TWI864185B - Encapsulation resin composition, and semiconductor device - Google Patents

Abstract

The present invention provides a sealing resin composition, which is easy to fill between a substrate and a large chip and is not easy to cause cracks in the sealing material even when the sealing resin composition is used to seal between a substrate and a large chip. The sealing resin composition contains a polysiloxane resin (A1) having two or more epoxy groups in one molecule, phosphoric acid (B) and phosphoric acid polyester (C).

Description

Sealing resin composition and semiconductor device

The present disclosure relates to a sealing resin composition and a semiconductor device, and more particularly to a sealing resin composition for sealing electronic parts such as semiconductor elements, and a semiconductor device having a sealing material made of the sealing resin composition.

Patent document 1 discloses a sealing liquid epoxy resin composition, which contains a liquid bisphenol epoxy resin, silicone rubber particles, silicone-modified epoxy resin, aromatic amine hardener, coupling agent, inorganic filler and organic solvent. It also discloses that even if the sealing liquid epoxy resin composition is applied to electronic component devices requiring low warpage, the warpage can be suppressed to a small level, and the reliability of strength, heat shock resistance, moisture resistance, etc. is still excellent. Prior art documents Patent document

Patent document 1: Japanese Patent Publication No. 2007-23272

The present disclosure aims to provide a sealing resin composition and a semiconductor device having a sealing material composed of a cured product of the sealing resin composition. Even when the sealing resin composition is used as a sealing material for sealing between a substrate and a large chip, it is easy to fill the space between the substrate and the chip and is not easy to cause cracks in the sealing material.

Means for solving the problem The present invention discloses a sealing resin composition containing an epoxy resin (A), phosphoric acid (B) and a phosphoric acid polyester (C). The epoxy resin (A) contains a polysilicone resin (A1) having two or more epoxy groups in one molecule.

The present invention discloses a semiconductor device in one aspect, comprising: a substrate, a mounting component mounted on the substrate, and a sealing material for sealing a gap between the substrate and the mounting component. The sealing material is formed by a cured product of the sealing resin composition.

1. Overview The sealing resin composition of this embodiment contains an epoxy resin (A), phosphoric acid (B) and a phosphoric acid polyester (C). The epoxy resin (A) contains a polysilicone resin (A1) having two or more epoxy groups in one molecule.

In the past, inorganic fillers (fillers) such as silica have been mixed into the sealing resin composition to improve the heat resistance and reduce the coefficient of thermal expansion (CTE) of the sealing material made of the resin composition. However, if the filler ratio in the resin composition is increased too much, the filler will easily agglomerate, and the viscosity of the resin composition will increase excessively, resulting in reduced fluidity, resulting in the possibility of reduced formability. In addition, if the formability of the resin composition is reduced when the resin composition is formed, there is a problem that the resin composition cannot be fully filled into the gap between the substrate and the semiconductor chip in the semiconductor device when the resin composition is used to seal the gap.

In recent years, the size of the chip has also increased. As the chip increases in size, the size of the sealant also increases, so the stress on the sealant tends to increase, and there are cases where the performance such as heat shock resistance cannot be fully obtained. Therefore, cracks and peeling of the sealant are easy to occur. In addition, when the sealant is made of a composition, if the chip is enlarged, it is also difficult to fully fill the composition between the base material such as the substrate and the chip.

In contrast, the sealing resin composition of the present embodiment can impart thermosetting properties to the sealing resin composition by including the polysilicone resin (A1) in the epoxy resin (A), and can reduce the storage elastic modulus of the sealing resin composition and the cured product of the sealing resin composition. Furthermore, the CTE of the cured product made from the sealing resin composition can be reduced. Furthermore, the sealing resin composition of the present embodiment can maintain a relatively low viscosity, and the thixotropic index can also be close to 1, so that it can have good fluidity.

Furthermore, the sealing resin composition contains phosphoric acid (B) and phosphoric acid polyester (C), which can improve the dispersibility of the components in the sealing resin composition. Therefore, even if the viscosity is easily increased due to the polysilicone resin (A1), the sealing resin composition can maintain good fluidity because the dispersibility has been improved. This makes it easy for the sealing resin composition to flow in the gap between the base material and the mounting substrate, so it is easy to make the sealing material fully fill the gap.

As described above, the sealing resin composition of the present embodiment can achieve good fluidity, and can achieve low CTE and low elastic modulus of the hardened material made from the sealing resin composition. In particular, the hardened material made from the sealing resin composition of the present embodiment contains polysilicone resin (A1), phosphoric acid (B) and phosphate polyester (C), thereby not only achieving low CTE and low elastic modulus, but also improving the fracture toughness K1c. In addition, in the present disclosure, the fracture toughness K1c refers to the resistance of a defective material to fracture when subjected to force. The fracture toughness is measured by the method described in the embodiments described later. Furthermore, the sealing resin composition of the present embodiment has high fracture toughness and can be used to produce a sealing material that is not prone to cracking. In particular, in the present embodiment, the semiconductor chip can be made less prone to cracking when the chip size is increased as the semiconductor device becomes more functional, and the reliability of the semiconductor device can be improved.

In the present disclosure, chip enlargement means that, for example, a semiconductor chip in a mounting part has a rectangular chip size with a side length of 25 mm or more in a top view, or has an area of 625 ^mm2 or more in a top view. However, in the present embodiment, the chip size is not limited to the above, and the composition of the present embodiment can be applied regardless of the chip size.

More specifically, the desired properties of the sealing resin composition can be achieved by appropriately adjusting the components described below.

As shown in FIG1 , the sealing resin composition of the present embodiment can be suitably used in a semiconductor device 1 as a sealing material 4 for sealing between a substrate 2 and a mounting part 3 such as a semiconductor chip. In particular, the sealing resin composition can be suitably used as a bottom filling material. When the sealing resin composition is used as a bottom filling material and the sealing material 4 is made of the sealing resin composition, cracks are less likely to occur in the sealing material 4. 2. Details

Detailed description of the ingredients that can be contained in the sealing resin composition. [Epoxy resin (A)]

The sealing resin composition of this embodiment contains an epoxy resin (A). The epoxy resin (A) is a thermosetting component. The epoxy resin (A) has at least one epoxy group in one molecule. In this embodiment, the epoxy resin (A) contains a polysilicone resin (A1) having two or more epoxy groups in one molecule.

