TW201810452A - Epoxy resin composition for semiconductor encapsulation and semiconductor device - Google Patents

Abstract

The invention provides an epoxy resin composition for semiconductor encapsulation is a resin composition used for forming an encapsulation element in the semiconductor device. According to the semiconductor device, semiconductor elements carried on a substrate are connected and encapsulated by joints made of silver alloy containing more than 85 mass% and less than 98 mass% of Ag. The resin composition is characterized by containing epoxy resin and a curing agent, and the glass transition temperature (Tg) of a curing substance of the resin composition is above 120 DEG C and below 200 DEG C.

Description

Epoxy composition for semiconductor sealing and semiconductor device

The present invention relates to an epoxy resin composition for semiconductor sealing and a semiconductor device.

In order to improve the humidity resistance reliability of a semiconductor device provided with a bonding wire, various studies have been made on a resin composition for sealing used in the manufacture of related semiconductor devices.

For example, Patent Document 1 describes an epoxy resin composition for semiconductor sealing containing a biphenyl epoxy resin having a hydrolyzable chlorine content of 10 to 20 ppm. This document 1 describes that forming a sealing material from the resin composition is useful for improving the moisture resistance reliability of a semiconductor device including a copper wire containing copper (Cu) as a main component.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1]: Japanese Patent Laid-Open No. 2013-67694

Regarding a semiconductor device manufactured using copper wires, when the related semiconductor device is used for a long period of time, the above-mentioned copper wires or a joint between the copper wires and the electrodes may cause a problem of corrosion. Therefore, the present inventors have conducted intensive research in order to fabricate a semiconductor device that uses silver (Ag) as the main material, which is less susceptible to corrosion than copper wires and is cheaper than gold wires. The main component of the silver wire, thereby suppressing the occurrence of the above-mentioned problems. As a result, the present inventors have found that when a sealing material in a semiconductor device provided with a silver wire is formed from the resin composition described in Patent Document 1, the obtained semiconductor device is still used when the obtained semiconductor device is used in a high temperature and high humidity environment. Defects such as silver wire corrosion may occur. Specifically, the present inventors have found that when a conventional semiconductor device provided with a silver wire is used in a high-temperature and high-humidity environment, the semiconductor device may have a problem in terms of electrical connectivity. Therefore, the present inventors have found that there is room for improvement in terms of humidity resistance reliability in a conventional semiconductor device provided with a silver wire in a high temperature and high humidity environment. It was also confirmed that the above-mentioned problems tend to be more pronounced in a semiconductor device including a silver wire having a low silver purity.

Based on the foregoing, the present invention provides a sealing technology for improving the moisture resistance reliability of a semiconductor device including a bonding wire containing silver (Ag) as a main component.

According to the present invention, there is provided an epoxy resin composition for sealing, which is used to form a sealing material in a semiconductor device which contains a semiconductor element mounted on a substrate and is connected to the semiconductor element and contains 85% by mass. The bonding wire composed of Ag alloy of 98% by mass or less of Ag is sealed. The resin composition contains an epoxy resin and a hardener. The glass transition temperature (Tg) of the hardened product of the resin composition is 120 ° C to 200 ° C. the following.

Furthermore, according to the present invention, there is provided a semiconductor device including: a semiconductor element mounted on a substrate; a bonding wire connected to the semiconductor element and composed of a silver alloy containing 85% by mass to 98% by mass of Ag; and The sealing material which seals the said semiconductor element and the said bonding wire, The said sealing material contains the hardened | cured material of the said epoxy resin composition for sealing.

According to the present invention, it is possible to provide a sealing technology for improving the moisture resistance reliability of a semiconductor device including a bonding wire containing silver (Ag) as a main component.

The above-mentioned objects and other objects, features, and advantages will be made clearer based on the preferred embodiments described below and the following drawings subordinate thereto.

FIG. 1 is a diagram showing an example of a semiconductor device according to this embodiment.

Hereinafter, embodiments will be described using drawings. In all drawings, the same constituent elements are assigned the same reference numerals, and descriptions thereof are appropriately omitted.

<Sealing epoxy resin composition>

The sealing epoxy resin composition (hereinafter also referred to as "the present resin composition") of this embodiment is a resin composition for forming a sealing material in a semiconductor device which is mounted on a substrate. A semiconductor element and a bonding wire connected to the semiconductor element and sealed with a silver alloy containing 85% by mass to 98% by mass of Ag are sealed. This resin composition contains an epoxy resin and a hardener, and the glass transition temperature (Tg) of the hardened | cured material of this resin composition is 120 degreeC or more and 200 degreeC or less. Thereby, it is possible to improve the humidity resistance reliability of a semiconductor device provided with a bonding wire composed of a silver alloy containing 85% by mass to 98% by mass of Ag in a high temperature and high humidity environment. Therefore, as a result, a semiconductor device including a bonding wire made of a silver alloy containing 85% by mass or more and 98% by mass or less of Ag has been subjected to a high temperature and high humidity environment. The reliability of the electrical connection is improved. In this embodiment, the humidity resistance reliability of the semiconductor device can be evaluated by, for example, a HAST test (Highly Accelerated Stress Test). Regarding the semiconductor device manufactured using this resin composition, as described in the example item described later, it can be confirmed that the HAST test is performed when the HAST test is performed at 130 ° C, 85% RH, and a voltage of 20 V for 240 hours. No poor electrical connectivity occurs in the device.

That is, the present resin composition has a structure that satisfies both of the following conditions.

The first condition is assumed to be used for forming a sealing material in a semiconductor device having a bonding wire composed of a silver alloy containing 85% by mass to 98% by mass of Ag.

The second condition is that the glass transition temperature (Tg) of a cured product of a resin composition containing an epoxy resin and a curing agent as essential components is controlled to 120 ° C or higher and 200 ° C or lower.

The inventors have found that the humidity resistance reliability can be improved in the following aspects, that is, when a semiconductor device is manufactured using the present resin composition having a structure that satisfies both of the above conditions, the semiconductor device is used in a high temperature and high humidity environment. In the obtained semiconductor device, it is possible to prevent corrosion of a bonding wire made of a silver alloy containing silver (Ag) as a main component. In particular, the above-mentioned effect of improving the humidity resistance reliability is remarkably exhibited when the silver purity of the bonding wire provided in the semiconductor device is 85% by mass or more and 98% by mass or less.

Regarding this point, comparative data of Examples 1 to 5 and Comparative Examples 1 to 3 will be disclosed in Examples described later.

Among them, the silver purity of the bonding wires provided in the semiconductor device to which the present resin composition is applied is 85% by mass or more and 98% by mass or less, and preferably 87% by mass or more and 96% by mass or less. The silver purity of the bonding wire is 85% by mass or more, preferably 87% by mass or more, and 98%. Mass% or less, preferably 96 mass% or less. Here, the above-mentioned silver purity of the bonding wire refers to a proportion of silver (Ag) as a main component thereof in a substance constituting the bonding wire.

The bonding wire of this embodiment is constituted by a silver alloy containing silver as a main component and containing other metals. Examples of the other metals include palladium.

