the semiconductor adhesive and the semiconductor chip and between the semiconductor chip and the substrate may cause stress and warp in the package. As the semiconductor chip and semiconductor wafer are formed into films, the warp of the package is more likely to occur.

[0013] Furthermore, in the above-mentioned stacked and multi-layered chip stack type package, warpage tends to be larger than that of a single-layer chip stack type package.

[0014] Such warping of the package may easily cause problems such as inability to perform overmolding and poor connection of the package. Therefore, there is a strong demand for reducing the warping of the package.

[0015] Here, as a method for achieving low warpage of the package, it is possible to consider making the semiconductor adhesive low in elasticity. As a method for making the semiconductor adhesive low in elasticity, it is possible to consider a method of lowering the glass transition temperature of the polymer component, a method of reducing the amount of inorganic filler added, a method of increasing the amount of organic filler added, etc. However, when using these methods to make the semiconductor adhesive low in elasticity, the operability of the semiconductor adhesive deteriorates or the melt viscosity becomes difficult to adjust, and it is difficult to simultaneously achieve these characteristics and low warpage of the package.

[0016] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a semiconductor adhesive capable of reducing warpage of the resulting package while suppressing reduction in adhesive strength and reliability, and a method for manufacturing a semiconductor device using the semiconductor adhesive and a semiconductor device.

[0017] Means for solving technical problems

[0018] In order to achieve the above object, the present invention provides a semiconductor adhesive, which contains a resin with a weight average molecular weight of less than 10,000, a curing agent, an inorganic filler, and a silicone rubber filler. According to the semiconductor adhesive, by using an inorganic filler and a silicone rubber filler in combination as fillers, it is possible to achieve low warpage of the resulting package while suppressing the reduction of adhesive force and reliability. In particular, by using a silicone rubber filler as an organic filler used in combination with an inorganic filler, the warpage of the resulting package can be greatly reduced.

[0019] The average particle size of the silicone rubber filler may be 30 μm or less. In this case, the warpage of the obtained package can be further reduced while the decrease in adhesive force and reliability can be more fully suppressed.

[0020] The inorganic filler may also contain a silica filler. In this case, the adhesive force and reliability can be further improved. In addition, the inorganic filler and the silicone rubber filler are more easily dispersed evenly, and can take into account good adhesive force and reliability at a higher level, as well as low warpage of the resulting package.

[0021] The adhesive for semiconductors may contain a polymer component having a weight average molecular weight of 10000 or more. In this case, the heat resistance and film forming properties of the adhesive for semiconductors can be improved.

[0022] The weight average molecular weight of the polymer component may be 30,000 or more. In addition, the glass transition temperature of the polymer component may be 100° C. or less. When the weight average molecular weight is 30,000 or more, film forming properties are improved. When the glass transition temperature is 100° C. or less, adhesion to a substrate and a semiconductor chip is improved.

[0023] The semiconductor adhesive may be in the form of a film. In this case, the semiconductor adhesive can be easily handled, thereby improving the workability and productivity during package manufacturing.

[0024] The content of the silicone rubber filler in the semiconductor adhesive may be 0.1% to 20% by mass based on the total solid content of the semiconductor adhesive. In this case, it is possible to achieve both good adhesion and reliability at a higher level and reduce warpage of the resulting package.

[0025] In the semiconductor adhesive, the mass ratio of the silicone rubber filler content to the inorganic filler content (mass of silicone rubber filler / mass of inorganic filler) may be 0.05 to 0.5. In this case, good adhesion and reliability can be achieved at a higher level, and the resulting package can have low warpage.

[0026] Furthermore, the present invention provides a method for manufacturing a semiconductor device, which is a method for manufacturing a semiconductor device in which the connection parts of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which the connection parts of a plurality of semiconductor chips are electrically connected to each other, and the method for manufacturing the semiconductor device includes: a step of sealing at least a part of the connection part using the semiconductor adhesive. According to the manufacturing method, a semiconductor device having excellent adhesion and reliability between the semiconductor chip and the wiring circuit board or the semiconductor chip and reduced warping can be obtained.

[0027] Furthermore, the present invention provides a semiconductor device, comprising: a connection structure formed by electrically connecting the connection parts of a semiconductor chip and a wiring circuit board, or a connection structure formed by electrically connecting the connection parts of a plurality of semiconductor chips; and an adhesive material for sealing at least a portion of the connection part, the adhesive material being formed from a cured product of the semiconductor adhesive. The semiconductor device has excellent bonding strength and reliability between the semiconductor chip and the wiring circuit board or the semiconductor chip, and has reduced warpage.

[0028] Effects of the Invention

[0029] According to the present invention, it is possible to provide a semiconductor adhesive capable of reducing warpage of the resulting package while suppressing a decrease in adhesive strength and reliability, and a method for manufacturing a semiconductor device using the semiconductor adhesive and a semiconductor device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic cross-sectional view showing one embodiment of a semiconductor device according to the present invention.

[0031] Figure 2It is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention.

[0032] Figure 3 It is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention. DETAILED DESCRIPTION

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings as appropriate.

[0034] In addition, in the drawings, the same or corresponding parts are denoted by the same reference numerals, and repeated descriptions are omitted. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right refer to positional relationships based on those shown in the drawings.

[0035] In addition, the dimensional ratios in the drawings are not limited to the ratios shown in the drawings.

[0036] In this specification, the numerical range represented by "~" indicates a range that includes the numerical values ​​recorded before and after "~" as the minimum and maximum values, respectively. In the numerical range recorded in stages in this specification, the upper limit value or lower limit value of the numerical range of a certain stage can be arbitrarily combined with the upper limit value or lower limit value of the numerical range of other stages. In the numerical range recorded in this specification, the upper limit value or lower limit value of the numerical range can also be replaced by the value shown in the embodiment. The so-called "A or B" only needs to include any one of A and B, and can also include both at the same time. Unless otherwise specified, the materials listed in this specification can be used alone or in combination of two or more. In this specification, "(meth)acrylic acid" refers to acrylic acid or its corresponding methacrylic acid.