The viscosity of the epoxy resin (A) at 25°C is preferably 100 mPa·s or more and 20 Pa·s or less. The viscosity of the epoxy resin (A) can be measured, for example, using a B-type rotational viscometer at a rotational speed of 50 rpm. [Polysilicone resin (A1)]

As described above, the sealing resin composition contains the polysilicone resin (A1). The polysilicone resin (A1) has two or more epoxy groups in one molecule.

The so-called polysilicone resin is a compound having a siloxane bond in the molecule. In the present embodiment, the polysilicone resin (A1) has at least one siloxane bond and two or more epoxy groups in one molecule. The polysilicone resin (A1) in the sealing resin composition of the present embodiment has a siloxane skeleton, which can help reduce CTE. Also, because it has an epoxy group, it can give the sealing resin composition thermosetting properties.

The polysilicone resin (A1) preferably has at least one epoxy group at one molecule end. In this case, the polysilicone resin (A1) is not easy to produce agglomeration, so it is not easy to increase the viscosity of the sealing resin composition excessively, so that good fluidity can be ensured. Here, one molecule end means the position of the end farthest from the silicon atom in the siloxane bond in the molecule, which is the linking chain bonded to the silicon atom. For example, even if the polysilicone resin (A1) is branched, the end can still be any position of each branch end. In the polysilicone resin (A1), if the epoxy group exists at the end of the molecule, the reactivity of the sealing resin composition is not easy to increase excessively, so the storage stability of the sealing resin composition can be maintained. Therefore, when the sealing resin composition is molded, the moldability (processability) can be maintained, and it is not easy to harden in the middle of molding, and it is easy to fill the gap between the substrate and the semiconductor chip.

The silicone resin (A1) is preferably in a liquid state at 25°C. In this case, it is particularly easy to adjust the viscosity of the sealing resin composition to a good viscosity for molding. Moreover, even if the sealing resin composition does not contain a solvent, it is still easy to adjust it to have an appropriate viscosity. The viscosity of the silicone resin (A1) at 25°C is preferably, for example, 1000 mPa·s or less.

The content of the polysilicone resin (A1) is preferably 0.1% by mass or more and 15.0% by mass or less relative to the total amount of the epoxy resin (A). This can help reduce the viscosity of the sealing resin composition and improve the fracture toughness K1c. The content of the polysilicone resin (A1) is preferably 0.5% by mass or more and 12.0% by mass or less, and even more preferably 1.0% by mass or more and 10.0% by mass or less. [Bisphenol-type epoxy resin (A2)]

The epoxy resin (A) preferably further contains a bisphenol type epoxy resin (A2). That is, the sealing resin composition preferably further contains a bisphenol type epoxy resin (A2). In this case, the sealing resin composition can be given thermosetting properties.

The bisphenol type epoxy resin (A2) contains, for example, at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol type epoxy resin, bisphenol S type epoxy resin, and derivatives of these resins. The bisphenol type epoxy resin (A2) preferably contains bisphenol F type epoxy resin. In this case, the sealing resin composition can be given better thermal curing properties. Bisphenol F type epoxy resin is a compound formed by two phenol skeletons linked by one ethylene chain. Bisphenol F type epoxy resin may also have a substituent in the phenol skeleton.

The viscosity of the bisphenol epoxy resin (A2) at 25°C is preferably, for example, 1000 mPa·s or more and 4000 mPa·s or less. [Aromatic amino epoxy resin (A3)]

The epoxy resin (A) preferably further contains an aromatic amine epoxy resin (A3). That is, the sealing resin composition preferably further contains an aromatic amine epoxy resin (A3). In this case, the storage stability of the sealing resin composition can be maintained, and at the same time, the sealing resin composition can be given better thermal curing properties.

The aromatic amino epoxy resin (A3) preferably has an aromatic ring, an amino group bonded to the aromatic ring, and three or more epoxy groups in one molecule. That is, the aromatic amino epoxy resin (A3) preferably has three or more functional groups.

The aromatic amino epoxy resin (A3) preferably has an aromatic ring, an amine group bonded to the aromatic ring, an epoxy group bonded to the amino group, and an epoxy group bonded to the amine group bonded to the aromatic ring at a different position. That is, when the aromatic amino epoxy resin (A3) has three or more epoxy groups, at least one of them is preferably bonded to the amine group bonded to the aromatic ring.

Specific examples of the aromatic amino epoxy resin (A3) include N,N-diglycolpropyl-p-glycidoxyaniline, etc. The aromatic amino epoxy resin (A3) is not limited to the aforementioned compounds.

The viscosity of the aromatic amino epoxy resin (A3) at 25° C. is preferably 400 mPa·s or more and 800 mPa·s or less.

The epoxy resin (A) preferably further contains at least one of a bisphenol epoxy resin (A2) and an aromatic amine epoxy resin (A3). It is more desirable that the sealing resin composition contains both the bisphenol epoxy resin (A2) and the aromatic amine epoxy resin (A3). In this case, it is easy to make the components in the sealing resin composition undergo a proper curing reaction, so that it is easy to seal the gap between the substrate and the semiconductor chip well with the sealing material made of the sealing resin composition. When the sealing resin composition contains the bisphenol type epoxy resin (A2) and the aromatic amino epoxy resin (A3), the mass ratio of the total amount of the bisphenol type epoxy resin (A2) and the aromatic amino epoxy resin (A3) relative to the epoxy resin (A) is preferably 85 mass % or more and 95 mass % or less.

When the sealing resin composition contains the bisphenol epoxy resin (A2) and the aromatic amine epoxy resin (A3), the total content of the bisphenol epoxy resin (A2) and the aromatic amine epoxy resin (A3) is preferably 30% by mass or more and 50% by mass or less, preferably 35% by mass or more and 45% by mass or less, and more preferably 30% by mass or more and 40% by mass or less, relative to the total amount of the sealing resin composition. Within this range, it is easier to maintain the fluidity of the sealing resin composition well, and the gap between the substrate and the semiconductor chip can be well filled, so that the gap between the substrate and the semiconductor chip can be fully sealed.

