TW201910422A - Epoxy resin composition - Google Patents

Abstract

The present invention relates to an epoxy resin composition comprising an epoxy resin, an inorganic filler and a curing agent, wherein the epoxy resin is an epoxy mixture resin of a low-viscosity epoxy resin having a viscosity of 500 to 4,000 cps at 25 DEG C and a multifunctional epoxy resin having tri- or more functionalities, and the inorganic filler has an average particle size of 0.1 [mu]m to 5 [mu]m.

Description

Epoxy resin composition

The present invention relates to an epoxy resin composition.

With the miniaturization, weight reduction, thinness, and multifunctionality of electronic products, the sealing and construction methods of semiconductor devices have also diversified. In particular, surface mount technology has become the mainstream in traditional pin insert types, and a surface mount technology package has an adhesive type for flip chips. This type is a technology that makes miniaturization and thinning possible through the connection of a wafer surface through a solder ball or a bump to a substrate, rather than through a wire bonding contact as usual.

However, if a flip-chip package adhered in this way is subjected to a thermal shock test, it is possible that reliability defects regarding the connection state between the circuit board and solder bumps may increase because Different thermal expansion coefficients of a chip, a wire board, and a solder ball can induce thermal stress. In order to alleviate the stress caused by heat, a process is performed in which a wafer is adhered to a substrate and a resin is filled into a space between the device and the substrate (a so-called underfill process). The material used for this process is an underfill material, and this material usually has a liquid phase, that is, this type of underfill process is performed by applying an underfill material such as an epoxy resin composition to a solder ball and a pad. (pad).

In view of workability, such underfill materials must have a packing ability to penetrate the pores between the wafer and the substrate. Such underfill materials must have a degree of resistance to solder balls. The coefficient of thermal expansion is too small for a small coefficient of thermal expansion. Considering reliability, such underfill materials must have good adhesion, that is, the adhesiveness at the interface between the wafer and the substrate. The underfill material must alleviate the aforementioned thermal stress. However, although its filling ability is excellent and processability is improved, defects such as bleeding and overflow may be caused after the filling by epoxy resin. If the reaction heat is small and sufficient volatilization and bubble removal are not completed, voids and processability defects may be caused.

Therefore, it is necessary to develop an epoxy resin composition system for underfill that can alleviate adhesion, filling ability and thermal stress, minimize defect generation, and has excellent processability and reliability.

[Prior Technical Document]

[Patent Literature]

(Patent Document 1) Korean Patent No. 10-0529256

One aspect of the present invention is to provide an epoxy resin composition.

The invention provides an epoxy resin composition comprising an epoxy resin, an inorganic filler and a curing agent, wherein the epoxy resin is a low-viscosity ring An epoxy resin mixture of an epoxy resin and a multifunctional epoxy resin. This low viscosity epoxy resin has a viscosity of 500 cps to 4,000 cps at 25 ° C. This multifunctional epoxy resin has Three or more functional groups, and the inorganic filler has an average particle diameter of 0.1 micrometer (μm) to 5 micrometers (μm).

Beneficial effect

According to the epoxy resin composition of the embodiment of the present invention, excellent fluidity and flowability can be achieved due to easy control of its viscosity, and stability can be achieved especially due to excellent adhesion, filling ability, and thermal stress Processability and excellent attachment reliability.

Hereinafter, the present invention will be described in more detail to assist in understanding the present invention.

It should be understood that the words or terms used in the description of the present invention and the scope of patent application should not be interpreted with the meaning of a dictionary definition generally used. It should be further understood that, based on the inventor's ability to appropriately define the meaning of words or terms to best describe the principles of the present invention, the words or words should be interpreted as having meanings consistent with the meaning of the technical concept of the present invention.

The epoxy resin composition according to the embodiment of the present invention includes an epoxy resin, an inorganic filler and a curing agent, and the epoxy resin is an epoxy resin of a low viscosity epoxy resin and a multifunctional epoxy resin. Resin mixture, this low viscosity epoxy resin has a viscosity of 500 cps to 4,000 cps at 25 ° C, this multifunctional epoxy resin has three or more functional groups, and the inorganic filler has a thickness of 0.1 microns to 5 The average particle size in microns.