[0037] <Adhesives for semiconductors>

[0038] The semiconductor adhesive of the present embodiment contains a resin having a weight average molecular weight of less than 10,000 (hereinafter referred to as "component (a)" as the case may be), a curing agent (hereinafter referred to as "component (b)" as the case may be), an inorganic filler (hereinafter referred to as "component (e)" as the case may be) and an organic filler (hereinafter referred to as "component (f)" as the case may be). In addition, the semiconductor adhesive of the present embodiment contains a silicone rubber filler as an organic filler. Furthermore, the semiconductor adhesive of the present embodiment contains a polymer compound having a weight average molecular weight of 10,000 or more (hereinafter referred to as "component (c)" as the case may be) and / or a flux (hereinafter referred to as "component (d)" as the case may be) as needed. Each component is described below.

[0039] (a) Resins with a weight average molecular weight of less than 10,000

[0040] As component (a), there is no particular limitation, and from the viewpoint of heat resistance, it is preferably a component that reacts with the curing agent of component (b). As component (a), it is preferred to have two or more reactive groups in the molecule. As component (a), for example, epoxy resin, phenolic resin, imide resin, urea-formaldehyde resin, melamine resin, silicone resin, (meth) acrylic compound, vinyl compound. Among them, from the viewpoint of excellent heat resistance and storage stability, epoxy resin, phenolic resin, imide resin are preferred, and epoxy resin and imide resin are more preferred. These (a) components can be used alone, and can also be used as a mixture or copolymer of two or more.

[0041] As epoxy resin, there is no particular limitation as long as it has two or more epoxy groups in the molecule, and examples thereof include: epoxy resins such as bisphenol A type, bisphenol F type, naphthalene type, phenol novolac type, cresol novolac type, phenol aralkyl type, biphenyl type, triphenylmethane type and dicyclopentadiene type, and various multifunctional epoxy resins. The epoxy resin can be used alone or in combination of two or more. Among them, from the viewpoint of heat resistance and operability, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin and triphenylmethane type epoxy resin are preferred.

[0042] As the imide resin, there is no particular limitation as long as it has two or more imide groups in the molecule, and examples thereof include naphthalene diimide resin, allyl naphthalene diimide resin, maleimide resin, amide imide resin, imide acrylate resin, various multifunctional imide resins, and various polyimide resins. The imide resin can be used alone or in combination of two or more.

[0043] From the viewpoint of suppressing decomposition during connection at high temperature to generate volatile components, when the temperature during connection is 250°C, component (a) preferably uses a resin having a thermal weight loss rate of 5% or less at 250°C, and when the temperature during connection is 300°C, it is preferably used a resin having a thermal weight loss rate of 5% or less at 300°C.

[0044] When an epoxy resin is used as component (a), the 1% thermal weight loss temperature of a liquid epoxy resin of bisphenol A or bisphenol F is below 250°C, so it is possible to decompose and generate volatile components when heated at high temperatures. Therefore, it is preferred to use an epoxy resin that is solid at room temperature (1 atmosphere, 25°C). When a liquid epoxy resin is used, it is preferably used in combination with a solid epoxy resin.

[0045] The weight average molecular weight of the component (a) is less than 10,000, but is preferably less than 10,000 from the viewpoint of film formation, and is preferably 100 or more from the viewpoint of optimizing the melt viscosity.

[0046] Therefore, the weight average molecular weight of the component (a) is preferably 100 or more and less than 10,000, more preferably 300 or more and 8,000 or less, and even more preferably 300 or more and 5,000 or less.

[0047] The content of component (a) is, for example, 5% to 75% by mass, preferably 15% to 60% by mass, and more preferably 30% to 50% by mass, based on the total solid content of the adhesive for semiconductors. By setting the content of component (a) to 5% by mass or more, the adhesive force and reliability are excellent, and if it is 75% by mass or less, the cured product is prevented from becoming too hard, and the warping of the package is easily reduced.

[0048] (b) Curing agent

[0049] As (b) curing agent, for example, phenolic resin curing agent, acid anhydride curing agent, amine curing agent, imidazole curing agent and phosphine curing agent can be cited. If (b) component contains phenolic hydroxyl group, acid anhydride, amine or imidazole, it shows fluxing activity that suppresses the formation of oxide film in the connection part, thereby improving the connection reliability and insulation reliability. Each curing agent is described below.

[0050] (bi) Phenolic resin curing agent

[0051] As a phenolic resin curing agent, there is no particular limitation as long as it has two or more phenolic hydroxyl groups in the molecule, and the following can be used: phenol novolac resin, cresol novolac resin, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane type multifunctional phenolic resin and various multifunctional phenolic resins. These can be used alone or as a mixture of two or more. In addition, liquid phenolic resin may decompose and produce volatile components when heated at high temperature, so it is preferred to use a phenolic resin that is solid at room temperature (1 atmosphere, 25°C).

[0052] From the viewpoint of improving curability, adhesion and storage stability, the equivalent ratio of (bi) phenolic resin curing agent to the above-mentioned (a) component (phenolic hydroxyl group / molar ratio of reactive groups of (a) component) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and further preferably 0.5 to 1.0. If the equivalent ratio is 0.3 or more, there is a tendency for improved curability and improved adhesion, and if it is 1.5 or less, there will be no excessive residual unreacted phenolic hydroxyl groups, the water absorption rate is suppressed to a low level, and there is a tendency for improved insulation reliability. Phenolic hydroxyl groups show fluxing activity for removing oxide films, so by containing a phenolic resin curing agent in the semiconductor adhesive, connectivity and reliability can be improved.

[0053] (b-ii) Anhydride curing agent

[0054] As anhydride curing agents, for example, methylcyclohexane tetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, and ethylene glycol bis-trimellitic anhydride ester can be used. These can be used alone or as a mixture of two or more. In addition, liquid acid anhydrides may decompose and produce volatile components when heated at high temperatures, so it is preferred to use acid anhydrides that are solid at room temperature (1 atmosphere, 25°C).

[0055] From the viewpoint of improving curability, adhesion and storage stability, the equivalent ratio of (b-ii) anhydride curing agent to the above-mentioned component (a) (molar ratio of anhydride group / reactive group of component (a)) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and further preferably 0.5 to 1.0. If the equivalent ratio is 0.3 or more, there is a tendency for improved curability and improved adhesion, and if it is 1.5 or less, there is no excess residual unreacted anhydride, the water absorption rate is suppressed to a low level, and there is a tendency for improved insulation reliability. Acid anhydride shows fluxing activity for removing oxide films, so by containing an acid anhydride curing agent in the adhesive for semiconductors, it is possible to improve connectivity and reliability.