The glass transition temperature (Tg) of the cured product of the present resin composition is 120 ° C to 200 ° C, preferably 125 ° C to 190 ° C, and more preferably 130 ° C to 180 ° C. When the glass transition temperature (Tg) of the cured product of the present resin composition is controlled in such a range, the semiconductor device including the silver wire having the above purity can be improved in a high temperature and high humidity environment. Reliability of electrical connections. In particular, in this embodiment, the glass transition temperature (Tg) of the hardened material of the resin composition is controlled so that the upper limit value or lower is achieved. As a result, the water absorption of the sealing material formed using the resin composition can be reduced. Sex. Therefore, when a semiconductor device manufactured using the resin composition is used in a high-temperature and high-humidity environment, it is possible to effectively suppress a decrease in the humidity resistance reliability of the semiconductor device.

From the same viewpoint, the glass transition temperature (Tg) of the cured product of the present resin composition is 120 ° C or higher, preferably 125 ° C or higher, more preferably 130 ° C or higher, and 200 ° C or lower, preferably 190. ℃ or lower, more preferably 180 ° C or lower.

Here, the hardened | cured material can be obtained by heat-treating this resin composition at 175 degreeC for 3 minutes, and heat-treating at 175 degreeC for 4 hours, for example.

Moreover, regarding this resin composition, the linear expansion coefficient CTE1 of the hardened | cured material obtained by heat-treating at 175 degreeC for 3 minutes, and further 4 hours at 175 degreeC is preferably 3 ppm / degreeC or less, for example. 100 ppm / ° C or more, more preferably 5 ppm / ° C or more and 50 ppm / ° C or less. As a result, in a semiconductor device manufactured using the resin composition, It is possible to suppress warping when using a semiconductor device.

From the same point of view, the linear expansion coefficient CTE1 of the cured product of the present resin composition below the glass transition temperature Tg is preferably 3 ppm / ° C or more, more preferably 5 ppm / ° C or more, and still more preferably 100 ppm / ° C or less, It is more preferably 50 ppm / ° C or lower.

In the present resin composition, for example, the linear expansion coefficient CTE2 of the cured product obtained by heat-treating at 175 ° C for 3 minutes and then heat-treating at 175 ° C for 4 hours is preferably in a temperature region exceeding the glass transition temperature Tg 5 ppm / ° C to 150 ppm / ° C, more preferably 10 ppm / ° C to 100 ppm / ° C. This makes it possible to suppress the occurrence of warping when a semiconductor device manufactured using the resin composition is used in a high temperature environment.

From the same viewpoint, the linear expansion coefficient CTE2 of the cured product of the present resin composition in a temperature region exceeding the glass transition temperature is preferably 5 ppm / ° C or more, more preferably 10 ppm / ° C or more, and still more preferably 150 ppm / ° C. Hereinafter, it is more preferably 100 ppm / ° C or lower.

The glass transition temperature Tg, the linear expansion coefficient CTE1, and the linear expansion coefficient CTE2 can be measured, for example, as follows. First, using a transfer molding machine, the resin composition was injection-molded at a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a hardening time of 3 minutes to obtain a test piece of 15 mm × 2 mm × 2 mm. Next, the obtained test piece was heat-treated under the conditions of 175 ° C and 4 hours to be hardened. Next, the above-mentioned test piece after post-hardening was measured using a thermomechanical analysis device, and the linear expansion coefficient CTE1 at the glass transition temperature Tg and glass transition temperature Tg or lower was calculated from the measurement results at a temperature exceeding the glass transition temperature Tg Coefficient of linear expansion of the region CTE2.

Hereinafter, the present resin composition and a semiconductor device including a sealing material composed of a cured product of the present resin composition will be described in detail.

First, the present resin composition will be described.

This resin composition is used for sealing a semiconductor element and a bonding wire which is connected to the semiconductor element and is made of a silver alloy containing 85% by mass or more and 98% by mass or less of Ag. In this embodiment, a case where a semiconductor package is formed by sealing a semiconductor element and the above-mentioned bonding wire using a cured product of the resin composition is exemplified.

The semiconductor element is mounted on a substrate such as a wafer pad or an organic substrate constituting a lead frame, or other semiconductor elements. At this time, the semiconductor element is electrically connected to a lead other than the lead frame, an organic substrate, or another semiconductor element via a bonding wire. The bonding wire is connected to, for example, an electrode pad provided on a semiconductor element. The electrode pad of a semiconductor element is made of, for example, a metal material whose main component is Al at least on the surface.

In this embodiment, the thermal time elastic modulus of the cured product of the present resin composition measured at 260 ° C is preferably 300 MPa to 1500 MPa, more preferably 400 MPa to 1400 MPa, and even more preferably 450 MPa to 1400 MPa. By controlling the value of the above-mentioned thermal time elastic modulus to fall within the above-mentioned numerical range, it is possible to effectively prevent the occurrence of defects such as interface peeling or cracking of a sealing material in a semiconductor device manufactured using the resin composition .

From the same point of view, the thermal time elastic modulus of the cured product of the present resin composition is preferably 300 MPa or more, more preferably 400 MPa or more, still more preferably 450 MPa or more, still more preferably 1500 MPa or less, and even more preferably 1400 MPa. the following.

Furthermore, the thermal time elastic modulus of the hardened material of the resin composition measured at 260 ° C can be measured, for example, using a dynamic viscoelasticity measuring device in accordance with JIS K-6911's three-point bending mode at a frequency of 10 Hz and a temperature of 260 ° C Measured. The unit is MPa.

In addition, regarding the present resin composition, the chloride ion concentration in the extract solution extracted from the hardened product of the resin composition under the conditions of 125 ° C. and 100% RH for 20 hours is preferably 1 g of the hardened product. 10 ppm or less, more preferably 9 ppm or less, even more preferably 8 ppm or less. In the present embodiment, when the above-mentioned chloride ion concentration is controlled so that the above-mentioned upper limit value is controlled, it is possible to reduce the water absorption of a sealing material formed using the resin composition. Therefore, in the present embodiment, when the chloride ion concentration is equal to or lower than the upper limit value, it is possible to effectively suppress a decrease in the moisture resistance reliability of a semiconductor device manufactured using the resin composition. In addition, when the above-mentioned chloride ion concentration is controlled so that the above-mentioned upper limit value is controlled, even a semiconductor device having the above-mentioned purity silver wire, it is possible to suppress the corrosion of the joint portion between the relevant silver wire and the electrode pad. . Therefore, when the said chloride ion concentration is below the said upper limit, as a result, the balance of the high temperature operation characteristic and the high temperature storage characteristic of this semiconductor device can also be improved.

The lower limit value of the chloride ion concentration may be, for example, 0 ppm or more, and may be, for example, 1 ppm or more.

The above-mentioned chloride ion concentration can be measured by the following method, for example.

First, a hardened product of a sealing epoxy resin composition constituting a sealing material of a semiconductor device is pulverized by a grinder for 3 minutes, sieved with a 200-mesh sieve, and the passed powder is used as a sample. 5 g of the obtained sample and 50 g of distilled water were sealed in a pressure-resistant container made of Teflon (registered trademark), and subjected to a treatment (pressure cooker treatment) at 125 ° C. and a relative humidity of 100% RH for 20 hours. After cooling to room temperature, the extracted water was centrifuged, filtered through a 20 μm filter, and the chloride ion concentration was measured using a capillary electrophoresis device (for example, CAPI-3300 manufactured by Otsuka Electronics Co., Ltd.). Since the value of the chloride ion concentration measured here is a value diluted 10 times from the chloride ion extracted from 5 g of the sample, it is converted into chlorine per 1 g of the hardened material by the following formula (a). The amount of ions. The unit is ppm.