According to the epoxy resin composition of the embodiment of the present invention, its viscosity can be easily controlled, its filling ability and fluidity can be excellent, its processability can be improved, and it is possible to minimize oozing or void defects that may be caused after the composition is filled. And thus can achieve excellent reliability.

Hereinafter, the present invention will be described in more detail.

An epoxy resin composition according to an embodiment of the present invention includes an epoxy resin, an inorganic filler, and a curing agent.

＜ Epoxy resin ＞

The epoxy resin according to the embodiment of the present invention includes two or more different kinds of epoxy resin mixtures, and may include a low-viscosity epoxy resin having a viscosity of 500 cps to 4,000 cps at 25 ° C and three or more Multifunctional epoxy resin with multiple functional groups.

The epoxy resin composition according to an embodiment of the present invention may include the epoxy resin in an amount of 10 to 60 parts by weight, particularly 15 to 50 parts by weight. If the epoxy resin is included in this content range, the viscosity can be easily controlled, the processability can be excellent, and the filling ability and flowability can be improved.

(Low viscosity epoxy resin with a viscosity of 500 cps to 4,000 cps at 25 ° C)

The epoxy resin composition according to the embodiment of the present invention includes a low viscosity epoxy resin having a viscosity of 500 cps to 4,000 cps at 25 ° C, and can improve the filling ability and fluidity (due to the excellent fluidity) (It can quickly penetrate into the gap between the wafer and the substrate). In this case, the viscosity can be measured by using, for example, a Brookfield viscometer.

Low viscosity epoxy resins with a viscosity of 500 cps to 4,000 cps can have a viscosity of 1,000 cps to 3,500 cps, and more particularly a viscosity of 1,500 cps to 3,500 cps. If the epoxy resin in this viscosity range is included, the viscosity can be easily controlled, the filling ability and fluidity can be improved, and the processability can be facilitated. If the epoxy resin contains a high-viscosity epoxy resin having a viscosity higher than 4,000 cps, after the underfill agent using the composition is filled on the substrate, the underfill agent may overflow out of the substrate, and the area where bleeding occurs may increase .

According to an embodiment of the present invention, the low viscosity epoxy resin having a viscosity of 500 cps to 4,000 cps may include the following compound of [Chemical Formula 1]:

[Chemical Formula 1]

In [Chemical Formula 1],

R is a hydrocarbon of 5 to 15 carbon atoms.

In particular, the compound of [Chemical Formula 1] is a low viscosity, low chlorine content epoxy resin, and may be bisphenol A-type, bisphenol F-type, or a resin mixture thereof. , And may especially include one of the following [Chemical Formula 2] compounds:

[Chemical Formula 2]

According to an embodiment of the present invention, the content of the low viscosity epoxy resin having a viscosity of 500 cps to 4,000 cps may be 10 parts by weight to 60 parts by weight, particularly 15 parts by weight to 50 parts by weight. If the content of the low-viscosity epoxy resin is higher than this range, the viscosity may increase to decrease the flowability and filling ability and reduce the processability. Conversely, if the content of the low-viscosity epoxy resin is lower than this range, the filling ability and fluidity may decrease.

(Polyfunctional epoxy resin with three or more functional groups)

The epoxy resin composition according to the embodiment of the present invention includes a polyfunctional epoxy resin having three or more functional groups, and can achieve high glass transition temperature (Tg) and increase cross-link density (cross-link). density).