[0056] (b-iii) Amine curing agent

[0057] As the amine curing agent, dicyandiamide and the like can be used. In addition, since liquid amines may decompose and generate volatile components when heated at high temperatures, it is preferable to use amines that are solid at room temperature (1 atmosphere, 25° C.).

[0058] From the viewpoint of improving curability, adhesion and storage stability, the equivalent ratio of (b-iii) amine curing agent to the above-mentioned component (a) (molar ratio of amine / reactive group of component (a)) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and further preferably 0.5 to 1.0. If the equivalent ratio is 0.3 or more, there is a tendency for improved curability and improved adhesion, and if it is 1.5 or less, there will be no excess unreacted amine remaining, the water absorption rate is suppressed to a low level, and there is a tendency for improved insulation reliability. Amines show fluxing activity for removing oxide films, so by containing amine curing agents in the adhesive for semiconductors, connectivity and reliability can be improved.

[0059] (b-iv) Imidazole curing agent (nitrogen atom contained is tertiary nitrogen atom)

[0060] Examples of the imidazole curing agent include 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, epoxy resin and imidazole series adduct, etc. Among them, from the viewpoint of making curability, adhesion and storage stability good, preferably 1-cyanoethyl-2-undecyl imidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecyl imidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct. These can be used alone or in combination of two or more. In addition, a latent curing agent that microencapsulates these to improve the potential can also be used.

[0061] The content of the imidazole curing agent (b-iv) is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the component (a). If the content is 0.1 parts by mass or more, the curability tends to be improved. If it is 20 parts by mass or less, the semiconductor adhesive will not cure before the metal joint is formed, and there is a tendency that poor connection is not easy to occur. The imidazole curing agent can be used alone as the curing agent (b), or it can be used as a curing accelerator together with the curing agents of the above (bi) to (b-iii).

[0062] (bv) Phosphine-based curing agent

[0063] Examples of the phosphine-based curing agent include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrakis(4-methylphenyl)borate, and tetraphenylphosphonium (4-fluorophenyl)borate.

[0064] The content of the phosphine-based curing agent (bv) is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the component (a). If the content of the phosphine-based curing agent is 0.1 parts by mass or more, the curability tends to be improved, while if it is 10 parts by mass or less, the film adhesive does not cure before the metal bonding is formed, and poor connection tends to be less likely to occur.

[0065] Phenolic resin curing agents, acid anhydride curing agents and amine curing agents can be used alone or as a mixture of two or more. Imidazole curing agents and phosphine curing agents can be used alone or together with phenolic resin curing agents, acid anhydride curing agents or amine curing agents.

[0066] (c) A polymer component having a weight average molecular weight of 10,000 or more

[0067] As (c) polymer components with a weight average molecular weight of more than 10000, there can be mentioned: phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate resin, acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, polyurethane resin, acrylic rubber, etc. Among them, from the aspect of excellent heat resistance and film formation, preferably phenoxy resin, polyimide resin, acrylic rubber, cyanate resin, polycarbodiimide resin, etc., more preferably phenoxy resin, polyimide resin, acrylic rubber, further preferably phenoxy resin. These polymer components can be used alone, and can also be used as a mixture or copolymer of two or more.

[0068] The mass ratio of component (c), component (a) and component (b) is not particularly limited. From the viewpoint of improving film forming properties and film forming properties by spin coating, etc., the total mass of component (a) and component (b) is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 4 parts by mass, and even more preferably 0.1 to 3 parts by mass relative to 1 part by mass of component (c). If the mass ratio is 0.01 parts by mass or more, there is a tendency to suppress the reduction in curability of the semiconductor adhesive and the reduction in adhesiveness, and if it is 5 parts by mass or less, there is a tendency to improve film forming properties and film forming properties.

[0069] The polyimide resin used as component (c) can be obtained by, for example, reacting tetracarboxylic dianhydride with diamine by a known method. More specifically, in an organic solvent, tetracarboxylic dianhydride and diamine are mixed in equimolar or substantially equimolar amounts (the order of addition of each component is arbitrary), and an addition reaction is carried out at a reaction temperature below 80°C, preferably at 0°C to 60°C. As the reaction proceeds, the viscosity of the reaction solution gradually increases, generating polyamic acid as a precursor of polyimide. In addition, in order to suppress the reduction of various properties of the adhesive for semiconductors, the above-mentioned tetracarboxylic dianhydride is preferably subjected to recrystallization purification treatment using acetic anhydride.

[0070] The molecular weight of the polyamic acid can also be adjusted by heating at a temperature of 50°C to 80°C to depolymerize the polyamic acid.

[0071] The polyimide resin can be obtained by subjecting the above-mentioned reaction product (polyamic acid) to dehydration ring closure. The dehydration ring closure can be performed by a thermal ring closure method of performing a heat treatment or a chemical ring closure method using a dehydrating agent.

[0072] From the viewpoint of good adhesion to the substrate and the semiconductor chip, the glass transition temperature (Tg) of the component (c) is preferably 100°C or less, more preferably 75°C or less. If Tg is 100°C or less, it is easy to fill the bumps formed on the semiconductor chip or the bumps formed on the substrate with the semiconductor adhesive, and there is a tendency to prevent the residue of bubbles and suppress the generation of voids. In addition, the above Tg is the Tg measured using a differential scanning calorimeter (manufactured by PerkinElmer, Inc., DSC-7 model) under the conditions of a sample amount of 10 mg, a heating rate of 5°C / min, and a measurement atmosphere of air.

[0073] The weight average molecular weight of component (c) is 10,000 or more in terms of polystyrene, but in order to show good film forming properties alone, it is preferably 20,000 or more, more preferably 30,000 or more, and further preferably 40,000 or more. When the weight average molecular weight is less than 10,000, the film forming properties may be reduced. In addition, considering the fluidity, the weight average molecular weight of component (c) is, for example, 1,000,000 or less, preferably 500,000 or less.

[0074] In the present specification, the weight average molecular weight means a weight average molecular weight measured in terms of polystyrene using high performance liquid chromatography (C-R4A manufactured by Shimadzu Corporation).