Formula (a): chloride ion concentration per sample unit mass = (chlorine ion concentration obtained by capillary electrophoresis device) × 50 ÷ 5

With regard to the present resin composition, the sulfur content in the hardened material of the resin composition is preferably 1 ppm or more and 400 ppm or less, more preferably 1 ppm or more and 300 ppm or less, and even more preferably 1 ppm or more with respect to the total amount of the hardened material. 200ppm or less. In this embodiment, by controlling the sulfur content to fall within the above-mentioned numerical range, it is possible to improve the adhesion of the sealing material and the bonding wire or the lead frame formed using the resin composition to the substrate and the semiconductor element. When the sulfur content is controlled to fall within the above numerical range, the silver wire or the junction between the silver wire and the electrode can be suppressed in the obtained semiconductor device even if the silver wire having the purity is used. Corrosion occurred. Therefore, when the sulfur content is controlled so that it falls within the above-mentioned numerical range, as a result, a semiconductor device having excellent reliability can be produced from the viewpoints of reflow resistance, humidity resistance reliability, and high-temperature operation characteristics. Furthermore, by controlling the sulfur content in the hardened material to fall within the above-mentioned numerical range, it is possible to improve the high-temperature storage characteristics of the semiconductor device. Examples of the high-temperature storage characteristics include maintenance of connection reliability of a connection portion between a bonding wire and a semiconductor element under high-temperature conditions.

From the same viewpoint, the sulfur content in the hardened material of the present resin composition is preferably 1 ppm or more, more preferably 400 ppm or less, more preferably 300 ppm or less, and still more preferably 200 ppm with respect to the total amount of the hardened material. the following.

The sulfur content can be measured by the following method, for example.

The hardened | cured material obtained by thermally hardening this resin composition under the conditions of 175 degreeC and 4 hours was pulverized, and the pulverized material was obtained. Next, the conditions for trapping with hydrogen peroxide water at 150 ° C for 8 hours The gas generated when heat treatment is applied to the pulverized material. Next, the sulfur content with respect to the total amount of the present resin composition was calculated from the amount of sulfate ions in the hydrogen peroxide water. The unit is ppm.

The gel time of the resin composition at 175 ° C is preferably 30 seconds or more and 80 seconds or less, and more preferably 35 seconds or more and 60 seconds or less. In this way, by controlling the gel time to be equal to or more than the above-mentioned lower limit value, it is possible to effectively suppress the occurrence of voids in the sealing material when the semiconductor device is manufactured. On the other hand, by controlling the gel time to be equal to or less than the above upper limit value, it is possible to suppress a decrease in the manufacturing efficiency of the semiconductor device.

From the same viewpoint, the gel time of the resin composition is preferably 30 seconds or longer, more preferably 35 seconds or longer, more preferably 80 seconds or shorter, and even more preferably 60 seconds or shorter.

The spiral flow of the resin composition measured by the EMMI-1-66 method is preferably 80 cm to 250 cm, more preferably 100 cm to 230 cm, and even more preferably 110 cm to 200 cm. Thereby, it is possible to suppress the occurrence of a defect such as an unfilled sealing material or a flow of gold wires when manufacturing a semiconductor device.

From the same point of view, the spiral flow of the present resin composition is preferably 80 cm or more, more preferably 100 cm or more, still more preferably 110 cm or more, still more preferably 250 cm or less, more preferably 230 cm or less, and even more preferably Below 200cm.

The spiral flow measured by the EMMI-1-66 method can be measured by the following method, for example. Using a low-pressure transfer molding machine ("KTS-15" manufactured by SHANGHAI SEIKI Co., Ltd.), the resin composition was injected in accordance with EMMI-1 at a mold temperature of 175 ° C, an injection pressure of 6.9 MPa, and a curing time of 120 seconds. The spiral flow measurement mold of -66 measures the flow length as a spiral flow. The unit is cm.

Among them, as a sealing molding method for a semiconductor device using the present resin composition Examples of the method include a transfer molding method, a compression molding method, and an injection molding method. Among them, a transfer molding method or a compression molding method is preferably used from the viewpoint that the filling properties of the resin composition are good. Therefore, the form of the present resin composition is preferably powder, granular, granular, flat, or sheet.

Next, the blend composition of the present resin composition will be described. As described above, the present resin composition contains an epoxy resin and a hardener as essential components.

(Epoxy resin)

As the epoxy resin used in the resin composition, monomers, oligomers, and polymers having two or more epoxy groups in one molecule can be used. Specific examples of such epoxy resins include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E epoxy resin, bisphenol S epoxy resin, and hydrogenated bisphenol A epoxy resin. Epoxy resin, bisphenol M epoxy resin (4,4 '-(1,3-phenylene diisopropylidene) bisphenol epoxy resin), bisphenol P epoxy resin (4,4 '-(1,4-phenylene diisopropylidene) bisphenol type epoxy resin), bisphenol Z type epoxy resin (4,4'-cyclohexadiene bisphenol type epoxy resin), four Bisphenol epoxy resins such as methyl bisphenol F epoxy resin, phenol novolac epoxy resin, brominated phenol novolac epoxy resin, cresol novolac epoxy resin, tetraphenol ethane type Novolac epoxy resins such as novolac epoxy resins, novolac epoxy resins with a fused aromatic hydrocarbon structure, biphenyl epoxy resins, xylylene epoxy resins, biphenylaralkyls (biphenyl aralkyl) epoxy resins and other aralkyl epoxy resins; naphthylene ether epoxy resin, naphthol epoxy resin, naphthalene epoxy resin, naphthalene diphenol epoxy resin, bifunctional or 4-functional epoxy naphthalene resin Epoxy resins with a naphthalene skeleton, such as binaphthyl epoxy resins, naphthalene aralkyl epoxy resins; anthracene epoxy resins; phenoxy epoxy resins; dicyclopentadiene epoxy resins; norborneol Olefinic epoxy resin; adamantane epoxy resin; fluorene epoxy resin, phosphorus-containing epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, bisphenol A novolac epoxy resin Resin, bixylenol type epoxy resin, trihydroxyphenylmethane type epoxy resin, stilbene type epoxy resin, tetraphenol ethane type epoxy resin, triglycidyl isocyanurate, etc. Epoxy resin; N, N, N ', N'-tetraepoxypropyl-m-xylylenediamine, N, N, N', N'-tetraepoxypropylbisaminomethylcyclohexane, N , N-glycidyl anilines and other glycidylamines, or copolymers of glycidyl (meth) acrylate and compounds having ethylenically unsaturated double bonds; epoxy resins with butadiene structure; Diglycidyl etherate of bisphenol; diglycidyl etherate of naphthalene diphenol; phenolic glycidyl etherate and the like. Among these, one kind may be used alone, or two or more kinds may be used simultaneously. Also, bisphenol type epoxy resins such as aralkyl type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and tetramethylbisphenol F type epoxy resin. The stilbene-type epoxy resin may be crystalline. Among them, from the viewpoint of improving the humidity resistance reliability in a high-temperature and high-humidity environment, it is preferable to include a biphenyl type epoxy resin.

In this embodiment, the content of the epoxy resin is preferably 3% by mass or more, more preferably 5% by mass or more with respect to the total amount of the resin composition. When the content of the epoxy resin is equal to or more than the above-mentioned lower limit value, it is possible to improve the adhesion between the sealing material and the semiconductor element in a semiconductor device including a sealing material produced using the resin composition. On the other hand, the content of the epoxy resin is preferably 20% by mass or less, and more preferably 17% by mass or less with respect to the total amount of the present resin composition. When the content of the epoxy resin is equal to or less than the above-mentioned upper limit value, it is possible to improve the heat resistance or moisture resistance of a sealing material formed using the resin composition. Therefore, when the content of the epoxy resin is within the above-mentioned numerical range, a semiconductor device including a sealing material made using the resin composition can improve its moisture resistance reliability and reflow resistance.