In addition, the components that can be contained in the epoxy resin (A) in the sealing resin composition are not limited to those described above, and may also contain resins having epoxy groups other than those described above. [Phosphoric acid (B)]

The sealing resin composition contains phosphoric acid (B). Phosphoric acid (B) has a structure represented by the following formula (1). [Chemical formula 1]

If the sealing resin composition contains phosphoric acid (B), the effect of the phosphoric acid polyester (C) described later on improving the dispersibility in the sealing resin composition can be promoted. Phosphoric acid (B) is preferably mixed into the sealing resin composition in the form of a mixture prepared by mixing with the phosphoric acid polyester (C). [Phosphate polyester (C)]

The sealing resin composition contains a phosphate polyester (C). If the sealing resin composition contains a phosphate polyester (C), it is easy to improve the dispersibility of the components in the sealing resin composition. Therefore, even if the sealing resin composition contains a polysilicone resin (A1) which is a silicon-containing compound, it is not easy for the viscosity of the sealing resin composition to increase excessively, and good fluidity can be ensured. In addition, it is not easy to hinder the effect of reducing the CTE of the cured product made from the sealing resin composition. In addition, since the sealing resin composition contains phosphoric acid (B) and phosphate polyester (C), it is not easy to reduce the dispersibility even if the ratio of the inorganic filler (filler) is increased. Therefore, it is easy to increase the ratio of the filler in the sealing resin composition, and it is easier to achieve the reduction of the CTE of the cured product made from the sealing resin composition.

The phosphoric acid polyester (C) may have a structure represented by the following formula (2). [Chemical Formula 2]

In formula (2), R ₁ , R ₂ and R ₃ are, for example, independently selected from the group consisting of alkyl, alkenyl and alkynyl. R ₁ , R ₂ and R ₃ may be independently long chain or branched chain. In addition, at least one of R ₁ , R ₂ and R ₃ may be a hydrogen atom. That is, the phosphate polyester (C) is a compound in which at least two hydrogen atoms in the formula (1) of phosphoric acid (B) are independently replaced by R ₁ , R ₂ and R ₃ .

The substituents R ₁ , R ₂ and R ₃ may also contain a phosphorus atom. For example, the phosphate polyester (C) may be a compound derived from polyphosphoric acid represented by the following formula (3). That is, the phosphate polyester (C) may also have two or more phosphorus atoms in one molecule. [Chemical Formula 3]

In formula (3), n is 2 or more. When the phosphate polyester (C) is derived from formula (3), it is sufficient as long as at least two hydrogen atoms in formula (3) are substituted by groups selected from the group consisting of alkyl, alkenyl and alkynyl groups. In addition, the phosphate polyester (C) may also have a hydroxyl group at the end. In addition, when n=1, it is equivalent to the phosphoric acid (B) shown in formula (1).

The phosphoric acid polyester (C) is not limited to the above, and may include, for example, a reaction product obtained by reacting a suitable alkyl ether, polyalkylene glycol monoalkyl ether, or the like with a phosphoric acid esterification agent.

Specific examples of the phosphate polyester (C) include phosphate polyesters that may be contained in BYK-W series (e.g., BYK-W9010, etc.) and DISPERBYK series (e.g., DISPERBYK-111, etc.) manufactured by BYK-CHEMIE Japan Co., Ltd.

In the sealing resin composition, the mass ratio of the phosphate polyester (C) is preferably greater than 0 mass % and less than 100 mass %, preferably greater than 0.01 mass % and less than 90 mass %, more preferably greater than 0.02 mass % and less than 50 mass %, and particularly preferably greater than 0.05 mass % and less than 10 mass %.

When the sealing resin composition contains silicon dioxide (E1), the combined mass ratio of phosphoric acid (B) and phosphoric acid polyester (C) relative to silicon dioxide (E1) is preferably 0.05 mass % or more and 1.0 mass % or less. In this case, the CTE of the cured product of the sealing resin composition can be further reduced. The mass ratio of phosphoric acid polyester (C) is preferably 0.1 mass % or more and 0.5 mass % or less, and even more preferably 0.2 mass % or more and 0.4 mass % or less. In this case, the sealing resin composition can be given better fluidity, thereby making it easier to fill the sealing resin composition in the gap.

In the sealing resin composition, the total mass ratio of phosphoric acid (B) and phosphoric acid polyester (C) relative to the silicone resin (A1) is preferably 30 mass % or more and 70 mass % or less, and more preferably 40 mass % or more and 60 mass % or less. [Curing aid (D)]

The sealing resin composition preferably contains a hardening aid (D). In this case, it can help the storage stability of the sealing resin composition. Moreover, when the sealing resin composition is hardened in this case, the speed of the hardening reaction can be controlled. In addition, the hardening aid (D) contains a hardening accelerator. The hardening aid (D) has the function of promoting the reaction of the hardening components in the sealing resin composition. In this embodiment, the hardening reaction of the polysilicone resin (A1) in the sealing resin composition can be slowly promoted. In addition, when the sealing resin composition contains hardening components such as bisphenol-type epoxy resin (A2) and aromatic amino epoxy resin (A3), the hardening of these components can also be promoted. In particular, in the present embodiment, when the epoxy resin (A) in the sealing resin composition is cured, the curing aid (D) can inhibit the curing reaction from progressing excessively. That is, the curing aid (D) is not likely to excessively increase the curing reactivity of the sealing resin composition, but can make the curing progress at a good curing speed. Therefore, even if the sealing resin composition begins to cure due to a rise in temperature during molding of the sealing resin composition, it is not likely to cure rapidly, and it is not likely to damage fluidity during molding, so that it can be cured after being fully filled.

The curing aid (D) preferably contains a chelate compound (D1). In this case, the metal atoms in the chelate compound (D1) can coordinate with the oxygen atoms of the epoxy resin (A), thereby suppressing the excessive heat curing reaction of the epoxy resin (A) in the sealing resin composition. In this way, the storage stability of the sealing resin composition can be further improved. In addition, the excessive increase in the viscosity of the sealing resin composition can also be suppressed. Therefore, the fluidity of the sealing resin composition can also be better maintained.