[0075] The content ratio of component (c) to component (a) is not particularly limited. From the viewpoint of maintaining a good film shape, component (a) is preferably 0.01 to 5 parts by mass, and more preferably 0.1 to 2 parts by mass, relative to 1 part by mass of component (c). If the content ratio is 0.01 parts by mass or more, there is a tendency to suppress the reduction in curability of the semiconductor adhesive and the reduction in adhesive strength, and if it is 5 parts by mass or less, there is a tendency to improve film formability and film forming properties.

[0076] (d) Flux

[0077] The semiconductor adhesive may contain (d) a flux, i.e., a flux activator which is a compound showing flux activity (activity of removing oxides and impurities). Examples of the flux include nitrogen-containing compounds having non-covalent electron pairs such as imidazoles and amines, carboxylic acids, phenols, and alcohols. In addition, organic acids such as carboxylic acids show flux activity more strongly than alcohols, and are likely to improve connectivity.

[0078] From the viewpoint of developing fluxing activity and improving connectivity, the content of the component (d) is preferably 0.1 to 5% by mass, more preferably 1 to 5% by mass, based on the total solid content of the adhesive for semiconductor.

[0079] (e) Inorganic fillers

[0080] The semiconductor adhesive of this embodiment contains an inorganic filler as the component (e). By containing the component (e), the viscosity of the semiconductor adhesive and the physical properties of the cured product can be controlled, and the generation of voids and moisture absorption when connecting the semiconductor chip and the substrate can be suppressed. In addition, by containing the component (e), the semiconductor adhesive can obtain excellent bonding strength and improve reliability such as reflow resistance and moisture resistance.

[0081] As the (e) component, for example, insulating inorganic fillers and whiskers can be cited. As the material of the insulating inorganic filler, glass, silica, alumina, silica·alumina, titanium oxide, mica, boron nitride, etc. can be cited, among which silica, alumina, silica·alumina, titanium oxide, boron nitride, etc. are preferred, silica, alumina, boron nitride are more preferred, and silica is further preferred. As the material of the whiskers, aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, boron nitride, etc. can be cited.

[0082] From the viewpoint of improving dispersibility and adhesive strength, component (e) is preferably a surface-treated filler. Examples of the surface treatment include glycidyl-based (epoxy-based), amine-based, phenyl-based, anilino-based, acrylic-based, and vinyl-based fillers.

[0083] As the surface treatment, from the perspective of ease of surface treatment, silane treatment using silane compounds such as epoxysilane, aminosilane, and acrylic silane is preferred. As the surface treatment agent, from the perspective of excellent dispersibility and fluidity and further improved adhesion, glycidyl, aniline, and (meth) acrylic acid compounds are preferred. As the surface treatment agent, from the perspective of storage stability, phenyl and (meth) acrylic acid compounds are preferred.

[0084] The particle size of the component (e) is preferably 1.5 μm or less from the viewpoint of preventing biting during flip chip connection, and more preferably 1.0 μm or less from the viewpoint of visibility (transparency). The average particle size of the component (e) can be measured, for example, by a wet-dry particle size distribution measuring device (manufactured by Beckman Coulter, Inc., LS13 320).

[0085] These components (e) may be used alone or as a mixture of two or more thereof. The shape of the component (e) is not particularly limited.

[0086] Based on the total solid content of the semiconductor adhesive, the content of component (e) is preferably 20% to 60% by mass, and more preferably 30% to 50% by mass. If the content is 20% by mass or more, especially 30% by mass or more, there is a tendency to further suppress the generation of voids and moisture absorption, and to further improve the reliability of adhesion, reflow resistance, and moisture resistance. On the other hand, if the content is 60% by mass or less, especially 50% by mass or less, there is a tendency to easily reduce the warpage of the resulting package, and to easily prevent biting during flip chip connection.

[0087] (f) Organic fillers

[0088] The semiconductor adhesive of this embodiment contains an organic filler as component (f). By containing component (f), the viscosity of the semiconductor adhesive and the physical properties of the cured product can be controlled, and the generation of voids and moisture absorption when connecting a semiconductor chip and a substrate can be suppressed.

[0089] As the material of the organic filler, for example, polyurethane, polyimide, silicone, methyl methacrylate resin and methyl methacrylate-butadiene-styrene copolymer resin (Methylmethacrylate ButadieneStyrene, MBS) can be cited. Compared with component (e), component (f) can impart flexibility to the semiconductor adhesive and its cured product at high temperatures such as 260°C, and is therefore suitable for improving reflow resistance and temperature cycle resistance. In addition, since it imparts flexibility, it is also effective in improving film formation.

[0090] These (f) components may be used alone or as a mixture of two or more thereof. The shape of the (f) component is not particularly limited.

[0091] The adhesive for semiconductors of the present embodiment contains a silicone rubber filler as the component (f). When the adhesive for semiconductors contains a silicone rubber filler, the warpage of the obtained package can be reduced.

[0092] As long as the silicone rubber filler is a filler containing silicone rubber as a constituent component of the filler, it can be a filler containing only silicone rubber or a filler compounded with other components. The silicone rubber filler can be a particle having a core-shell structure. As a core-shell structure, a structure having a core layer (core material) and a shell layer (surface layer) provided in a manner of covering the core layer can be cited. The composition of the core layer and the shell layer can be the same or different. In addition, the core layer and the shell layer may not have a clear boundary line. As a silicone rubber filler, for example, composite particles in which the core layer is composed of silicone rubber particles and the shell layer is composed of other components other than the silicone rubber particles can be used. As such a composite particle, a silicone composite powder in which the core layer is composed of silicone rubber particles and the shell layer is composed of a silicone resin having a higher glass transition temperature and elastic modulus than the silicone rubber particles in the core layer can be preferably cited. This silicone composite powder can suppress the silicone rubber particles in the core layer from swelling due to the constituent materials of the solvent or the semiconductor adhesive through the shell layer, and form agglomerates between the silicone rubber particles.

[0093] The average particle size of the silicone rubber filler is preferably 0.1 μm to 50 μm, more preferably 0.1 μm to 30 μm, and further preferably 0.1 μm to 10 μm. If the average particle size is 50 μm or less, there is a tendency for the connectivity during installation to become good. The average particle size of the silicone rubber filler can be measured, for example, by a wet-dry particle size distribution measuring device (manufactured by Beckman Coulter, Inc., LS13 320).