A polyfunctional epoxy resin having three or more functional groups may include one or more compounds selected from the group consisting of bisphenol A-type epoxy resin, bisphenol F-type epoxy resin F-type epoxy resin), bisphenol S-type epoxy resin, phenol novolac-type epoxy resin, cresol novolac-type epoxy resin epoxy resin), alkylphenol novolac-type epoxy resin, bisphenol-type epoxy resin, naphthalene-type epoxy resin, bicyclic Dicyclopentadiene-type epoxy resin, triglycidyl isocyanate, acyclic epoxy resin, and p-amino phenol- type epoxy resin). For example, the polyfunctional epoxy resin may include Epikote 152, Epikote 154, Epikote 828 and YX-4000 of Japan Epoxy Resins Co., Ltd., Dainippon Ink and Chemicals Co. , DIC) Epicron N-660, N-673 and N-695, Kukdo Chemistry Co., Ltd. YDCN-500-4P, YDCN-638, YH-300 and YH-325, Japan JER 630 and JER 604 of Japan Epoxy Resins Co., Ltd. and Compoceran E201 and E202 of Arakawa Chemical Industries, Ltd., but are not limited thereto.

More specifically, the polyfunctional epoxy resin according to the embodiment of the present invention may include an epoxy resin, a pair of p-amino phenol-type epoxy resins, and a mixture thereof. Here, the epoxy resin In the process, a liquid phase bisphenol A-type epoxy resin is dissolved in a trifunctional reactive diluent; in particular, it further comprises an epoxy resin and a pair of aminophenol-type epoxy resins. A mixture of p-amino phenol-type epoxy resin to improve fluidity and filling capacity. In this epoxy resin, a liquid phase bisphenol A-type epoxy resin is dissolved in three Functional group reactive diluent.

An epoxy resin having a liquid phase bisphenol A-type epoxy resin dissolved in a trifunctional reactive diluent can be advantageous in providing low viscosity, curing at low temperature, and noncrystallinity.

According to an embodiment of the present invention, the trifunctional reactive diluent may include three functional groups selected from the group consisting of a hydroxyl group, a formyl group, a carbonyl group, a carboxyl group, and an amine group. (amino group), a nitro group, an epoxy group, an acrylic group, and an unsaturated bond.

In particular, the trifunctional reactive diluent may include three epoxy groups as functional groups.

In particular, the polyfunctional epoxy resin may have a viscosity of 4,000 cps to 6,000 cps, and may include the following trifunctional reactive diluent of [Chemical Formula 3]:

[Chemical Formula 3]

In addition, the p-amino phenol-type epoxy resin according to an embodiment of the present invention may include, for example, N, N-bis (2,3-epoxypropyl) -4- (2, 3-Glycidoxy) aniline resin (N, N-bis (2,3-epoxypropyl) -4- (2,3-epoxypropoxy) aniline resin), and can be expressed as the following [Chemical Formula 4]:

[Chemical Formula 4]

According to the embodiment of the present invention, if an epoxy resin (in this epoxy resin, a liquid phase bisphenol A-type epoxy resin is dissolved in a trifunctional reactive diluent) and p-amino group are used. The resin mixture of p-amino phenol-type epoxy resin may have a weight mixing ratio of, for example, 1: 0.6 to 1: 1.5, especially 1: 0.7 to 1: 1.

According to an embodiment of the present invention, the polyfunctional epoxy resin may be contained in an amount of 5 to 20 parts by weight, and more particularly 5 to 15 parts by weight. If the content of the polyfunctional epoxy resin is below this range, heat resistance, chemical resistance, and electrical properties may be insufficient, and if the content of the polyfunctional epoxy resin is higher than Within this range, flame retardancy and adhesion may decrease.

According to an embodiment of the present invention, in the epoxy resin, the content of the low viscosity epoxy resin may be higher than the content of the polyfunctional epoxy resin having three or more functional groups.

According to an embodiment of the present invention, the weight mixing ratio of the low viscosity epoxy resin (having a viscosity of 500 to 4,000 cps) and the polyfunctional epoxy resin (having three or more functional groups) may be 1: 0.1 to 1: 0.8, especially 1: 0.3 to 1: 0.6. If the weight mixing ratio range is satisfied, the viscosity of the epoxy resin composition can be easily controlled, and excellent fluidity can be achieved, thereby improving the filling ability and fluidity, and achieving a high glass transition temperature (Tg).

