WO2016059980A1 - Liquid epoxy resin composition - Google Patents

Abstract

The purpose of the present invention is to provide a liquid epoxy resin composition which is able to be used as a sealing agent for fine-pitch COF mounting, and which is capable of suppressing the occurrence of migration in a high-temperature high-humidity test by suppressing separation during a cooling process in a sealing step or during a reliability test without lowering the fluidity. A liquid epoxy resin composition which is characterized by containing (A) a liquid epoxy resin, (B) an acid anhydride curing agent, (C) an imidazole compound curing accelerator and (D) an elastomer having a core-shell structure, said elastomer having been subjected to master batch processing. This liquid epoxy resin composition is also characterized in that the component (D) is contained in an amount of 1-10 parts by mass per 100 parts by mass of the liquid epoxy resin composition.

Description

Liquid epoxy resin composition

The present invention relates to a liquid epoxy resin composition, and more particularly to a liquid epoxy resin composition suitable for an underfill agent for a semiconductor element for chip-on-film package.

Flip chip bonding is used in semiconductor packages such as COF (Chip On Film) packages, which are mounting methods for semiconductor elements that can support higher density and higher output of semiconductor devices such as liquid crystal driver ICs. Yes. In general, in flip chip bonding, a semiconductor element and a substrate are joined by bumps, and a gap between the semiconductor element and the substrate is sealed with a liquid semiconductor sealing agent called an underfill material.

In recent years, in order to meet the demand for higher density and higher output of liquid crystal driver ICs, fine pitches of wiring patterns on which liquid crystal driver ICs are mounted have been advanced. With this fine pitch, the operating temperature of the liquid crystal driver IC is steadily rising. In a semiconductor package sealed with an underfill agent, for example, when a potential difference is applied between wirings in a high-temperature and high-humidity atmosphere at a temperature of 85 ° C. and a humidity of 85%, migration occurs between the wirings. Migration is a phenomenon in which the metal of the wiring pattern is eluted by an electrochemical reaction, resulting in a decrease in resistance value between the wirings.

Conventionally, in a liquid crystal driver IC, in order to electrically connect a semiconductor element and a circuit board, a gold wiring is used for the semiconductor element or the circuit board, and the semiconductor element and the gold wiring are sealed with a sealing resin. It stopped. In recent years, demand for cost reduction for semiconductor devices has been severe, and the price of gold has soared. Since the cost of conventional gold wiring is high, bonding by copper wiring has been studied.

Since this copper wiring is more easily corroded than gold wiring, there is a concern about migration between copper wiring. Migration is a phenomenon in which copper in a copper wiring is eluted by an electrochemical reaction, resulting in a decrease in resistance value. The copper wiring acts as an electrode when the semiconductor device operates. FIG. 1 is a schematic diagram for explaining the migration of copper wiring. The migration starts with the anode 2, Cu is eluted by the reaction formula: Cu + (OH ⁻ ) → Cu (OH), and Cu (OH) moves on the substrate 1 in the direction of the solid arrow, that is, toward the cathode 3, In the cathode 3, Cu is deposited on the substrate 1 in the direction of the broken line arrow, that is, in the direction of the anode 2 by the reaction formula: CuOH + H ₃ O ⁺ → Cu + 2H ₂ O. Normally, copper wiring is sealed with an epoxy resin-based resin composition, but migration occurs due to OH ⁻ or H ₃ O ⁺ derived from H ₂ O absorbed in the epoxy resin. Furthermore, migration is dramatically accelerated if there are Cl 2 ⁻ ions in the atmosphere. This Cl ⁻ ion is usually present as an impurity of the epoxy resin. When migration occurs, the resistance value between the anode and cathode of the copper wiring decreases, and when migration proceeds, the anode and cathode are short-circuited. In addition, Cu (OH) may be Cu (OH) ₂ or Cu (OH) ⁺ precisely, and in the case of Cu (OH) ₂ , it moves to the cathode side due to the concentration difference. In the case of Cu (OH) ⁺ , it moves electrically.