The chelate compound (D1) comprises, for example, at least one compound selected from the group consisting of aluminum acetylacetonate, titanium acetylacetonate, titanium tetraacetylacetonate, titanium acetylacetate, zirconium ethyl acetylacetate and zirconium tetraacetylacetonate. The chelate compound (D1) preferably contains aluminum acetylacetonate.

When a curing aid (D) is contained, the mass ratio of the curing aid (D) relative to the epoxy resin (A) is preferably 0.01 mass % or more and 2.0 mass % or less, preferably 0.03 mass % or more and 1.5 mass % or less, and more preferably 0.1 mass % or more and 1.0 mass % or less. Within this range, the curability of the epoxy resin (A) in the sealing resin composition can be good, and even if the chip size is enlarged, the cured product of the sealing resin composition can still fully seal the gap between the substrate and the semiconductor chip.

The content of the chelating compound (D1) relative to the hardening aid (D) is preferably 20% by mass or more and 100% by mass or less, more preferably 30% by mass or more and 90% by mass or less, and even more preferably 50% by mass or more and 70% by mass or less. [Inorganic filler (E)]

The sealing resin composition preferably contains an inorganic filler (E). The inorganic filler (E) can help reduce the linear expansion coefficient of the cured product made from the sealing resin composition. Furthermore, in the present embodiment, the sealing resin composition contains phosphoric acid (B) and phosphate polyester (C), so even if it contains an inorganic filler (E), it is not easy to reduce the dispersibility of the sealing resin composition. Therefore, it is not easy for the viscosity of the sealing resin composition to increase excessively, and the fluidity can be maintained, and it is not easy for the thixotropic property to deteriorate. Thereby, even if the content of the inorganic filler (E) in the sealing resin composition is increased, the fluidity is still not easy to deteriorate, and the linear expansion coefficient of the sealing resin composition can be reduced.

The inorganic filler (E) preferably contains silica (E1), and preferably at least a portion of the silica (E1) has been surface treated with a coupling agent. In this case, the silica (E1) can be easily made to be compatible with the polysilicone resin (A1), so that the dispersibility of the sealing resin composition can be further improved. The coupling agent is, for example, a silane coupling agent. The silane coupling agent can be, for example, a compound having at least one functional group selected from the group consisting of an epoxy group, an amino group, a (meth)acryl group and a phenyl group. The silane coupling agent is preferably a silane coupling agent having a phenyl group. That is, preferably at least a portion of the silica (E1) has been surface treated with a silane coupling agent having a phenyl group. At this time, the silicon dioxide (E1) and the polysilicone resin (A1) in the sealing resin composition can be particularly compatible, and the dispersibility of the sealing resin composition can be further improved.

When the inorganic filler (E) contains silica (E1), the silica (E1) preferably includes a first silica filler (E11) and a second silica filler (E12) having an average particle size different from that of the first silica filler (E11). The "average particle size" disclosed herein is a volume average particle size. The volume average particle size is calculated from a particle size distribution measured by a laser diffraction scattering method. The particle size distribution can be measured, for example, using a laser diffraction particle size distribution measuring device, and an example of the laser diffraction particle size distribution measuring device is the LA-960 series manufactured by Horiba, Ltd.

The average particle size of the first silica filler (E11) is preferably greater than 0.1µm and less than 1.5µm, and the standard deviation of the particle size distribution of the first silica filler (E11) is preferably greater than 0.01 and less than 1.0. In addition, the average particle size of the second silica filler (E12) is preferably greater than 10% and less than 50% of the average particle size of the first silica filler (E11), and the standard deviation of the particle size distribution of the second silica filler (E12) is preferably greater than 0.01 and less than 1.0. Here, the "standard deviation of particle size distribution" disclosed in the present invention is an indicator of the width of the particle size distribution. The standard deviation of the particle size distribution can be used to determine whether the particle sizes are consistent. The standard deviation of the particle size distribution can be calculated as follows. Similar to the above-mentioned average particle size (volume average particle size), the standard deviation can be calculated from the particle size data of each particle and the average particle size in the particle size distribution measured by the laser diffraction scattering method. In the silica (E1) in the sealing resin composition, if the standard deviation of the particle size distribution of the silica particles of the first silica filler (E11) and the second silica filler (E12) is greater than 0.01 and less than 1.0, the viscosity of the sealing resin composition can be further reduced. Thereby, the fluidity of the sealing resin composition can be ensured. Therefore, when the gap between the substrate and the semiconductor element is sealed with the sealing resin composition, better formability can be achieved.

The average particle size of the first silica filler (E11) is preferably 0.1 µm or more and 1.0 µm or less. Furthermore, the standard deviation of the particle size distribution of the first silica filler (E11) is preferably 0.01 or more and 0.6 or less, preferably 0.02 or more and 0.40 or less, more preferably 0.02 or more and 0.36 or less, and particularly preferably 0.05 or more and 0.36 or less. The average particle size of the second silica filler (E12) is not particularly limited as long as it satisfies the above conditions. For example, the average particle size of the second silica filler (E12) can be set to 0.01 µm or more and 0.75 µm or less. The standard deviation of the particle size distribution of the second silica filler (E12) is preferably 0.01 or more and less than 0.10, more preferably 0.02 or more and 0.08 or less, further preferably 0.03 or more and 0.08 or less, and particularly preferably 0.04 or more and 0.06 or less.