(hardener)

As described above, the present resin composition contains a hardener as an essential component. With this, we can provide This resin composition has high fluidity and handleability.

Among them, the hardener of this embodiment can be roughly classified into three types: a compound hardener, a catalyst hardener, and a condensation hardener.

Examples of the additional molding hardener include aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), and m-xylylenediamine (MXDA); diaminodiphenylmethane (DDM) Aromatic polyamines such as m-phenylenediamine (MPDA), diaminodiphenylhydrazone (DDS), and polyamine compounds such as dicyandiamine (DICY) and organic acid dihydrazine; hexahydrophthalic anhydride ( (HHPA), alicyclic anhydrides such as methyltetrahydrophthalic anhydride (MTHPA), aromatic anhydrides such as trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), benzophenone tetracarboxylic acid (BTDA), etc. Acid anhydrides; phenol resin-based hardeners such as novolac phenol resins, polyvinyl phenol; polythiol compounds such as polysulfides, thioesters, and thioethers; isocyanate compounds such as isocyanate prepolymers and blocked isocyanates; carboxylic acids Polyester resins and other organic acids.

Examples of the catalyst-type hardener include tertiary amine compounds such as dimethylbenzylamine (BDMA), 2,4,6-tridimethylaminomethylphenol (DMP-30); 2-methylimidazole, Imidazole compounds such as 2-ethyl-4-methylimidazole (EMI24); Lewis acids such as BF3 complex.

Examples of the condensation-type curing agent include soluble phenol resin type phenol resins; urea resins such as methylol-containing urea resins; melamine resins such as methylol-containing melamine resins, and the like.

The hardener of this embodiment is preferably a phenol resin-based hardener from the viewpoint of improving the balance of the flame resistance, moisture resistance, electrical characteristics, hardenability, and storage stability of the obtained sealing material. As the phenol resin-based curing agent, all monomers, oligomers, and polymers having two or more phenolic hydroxyl groups in one molecule can be used, and the molecular weight and molecular structure are not limited.

Examples of the phenol resin-based hardener include novolac resins such as phenol novolac resin, cresol novolac resin, and bisphenol novolac resin; polyvinyl phenol; biphenylaralkyl type Polyfunctional phenol resins such as phenol resins or triphenol methane phenol resins; modified phenol resins such as terpene modified phenol resins and dicyclopentadiene modified phenol resins; have a phenylene skeleton and / or a phenylene Skeletal phenol aralkyl resins, aralkyl resins such as naphthol aralkyl resins with phenylene and / or biphenylyl skeletons; bisphenol compounds such as bisphenol A, bisphenol F, etc. Among these, one kind may be used alone, or two or more kinds may be used simultaneously. Among them, from the viewpoint of improving the humidity resistance reliability of the semiconductor device under high-temperature and high-humidity environment conditions, it is preferable to include a polyfunctional phenol resin.

In this embodiment, the content of the curing agent is preferably 2% by mass or more and 15% by mass or less, more preferably 3% by mass or more and 13% by mass or less, and still more preferably 4% by mass or more, with respect to the total amount of the resin composition. 11% by mass or less. When the content of the hardener is equal to or more than the above-mentioned lower limit value, the fluidity of the resin composition can be made good, and the moldability can be improved. On the other hand, when the content of the hardener is equal to or less than the above-mentioned upper limit value, the moisture resistance characteristics of a sealing material formed using the resin composition can be improved. Therefore, when the content of the hardener is equal to or less than the above-mentioned upper limit value, as a result, the moisture resistance reliability and reflow resistance of the semiconductor device can be improved.

From the same viewpoint, the content of the hardener in the present resin composition is preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 4% by mass or more, with respect to the total amount of the resin composition. It is preferably 15% by mass or less, more preferably 13% by mass or less, and even more preferably 11% by mass or less.

(Filler)

The present resin composition can further contain a filler, for example. As a related filling material, Inorganic filling materials or organic filling materials generally used for semiconductor sealing materials. Specifically, examples of the inorganic filler include silicon dioxide such as melt-pulverized silicon dioxide, molten spherical silicon dioxide, crystalline silicon dioxide, and secondary agglomerated silicon dioxide; aluminum oxide; titanium white; and hydroxide Aluminum; talc; clay; mica; glass fiber, etc. Examples of the organic filler include silicone powder and polyethylene powder. Among these fillers, one kind may be used alone, or two or more kinds may be used simultaneously. Among them, inorganic fillers are preferred, and fused spherical silica is particularly preferred.

In addition, as the shape of the filler, from the viewpoint of suppressing an increase in the melt viscosity of the resin composition for sealing and simultaneously increasing the content of the filler, it is preferably as spherical as possible and has a wide particle size distribution.

In addition, it is possible to increase the filling amount by mixing the particles with different sizes, but it is preferable that the average particle diameter d50 is 0.01 μm or more and 150 μm or less from the viewpoint of filling properties around the semiconductor element. This makes it possible to achieve both good fluidity and filling properties around the semiconductor element.

The average particle diameter d50 of the inorganic filler can be measured using, for example, a laser diffraction particle size distribution measuring device (manufactured by HORIBA, LA-500).

In this embodiment, the content of the filler relative to the total amount of the resin composition is preferably 35 mass% or more and 95 mass% or less, more preferably 50 mass% or more and 93 mass% or less, and still more preferably 65 mass% or more. 90% by mass or less. By setting the content of the filler to the above lower limit value or higher, low moisture absorption and low thermal expansion properties can be improved, and moisture resistance reliability or reflow resistance can be more effectively improved. Furthermore, by setting the content of the filler to be equal to or less than the above-mentioned upper limit value, it is possible to suppress a decrease in moldability due to a decrease in the fluidity of the resin composition, a flow of a bonding wire due to an increase in viscosity, and the like.

From the same point of view, the content of the filler in the present resin composition is preferably 35% by mass or more, more preferably 50% by mass or more, and still more preferably 65% by mass or more relative to the total amount of the resin composition. Furthermore, it is preferably 95% by mass or less, more preferably 93% by mass or less, and even more preferably 90% by mass or less.