In order to suppress this migration, an underfill agent containing a metal ion binder has been reported (Patent Document 1). This underfill agent suppresses migration by immobilizing metal ions eluted by an electrochemical reaction with a metal ion binder.

However, when a metal ion binder is contained in the underfill agent, the properties of the underfill agent such as the underfill agent thickening during storage and the glass transition temperature of the underfill agent are reduced. There's a problem. In addition, when a metal ion binder is included in the underfill agent, there is a problem of deterioration in adhesion and heat resistance due to the addition of a material that is not incorporated into the polymer skeleton, and a halogen concentration that easily induces migration. There is also a problem that the material cost required for the processing for lowering becomes high.

On the other hand, as a chip-on-film (hereinafter referred to as COF) mounting sealant, it includes (A) an epoxy resin, (B) an acid anhydride-based curing agent, and (C) an imidazole-based and / or triazine-based curing accelerator. A COF mounting sealant in which the component (C) is 0.6 to 10 parts by weight with respect to the total of 100 parts by weight of the component (A), the component (B), and the component (C) has been reported (patent) Reference 2).

In this COF mounting sealant, the generation of voids is suppressed by the curing speed, and sufficient adhesion to the film substrate is obtained, and as a result, a highly reliable semiconductor component can be obtained. For fine pitches (for example, 30 μm pitch is now required compared to 50 μm pitch in the past), reliability in peeling test after high temperature and high humidity test is sufficient is not.

JP-A-2005-333085 International Publication No. 2007/132828

The present invention can be used as a fine-pitch COF mounting sealant, and maintains high flow performance while suppressing peeling during cooling or reliability testing in the sealing process, thereby enabling high-temperature and high-humidity testing. It aims at providing the liquid epoxy resin composition which can suppress generation | occurrence | production of the migration which generate | occur | produces by this.

The present invention relates to a liquid epoxy resin composition, a liquid semiconductor sealing material, and a semiconductor device that have solved the above problems by having the following configuration.
[1] containing (A) a liquid epoxy resin, (B) an acid anhydride curing agent, (C) an imidazole compound curing accelerator, and (D) an elastomer having a core-shell structure subjected to a masterbatch treatment,
The liquid epoxy resin composition, wherein the component (D) is 1 to 10 parts by mass with respect to 100 parts by mass of the liquid epoxy resin composition.
[2] The liquid epoxy resin composition according to the above [1], wherein the component (D) is an elastomer having a core-shell structure masterbatch-treated with a bisphenol type epoxy resin.
[3] The liquid epoxy resin composition according to [1] or [2], further comprising (E) a coupling agent.
[4] A liquid semiconductor encapsulant comprising the liquid epoxy resin composition according to any one of [1] to [3].
[5] A liquid encapsulant for a liquid crystal driver comprising the liquid semiconductor encapsulant according to [4] above.
[6] A semiconductor device having a flip chip type semiconductor element encapsulated with the liquid semiconductor encapsulant described in [4].
[7] A liquid crystal driver having a flip chip type semiconductor element sealed using the liquid sealing material for a liquid crystal driver according to the above [5].

According to the present invention [1], it can be used as a fine pitch COF mounting sealant, and suppresses peeling during cooling or reliability testing in the sealing process without deteriorating fluidity. Thereby, the liquid epoxy resin composition which can suppress the migration which generate | occur | produces in a high temperature, high humidity test can be provided.

According to the present invention [4], it is possible to easily provide a liquid semiconductor encapsulant capable of producing a highly reliable semiconductor component in which migration that occurs in a high-temperature and high-humidity test is suppressed.

According to the present invention [6], it is possible to provide a highly reliable semiconductor component in which migration that occurs in a high-temperature and high-humidity test is suppressed.

It is a mimetic diagram explaining migration in case an electrode is Cu. It is a schematic diagram explaining the evaluation method of the injectability of a resin composition. It is a photograph of the part which does not peel after hardening. It is the photograph of the location where peeling generate | occur | produced after hardening. It is the photograph of the location where peeling generate | occur | produced after hardening. 6 is an enlarged photograph of the appearance of Example 3. 10 is an enlarged photograph of the appearance of Comparative Example 4.