It is preferred that the first silica filler (E11) and the second silica filler (E12) are both wet silica. Wet silica refers to amorphous silica synthesized in a liquid. For example, wet silica can be produced by at least one method selected from the group consisting of a sedimentation method and a sol-gel method. Wet silica is particularly preferably produced by a sol-gel method. In this case, the average particle size of the wet silica particles can be suppressed to a smaller size, such as 0.1µm or more and 1.5µm or less, and it is not easy to generate uneven particle size distribution. That is, in this case, the particle sizes of the first silica filler (E11) and the second silica filler (E12) can be easily made consistent. In addition, the sol-gel method is a method of synthesizing a solid substance from a sol state in which microparticles such as colloids are dispersed in a solution, through a gel state in which fluidity disappears, and the synthesis method can be an appropriate method. In addition, the fact that the first silica filler (E11) disclosed in the present invention is produced using the sol-gel method can be confirmed by cutting off particles of the appropriate first silica filler (E11) and observing its cross section. Specifically, for example, a cured product of a sealing resin composition can be cut, and its cross section can be observed with an electron microscope and the particle size of the silica on the cross section can be measured to determine whether it is a product produced using the sol-gel method. The fact that the second silica filler (E12) and the third silica filler (E13) described later were produced by the sol-gel method can also be confirmed in the same manner as the first silica filler (E11).

The silica (E1) may also preferably further include a third silica filler (E13) having an average particle size different from that of the first silica filler (E11) and the second silica filler (E12). That is, the sealing resin composition may also preferably contain the first silica filler (E11), the second silica filler (E12) and the third silica filler (E13). When the silica (E1) contains the third silica filler (E13), the average particle size of the third silica filler (E13) is not particularly limited as long as it is smaller than the average particle size of the second silica filler (E12). The standard deviation of the particle size distribution of the third silica filler (E13) is preferably 0.01 or more and less than 0.10, more preferably 0.02 or more and less than 0.09, more preferably 0.03 or more and less than 0.08, and particularly preferably 0.04 or more and less than 0.06. When the sealing resin composition contains the third silica filler (E13), the fluidity of the sealing resin composition can be further reduced, and even if the fluidity of the sealing resin composition is reduced, it can still have good thixotropic properties. The mass ratio of the third silica filler (E13) relative to the total amount of silica (E1) is preferably 5 mass % or more and 40 mass % or less. When the mass ratio of the third silica filler (E13) to the total amount of silica (E1) is 5 mass % or more, the thixotropic properties can be improved; when the mass ratio is 40 mass % or less, good fluidity can be maintained.

When the silica (E1) contains the third silica filler (E13), the third silica (E13) is preferably wet silica. In this case, the third silica filler (E13) is preferably wet silica produced by a sol-gel method. In this case, it is easy to adjust the first silica filler (E11), the second silica filler (E12) and the third silica filler (E13) to silica particles having the same particle size.

The first silica filler (E11) may also be surface treated with a coupling agent. The surface treatment of the silica filler may be, for example, by reacting a coupling agent (e.g., a silane coupling agent) with wet silica prepared by a sol-gel method. Similarly, the second silica filler (E12) and the third silica filler (E13) may also be surface treated with a coupling agent.

The mass ratio of the first silica filler (E11) to the second silica filler (E12) of the silica (E1) is preferably in the range of 60:40 to 98:2. When the silica (E1) further includes a third silica filler (E13), the mass ratio of the first silica filler (E11), the second silica filler (E12) to the third silica filler (E13) is preferably in the range of 60:30:10 to 90:8:2.

When an inorganic filler (E) is contained, the content of the inorganic filler (E) is preferably 50% by mass or more and 75% by mass or less relative to the total amount of the sealing resin composition. In this case, the CTE of the sealing resin composition can be further reduced. In this embodiment, even if the ratio of the inorganic filler is relatively increased, the fluidity of the sealing resin composition can be maintained particularly well. Therefore, it is less likely that the sealing resin composition is not filled into the gap. The content of the inorganic filler (E) is preferably 50% by mass or more and 70% by mass or less, and even more preferably 55% by mass or more and 65% by mass or less.

As long as the effects of the present disclosure are not impaired, the inorganic filler (E) may also contain fillers other than silicon dioxide. [Other ingredients]

As long as the effects of the present disclosure are not impaired, the sealing resin composition may contain components other than those described above. For example, the sealing resin composition may also contain resin components other than those described above.

Furthermore, the sealing resin composition may contain appropriate additives. Examples of additives include hardeners, fluxes, viscosity modifiers, surface modifiers, silane coupling agents, defoaming agents, leveling agents, stress reducing agents, and pigments.

For example, the sealing resin composition preferably contains a silane coupling agent. In this case, the compatibility between the polysilicone resin (A1) and the silane coupling agent in the sealing resin composition is improved, and the dispersibility of the sealing resin composition is more easily improved. In addition, when the sealing resin composition contains silica (E1), the dispersibility of the sealing resin composition is also more easily improved. The silane coupling agent may be any suitable coupling agent, for example, epoxysilane coupling agents such as 2-(3,4-epoxyhexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane.

The sealing resin composition preferably contains no organic solvent or the content of the organic solvent is preferably 0.5 mass % or less.

The sealing resin composition can be obtained, for example, by blending the above ingredients and, if necessary, adding appropriate additives and mixing. Specifically, the sealing resin composition can be prepared, for example, by the following method.

First, the components that may be included in the sealing resin composition described above are mixed simultaneously or sequentially to obtain a mixture, and the mixture is stirred and mixed while being heated or cooled as required.

Then, additives are added to the mixture as required, and the mixture is stirred and mixed again until it is uniformly dispersed while heating or cooling the mixture as required. Thus, a sealing resin composition can be obtained. In order to stir the mixture, for example, a stirrer, a planetary mixer, a ball mill, a three-roll mill, a bead mill, etc. can be appropriately combined as required.

The viscosity of the sealing resin composition at 25°C is preferably less than 35Pa·s. At this time, when the sealing resin composition is formed, the coating workability and discharge stability using the spray dispenser can be improved. In addition, good filling of the bottom of the mounting parts such as semiconductor chips can be achieved. The viscosity of the sealing resin composition at 25°C is preferably below 25Pa·s, and is more preferably below 20Pa·s. There is no special limit to the lower limit of the viscosity of the sealing resin composition at 25°C, for example, it is above 2Pa·s.

The sealing resin composition can be cured by heating, for example. The heating conditions, such as the heating temperature, heating time, and maximum heating temperature, can be appropriately adjusted depending on the type of the curable component (A) and the type of the curing agent.