(Coupling agent)

The filler can be surface-treated with a coupling agent. As the coupling agent, various silane-based compounds such as epoxy silane, mercapto silane, amine silane, alkyl silane, ureido silane, vinyl silane, methacrylic silane, titanium compounds, aluminum chelate compounds, Known coupling agents such as aluminum / zirconium-based compounds. Examples of these include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (β-methoxyethoxy) silane, and γ-methyl. Propylene methoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidylpropyltrimethoxysilane (3-glycidyl ether) (Propyltrimethoxysilane), γ-glycidyl ether propyltriethoxysilane, γ-glycidyl ether propylmethyldimethoxysilane, γ-methacryloxypropylmethyl Diethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxy Silane, γ-anilinepropyltrimethoxysilane, γ-anilinepropylmethyldimethoxysilane, γ- [bis (β-hydroxyethyl)] aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, N-β- ( Aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxy Silane, γ- (β-aminoethyl) aminopropyldimethoxymethylsilane, N- (trimethoxysilylpropyl) ethylenediamine, N- (dimethoxymethyl) (Silyl isopropyl) ethylenediamine, methyltrimethoxysilane, Dimethyldimethoxysilane, methyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, γ-chloropropyl Trimethoxysilane, hexamethyldisila, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-propenyloxypropyl Silane-based coupling agents such as trimethoxysilane, hydrolysates of 3-triethoxysilyl-N- (1,3-dimethyl-butylene) propylamine, isopropyltriisostearyl alcohol Titanate, Isopropyltris (dioctyl pyrophosphate) Titanate, Isopropyltris (N-aminoethyl-aminoethyl) titanate, Tetraoctylbis (di (ten Trialkyl) phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (di (tridecyl)) phosphite titanate, bis ( (Dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethynyl titanate, isopropyl trioctylfluorenyl titanate, isopropyl dimethylpropenyl isohard Aliphatic Titanate, Isopropyl Tridecylbenzenesulfonyl Titanate, Isopropyl Stearate Diacrylate Titanate, Isopropyl Titanates such as tris (dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, tetraisopropyl bis (dioctyl phosphite) titanate Couplings, etc. Among these, one kind may be used alone, or two or more kinds may be used in combination. Among them, silane compounds of epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane or vinylsilane are more preferable. From the viewpoint of reflow resistance and the like, in order to improve the reliability of the semiconductor device, it is particularly preferable to use mercaptosilane.

The surface treatment of the filler with a coupling agent can be performed, for example, as follows. First, after the filling material is put into the mixer, stirring is started, and a coupling agent is further added thereto, and these are stirred for 1 to 5 minutes to obtain a mixture of the filling material and the coupling agent. The mixing time is, for example, 1 minute or more and, for example, 5 minutes or less.

Next, the mixture was removed from the mixer and left to stand. The placement time can be appropriately selected, for example If it can be set to 3 minutes to 1 hour. Thereby, a filler which has been surface-treated with a coupling agent is obtained. From the same viewpoint, the above-mentioned standing time is, for example, 3 minutes or more, and, for example, 1 hour or less.

Moreover, you may heat-process the filling material after a standing process. The heat treatment can be performed under conditions of, for example, 30 to 80 ° C. and 0.1 to 10 hours. The temperature of the heat treatment is, for example, 30 ° C or higher and, for example, 80 ° C or lower. The time for the heat treatment is, for example, 0.1 hour or more, and for example, 10 hours or less.

Furthermore, in the present embodiment, a spraying agent can be sprayed on the filling material in the mixer and the filling material can be stirred to obtain a mixture of the filling material and the coupling agent. As the atomizer, for example, a device capable of ejecting fine liquid droplets provided with a two-fluid nozzle or the like can be used. By using such a sprayer, it is preferable that the surface of the filling material is more uniformly treated by the coupling agent.

In this embodiment, the content of the coupling agent is preferably 0.05% by mass or more and 2% by mass or less, more preferably 0.1% by mass or more and 1% by mass or less, and still more preferably 0.1% by mass or more with respect to the total amount of the resin composition. 0.5 mass% or less. By making content of a coupling agent more than the said lower limit, the dispersibility of the filler in this resin composition can be made favorable. Therefore, it is possible to more effectively improve humidity resistance reliability, reflow resistance, and the like. On the other hand, by setting the content of the coupling agent to be equal to or less than the above-mentioned upper limit value, the fluidity of the present resin composition can be made good, and the moldability can be improved.

From the same viewpoint, the content of the coupling agent in the present resin composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and more preferably 2% by mass relative to the total amount of the resin composition. Hereinafter, it is more preferably 1% by mass or less, and still more preferably 0.5% by mass or less.

(Ion trapping agent)

The present resin composition can further contain, for example, an ion trapping agent. When the relevant ion trapping agent is contained, impurity ions contained in the resin composition can be ion-exchanged. As a result, it can be produced from the viewpoints of reflow resistance, humidity resistance reliability, and high-temperature operation characteristics. Semiconductor device with excellent reliability.

Examples of the ion trapping agent include inorganic ion exchangers such as hydrotalcites and polyvalent metal acid salts. Among these, one kind may be used alone, or two or more kinds may be used in combination. Among them, the use of hydrotalcites is particularly preferable from the viewpoint of improving the high-temperature storage characteristics of a semiconductor device manufactured using the resin composition.

In this embodiment, the content of the ion trapping agent is preferably 0.05% by mass or more and 1% by mass or less, more preferably 0.1% by mass or more and 0.8% by mass or less, and still more preferably 0.15% by mass relative to the total amount of the sealing resin composition. Above 0.5% by mass. When the content of the ion trapping agent is at least the above-mentioned lower limit value, the high-temperature storage characteristics of a semiconductor device obtained by using the resin composition can be more effectively improved. On the other hand, by setting the content of the ion trapping agent to be equal to or less than the above-mentioned upper limit value, the moisture resistance reliability and reflow resistance of a semiconductor device manufactured using the resin composition can be improved.

From the same viewpoint, the content of the ion trapping agent in the resin composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.15% by mass relative to the total amount of the sealing resin composition. % Or more, more preferably 1% by mass or less, more preferably 0.8% by mass or less, still more preferably 0.5% by mass or less.

(Hardening accelerator)

This resin composition can further contain a hardening accelerator, for example.

Regarding the hardening accelerator, as long as it is an epoxy group and a hardener (e.g., phenol) that promote epoxy resins The resin-based curing agent may be a phenolic hydroxyl group), and can be used by users of epoxy resin compositions for general semiconductor sealing. Examples of the hardening accelerator include phosphorus atom-containing compounds such as organic phosphines, tetra-substituted phosphonium compounds, phosphate betaine compounds, adducts of phosphine compounds and quinone compounds, adducts of sulfonium compounds and silane compounds; and examples There are 1,8-diazabicyclo [5.4.0] undecene-7, dimethylbenzylamine, 2-methylimidazole and other fluorene or tertiary amines, and the aforementioned fluorene and amine quaternary fluorene and the like contain A nitrogen atom compound and the like may be used singly or in combination of two or more kinds.

The content of the hardening accelerator is preferably 0.05% by mass or more and 1% by mass or less, and more preferably 0.1% by mass or more and 0.8% by mass or less with respect to the total amount of the resin composition. By making content of a hardening accelerator more than the said lower limit, the fall of the rigidity of this resin composition can be suppressed. Moreover, by making content of a hardening accelerator into the said upper limit or less, the fall of the fluidity | liquidity of this resin composition can be suppressed.

From the same viewpoint, the content of the hardening accelerator in the present resin composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and more preferably 1% by mass relative to the total amount of the resin composition. % Or less, more preferably 0.8% by mass or less.

The content of the hardening accelerator is preferably 0.1% by mass or more and 2% by mass or less, and more preferably 0.2% by mass or more and 1.5% by mass or less based on the total amount of the epoxy resin and the curing agent contained in the resin composition. By making content of a hardening accelerator more than the said lower limit, the fall of the rigidity of this resin composition can be suppressed. Moreover, by making content of a hardening accelerator into the said upper limit or less, the fall of the fluidity | liquidity of this resin composition can be suppressed.

From the same viewpoint, the content of the hardening accelerator in the present resin composition is preferably 0.1% by mass or more relative to the total amount of the epoxy resin and the hardener contained in the resin composition. It is more preferably 0.2% by mass or more, more preferably 2% by mass or less, and even more preferably 1.5% by mass or less.