[Liquid epoxy resin composition]
The liquid epoxy resin composition of the present invention comprises (A) a liquid epoxy resin, (B) an acid anhydride curing agent, (C) an imidazole compound curing accelerator, and (D) an elastomer having a core-shell structure subjected to a masterbatch treatment. Contains,
The component (D) is 1 to 10 parts by mass with respect to 100 parts by mass of the liquid epoxy resin composition.

As component (A), aminophenol type epoxy resin, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid naphthalene type epoxy resin, liquid hydrogenated bisphenol type epoxy resin, liquid alicyclic epoxy resin, liquid alcohol Examples include ether type epoxy resins, liquid cycloaliphatic type epoxy resins, liquid fluorene type epoxy resins, and liquid siloxane-based epoxy resins. From the viewpoint of suppression of migration, adhesiveness, and fluidity of the liquid epoxy resin composition after curing. From the viewpoints of curability and adhesion of the liquid epoxy resin composition, heat resistance and durability of the liquid epoxy resin composition after curing, liquid bisphenol A epoxy resin and liquid bisphenol F are preferable. A type epoxy resin is preferred.

The aminophenol type epoxy resin that can be contained in the component (A) suppresses the occurrence of migration of the liquid epoxy resin composition after curing by forming a resin skeleton having a high crosslinking density. The aminophenol type epoxy resin is preferably represented by the formula (1):

Wherein two functional groups are in the ortho-position or para-position, and the formula (2):

Is particularly preferable from the viewpoints of curability, heat resistance, adhesiveness, durability, and migration resistance.

The epoxy equivalent of the component (A) is preferably 80 to 250 g / eq from the viewpoint of adjusting the viscosity. Commercially available products of component (A) include Daicel Chemical's bisphenol A type epoxy resin (product name: LX-01), Mitsubishi Chemical's aminophenol type epoxy resin (grade: JER630, JER630LSD), Nippon Steel Chemical's bisphenol A type. Epoxy resin (product name: YDF8170), Nippon Steel Chemicals bisphenol F type epoxy resin (product name: YDF870GS), DIC naphthalene type epoxy resin (product name: HP4032D), Shin-Etsu Chemical siloxane epoxy resin (product name: TSL9906), etc. Can be mentioned. (A) A component may be individual or may use 2 or more types together.

Component (B) imparts good reactivity (curing speed) and appropriate viscosity imparting to the liquid epoxy resin composition. As component (B), methyltetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, alkylated tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyl hymic acid Examples include anhydrides, succinic anhydrides substituted with alkenyl groups, methyl nadic anhydrides, glutaric anhydrides, and the like, and methylbutenyl tetrahydrophthalic anhydride is preferred. Examples of commercially available products include acid anhydrides (grade: YH306, YH307) manufactured by Mitsubishi Chemical. (B) A component may be individual or may use 2 or more types together.

(C) The component imparts an appropriate curing rate to the liquid epoxy resin composition. Examples of the component (C) include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and the like. . Commercially available products of component (C) include 2-phenyl-4-methylimidazole (product name: 2P4MZ) manufactured by Shikoku Chemicals, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)] manufactured by Shikoku Chemicals -Ethyl-s-triazine (product name: 2MZA). (C) A component may be individual or may use 2 or more types together.

The component (D) imparts injectability to the liquid epoxy resin composition and suppresses peeling and migration of the liquid epoxy resin composition after curing. Examples of the elastomer having a core-shell structure that is masterbatch-treated with the component (D) include core: polybutadiene, shell: acrylic copolymer, core: silicone resin, shell: acrylic copolymer, and the like, and a liquid epoxy resin composition Since the shrinkage stress of the liquid epoxy resin composition can be lowered due to the low elastic modulus in the use temperature range, a core: polybutadiene and a shell: acrylic copolymer are preferable. Commercially available elastomers having a core-shell structure include Kaneka core-shell rubber (product name: MX-137) and Mitsubishi Rayon core-shell rubber (product name: W5500).