[0094] Based on the total solid content of the adhesive for semiconductors, the content of the silicone rubber filler is preferably 0.1% to 20% by mass, more preferably 1% to 18% by mass, and further preferably 3% to 15% by mass. If the content is 0.1% by mass or more, there is a tendency to easily reduce elasticity, and if it is 20% by mass or less, there is a tendency to easily make the melt viscosity appropriate.

[0095] From the viewpoint of more fully obtaining the effect of the present invention, the content of the silicone rubber filler in the component (f) is preferably 50% by mass or more, more preferably 80% by mass or more, based on the total amount of the component (f). In addition, the content of the silicone rubber filler may also be 100% by mass.

[0096] The mass ratio of the content of the silicone rubber filler to the content of the component (e) (mass of the silicone rubber filler / mass of the inorganic filler) is preferably 0.05 to 0.5, more preferably 0.08 to 0.4, and further preferably 0.1 to 0.3. By making the mass ratio within the above range, it is possible to achieve both good adhesion and reliability at a higher level and low warpage of the resulting package.

[0097] Based on the solid content of the semiconductor adhesive as a whole, the total content of component (e) and component (f) is preferably 30% to 90% by mass, and more preferably 40% to 80% by mass. If the content is 30% by mass or more, there is a tendency to further improve the adhesive force. If the content is 90% by mass or less, there is a tendency to suppress the viscosity from increasing and thus reducing the fluidity of the semiconductor adhesive and the trapping of the filler into the connection portion, thereby obtaining good connection reliability.

[0098] From the viewpoint of insulation reliability, the filler is preferably insulating. The semiconductor adhesive preferably does not contain conductive metal fillers such as silver fillers and solder fillers. Semiconductor adhesives (circuit connection materials) that do not contain conductive fillers (conductive particles) are sometimes also referred to as NCF (Non-Conductive-FILM: non-conductive film) or NCP (Non-Conductive-Paste: non-conductive glue). The semiconductor adhesive involved in this embodiment can be appropriately used as NCF or NCP.

[0099] The semiconductor adhesive may further contain ion traps, antioxidants, silane coupling agents, titanium coupling agents, leveling agents, etc. These may be used alone or in combination of two or more. The amounts of these additives may be appropriately adjusted to bring out the effects of each additive.

[0100] The adhesive for semiconductors of the present embodiment can be formed into a film shape. An example of a method for producing a film-shaped adhesive using the adhesive for semiconductors of the present embodiment is shown below.

[0101] First, the necessary components among the components (a) to (f) and additives are added to an organic solvent, and dissolved or dispersed by stirring, mixing, kneading, etc. to prepare a resin varnish. Then, the resin varnish is applied to a substrate film subjected to a release treatment using a knife coater, a roll coater, an applicator, etc., and the organic solvent is removed by heating, thereby forming a film-like adhesive on the substrate film.

[0102] The thickness of the film adhesive is not particularly limited, but is, for example, preferably 0.5 to 1.5 times, more preferably 0.6 to 1.3 times, and even more preferably 0.7 to 1.2 times the height of the bump before connection.

[0103] If the thickness of the film adhesive is more than 0.5 times the height of the bump, the generation of voids caused by the lack of adhesive filling can be fully suppressed, thereby further improving the connection reliability. Furthermore, if the thickness is less than 1.5 times, the amount of adhesive squeezed out from the chip connection area during connection can be fully suppressed, thereby fully preventing the adhesive from adhering to unnecessary parts. If the thickness of the film adhesive is greater than 1.5 times, a large amount of adhesive must be excluded from the bump, which is prone to poor conduction. Furthermore, for the weakening of the bump caused by narrow pitch and multi-pin (miniaturization of the bump diameter), the exclusion of a large amount of resin will increase the damage to the bump, so it is not preferred.

[0104] In general, since the height of the bump is 5 μm to 100 μm, the thickness of the film adhesive is preferably 2.5 μm to 150 μm, and more preferably 3.5 μm to 120 μm.

[0105] The organic solvent used in the preparation of the resin varnish preferably has the property of being able to dissolve or disperse each component uniformly, and examples thereof include: dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. These organic solvents can be used alone or in combination of two or more. The stirring, mixing and kneading when preparing the resin varnish can be carried out using, for example, a stirrer, a grinder, a three-roller, a ball mill, a bead mill or a homogenizer.

[0106] The substrate film is not particularly limited as long as it has heat resistance that can withstand the heating conditions for volatilizing the organic solvent, and examples thereof include: polyolefin films such as polypropylene films and polymethylpentene films; polyester films such as polyethylene terephthalate films and polyethylene naphthalate films; polyimide films and polyetherimide films. The substrate film is not limited to a single-layer film including these films, but may also be a multilayer film including two or more materials.

[0107] The drying conditions for volatilizing the organic solvent from the resin varnish applied to the substrate film are preferably set to conditions that allow the organic solvent to fully volatilize, and specifically, heating is preferably performed at 50° C. to 200° C. for 0.1 to 90 minutes. The organic solvent is preferably removed to 1.5% by mass or less relative to the total amount of the film adhesive.

[0108] Furthermore, the adhesive for semiconductors of the present embodiment can be formed directly on a wafer. Specifically, for example, the adhesive for semiconductors can be formed directly on a wafer by spin coating the resin varnish directly on the wafer to form a film and then removing the organic solvent.

[0109] <Semiconductor devices>

[0110] In the semiconductor device of this embodiment, the following is used Figure 1 and Figure 2 to explain. Figure 1 FIG. 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device of the present invention. Figure 1 As shown in (a) of FIG. 1 , the semiconductor device 100 includes: a semiconductor chip 10 and a substrate (wiring circuit substrate) 20 facing each other, wirings 15 respectively arranged on the facing surfaces of the semiconductor chip 10 and the substrate 20, connection bumps 30 connecting the wirings 15 of the semiconductor chip 10 and the substrate 20, and an adhesive material 40 seamlessly filled in the gap between the semiconductor chip 10 and the substrate 20. The semiconductor chip 10 and the substrate 20 are connected by flip chip via the wirings 15 and the connection bumps 30. The wirings 15 and the connection bumps 30 are sealed by the adhesive material 40 and isolated from the external environment.