In this resin composition, colorants such as carbon black and red dandelion; low-stress components such as silicone oil or silicone rubber; natural waxes such as palm wax, synthetic waxes, and higher fatty acids such as zinc stearate may also be appropriately blended as required. Release agents such as metal salts or paraffin; various additives such as flame retardants such as aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, phosphazene, and antioxidants.

<Semiconductor device>

Next, a semiconductor device 100 according to this embodiment will be described.

FIG. 1 is a diagram showing an example of a semiconductor device according to this embodiment.

As shown in FIG. 1, the semiconductor device 100 includes: a semiconductor element 20 mounted on a substrate 30; a bonding wire 40 connected to the semiconductor element 20 and composed of a silver alloy containing 85% by mass to 98% by mass of Ag; A sealing material 50 that seals the semiconductor element 20 and the bonding wire 40 and contains a cured product of the resin composition. The bonding wire 40 is connected to the semiconductor element 20 and, as described above, is formed of an alloy containing Ag as a main component. The sealing material 50 is formed of a cured product of the resin composition, and seals the semiconductor element 20 and the bonding wire 40.

The semiconductor element 20 is mounted on a substrate 30. The substrate 30 is, for example, a lead frame or an organic substrate. The substrate 30 is connected to a bonding wire 40. FIG. 1 illustrates a case where a semiconductor element 20 is mounted on a wafer pad 32 in a substrate 30 that is a lead frame via a wafer adhesive 10. The substrate 30 that is a lead frame is made of, for example, a metal material containing Cu or 42 alloy as a main component. The semiconductor element 20 may be disposed on another semiconductor element.

A plurality of electrode pads 22 are formed on the upper surface of the semiconductor element 20, for example. At least the surface layer of the electrode pad 22 provided in the semiconductor element 20 is made of, for example, a metal material containing Al as a main component. Thereby, the connection reliability of the bonding wire 40 and the electrode pad 22 can be improved.

FIG. 1 illustrates a case where the bonding wire 40 electrically connects the electrode pad 22 of the semiconductor element 20 and the outer lead 34 in the substrate 30.

The sealing material 50 is formed of a cured product of the present resin composition. Therefore, a semiconductor device 100 having good adhesion to the substrate 30 or the bonding wire 40, excellent reflow resistance, humidity resistance reliability, and high-temperature operation characteristics can be obtained. In addition, it is possible to improve the high-temperature storage characteristics of the semiconductor device 100.

The semiconductor device 100 is manufactured in the following manner, for example.

First, a semiconductor element 20 is mounted on a substrate 30. Next, the substrate 30 and the semiconductor element 20 are connected to each other by a bonding wire 40. Next, the semiconductor element 20 and the bonding wire 40 are sealed with the present resin composition. The method of the seal molding is not particularly limited, but examples thereof include a transfer molding method and a compression molding method. Thereby, the semiconductor device 100 can be manufactured.

In addition, as a method of sealing a semiconductor element using the present resin composition, the following method is mentioned, for example.

Hereinafter, as an example of a method for sealing a semiconductor element using the present resin composition, a case where the semiconductor element is sealed by compression molding using the present resin composition in a granular form will be described as an example.

First, a resin material supply container containing a granular resin composition is provided between an upper mold and a lower mold of a compression molding mold. Next, the semiconductor device is fixed to one of the upper mold and the lower mold of the compression molding mold by a jig or a fixing mechanism such as an adsorption. In the following, a case where a semiconductor device is fixed to an upper mold of a compression molding mold such that a surface on one side on which a semiconductor element is mounted is opposed to a resin material supply container will be described.

Next, while reducing the distance between the upper mold and the lower mold of the mold under reduced pressure, The weighed particulate resin composition is supplied into the lower mold cavity provided by the lower mold by a resin material supply mechanism such as a gate constituting the bottom surface of the resin material supply container. Thereby, the granular resin composition is heated to a predetermined temperature in the lower mold cavity, and becomes a molten state. Next, the upper and lower molds of the mold are combined to press the present resin composition in a molten state against a semiconductor element mounted on a semiconductor device fixed to the upper mold. Thereby, a region between the semiconductor element and the substrate can be filled with the present resin composition in a molten state. After that, the resin composition is cured over a predetermined period of time while maintaining the state of the upper mold and the lower mold that are bonded to the mold. Here, when compression molding is performed, it is preferable to perform resin sealing while reducing the pressure in the mold, and more preferably, the vacuum is performed. Thereby, at least the area between the semiconductor element and the substrate can be satisfactorily filled without the portion not filled with the resin composition.

In addition, when the granular resin composition is used for compression molding, the molding temperature is preferably 50 to 250 ° C, more preferably 50 to 200 ° C, and even more preferably 80 to 180 ° C. The molding temperature is preferably 50 ° C or higher, more preferably 80 ° C or higher, and still more preferably 250 ° C or lower, more preferably 200 ° C or lower, and still more preferably 180 ° C or lower.

The molding pressure is preferably 0.5 to 12 MPa, and more preferably 1 to 10 MPa. The molding pressure is preferably 0.5 MPa or more, more preferably 1 MPa or more, still more preferably 12 MPa or less, and even more preferably 10 MPa or less.

By setting the molding temperature and pressure to the above-mentioned ranges, it is possible to prevent two problems, that is, occurrence of a portion of the resin composition which is not filled in a molten state, and displacement of the semiconductor element.

Next, as an example of a method for sealing a semiconductor element using the present resin composition, a case where the semiconductor element is sealed by compression molding using the sheet-shaped present resin composition will be described as an example.

First, a semiconductor device is fixed to one of an upper mold and a lower mold of a compression molding mold by a jig or a fixing mechanism such as an adsorption. In the following, a case where a semiconductor device is fixed to an upper mold of a compression molding mold such that a surface on one side on which a semiconductor element is mounted faces a resin material supply container will be described as an example.

Next, a sheet-shaped present resin composition is placed in the lower mold cavity of the mold so as to correspond to the position of the semiconductor element fixed to the upper mold of the mold. Next, by reducing the distance between the upper mold and the lower mold of the mold under reduced pressure, the sheet-like resin composition is heated to a predetermined temperature in the cavity of the lower mold to be in a molten state. Thereafter, the upper and lower molds of the mold are combined to press the present resin composition in a molten state against the semiconductor element mounted on the semiconductor device fixed to the upper mold. This makes it possible to fill a region between the semiconductor element and the substrate with the present resin composition in a molten state. After that, the resin composition is cured over a predetermined period of time while maintaining the state of the upper mold and the lower mold that are bonded to the mold. Here, when compression molding is performed, it is preferable to perform resin sealing while reducing the pressure in the mold, and more preferably, the vacuum is performed. Thereby, at least the area between the semiconductor element and the substrate can be filled well without leaving unfilled portions of the resin composition.

When the sheet-shaped resin composition is used for compression molding, the molding temperature is preferably 50 to 250 ° C, more preferably 50 to 200 ° C, and even more preferably 80 to 180 ° C. The molding temperature is preferably 50 ° C or higher, more preferably 80 ° C or higher, more preferably 250 ° C or lower, even more preferably 200 ° C or lower, and still more preferably 180 ° C or lower.

The molding pressure is preferably 0.5 to 12 MPa, and more preferably 1 to 10 MPa. The molding pressure is preferably 0.5 MPa or more, more preferably 1 MPa or more, still more preferably 12 MPa or less, and even more preferably 10 MPa or less.