Masterbatch processing to an elastomer having a core-shell structure can be performed with a curing agent such as an epoxy resin or an acid anhydride, and an epoxy resin, particularly a bisphenol type epoxy resin is preferred from the viewpoint of storage stability and presence or absence of adverse effects on humidity. . Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin and bisphenol F type epoxy resin, and bisphenol F type epoxy resin is more preferable.

(D) Although a form is not specifically limited, (D) Component dispersibility, Workability | operativity in the filtration process at the time of liquid epoxy resin composition manufacture, injection | pouring property of a liquid epoxy resin composition, a viewpoint of hardening shrinkage stress reduction Therefore, it is spherical and the average particle diameter is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm. Here, the average particle diameter is measured with a laser diffraction particle size distribution measuring apparatus (model number: LS13320) manufactured by BECKMAN COULTER.

(E) The elastomer having a core-shell structure as the component (D) is preferably 20 to 40 parts by mass with respect to 100 parts by mass in total of the elastomer having the core-shell structure and the epoxy resin subjected to the masterbatch treatment. (D) A component may be individual or may use 2 or more types together.

The component (B) is preferably a ratio of 0.6 to 1.2 equivalents, more preferably 0.6 to 1.0 equivalents with respect to the component (A): 1 equivalent. The equivalent of (A) component is an epoxy equivalent, and the equivalent of (B) component is an acid anhydride equivalent. If it is 0.6 or more, the reactivity, the moisture resistance reliability in the high temperature and high humidity test of the liquid epoxy resin composition after curing, and the migration resistance are good, while if it is 1.2 or less, the viscosity is increased. The magnification does not become too high, and the generation of voids is suppressed.

Component (C) is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 5 parts by weight, and still more preferably 0.3 to 3.0 parts by weight with respect to 100 parts by weight of component (A). Part contained. When it is 0.05 parts by mass or more, the reactivity is good, and when it is 5 parts by mass or less, the moisture resistance reliability is good, and the thickening ratio is stable.

(D) Component is 1 to 10 parts by mass with respect to 100 parts by mass of the liquid epoxy resin composition. When the component (D) is less than 1 part by mass, the liquid epoxy resin composition after curing is peeled off and migration resistance is lowered. On the other hand, when (D) component exceeds 10 mass parts, the injectability of a liquid epoxy resin will fall.

It is preferable from the viewpoint of adhesiveness that the liquid epoxy resin composition further contains (E) a coupling agent. As the component (E), 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, vinyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyltrimethoxysilane, 3-acrylic Examples include loxypropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, and 3-isocyanatopropyltriethoxysilane. Trimethoxysilane and 3-aminopropyltrimethoxysilane are preferred. Examples of commercially available products include KBM403, KBE903, and KBE9103 manufactured by Shin-Etsu Chemical.

The component (E) is preferably contained in an amount of 0.05 to 5.0 parts by mass, more preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the component (A). Adhesion improves when it is 0.05 parts by mass or more, and the adhesive strength after the moisture resistance test of the liquid epoxy resin composition after curing becomes better, and when it is 5.0 parts by mass or less, the liquid resin composition Foaming of the product is suppressed.

In the liquid epoxy resin composition of the present invention, a filler such as a silica filler, a leveling agent, an antifoaming agent, a decoloring agent, an antioxidant, a pigment, and a dye are added as necessary without departing from the object of the present invention. Etc. can be mix | blended.

The viscosity of the liquid epoxy resin composition at a temperature of 25 ° C. is preferably 50 to 820 mPa · s from the viewpoint of injectability. Here, the viscosity is measured with an E-type viscometer (model number: TVE-22H) manufactured by Toki Sangyo Co., Ltd.

The liquid epoxy resin composition preferably has a viscosity increase rate after 24 hours of 150% or less, and preferably a viscosity increase rate after 48 hours of 300% or less. Here, the rate of increase in viscosity is measured by measuring the viscosity after storing the liquid epoxy resin composition at room temperature for 24 hours and 48 hours, [{(viscosity after 24 or 48 hours) / (initial viscosity)} × 100]. Is a viscosity increase rate (unit:%).