The glass transition temperature Tg of the cured product of the sealing resin composition is preferably 80°C or higher. In addition, the glass transition temperature Tg is preferably less than 180°C. As long as the glass transition temperature Tg is 80°C or higher, the cured product of the sealing resin composition has heat resistance. It is preferred that the glass transition temperature Tg is 90°C or higher and 170°C or lower. The glass transition temperature can be measured, for example, by TMA (Thermomechanical Analysis).

The coefficient of linear expansion (CTE) of the cured product of the sealing resin composition below the glass transition temperature Tg is preferably 20ppm/°C or more and 40ppm/°C or less, preferably 30ppm/°C or less, and even more preferably 25ppm/°C or less. In this case, the sealing resin composition and the cured product of the sealing resin composition are less likely to warp due to heating. Therefore, cracks are less likely to occur in the cured product of the sealing resin composition. The coefficient of linear expansion of the cured product of the sealing resin composition can be calculated from the Tg of the result measured by TMA, and the slope of the tangent obtained from the dimensional change at a temperature below Tg and the dimensional change at any temperature above Tg.

The storage elastic modulus of the cured product of the sealing resin composition at 25°C is preferably 6.0 GPa or more and 12.0 GPa or less, preferably 6.5 GPa or more and 10 GPa or less. At this time, the cured product of the sealing resin composition is not easy to change in size due to heating. Thereby, it is more difficult to generate cracks in the cured product of the sealing resin composition. The storage elastic modulus of the cured product of the sealing resin composition can be measured using a DMA device in accordance with JIS K6911.

The fracture toughness K1c of the cured product of the sealing resin composition at 25°C is preferably 2.0MPa・m ^1/2 or more. In this case, cracks are less likely to occur in the cured product of the sealing resin composition. This can improve the reliability of semiconductor devices having a sealing material composed of the cured product of the sealing resin composition. The fracture toughness K1c of the cured product is preferably 2.5MPa・m ^1/2 or more, and even more preferably 3.0MPa・m ^1/2 or more. In addition, the fracture toughness K1c can be measured in accordance with JIS R1607. Specifically, it can be measured using the method described in the embodiments described below.

As described above, the sealing resin composition of this embodiment can be suitably used as an underfill material. The sealing resin composition is particularly suitably used as a post-feed underfill material, especially in flip chip mounting. 2.2. Semiconductor device

FIG1 shows an example of a semiconductor device 1 of this embodiment. The semiconductor device 1 includes a substrate 2 supporting a mounting component 3 such as a semiconductor chip, the mounting component 3 mounted face-down on the substrate 2, and a sealing material 4 for sealing a gap between the substrate 2 and the mounting component 3. The sealing material 4 is formed of a cured product of the liquid sealing resin composition described above.

The semiconductor device 1 and the method for manufacturing the same are described in detail.

The semiconductor device 1 includes a substrate 2 having conductive wiring 21, a mounting component 3 such as a semiconductor chip having bump electrodes 33 and mounted on the substrate 2 by bonding the bump electrodes 33 to the conductive wiring, and a sealing material 4 covering the bump electrodes 33. The sealing material 4 is a cured product of the sealing resin composition described above.

The substrate 2 is, for example, a mother substrate, a package substrate, or an interposer substrate. For example, the substrate 2 has an insulating substrate made of glass epoxy, polyimide, polyester, ceramic, etc., and a conductor wiring 21 made of a conductor such as copper formed on the surface thereof. The conductor wiring 21 has, for example, an electrode pad.

The mounting component 3 is, for example, a semiconductor chip. The semiconductor chip is, for example, a flip chip chip such as a BGA (ball grid array), an LGA (land grid array), or a CSP (chip size package). The semiconductor chip may also be a PoP (Package-on-Package) chip.

The mounting component 3 may also have a plurality of bump electrodes 33. The bump electrode 33 has solder. For example, as shown in FIG. 1 , the bump electrode 33 has a guide post 31 and a solder bump 32 disposed at the front end of the guide post 31. The solder bump 32 is made of solder, so the bump electrode 33 has solder. The guide post 31 is made of copper, for example.

There is no particular restriction on the melting point of the solder (e.g., the solder in the solder bump 32) of the bump electrode 33. For example, as long as it can melt at a temperature below the mounting temperature (e.g., 220-260°C) when mounting the mounting component 3 such as a semiconductor chip. In addition, there is no particular restriction on the composition of the solder, and it can be an appropriate composition, such as Sn-Ag solder and Sn-Ag-Cu solder. In addition, the structure of the bump electrode 33 with solder is not limited to the above. For example, the bump electrode 33 may only have a spherical solder bump 32 (solder ball). That is, the bump electrode 33 may not have a guide column.

In the semiconductor device 1 shown in FIG1 , the sealing material 4 fills the entire gap between the substrate 2 and the mounting component 3. Thus, the sealing material 4 covers the entire bump electrode 33 and covers the junction between the bump electrode 33 and the conductive wiring 21. That is, the sealing material 4 is a so-called bottom filler.

The manufacturing method of the semiconductor device 1 will be described by taking an example, but the manufacturing method of the semiconductor device 1 is not limited to the method described below, as long as the gap between the substrate 2 and the mounting part 3 can be sealed by covering the gap with the sealing resin composition described above in the semiconductor device 1.

First, a substrate 2 having a conductive wiring 21 and a mounting component 3 having a bump electrode 33 are prepared, and the mounting component 3 is arranged on the substrate 2 and the bump electrode 33 is arranged on the conductive wiring 21 .

Next, a sealing resin composition is arranged so as to cover the bump electrode 33, and the sealing resin composition and the bump electrode 33 are subjected to a heat treatment to harden the sealing resin composition to produce the sealing material 4, and the bump electrode 33 is electrically connected to the conductive wiring 21. Here, the arrangement of the sealing resin composition is not limited to the case where a solid sealing resin composition is arranged on the sealing object (such as the bump electrode 33), but also includes the case where a liquid sealing resin composition is applied to the sealing object, and the case where the liquid sealing resin composition is arranged in a manner of covering the sealing object by injecting the liquid sealing resin composition into the gap between the sealing objects.