[0111] like Figure 1 As shown in (b), the semiconductor device 200 includes: a semiconductor chip 10 and a substrate 20 facing each other, bumps 32 respectively arranged on the facing surfaces of the semiconductor chip 10 and the substrate 20, and an adhesive material 40 seamlessly filled in the gap between the semiconductor chip 10 and the substrate 20. The semiconductor chip 10 and the substrate 20 are connected to each other through the facing bumps 32 and are connected by flip chip. The bumps 32 are sealed by the adhesive material 40 and isolated from the external environment. The adhesive material 40 is a cured product of the semiconductor adhesive of this embodiment.

[0112] Figure 2 FIG. 2 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention. Figure 2 As shown in (a) of FIG. 1 , the semiconductor device 300 is the same as the semiconductor device 100 except that two semiconductor chips 10 are flip-chip connected by wiring 15 and connection bumps 30. Figure 2 As shown in FIG. 2( b ), the semiconductor device 400 is the same as the semiconductor device 200 except that two semiconductor chips 10 are flip-chip connected by bumps 32 .

[0113] The semiconductor chip 10 is not particularly limited, and an element semiconductor composed of the same element such as silicon and germanium, or a compound semiconductor such as gallium arsenide and indium phosphide can be used.

[0114] As the substrate 20, there is no particular limitation if it is a circuit substrate, and the following can be used: a circuit substrate with wiring (wiring pattern) 15 formed by etching away unnecessary parts of a metal film on the surface of an insulating substrate with glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine, etc. as the main components; a circuit substrate with wiring 15 formed on the surface of the above-mentioned insulating substrate by metal plating, etc.; a circuit substrate with wiring 15 formed by printing a conductive material on the surface of the above-mentioned insulating substrate.

[0115] The connecting parts such as the wiring 15 and the bump 32 contain gold, silver, copper, solder (main components such as tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), nickel, tin, lead, etc. as main components, and may also contain multiple metals.

[0116] Among the above metals, from the viewpoint of forming a package with excellent electrical and thermal conductivity of the connection portion, gold, silver and copper are preferred, and silver and copper are more preferred. From the viewpoint of forming a package with reduced cost, silver, copper and solder are preferred due to their low cost, copper and solder are more preferred, and solder is further preferred. If an oxide film is formed on the surface of the metal at room temperature, there is a case where productivity decreases and costs increase. Therefore, from the viewpoint of suppressing the formation of an oxide film, gold, silver, copper and solder are preferred, gold, silver and solder are more preferred, and gold and silver are further preferred.

[0117] A metal layer having gold, silver, copper, solder (main component is, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. as a main component may be formed on the surface of the wiring 15 and the bump 32 by, for example, plating. The metal layer may contain only a single component or may contain multiple components. Furthermore, the metal layer may be a single layer or a structure in which multiple metal layers are stacked.

[0118] Figure 1 In (b), the bump 32 provided on the surface of the semiconductor chip 10 may also have a multilayer structure including a copper pillar and a solder portion. In this case, the copper pillar is preferably arranged on the semiconductor chip 10 side, and the solder portion is provided at the end of the copper pillar.

[0119] Furthermore, in the semiconductor device of this embodiment, a plurality of structures (packages) shown in the semiconductor devices 100 to 400 may be stacked. In this case, the semiconductor devices 100 to 400 may be electrically connected to each other through bumps or wirings containing gold, silver, copper, solder (main components of which are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), tin, nickel, or the like.

[0120] As a method of stacking a plurality of semiconductor devices, Figure 3As shown, for example, TSV (Through-Silicon Via: through silicon via technology) technology can be cited. Figure 3 FIG. 1 is a schematic cross-sectional view showing another embodiment of a semiconductor device of the present invention, and is a semiconductor device using TSV technology. Figure 3 In the semiconductor device 500 shown, the wiring 15 formed on the interposer 50 is connected to the wiring 15 of the semiconductor chip 10 via the connection bump 30, thereby flip-chip connecting the semiconductor chip 10 and the interposer 50. The gap between the semiconductor chip 10 and the interposer 50 is filled with an adhesive material 40 without a gap. On the surface of the semiconductor chip 10 on the side opposite to the interposer 50, the semiconductor chip 10 is repeatedly stacked via the wiring 15, the connection bump 30 and the adhesive material 40. The wiring 15 on the pattern surface of the front and back of the semiconductor chip 10 is connected to each other through the through electrode 34 filled in the hole penetrating the inside of the semiconductor chip 10. In addition, as the material of the through electrode 34, copper, aluminum, etc. can be used.

[0121] This TSV technology can also obtain signals from the back side of a semiconductor chip that is not usually used. Furthermore, since the through electrode 34 vertically passes through the semiconductor chip 10, the distance between the opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50 can be shortened, allowing for flexible connection. In this TSV technology, the semiconductor adhesive of this embodiment can be used as a semiconductor adhesive between opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50.

[0122] Furthermore, in a bump forming method with a high degree of freedom, such as the area bump chip technology, a semiconductor chip can be directly packaged on a motherboard without passing through an interposer. The semiconductor adhesive of this embodiment can also be applied to such a case where a semiconductor chip is directly packaged on a motherboard. In addition, the semiconductor adhesive of this embodiment can also be applied to sealing a gap between two wiring circuit substrates when two wiring circuit substrates are stacked.

[0123] <Method for manufacturing semiconductor device>

[0124] Next, a method for manufacturing the semiconductor device according to the present embodiment will be described.

[0125] First, a film adhesive is attached to a substrate or a semiconductor chip. The film adhesive can be attached by heat pressing, roller lamination, vacuum lamination, etc. The supply area and thickness of the film adhesive are appropriately set according to the size of the semiconductor chip or substrate and the height of the connection bump. The film adhesive can be attached to the semiconductor chip, or after being attached to the semiconductor wafer, it can be singulated into semiconductor chips by cutting to produce a semiconductor chip attached with a film adhesive.

[0126] After attaching the film adhesive to the substrate or semiconductor chip, a connection device such as a flip chip bonding machine is used to align the connection bumps (solder bumps, etc.) of the semiconductor chip with the wiring (copper wiring, etc.) of the substrate. Next, the semiconductor chip and the substrate are pressed while being heated to a temperature above the melting point of the connection bumps, thereby connecting the semiconductor chip and the substrate, and the gap between the semiconductor chip and the substrate is sealed and filled with the film adhesive. A semiconductor device is obtained by the above.