The epoxy resin composition of the present invention is suitable as a sealant for semiconductor elements utilizing flip chip bonding, and is particularly suitable as a sealant for chip-on-film packages, especially a liquid sealant for liquid crystal drivers.

[Method for producing liquid epoxy resin composition]
The liquid epoxy resin composition described above is manufactured by dispersing an elastomer having a core-shell structure in a bisphenol type epoxy resin, etc., forming the component (D) as a master batch, and then mixing the components (A) to (D). can do.

Usually, an elastomer having a core-shell structure (hereinafter referred to as a core-shell elastomer) is produced by emulsion polymerization in water. Conventionally, a liquid epoxy resin composition has been produced by using a core-shell elastomer obtained by dehydrating a suspension containing a core-shell elastomer produced by emulsion polymerization in water as it is. However, the core-shell elastomer obtained by this method aggregates in the liquid epoxy resin composition and is detected as a foreign substance. Further, in the production of a liquid sealant for a liquid crystal driver, there is a filtering step using a fine mesh, and there is a problem that filtering cannot be performed if there are aggregates.

For this reason, in the present invention, an epoxy resin is added to a suspension containing a core-shell elastomer prepared by emulsion polymerization in water, and the core-shell elastomer is coated with the epoxy resin and then dehydrated to prepare the component (D). By doing so, it becomes possible to prevent aggregation of the core-shell elastomer in the liquid epoxy resin composition.

A core-shell elastomer masterbatch can be obtained by substituting the water component with an epoxy resin from a core-shell elastomer-containing suspension prepared by emulsion polymerization. Here, when replacing the water component, if the core-shell elastomer is removed from the suspension by drying, aggregates are formed. Since it is difficult to disperse the aggregates in the primary particles in the epoxy resin, it is necessary to replace the aggregates with the liquid phase without taking them out of the suspension.

The liquid resin composition of the present invention is obtained, for example, by stirring, melting, mixing, and dispersing the components (A) to (D) and other additives simultaneously or separately, with heat treatment as necessary. be able to. The mixing, stirring, dispersing and the like devices are not particularly limited, and a raikai machine equipped with a stirring and heating device, a three-roll mill, a ball mill, a planetary mixer, a bead mill and the like can be used. . Moreover, you may use combining these apparatuses suitably.

The liquid epoxy resin composition of the present invention is formed and applied at a desired position on the substrate by a dispenser, printing or the like. Here, the liquid epoxy resin composition is formed between a substrate such as a flexible wiring substrate and a semiconductor element so that at least a part thereof is in contact with the wiring of the substrate.

Curing of the liquid resin composition of the present invention is preferably carried out at 120 to 160 ° C. for 5 to 120 minutes. Particularly when cured within 200 seconds, productivity when used as a sealant for chip-on-film packages is improved. From the viewpoint of

A desired semiconductor element and substrate can be used, but a combination of a flip chip bonding semiconductor element and a substrate for COF package is preferable.

Thus, the liquid resin composition of the present invention is very suitable for a liquid semiconductor encapsulant, particularly a liquid encapsulant for a liquid crystal driver, and a liquid crystal driver sealed using this liquid semiconductor encapsulant, etc. The semiconductor device having the flip-chip type semiconductor element has excellent migration resistance and high reliability because peeling in the reliability test is suppressed.

The present invention will be described with reference to examples, but the present invention is not limited thereto. In the following examples, parts and% represent parts by mass and mass% unless otherwise specified.