＜ Inorganic fillers ＞

The epoxy resin composition according to the embodiment of the present invention includes an inorganic filler. The inorganic filler has an average particle diameter (D ₅₀ ) of 0.1 μm to 5 μm, and can increase the bonding between the resin and the inorganic filler. Binding (binding force), and reducing the exudation of a specific surface area due to an increase in viscosity, but also to improve mechanical properties and reduce stress.

The inorganic filler may include a variety of inorganic materials. These inorganic materials may have a low thermal expansion coefficient. However, for example, silicon dioxide (D ₅₀ ) having an average particle diameter (D ₅₀ ) of 0.2 μm to 3 μm may be used. silica), and more particularly 0.5 to 2 microns. In this case, the average particle diameter (D ₅₀ ) of the silicon dioxide particles can be measured by using, for example, a laser diffraction method. According to the laser diffraction method, a particle diameter of about several millimeters can usually be measured from a submicron range, and measurement results with high reproducibility and resolution can be obtained.

According to the embodiment of the present invention, if an inorganic filler having an average particle diameter is used together with an epoxy resin, the bonding force between the epoxy resin and the inorganic filler can be increased, and the bleeding of a specific surface area due to an increase in viscosity can be reduced. In addition, the thermal expansion coefficient at a high temperature can be reduced to improve the warpage phenomenon of the package.

In addition, micro-silicon dioxide having a small particle diameter of 1 micron or less can be used to fill a tiny bump gap, and for example, pulverized silicon dioxide large particles of 1 micron or less can be used. When filling liquid-phase resin, pulverized large particles can reduce viscosity, and high-density filling systems are possible.

According to the embodiment of the present invention, the content of the inorganic filler can play a decisive role in increasing the binding force with the epoxy resin and achieving a low thermal expansion coefficient at high temperatures, and may be, for example, 45 to 70 parts by weight, and especially 50 to 50 parts Parts to 65 parts by weight. If the inorganic filler is included in the foregoing content range, the binding force between the inorganic filler and the resin can be increased, wafer cracking can be avoided, and the occurrence of bleeding can be minimized. If the content of the inorganic filler is lower than the foregoing range, it may have a large thermal expansion coefficient, and cracks may occur during the thermal shock test, and if the content of the inorganic filler is higher than the foregoing range, the viscosity increases excessively and may increase Defective workability. If a solvent is used to reduce the viscosity, it may adversely affect the physical properties after curing, and when the volatilization and bubble control are not fully achieved during the underfill process, voids may be formed.

According to an embodiment of the present invention, a weight mixing ratio of the epoxy resin mixture and the inorganic filler may be 1: 0.7 to 1: 3. In particular, the weight mixing ratio of the low-viscosity epoxy resin and the inorganic filler may be 1: 1.1 to 1: 2. As the weight mixing ratio is in this range, the binding force with the resin can be improved, and the occurrence of bleeding can be minimized. More specifically, when the content of the inorganic filler is too low, voids and overflows may occur due to uneven fluidity, and the viscosity is too low to cause exudation. In addition, if the content of the inorganic filler is too high, voids may be generated.

＜ curing agent ＞

The epoxy resin composition according to the embodiment of the present invention may include a curing agent for controlling the curing rate.

The curing agent may be an amine-based curing agent, especially an amine-based curing agent having a viscosity of less than 300 cps. In this case, compared with the case of using other kinds of curing agents (for example, an acid anhydride curing agent), this case may be advantageous for controlling reactivity. More specifically, the curing agent may include at least one material selected from the group consisting of polyoxypropylene diamine, modified aliphatic amine, and modified alicyclic amine. For example, commercially available amine-based curing agent XHL-0245 from Shin-A T & C Company can be used.

According to an embodiment of the present invention, the epoxy resin composition may include a curing agent in an amount of 5 parts by weight to 15 parts by weight, and within the foregoing range, the curing rate can be easily controlled, and appropriate curing properties can be obtained. Improve processability.