[0127] The connection load can be set by considering the number and height deviation of the connection bumps, the deformation of the connection bumps or the wiring of the bumps receiving the connection parts due to the pressurization. Regarding the connection temperature, the temperature of the connection part is preferably above the melting point of the connection bumps, but it can be a temperature that can form a metal joint of each connection part (bump or wiring). In the case where the connection bump is a solder bump, the connection temperature can also be above about 220°C.

[0128] The connection time during connection varies depending on the constituent metal of the connection portion, but from the viewpoint of improving productivity, the shorter the time, the better. In the case where the connection bump is a solder bump, the connection time is preferably less than 20 seconds, more preferably less than 10 seconds, and further preferably less than 5 seconds. In the case of using a solder bump to connect in a short time, the connection time is preferably less than 4 seconds, more preferably less than 3 seconds, and further preferably less than 2 seconds. In this way, by connecting in a short time, more high-reliability packages can be manufactured. Here, the connection time refers to the time when the above-mentioned connection temperature is applied to the connection bump. In the case of copper-copper or copper-gold metal connection, the connection time is preferably less than 60 seconds. In the case where the connection bump is a solder bump, it is preferred to melt the solder during connection, remove the oxide film and impurities on the surface, and form a metal joint at the connection portion.

[0129] In the method for manufacturing a semiconductor device of this embodiment, temporary fixing (with a semiconductor adhesive interposed therebetween) may also be performed after alignment, and a heat treatment may be performed using a reflow furnace, thereby melting the connection bumps and connecting the semiconductor chip and the substrate. In the temporary fixing stage, it is not necessary to form a metal joint, so compared with the above-mentioned method of pressing while heating, pressing can be performed under low load, short time, and low temperature, thereby improving productivity and suppressing degradation of the connection portion.

[0130] Furthermore, after the semiconductor chip and the substrate are connected, a heating treatment may be performed in an oven or the like to further improve the connection reliability and insulation reliability. The heating temperature is preferably a temperature at which the film adhesive is cured, and more preferably a temperature at which the film adhesive is completely cured. The heating temperature and the heating time may be appropriately set.

[0131] In the method for manufacturing a semiconductor device of the present embodiment, a paste-like semiconductor adhesive may be supplied onto the substrate or the semiconductor chip instead of the film-like adhesive. The semiconductor adhesive may be supplied by a coating method such as spin coating.

[0132] As mentioned above, although the preferred embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment.

[0133] Example

[0134] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the Examples.

[0135] The compounds used in each of the Examples and Comparative Examples are as follows.

[0136] (a) Component: Resin with a weight average molecular weight of less than 10,000

[0137] (a-1): a trisphenol methane skeleton-containing multifunctional epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "EP1032H60", weight average molecular weight: 800 to 2000)

[0138] (a-2): Bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "YL983U", weight average molecular weight: about 340)

[0139] (a-3): Flexible semi-solid epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "YX7110B60", weight average molecular weight: about 1000 to 5000)

[0140] (b) Component: Curing agent: 2,4-diamino-6-[2'-methylimidazole-(1')]-ethyl-s-triazine isocyanuric acid adduct (manufactured by Shikoku Chemicals Corp., trade name "2MAOK-PW")

[0141] (c) Component: polymer compound having a weight average molecular weight of 10,000 or more: phenoxy resin (manufactured by Tohto Kasei Co., Ltd., trade name "ZX1356", Tg: about 71° C., weight average molecular weight: about 63,000)

[0142] (d) Ingredients: Flux (carboxylic acid): glutaric acid (melting point: about 95°C)

[0143] (e) Ingredients: Inorganic filler

[0144] (e-1) Silica filler (manufactured by Admatechs Co., Ltd., trade name "SE2050", average particle size: 0.5 μm)

[0145] (e-2) Methacrylic acid surface treated nano-silica filler (manufactured by Admatechs Co., Ltd., trade name "YA050C-SM", average particle size: about 50 nm)

[0146] (f) Ingredients: Organic filler

[0147] (f-1): Silicone composite powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KMP-602", average particle size: 30 μm, spherical powder obtained by coating the surface of spherical silicone rubber powder with silicone resin)

[0148] (f-2): Silicone composite powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KMP-600", average particle size: 5 μm, spherical powder obtained by coating the surface of spherical silicone rubber powder with silicone resin)

[0149] (f-3): Silicone composite powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KMP-605", average particle size: 2 μm, spherical powder obtained by coating the surface of spherical silicone rubber powder with silicone resin)

[0150] (f-4): Silicone composite powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X-52-7030", average particle size: 0.8 μm, spherical powder obtained by coating the surface of spherical silicone rubber powder with silicone resin)

[0151] (f-5): Core-shell type organic fine particles (manufactured by Rohm and Haas Japan, trade name "EXL-2655", core part: butadiene / styrene copolymer, shell part: PMMA / styrene copolymer)

[0152] (Examples 1 to 4 and Comparative Examples 1 and 2)

[0153] <Production of film adhesive>

[0154] The components (a), (b), (c), (d), (e) and (f) in the amounts (unit: parts by mass) shown in Table 1 were added to an organic solvent (methyl ethyl ketone) in such a manner that the NV value ([mass of the coating component after drying] / [mass of the coating component before drying]×100) became 60% by mass. Then, the same mass of the components (a) to (f) as the total amount of the organic solvent was added. The zirconium dioxide beads were stirred for 30 minutes using a ball mill (Fritsch Japan Co., Ltd., planetary micro-pulverizer P-7). After stirring, the zirconium dioxide beads were removed by filtration to prepare a coating varnish.

[0155] The obtained coating varnish was applied using a table coater (manufactured by Hirano Kinzoku Co., Ltd.) and dried at 80° C. for 5 minutes, thereby obtaining a film-like adhesive having a film thickness of 20 μm.

[0156] The adhesive strength and reliability of the film adhesives obtained in Examples and Comparative Examples, and the warpage of semiconductor devices produced using the film adhesives were evaluated by the evaluation methods shown below. The evaluation results are shown in Table 1.