[Examples 1 to 11 and Comparative Examples 1 to 7]
Liquid resin compositions (hereinafter referred to as “resin compositions”) were prepared with the formulations shown in Tables 1 and 2. In Examples 1 to 11 and Comparative Examples 2 to 3, the components (A) to (D) were mixed in the formulations shown in Tables 1 and 2 for 5 minutes at room temperature using a planetary stirring deaerator. Since the mass ratio of the core-shell rubber (D) component to the bisphenol F-type epoxy resin was 1: 2, the component (A) bisphenol F-type epoxy resin was used in the master batch of the (D) component. Was subtracted and added. In Comparative Example 4, the core-shell rubber obtained by drying the core-shell rubber-containing water suspension was used in place of the component (D). In addition, the master batch of the component (D ′) used in Comparative Example 6 was performed using three rolls. The mass ratio of the solid rubber and the mold epoxy resin as the component (D ′) was 1: 2.

[Evaluation of viscosity]
The viscosity (initial viscosity, unit: mPa · s) of the resin composition immediately after production (within 30 minutes) was measured with an E-type viscometer (model number: TVE-22H) manufactured by Toki Sangyo Co., Ltd. Tables 1 and 2 show the measurement results of the initial viscosity. Further, the viscosity of the resin composition after being stored at room temperature for 24 hours and 48 hours is measured, and [{(viscosity after 24 or 48 hours) / (initial viscosity)} × 100] is a viscosity increase rate (unit:%). ). Tables 1 and 2 show the results.

[Evaluation of flexural modulus]
The prepared resin composition is sandwiched between a glass plate coated with a release agent and cured into a 350 μm sheet at 60 ° C. for 60 minutes. A universal testing machine (AG-manufactured by Shimadzu Corporation AG- The flexural modulus at room temperature was determined using I). In addition, it measured by n = 3 and used the average value. The film thickness and width of the test piece were measured at five points, and the average value was used as the calculated value. The flexural modulus is preferably 2.0 to 4.2 GPa. Tables 1 and 2 show the evaluation results of the flexural modulus.

[Evaluation of amount of extracted Cl ions]
A sample obtained by curing the produced resin composition at 150 ° C. for 60 minutes was pulverized to about 5 mm square. Cured coating: Extraction obtained by adding 25 cm ³ of ion-exchanged water to 2.5 g and placing in a PCT test tank (121 ° C. ± 2 ° C./humidity 100% / 2 atm bath) for 20 hours and then cooling to room temperature The solution was used as a test solution. The Cl ion concentration of the extract obtained by the above procedure was measured using an ion chromatograph. Tables 1 and 2 show the evaluation results of the extracted Cl ion amount.

[Evaluation of injectability]
In FIG. 1, the schematic diagram explaining the evaluation method of the injectability of a resin composition is shown. First, as shown in FIG. 2A, a test piece in which a 20 μm gap 40 was provided on the substrate 20 and the glass plate 30 was fixed instead of the semiconductor element was produced. However, as the substrate 20, a glass substrate was used instead of the flexible substrate. Next, this test piece is placed on a hot plate set at 110 ° C., and as shown in FIG. 2 (B), the prepared resin composition 10 is applied to one end side of the glass plate 30, and FIG. ), The time until the gap 40 was filled with the resin composition 11 was measured. The case where the gap 40 was satisfied within 90 seconds was determined as “good”, and the case where it exceeded 90 seconds was determined as “bad”. Tables 1 and 2 show the injectability evaluation results.

[Evaluation of peeling after curing]
Peeling after curing was evaluated using TEG (30 um pitch, manufactured by Hitachi VLSI). The produced underfill was applied to the TEG with a dispenser and cured with a hot air dryer at 150 ° C. for 5 minutes. The TEG was allowed to stand at room temperature until it reached room temperature, and was observed from the film side of the TEG at room temperature using an optical microscope at a magnification of 200 times. It was observed whether or not there was a peeled portion between the bumps. When there was no peeled portion, “◯” was indicated, and when even one peel was confirmed, “×” was indicated. FIG. 3 shows a photograph of a portion where there is no separation after curing, and FIGS. 4 and 5 show photographs of a portion where separation occurs after curing. In FIG. 3, there was no separation, whereas in FIGS. 4 and 5, separation was confirmed at the location indicated by the arrow. Tables 1 and 2 show the evaluation results of peeling after curing.