In addition, the above sequence does not need to be the same as above. For example, the mounting component 3 may be arranged on the substrate 2, and the bump electrode 33 may be arranged on the conductive wiring 21, and then the sealing resin composition may be arranged in a manner covering the bump electrode 33. Conversely, the sealing resin composition may be arranged in a manner covering the bump electrode 33, and then the mounting component 3 may be arranged on the substrate 2, and the bump electrode 33 may be arranged on the conductive wiring 21. In addition, in the manufacturing step, as long as the sealing resin composition can be arranged in a manner covering the bump electrode 33, the sealing resin composition may be arranged at any position of the mounting component 3 and the substrate 2 at any time.

Specifically, when manufacturing the sealing material 4 as shown in FIG. 1 , for example, after first disposing the sealing resin composition on the substrate 2, the mounting component 3 is disposed on the substrate 2 in such a manner that the sealing resin composition is interposed between the substrate 2 and the mounting component 3 and the bump electrode 33 is disposed on the conductive wiring 21. In this way, the sealing resin composition can be disposed in such a manner as to cover the bump electrode 33. Alternatively, after first disposing the mounting component 3 on the substrate 2 in such a manner that the bump electrode 33 is disposed on the conductive wiring 21, the sealing resin composition can be supplied between the substrate 2 and the mounting component 3, so that the sealing resin composition is interposed between the substrate 2 and the mounting component 3 and the sealing resin composition is disposed in such a manner as to cover the bump electrode 33.

When manufacturing the sealing material 4 shown in FIG. 1 , for example, the sealing resin composition is first arranged on the mounting component 3 in such a manner as to cover the bump electrode 33. Then, the mounting component 3 is arranged on the substrate 2 in such a manner that the sealing resin composition is interposed between the substrate 2 and the mounting component 3 and the bump electrode 33 is arranged on the conductive wiring 21. In this way, the sealing resin composition can be arranged in such a manner as to cover the bump electrode 33.

When the sealing resin composition is disposed on the substrate 2 or the mounting component 3, the sealing resin composition can be disposed, for example, by a method using a dispenser, a screen printing method, an inkjet method, or a dipping method.

The heat treatment of the sealing resin composition and the bump electrode 33 is performed using a heating furnace such as a reflow furnace. Alternatively, the heat treatment may be performed using an appropriate method using equipment other than a reflow furnace. When the sealing resin composition and the bump electrode 33 are subjected to the heat treatment, the solder of the bump electrode 33 melts, the bump electrode 33 and the conductive wiring 21 are electrically connected, and the sealing resin composition hardens to produce a sealing material 4. Thus, a semiconductor device 1 can be obtained. The conditions for the heat treatment can be appropriately set according to the composition of the sealing resin composition. In the heat treatment, the maximum heating temperature is preferably, for example, above 220°C and below 260°C. In addition, although one example of heat treatment is described above, it is not limited to the above, and the maximum heating temperature can be appropriately set according to the composition of the sealing resin composition, etc.

Examples The following are specific examples of the present disclosure. However, the present disclosure is not limited to the examples. 1. Preparation of resin composition [Examples 1 to 5 and Comparative Examples 1 to 5]

The components shown in Table 1 below are added to a mixer according to the mixing ratio (mass parts) shown in Table 1, stirred and mixed, and uniformly dispersed using a three-roll mill to obtain a resin composition. The details of the components shown in Table 1 are as follows. (Epoxy resin)

・Epoxy-modified polysilicone resin 1: manufactured by Momentive Performance Materials Japan LLC., product name TSL9906, polysilicone resin with epoxy modified at both ends. ・Epoxy-modified polysilicone resin 2: manufactured by ADEKA Co., Ltd., product name EP-3400L, polysilicone resin with epoxy modified at both ends.

・Bisphenol type epoxy resin: Bisphenol F type epoxy resin (manufactured by Tohto Chemical Industry Co., Ltd., product name YDF8170. Epoxy equivalent 175 eq./g).

・Aromatic amino epoxy resin: manufactured by jRR Co., Ltd., product name 636. (Mixture of phosphoric acid and phosphoric acid polyester)

・Mixture of phosphoric acid and phosphoric acid polyester: BYK-CHEMIE Japan Co., Ltd., product name BYK-W 9010 (composition: phosphoric acid polyester content is 90% by weight or more and less than 100% by weight, phosphoric acid content is 1% by weight or more and less than 10% by weight). (hardener)

・Amine hardener: Made by Nippon Kayaku Co., Ltd., product name KAYAHARD A-A. Amine equivalent 65eq./g. (Hardening aid)

・Chelate compound 1: Made by Kawaken Fine Chemicals Co., Ltd., product name Aluminum Chelate A(W). Metal chelate hardening aid. Aluminum tris-acetylacetonate.

・Chelating compound 2: Matsumoto Fine Chemical Co. Ltd., product name TC-100. Titanium tris-acetylacetonate. (Inorganic filler)

・Silica 1: Silica produced by a sol-gel method and surface-treated with a silane coupling agent having a phenyl group (average particle size 1.0 µm, standard deviation of particle size distribution 0.04 or more and 0.5 or less).

・Silica 2: Silica produced by the sol-gel method and surface-treated with a silane coupling agent having a phenyl group (average particle size 0.3µm, standard deviation of particle size distribution 0.04 or more and 0.5 or less).

・Silica 3: Silica produced by the sol-gel method and surface-treated with a silane coupling agent having a phenyl group (average particle size 0.1µm, standard deviation of particle size distribution 0.04 or more and 0.5 or less).

・Silica 4: Silica produced by a sol-gel method and surface-treated with phenylsilane (average particle size 50 nm, standard deviation of particle size distribution 0.04 or more and 0.5 or less).

・Silica 5: Silica produced by the sol-gel method and surface-treated with phenylsilane (average particle size 10 nm, standard deviation of particle size distribution 0.04 or more and 0.5 or less). (Additive)

・Coupling agent: Epoxysilane (Silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd., product name KBM403).