[0157] <Measurement of Adhesion Strength>

[0158] The film adhesive was cut into a specified size (3.2 mm long × 3.2 mm wide × 0.02 mm thick), attached to a silicon chip (3 mm long × 3 mm wide × 0.725 mm thick) at 70°C, and pressed onto another silicon chip (5 mm long × 5 mm wide × 0.725 mm thick) using a thermal compression tester (manufactured by Hitachi Chemical TechnoPlant Co., Ltd.) (compression bonding conditions: compression bonding at a compression head temperature of 190°C for 5 seconds, compression bonding at a compression head temperature of 240°C for 5 seconds, and a load of 0.5 MPa). Then, it was cured (175°C, 2 hours) in a clean oven (manufactured by Tabai Espec Co., Ltd.) to obtain a test sample.

[0159] The above-mentioned test samples were placed in a constant temperature and humidity chamber (manufactured by Tabai Espec Co., Ltd.) at 85°C and 85% relative humidity for 24 hours. After being taken out, the adhesion strength (adhesion strength at 250°C after moisture absorption) was measured using an adhesion force measuring device (manufactured by Dage Arctek Co., Ltd.) on a hot plate at 250°C at a tool height of 0.05 mm from the upper surface of the silicon chip on the lower side and a tool speed of 0.05 mm / s.

[0160] <Evaluation of reflow resistance>

[0161] The film adhesive was cut into a predetermined size (7.3 mm in length × 7.3 mm in width × 0.04 mm in thickness), attached to the bump side of a semiconductor chip with solder bumps (chip size: 7.3 mm in length × 7.3 mm in width × 0.15 mm in thickness, metal of the connection part: copper pillar + solder, bump height (total height of copper pillar + solder): about 45 μm), and mounted on a glass epoxy substrate (thickness of glass epoxy substrate: 0.42 mm, thickness of copper wiring: 9 μm) using a flip chip mounting device "FCB3" (mounting conditions: after temporary compression at 100°C / 0.5 MPa / 1s, the temperature was raised to 180°C / 0.5 MPa / 2s, and then formal compression was performed at 260°C / 0.5 MPa / 5s) to obtain a semiconductor device. The film adhesive was made 40 μm thick by laminating two sheets of adhesive with a film thickness of 20 μm. The stage temperature on which the substrate is placed during the crimping is 80° C. The semiconductor device was molded using a sealing material (manufactured by Hitachi Chemical Co., Ltd., trade name “CEL9750ZHF10”) at 180° C., 6.75 MPa, and 90 seconds, and cured in a clean oven (manufactured by Tabai Espec Co., Ltd.) (175° C., 2 hours) to obtain a test sample.

[0162] Next, the test sample was processed under JEDEC (Joint Electron Device Engineering Council) Level 2 conditions and then passed through a reflow furnace (manufactured by Tamura Corporation) three times (reaching a maximum temperature of 260°C). The connection resistance of the package before and after reflow was measured using a multimeter (manufactured by Custom Co., Ltd.). The case where the change in the connection resistance value before and after reflow was less than 5Ω was evaluated as "A", and the case where the change exceeded 5Ω or the connection was poor was evaluated as "B".

[0163] <Warp Evaluation>

[0164] A semiconductor device was made using the same method as the evaluation of reflow resistance and used as a test sample. For the above test sample, a non-contact shape measuring device (manufactured by Sony Group Corporation) was used to measure the shape of the two sides in the diagonal direction when the chip was observed from above. The difference between the maximum and minimum values ​​of the concave and convex of each side was taken as the warpage (μm), and the warpage was evaluated using the average value of the two sides. The case where the warpage is less than 70μm is evaluated as "A", and the case where it exceeds 70μm is evaluated as "B".

[0165] [Table 1]

[0166]

[0167] The results shown in Table 1 show that the semiconductor adhesives of Examples 1 to 4 containing an inorganic filler and a silicone rubber filler have superior adhesive strength and reflow resistance and achieve reduced warpage compared to the semiconductor adhesives of Comparative Examples 1 and 2.

[0168] Explanation of symbols

[0169] 10. Semiconductor Chip

[0170] 15 Wiring (connection)

[0171] 20 Substrate (wiring circuit board)

[0172] 30 Connecting bump

[0173] 32 Bump (connection part)

[0174] 34 Through electrode

[0175] 4 Adhesive materials

[0176] 50 Intermediary Layer

[0177] 100, 200, 300, 400, 500, 600 Semiconductor devices

Claims

1. A semiconductor adhesive comprising: Resins with a weight average molecular weight of less than 10,000, curing agents, inorganic fillers, silicone rubber fillers, polymer components with a weight average molecular weight of more than 10,000, and fluxing agents, The content of the inorganic filler is 20% to 50% by mass based on the total solid content of the semiconductor adhesive. The semiconductor adhesive is in the form of a film having a thickness of 2.5 to 20 μm.

2. The semiconductor adhesive according to claim 1, wherein The average particle size of the silicone rubber filler is 2 to 50 μm.

3. The adhesive for semiconductor according to claim 1 or 2, wherein: The average particle size of the silicone rubber filler is greater than 5 μm.

4. The adhesive for semiconductor according to claim 1 or 2, wherein: The average particle size of the silicone rubber filler is less than 30 μm.

5. The adhesive for semiconductor according to claim 1 or 2, wherein: The inorganic filler contains a silica filler.

6. The adhesive for semiconductor according to claim 1 or 2, wherein: The weight average molecular weight of the polymer component is 30,000 or more, and the glass transition temperature of the polymer component is 100° C. or less.

7. The adhesive for semiconductor according to claim 1 or 2, wherein: The content of the silicone rubber filler is 0.1% by mass to 20% by mass based on the total solid content of the adhesive for semiconductor.

8. The adhesive for semiconductor according to claim 1 or 2, wherein: The mass ratio of the content of the silicone rubber filler to the content of the inorganic filler is 0.05 to 0.

5.

9. A method for manufacturing a semiconductor device, wherein the semiconductor device is a semiconductor device in which the connection parts of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which the connection parts of a plurality of semiconductor chips are electrically connected to each other, the method comprising: A step of sealing at least a portion of the connection portion using the semiconductor adhesive according to any one of claims 1 to 8.

10. A semiconductor device comprising: A connection structure in which the connection portions of a semiconductor chip and a printed circuit board are electrically connected to each other, or a connection structure in which the connection portions of a plurality of semiconductor chips are electrically connected to each other; and an adhesive material that seals at least a portion of the connection, The adhesive material is formed of a cured product of the adhesive for semiconductor according to any one of claims 1 to 8.

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