[Appearance evaluation]
Evaluation of the appearance of the sample on which the peeling after curing was evaluated was performed at 200 × magnification using an optical microscope. FIG. 6 shows an enlarged photograph of the appearance of Example 3, and FIG. 7 shows an enlarged photograph of the appearance of Comparative Example 4. The pattern pitch in FIGS. 6 and 7 is 30 μm. In Example 3 shown in FIG. 6, the appearance was “◯”. On the other hand, in Comparative Example 4 shown in FIG. 7, peeling (delamination) was observed in a portion surrounded by a white broken line in the photograph. Tables 1 and 2 show the results of evaluation of appearance peeling.

[Evaluation of migration resistance]
In order to evaluate the ion migration resistance of the resin composition, a high temperature and high humidity bias test (THB test) was conducted. The test method is as follows. The prepared resin composition is applied in a thickness of 20 μm onto a polyimide tape substrate having tin wiring (0.2 ± 0.05 μm) copper wiring (pattern width: 15 μm, line width: 15 μm, pattern pitch: 30 μm). And it processed at 150 degreeC for 30 minute (s), the sealing agent was hardened, and the test piece was produced. With respect to this test piece, an ion migration evaluation system (manufactured by Espec Co., Ltd.) was used to measure a change in resistance value when a voltage of DC 60 V was applied at 85 ° C./85% humidity, and the resistance value was 1.00 ×. The migration of the copper wiring was evaluated (unit: time) with the time point below 10 ⁷ Ω as a threshold value. For those whose resistance value did not fall below the threshold, the test was terminated when 1000 hours were exceeded. Tables 1 and 2 show the migration resistance evaluation results.

As can be seen from Tables 1 and 2, in all of Examples 1 to 11, the viscosity is the desired value, the rate of increase in viscosity is low, the flexural modulus is the desired value, the amount of extracted Cl is low, and the injectability is good. There was no peeling after curing, the appearance was satisfactory, and the migration resistance was excellent. On the other hand, Comparative Example 1 not containing the component (D) and Comparative Example 2 having too little component (D) had peeling after curing and poor migration resistance. Comparative Example 3 having too much component (D) had poor injectability. In addition, instead of the component (D), Comparative Example 4 using a core-shell rubber without a masterbatch treatment, Comparative Example 5 using a solid rubber without a corebatch without a masterbatch treatment, and a solid rubber subjected to a masterbatch treatment are used. Comparative Example 6 was poor in injectability and poor in appearance. Comparative Example 7 using liquid rubber instead of the component (D) had a large amount of extracted Cl and poor migration characteristics.

The liquid resin composition of the present invention can be used as a fine pitch COF mounting sealant, and suppresses peeling during cooling in a sealing process or during a reliability test without deteriorating fluidity. Thus, the occurrence of migration that occurs in the high-temperature and high-humidity test can be suppressed, and is particularly suitable for a flip-chip type semiconductor element, particularly a semiconductor device including a liquid crystal driver.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Cathode 10, 11 Liquid resin composition 20 Substrate 30 Glass plate 40 Gap

Claims (7)

(A) a liquid epoxy resin, (B) an acid anhydride curing agent, (C) an imidazole compound curing accelerator, and (D) a masterbatch-treated elastomer having a core-shell structure,
The liquid epoxy resin composition, wherein the component (D) is 1 to 10 parts by mass with respect to 100 parts by mass of the liquid epoxy resin composition. The liquid epoxy resin composition according to claim 1, wherein the component (D) is an elastomer having a core-shell structure that is masterbatch-treated with a bisphenol type epoxy resin. Furthermore, (E) Liquid epoxy resin composition of Claim 1 or 2 containing a coupling agent. A liquid semiconductor encapsulant comprising the liquid epoxy resin composition according to any one of claims 1 to 3. A liquid encapsulant for a liquid crystal driver, comprising the liquid semiconductor encapsulant according to claim 4. A semiconductor device having a flip-chip type semiconductor element encapsulated with the liquid semiconductor encapsulant according to claim 4. A liquid crystal driver comprising a flip chip type semiconductor element sealed using the liquid sealing material for a liquid crystal driver according to claim 5.

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