・Colorant: Carbon black (manufactured by jER Co., Ltd., product name MA100). 2. Evaluation 2.1. Viscosity

The viscosity of the resin composition prepared in 1. above was measured using a BM viscometer (model TVB-10 manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25°C, rotor No. 6 and a rotation speed of 5 rpm. Based on the obtained measurement results, the following criteria were used for evaluation.

A: Viscosity is less than 25Pa・s.

B: The viscosity is 25 Pa·s or more and 35 Pa·s or less.

C: Viscosity is 35Pa or more. 2.2. Tactile index

Measure the viscosity at 25°C in the same way as in 2.1. above. Then, change the rotation speed from 5 rpm to about one-tenth of the rotation speed of 5 rpm to measure the viscosity. Calculate the viscosity change rate (viscosity at low speed/viscosity at high speed) from the viscosity before the rotation speed change (at low speed) and the viscosity after the rotation speed change (at high speed), and use this as the thixotropic index (TI). Based on the obtained thixotropic index, evaluate according to the following criteria.

A: TI is greater than 0.7 and less than 1.5.

B: TI is greater than 1.5 and less than 2.5.

C: TI is 2.5 or above. 2.3. Liquidity

Place two flat glass plates on a heatable stand (carrier) with a gap of 10µm, and set the carrier temperature at 90°C to heat the two glass plates. After the temperature of the glass plates reaches 90°C, inject the resin composition prepared in 1. above into the gap of 10µm, and use the capillary phenomenon to make it flow in the gap. And measure the time from the start of injection to the time when the resin composition travels to a distance of 30mm. Based on the results obtained by the measurement, evaluate according to the following criteria.

A: The time to travel to 30 mm is less than 300 seconds.

B: The time to reach 30 mm is 300 seconds or more and less than 500 seconds.

C: The time to reach 30 mm is more than 500 seconds. 2.4. Glass transition temperature (DMA test)

The resin composition prepared in 1. above is applied on a substrate and heated at a heating temperature of 100° C. for a heating time of 2 hours. The temperature is then further raised to a heating temperature of 150° C. for a heating time of 2 hours to cure the resin composition, thereby obtaining a cured product of the resin composition.

Next, the obtained hardened material was measured by a dynamic viscoelasticity measurement (DMA) device (model DMA7100 manufactured by Hitachi High-Tech Science Co.) at a heating rate of 5°C/min from room temperature -60°C to 280°C, and the glass transition temperature of the hardened material was obtained from the obtained results. The values of the obtained glass transition temperature (°C) are listed in Table 1. 2.5. Linear expansion coefficient (TMA test)

The cured product of the resin composition produced under the same conditions as in 2.4. above was heated from -60°C to 280°C using a thermomechanical analysis (TMA) device (manufactured by Hitachi High-Tech Science Co., model TMA7000) at a load of 1g and a heating rate of 5°C/min. The dimensional change was measured and the linear expansion coefficient was calculated from the obtained results and evaluated according to the following criteria.

A: Less than 35ppm/℃.

C: 35ppm/℃ or above. 2.6. Elastic modulus (storage elastic modulus)

For the cured product of the resin composition produced under the same conditions as in 2.4. above, the elastic modulus at each temperature was measured using a DMA device under the same conditions as in 2.4. The storage elastic modulus was calculated from the obtained results and evaluated according to the following criteria.

A: 6.5 GPa or more and less than 12.0 GPa.

C: 12.0GPa or more. 2.7. Fracture toughness (K1c test)

A test specimen (length L: 50 mm, width W: 10 mm, thickness B: 5 mm) was made from a hardened product of a resin composition prepared under the same conditions as in 2.4. above, and a pre-crack with a crack length a: 4 mm was made on the specimen. In accordance with JIS R1607 (Test method for fracture toughness at room temperature of precision ceramics), pressure was applied to the specimen at a speed of 10 mm/min, and the test force before fracture was measured. From the obtained measurement results, the K1c value was calculated according to the following formulas (1) and (2), and the obtained values are listed in Table 1. The larger the value of the fracture toughness K1c, the higher the resistance to cracks can be evaluated. [Mathematical formula 1] …(1) [Mathematical formula 2] …(2)

In the above formulas (1) and (2), Pα: maximum load before the test piece breaks [kgf], S: distance between three-point bending support points [mm], B: thickness of the test piece [mm], W: width of the test piece [mm], a: length of pre-crack [mm]. [Table 1]

1: Semiconductor device 2: Substrate 3: Mounting parts 4: Sealing material 21: Conductor wiring 31: Guide pillar 32: Solder bump 33: Bump electrode

FIG. 1 is a schematic cross-sectional view showing a semiconductor device according to an embodiment of the present disclosure.

1:Semiconductor devices

2: Base material

3: Install parts

4: Sealing material

21: Conductor wiring

31: Guide pillar

32: Solder bumps

33: Bump electrode

Claims (6)

A sealing resin composition comprises: an epoxy resin (A), phosphoric acid (B), and a phosphoric acid polyester (C); wherein the epoxy resin (A) comprises a polysilicone resin (A1) having two or more epoxy groups in one molecule, wherein the epoxy resin (A) further comprises a bisphenol F type epoxy resin (A2) and an aromatic amino epoxy resin (A3). , wherein the content of the polysilicone resin (A1) is greater than 0.1 mass % and less than 15.0 mass % relative to the aforementioned epoxy resin (A), and wherein the mass ratio of the total amount of the bisphenol type epoxy resin (A2) and the aromatic amino epoxy resin (A3) relative to the aforementioned epoxy resin (A) is greater than 85 mass % and less than 95 mass %. The sealing resin composition of claim 1 further contains a hardening aid (D), and the hardening aid (D) contains a chelating compound (D1). The sealing resin composition of claim 1 or 2 further contains an inorganic filler (E). As in claim 3, the sealing resin composition, wherein the inorganic filler (E) contains silicon dioxide (E1), and at least a portion of the silicon dioxide (E1) is surface-treated with a coupling agent. If the sealing resin composition in claim 1 or 2 is a bottom filling material. A semiconductor device comprising: a substrate, a mounting part mounted on the substrate, and a sealing material for sealing the gap between the substrate and the mounting part; and the sealing material is composed of a cured product of a sealing resin composition as described in any one of claims 1 to 5.