＜ Additives ＞

The epoxy resin composition according to the embodiment of the present invention may further include various additives in addition to the foregoing components, as long as the object of the present invention is not impaired. For example, a defoaming agent, a coloring agent, a silane coupling agent, and a surface tension controlling agent to improve permeability can be additionally used agent), thixotropy controlling agent, stress relieving agent or dispersing agent used to improve agglomeration of inorganic fillers; colorants such as those used to improve the appearance of products Carbon black, etc .; Silane coupling agents, such as glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyl, are used to improve mechanical properties and adhesion. 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; Shake control agents such as fumed silica to improve shake and moldability; stress relief agents Examples include silicon powder, rubber powder, and surface-modified silicon powder.

According to an embodiment of the present invention, an additive may be included in an amount of 0.1 to 5 parts by weight, especially 0.5 to 3 parts by weight. In particular, the dispersing agent and the defoaming agent can improve the cohesiveness of the void improving effect and the inorganic filler, and can each contain a dispersing agent and an antifoaming agent in a range of 0.1 parts by weight to 0.7 parts by weight.

At the same time, the epoxy resin composition according to the embodiment of the present invention can be prepared by, for example, injecting an epoxy resin, an inorganic filler, a curing agent, and other additives at one time or injecting materials one by one, and heating and stirring when necessary, Mix and disperse. Examples of the apparatus for mixing, stirring, and dispersing the mixture are not specifically limited, but a mixture pulverizer, a triaxial roll mill, a ball mill, A vacuum mortar, a planetary-type mixer, or the like, or a suitable combination of these instruments may be used.

Meanwhile, the molding process can use a common dispensing process, and can be cured in an oven at 130 ° C for about 30 minutes. Depending on the situation, the curing temperature can be changed and the curing accelerator can be controlled to reduce the curing time.

In view of the pore filling ability and process processability of the resin composition, if a Brookfield viscometer is used to measure the viscosity of the epoxy resin composition according to the embodiment of the present invention at 10 rpm at 25 ° C, it may be, for example, 5,000 cps to 50,000 cps, especially 10,000 cps to 30,000 cps, and more particularly 12,000 cps to 25,000 cps. If the viscosity falls within the aforementioned range, processability, defect generation rate, and filling ability can be improved. If the viscosity of the epoxy resin composition according to the present invention is less than 5,000 cps, resin overflow may cause bleeding, and if the viscosity is more than 50,000 cps, the pore filling time is too long and the processability during the dispensing process may be weakened.

According to the epoxy resin composition according to the embodiment of the present invention, the viscosity control system is easy, and excellent fluidity and fluidity can be achieved. In particular, adhesiveness, filling ability, and thermal stress can be excellent, and stable Processability and excellent adhesion reliability. If such an epoxy resin composition is used as an underfill material for manufacturing a semiconductor device, and more particularly a flip-chip underfill, excellent reliability can be obtained.

Hereinafter, the present invention will be described in more detail through examples. The embodiments according to the present invention can be changed to other various types, and the scope of the present invention should not be limited to the following embodiments. Embodiments of the present invention are provided to provide a complete description of the present invention to those skilled in the art.

Examples

Example 1

An epoxy resin composition was prepared using an epoxy resin, an inorganic filler, a curing agent, and an additive (parts by weight) shown in Table 1 below.

In particular, an epoxy resin mixture of an amine curing agent, a low viscosity epoxy resin, and a polyfunctional epoxy resin are mixed in a planetary mixer. Put silicon dioxide and carbon black with an average particle size of about 0.3 microns into the mixer and mix them. Then add additives (such as silane compound), dispersant and defoamer to the mixer and stir to prepare epoxy. Resin composition.

Example 2

Except that the epoxy resin and the inorganic filler were changed to the contents shown in Table 1 below, the method as in Example 1 was performed to prepare an epoxy resin composition.

Example 3

Except that the epoxy resin and the inorganic filler were changed to the contents shown in Table 1 below, the method as in Example 1 was performed to prepare an epoxy resin composition.

Example 4

Except changing the low-viscosity epoxy resin and the polyfunctional epoxy resin to the contents shown in Table 1 below, the method as in Example 1 was performed to prepare the epoxy resin composition.

Comparative Example 1

Except not using a polyfunctional epoxy resin having three or more functional groups and increasing the content of the low viscosity epoxy resin as shown in Table 1 below, the method as in Example 1 was performed to prepare an epoxy resin composition.