By setting the molding temperature and pressure to the above-mentioned ranges, it is possible to prevent two problems, that is, occurrence of a portion of the resin composition which is not filled in a molten state, and displacement of the semiconductor element.

In addition, the present invention is not limited to the above-mentioned embodiments, and modifications, improvements, and the like within a range in which the object of the present invention can be achieved are included by the inventor.

The present invention includes the following aspects.

An epoxy resin composition for sealing, which is used to form a sealing material in a semiconductor device which is composed of a semiconductor element mounted on a substrate and a semiconductor element connected to the semiconductor element and containing 85% by mass or more and 98% by mass A bonding wire made of a silver alloy having an Ag of less than% is sealed. The resin composition contains an epoxy resin and a hardener. The glass transition temperature (Tg) of the hardened product of the resin composition is 120 ° C or higher and 200 ° C or lower.

2. The epoxy resin composition for sealing as described in 1 whose thermal time elastic modulus of the hardened | cured material of this epoxy resin composition for sealing measured at 260 degreeC is 300 MPa or more and 1500 MPa or less.

3. The epoxy resin composition for sealing according to 1 or 2, wherein the epoxy resin contains a biphenyl type epoxy resin.

4. The sealing epoxy resin composition according to any one of 1 to 3, wherein the curing agent contains a polyfunctional phenol resin.

5. The sealing epoxy resin composition according to any one of 1 to 4, wherein the cured product of the sealing epoxy resin composition is extracted under the conditions of 125 ° C. and a relative humidity of 100% RH for 20 hours. The chloride ion concentration in the extracted liquid was 10 ppm or less per 1 g of the cured product.

6. The sealing epoxy resin composition according to any one of 1 to 5, further comprising an inorganic filler.

7. The epoxy resin composition for sealing according to any one of 1 to 6, wherein the epoxy resin The content of N is 3% by mass or more and 20% by mass or less based on the total amount of the epoxy resin composition for sealing.

8. The sealing epoxy resin composition according to any one of 1 to 7, wherein a content of the curing agent is 2% by mass or more and 15% by mass or less with respect to the total amount of the sealing epoxy resin composition.

9. The epoxy resin composition for sealing according to any one of 1 to 8, wherein the sulfur content in the cured material of the epoxy resin composition for sealing is 1 ppm or more and 400 ppm relative to the total amount of the cured material the following.

10. A semiconductor device comprising: a semiconductor element mounted on a substrate; a bonding wire connected to the semiconductor element and composed of a silver alloy containing 85% by mass to 98% by mass of Ag; and the semiconductor element and the A sealing material for bonding wire sealing, the sealing material containing a cured product of the epoxy resin composition for sealing according to any one of 1 to 9.

The embodiments of the present invention have been described above with reference to the drawings, but these are examples of the present invention, and various structures other than the above can be adopted.

[Example]

Hereinafter, the present invention will be described using examples and comparative examples, but the present invention is not limited to these.

<Preparation of the epoxy resin composition for sealing>

Regarding each of Examples 1 to 5 and Comparative Examples 1 to 3, a sealing resin composition was prepared as follows. First, each raw material blended according to Table 1 is mixed using a mixer at normal temperature. Thereafter, roll kneading is performed at 70 to 100 ° C. Next, the obtained kneaded material was cooled, and then pulverized to obtain a powdery and granular sealing resin composition. The details of each component in Table 1 are as follows. The unit in Table 1 is mass%.

(Epoxy resin)

． Epoxy resin 1: Biphenyl epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX400HK)

． Epoxy resin 2: Trihydroxyphenylmethane type epoxy resin (manufactured by Mitsubishi Chemical Corporation, 1032H-60)

． Epoxy resin 3: Biphenylaralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000L)

(hardener)

． Hardener 1: Triphenol methane-type phenol resin (manufactured by Meisei Chemicals, MEH7500)

． Hardener 2: Biphenylaralkyl-type phenol resin (Meihsin Kasei Corporation, MEH-7851SS)

(Inorganic filler)

． Inorganic filling material 1: Fused spherical silica (manufactured by Denki Kogyo Co., Ltd., FB-950, average particle diameter d50: 23 μm)

． Inorganic filler 2: Fused spherical silicon dioxide (manufactured by ADMATECHS, SO-25R, average particle diameter d50: 0.5 μm)

(other)

． Hardening accelerator: Triphenylphosphine (K.I Chemical Industry Co., LTD., TPP)

． Low stress agent: Silicone oil (manufactured by Dow Corning Toray, FZ-3730)

． Colorant: carbon black (manufactured by Mitsubishi Chemical Corporation, # 5)

． Silane coupling agent: 3-glycidyl ether propyltrimethoxysilane (manufactured by Chisso Corporation, S510)

． Release agent: palm wax (manufactured by Toa Kasei Co., Ltd.)

． Ion trapping agent: Hydrotalcite (DHT-4H, manufactured by Kyowa Chemical Co., Ltd.)

In Examples 1 to 5 and Comparative Examples 1 to 3, the surface treatment of the inorganic filler with a silane coupling agent was performed as follows.

First, after the inorganic filler 1 and the inorganic filler 2 are put into the mixer, stirring is started, a silane coupling agent is further added thereto, and these are stirred for 3.0 minutes to obtain the inorganic filler 1, the inorganic filler 2 and the silane coupling agent. mixture. Next, the mixture is taken out from the mixer and left for a predetermined time. Thereby, an inorganic filler which has been surface-treated with a silane coupling agent is obtained.

<Fabrication of Semiconductor Devices of Examples 1 to 5 and Comparative Example 3>

Regarding each of Examples 1 to 5 and Comparative Example 3, a semiconductor device was produced in the following manner.

A TEG (Test Element Group) wafer (3.5 mm x 3.5 mm) provided with an aluminum electrode pad was mounted on a wafer pad portion of a lead frame whose surface was plated with Ag. Next, an electrode pad (hereinafter, referred to as an electrode pad) of the TEG wafer and an outer lead portion of the lead frame were wire-bonded using a bonding wire made of a silver alloy containing 96% by mass of Ag at a wire pitch of 120 μm.

Using a low-pressure transfer molding machine, under the conditions of a mold temperature of 175 ° C., an injection pressure of 10.0 MPa, and a hardening time of 2 minutes, the structure obtained in the above manner was hermetically molded using an epoxy resin composition for sealing to produce a semiconductor sealing body. Thereafter, the obtained semiconductor sealing body was post-cured under the conditions of 175 ° C and 4 hours to obtain a semiconductor device.

<Fabrication of Semiconductor Device of Comparative Example 1>

Except for using a bonding wire composed of a copper alloy (excluding Ag) containing 99.9% by mass of Cu as a bonding wire, the semiconductors were fabricated in the same manner as in Examples 1 to 5 and Comparative Example 3. 体 装置。 Body device.

<Fabrication of Semiconductor Device of Comparative Example 2>

A semiconductor device was manufactured in the same manner as in Examples 1 to 5 and Comparative Example 3 except that a bonding wire made of a silver alloy containing 99.5% by mass of Ag was used as the bonding wire.

The obtained epoxy resin composition for sealing and each semiconductor device were measured and evaluated as shown below.

Spiral flow: Using a low-pressure transfer molding machine ("KTS-15" manufactured by Shangying Precision Machinery Co., Ltd.), Examples 1 to 5, and The sealing epoxy resin compositions of Comparative Examples 1 to 3 were poured into a mold for spiral flow measurement according to EMMI-1-66, and the flow length was measured. The unit is cm.