Comparative Example 2

Except using a high viscosity epoxy resin having a viscosity of 5,000 cps to 6,000 cps as shown in Table 1 below (instead of a low viscosity epoxy resin having a viscosity of 2,000 cps to 3,000 cps), the method as in Example 1 was performed to prepare Epoxy resin composition.

Comparative Example 3

Except using silicon dioxide having an average particle diameter of about 10 microns (instead of silicon dioxide having an average particle diameter of about 0.3 microns) shown in Table 1 below, the method as in Example 1 was performed to prepare an epoxy resin composition Thing.

Comparative Example 4

Except that the epoxy resin and the inorganic filler were changed to the contents shown in Table 1 below, the method as in Example 1 was performed to prepare an epoxy resin composition.

Comparative Example 5

Except that the epoxy resin and the inorganic filler were changed to the contents shown in Table 1 below, the method as in Example 1 was performed to prepare an epoxy resin composition.

[Table 1]

Test example

1) viscosity

Cone & Plate-type Brookfield viscometer was used to measure the viscosity at 25 ° C.

2) Flow rate

The underfill is filled in the package on the glass substrate at 100 ° C (18 micron bump gap)

3) Hollow

After filling the underfill in a package on a hot substrate at a temperature of 100 ° C (18 micron bump gap), the cavity was confirmed through the glass substrate with the naked eye and a microscope.

4) Exudation

After filling the underfill in a package on a hot substrate at a temperature of 100 ° C. (bump gap of 18 microns), the size of the underfill filler flowing out of the glass substrate was measured using a microscope.

[Table 2]

As shown in Table 2 above, when Example 1 of the present invention is compared with Comparative Example 1 and Comparative Example 2, Example 1 of the present invention has a viscosity in a specific range of 12,000 cps to 25,000 cps, and a small amount of voids and overflow occur. .

Especially the viscosity, the epoxy resin composition of Example 1 has an appropriate viscosity of 2,400 cps, and its fluidity, filling ability, and fluidity are good, and therefore, its processability is excellent.

At the same time, when comparing the size of the underfill that overflowed from the glass substrate after the underfill was filled, the fillet size of Example 1 was 280 microns, but Comparative Example 1 that did not include a polyfunctional epoxy resin and used The fillet size of Comparative Example 2 of the high viscosity epoxy resin rather than the low viscosity epoxy resin is 370 μm to 460 μm, which is 1.2 to 1.6 times that of Example 1.

In addition, Table 3 below shows the test results of changing the contents of the low viscosity epoxy resin and the polyfunctional epoxy resin having three or more functional groups.

[table 3]

As shown in Table 3 above, it was found that the viscosity, flow rate, and voids significantly changed with the contents of the low-viscosity epoxy resin and the polyfunctional epoxy resin.

In particular, the epoxy resin composition of Example 1 has a viscosity of 24,000 cps at 10 rpm, but the epoxy resin composition of Example 4 (contains a polyfunctional epoxy resin containing significantly more than a low viscosity epoxy resin) ), The viscosity of the composition was found to increase significantly to 51,000 cps. Therefore, the flow rate of Example 1 was found to be 2 or more times faster than that of Example 4.

In addition, no void was observed in the epoxy resin composition of Example 1, but voids were generated in the epoxy resin composition of Example 4.

Meanwhile, Table 4 shows the test results based on the average particle diameter of silicon dioxide.

[Table 4]

As shown in Table 4 above, when comparing the epoxy resin composition of Example 1 (using an average particle diameter of 0.3 micron) and the composition of Comparative Example 3 (using an average particle diameter of about 10 micron), It is found that the flow rate is different from the void.

In particular, the flow rate of the epoxy resin composition of Example 1 was 21 seconds, while the flow rate of the epoxy resin composition of Comparative Example 3 was 31 seconds, and it was found that the flow rate of Comparative Example 3 was reduced to 1 in Example 1 /1.5.

In addition, when the cavity is observed through the glass substrate with the naked eye or a microscope after the underfill is filled, the cavity is not generated when the epoxy resin composition of Example 1 is used (silicon dioxide having an average particle diameter of about 0.3 μm). In contrast, when the epoxy resin composition of Comparative Example 3 was used (silicon dioxide having an average particle diameter of about 10 μm), voids were found to be formed.

In addition, Table 5 below shows the test results of the weight mixing ratio of the epoxy resin mixture and the inorganic filler.

[table 5]

As shown in Table 5 above, it was found that the viscosity, flow rate, voids, exudation, and overflow significantly change with the weight mixing ratio of the epoxy resin mixture and the inorganic filler.

In particular, when comparing Example 2 and Comparative Example 4, it was found that the content of the inorganic filler decreases and the viscosity decreases, so that the flow rate increases. However, when the content of the inorganic filler is too low, as in Comparative Example 4, voids and overflow occur due to uneven fluidity, and the viscosity is too low to cause exudation.

In addition, when comparing Example 3 with Comparative Example 5, it was found that the viscosity increases as the content of the inorganic filler increases, and thus the flow rate becomes slower. At this time, if the content of the inorganic filler is too high, as in Comparative Example 5, it is found that the void performance is not good.

Claims (11)

An epoxy resin composition includes: an epoxy resin; an inorganic filler; and a curing agent; wherein the epoxy resin is an epoxy resin with a low viscosity epoxy resin and a multifunctional epoxy resin; Mixture, the low viscosity epoxy resin has a viscosity of 500 cps to 4,000 cps at 25 ° C, the multifunctional epoxy resin has three or more functional groups, and the inorganic filler has 0.1 micron (μm) To an average particle size (D ₅₀ ) of 5 micrometers (μm). The epoxy resin composition according to item 1 of the scope of patent application, wherein the inorganic filler is a silica having a mean particle diameter (D ₅₀ ) of 0.2 micrometer (μm) to 3 micrometers (μm). ). The epoxy resin composition according to item 1 of the scope of patent application, wherein the content of the epoxy resin is 10 to 60 parts by weight, the content of the inorganic filler is 45 to 70 parts by weight, and the curing agent is The content is 5 to 15 parts by weight. The epoxy resin composition according to item 1 of the patent application scope, wherein a weight mixing ratio of one of the low viscosity epoxy resin and the multifunctional epoxy resin is 1: 0.1 to 1: 0.8. The epoxy resin composition according to item 1 of the scope of patent application, wherein the low viscosity epoxy resin comprises a compound represented by the following [Chemical Formula 1], [Chemical Formula 1], R is a compound having 5 to 10 Carbon atom hydrocarbon group. [Chemical Formula 1] The epoxy resin composition according to item 5 of the scope of patent application, wherein [Chemical Formula 1] includes a compound represented by the following [Chemical Formula 2]. [Chemical Formula 2] The epoxy resin composition according to item 1 of the scope of the patent application, wherein the multifunctional epoxy resin is a bisphenol A-type epoxy resin having a liquid phase dissolved in a trifunctional A reactive diluent, an epoxy resin, a pair of p-amino phenol-type epoxy resins, or a mixture thereof. The epoxy resin composition according to item 7 of the scope of application for a patent, wherein the liquid phase bisphenol A type epoxy resin is dissolved in the trifunctional reactive diluent, the epoxy resin and the p-aminophenol type ring The weight ratio of the oxygen resin is 1: 0.6 to 1: 1.5. The epoxy resin composition according to item 1 of the scope of the patent application, wherein a weight mixing ratio of the epoxy resin and the inorganic filler is 1: 0.7 to 1: 3. The epoxy resin composition according to item 1 of the patent application scope, wherein the curing agent comprises an amine-based curing agent. The epoxy resin composition according to item 1 of the scope of patent application, wherein the epoxy resin composition further comprises at least one additive, the at least one additive is selected from a defoaming agent and a coloring agent. agent), a silane coupling agent, a surface tension controlling agent, a thixotropy controlling agent, a stress relieving agent, and a dispersant ( dispersing agent) and a combination of the above.