Gel time: After melting the sealing epoxy resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 on a hot plate heated to 175 ° C, the time until hardening was measured while stirring with a spatula. The unit is second.

Glass transition temperature, linear expansion coefficient (CTE1, CTE2)

About each Example and each comparative example, the glass transition temperature and linear expansion coefficient of the hardened | cured material of the obtained sealing resin composition were measured as follows. First, using a transfer molding machine, a resin composition for sealing was injection-molded at a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 3 minutes to obtain a test piece of 15 mm × 4 mm × 4 mm. Next, the obtained test piece was post-cured at 175 ° C for 4 hours, and then a thermomechanical analysis device (manufactured by Seiko Instruments Inc., TMA100) was used at a measurement temperature range of 0 ° C to 320 ° C and a temperature increase rate of 5 ° C / Measurements were made under conditions of minutes. The linear expansion coefficient below the glass transition temperature is calculated from the measurement results (CTE1), coefficient of linear expansion (CTE2) exceeding the glass transition temperature. The unit of glass transition temperature is ° C, and the unit of CTE1 and CTE2 is ppm / ° C.

The thermal time elastic modulus of the cured product of the resin composition measured at 260 ° C: First, using a transfer molding machine, inject the molding resin composition at a mold temperature of 175 ° C, an injection pressure of 9.8 MPa, and a curing time of 3 minutes. A 15 mm × 4 mm × 4 mm test piece was obtained. Next, using a dynamic viscoelasticity measuring device, according to JIS K-6911's three-point bending mode, the storage elastic modulus at a frequency of 10 Hz and a measurement temperature of 260 ° C. was used as the thermal time elastic modulus. The unit is MPa.

Chloride ion concentration per 1 g of hardened material: Screened with a 200-mesh sieve, the sealing material cut from the semiconductor device was pulverized by a grinder for 3 minutes, and the powder passed through the sieve was prepared as a sample. 5 g of the obtained sample and 50 g of distilled water were placed in a pressure-resistant container made of Teflon (registered trademark) and hermetically sealed, and subjected to a treatment (pressure cooker treatment) at a temperature of 125 ° C. and a relative humidity of 100% RH for 20 hours. Next, after cooling to room temperature, the extracted water was centrifuged, filtered through a 20 μm filter, and the chloride ion concentration was measured using a capillary electrophoresis device (“CAPI-3300” manufactured by Otsuka Electronics Co., Ltd.).

The value of the chloride ion concentration measured here is a 10-fold dilution of the chloride ion extracted from 5 g of the sample. Therefore, it is converted into 1 g of the sealing material by the following formula (a), that is, 1 g of the hardened material. The amount of chloride ions in. The unit is ppm.

Formula (a): chloride ion concentration per sample unit mass = (chlorine ion concentration obtained by capillary electrophoresis device) × 50 ÷ 5

Sulfur content in the hardened material of the resin composition: The hardened material obtained by thermally curing the sealing epoxy resin composition under conditions of 175 ° C and 4 hours is pulverized to obtain Shreds. Next, the gas generated when the above-mentioned pulverized material was heat-treated under conditions of 150 ° C. and 8 hours was captured with hydrogen peroxide water. Next, the sulfur content in the hardened | cured material of the epoxy resin composition for sealing was calculated from the amount of sulfuric acid ions in the said hydrogen peroxide water. The unit is ppm.

Moisture resistance reliability: For each of Examples 1 to 5 and Comparative Examples 1 to 3, a HAST test was performed on the obtained semiconductor device in accordance with IEC68-2-66, and electrical connection was shown for 50 semiconductor devices used in the test From the viewpoint of the occurrence of the proportion of defects (bad incidence). Furthermore, the unit is%. Moreover, the test conditions in the said HAST test were set as the conditions which set the temperature to 130 degreeC, and processed at 85% RH and the voltage of 20V for 240 hours.

As can be seen from the above Table 1, the semiconductor devices of the examples are all excellent in moisture resistance reliability. In addition, the semiconductor device of Example 1 and the semiconductor device of Comparative Example 2 have a common structure except that the silver purity of the silver wires provided in the semiconductor device is different. In addition, the semiconductor device of Example 1 has a higher humidity resistance reliability than the semiconductor device of Comparative Example 2. From this, it can be seen that the present resin composition is useful for improving the moisture resistance reliability of a semiconductor device including a bonding wire made of a silver alloy containing 85% by mass or more and 98% by mass or less of Ag.

In addition, it can be seen from Comparative Examples 1 to 5 and Comparative Example 3 that by adopting a structure that simultaneously satisfies the following Condition 1 and Condition 2, the moisture resistance reliability of the semiconductor device is improved.

Condition 1: A bonding wire made of a silver alloy containing 85% by mass or more and 98% by mass or less of Ag is provided.

Condition 2: The glass transition temperature (Tg) of the hardened | cured material of a resin composition is 120 degreeC or more and 200 degreeC or less.

This case claims the priority based on Japanese application Japanese Patent Application No. 2016-070279 filed on March 31, 2016, and the entire disclosure thereof is incorporated into this specification.

Claims (10)

An epoxy resin composition for sealing is used to form a sealing material in a semiconductor device which contains a semiconductor element mounted on a substrate and is connected to the semiconductor element and contains 85% by mass or more and 98% by mass or less. A bonding wire made of a silver alloy of Ag is hermetically sealed. The resin composition contains an epoxy resin and a hardener. The glass transition temperature (Tg) of the hardened product of the resin composition is 120 ° C or higher and 200 ° C or lower. For example, the epoxy resin composition for sealing according to item 1 of the scope of application, wherein the thermal modulus of time of the cured product of the epoxy resin composition for sealing measured at 260 ° C is 300 MPa or more and 1500 MPa or less. For example, the epoxy resin composition for sealing according to claim 1 or 2, wherein the epoxy resin contains a biphenyl type epoxy resin. For example, the sealing epoxy resin composition according to item 1 or 2 of the patent application scope, wherein the hardener contains a polyfunctional phenol resin. For example, the epoxy resin composition for sealing according to item 1 or 2 of the application, wherein the hardened product of the epoxy resin composition for sealing is extracted under the conditions of 125 ° C, relative humidity 100% RH, and 20 hours. The chloride ion concentration in the extract was 10 ppm or less per 1 g of the hardened material. For example, the epoxy resin composition for sealing according to item 1 or 2 of the patent application scope further contains an inorganic filler. For example, the epoxy resin composition for sealing according to item 1 or 2 of the patent application scope, wherein the content of the epoxy resin is 3% by mass or more relative to the total amount of the epoxy resin composition for sealing. Mass% or less. For example, the sealing epoxy resin composition according to item 1 or 2 of the patent application scope, wherein the content of the hardener is 2% by mass or more and 15% by mass or less with respect to the total amount of the sealing epoxy resin composition. For example, the sealing epoxy resin composition according to item 1 or 2 of the patent application scope, wherein the sulfur content in the hardened material of the sealing epoxy resin composition is 1 ppm or more and 400 ppm or less with respect to the total amount of the hardened material. A semiconductor device includes: a semiconductor element mounted on a substrate; a bonding wire connected to the semiconductor element and composed of a silver alloy containing 85% by mass to 98% by mass of Ag; and the semiconductor element and the bonding wire A sealing sealing material containing a hardened product of the epoxy resin composition for sealing in the scope of claims 1 or 2.