JPH10298525A - Anisotropic conductive adhesive resin composition and anisotropic conductive adhesive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anisotropic conductive adhesive resin composition having high connection reliability between circuits to be connected and high insulation reliability between adjacent circuits even after a reliability test. I do. SOLUTION: In a resin composition mainly composed of 100 parts by weight of a composition comprising an epoxy resin, polyphenylene ether and a curing agent and 5 to 50 parts by weight of an elastomer, 0.1 to 15 vol. %contains. The heat resistance of the cured product of the anisotropic conductive adhesive resin composition can be increased by blending the polyphenylene ether.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic connection between fine circuits, for example, a connection between a liquid crystal display (LCD) and a flexible circuit board, and a micro junction between a semiconductor IC and a circuit board for mounting an IC. The present invention relates to an anisotropic conductive adhesive resin composition and an anisotropic conductive adhesive film used for assembling parts and the like.

[0002]

2. Description of the Related Art With the recent miniaturization and thinning of electronic devices, the necessity of connection between minute circuits and connection between minute components and minute circuits has been increasing. The use of a conductive adhesive or a conductive film having the same has been performed. The anisotropic conductive adhesive film is formed by casting and drying an anisotropic conductive adhesive resin composition containing a predetermined amount of conductive particles on a release film, and is formed in a sheet form or a fixed form. It is used by slitting it into a ribbon shape of width. When connecting using an anisotropic conductive adhesive film, for example, when connecting two circuit boards, the anisotropic conductive adhesive film formed on the release film is placed on the circuit of one circuit board and separated. Applying a predetermined temperature and pressure from the mold film side and temporarily compressing, then peeling off the release film, aligning the circuits, overlaying the circuit of the other circuit board on the anisotropic conductive adhesive film, By performing thermocompression bonding at a temperature, pressure, and time, electrical connection between two circuit boards can be made. At this time, insulation between adjacent circuits on the same circuit board is reduced. It can be secured.

[0003] The anisotropic conductive adhesive film is classified into a thermoplastic type and a thermosetting type.
Recently, epoxy resin-based thermosetting types, which are more reliable than thermoplastic types, are widely used.

[0004]

However, since the heat resistance of the conventional thermosetting type is insufficient, the insulating adhesive resin component is deteriorated by the temperature and humidity in the long-term reliability test, and the adjacent adhesive resin component is deteriorated. There has been a problem that the insulation properties of the circuit cannot be stably obtained. The present invention has been made in view of the above points, and even after a reliability test, anisotropic conductive adhesive having high connection reliability between circuits to be connected and high insulation reliability between adjacent circuits. It is an object to provide an agent resin composition and an anisotropic conductive adhesive film.

[0005]

The anisotropic conductive adhesive resin composition according to the present invention is obtained by mixing 5 to 50 parts by weight of an elastomer with 100 parts by weight of a composition comprising an epoxy resin, polyphenylene ether and a curing agent. In a resin composition mainly containing a resin, 0.1 to 15 vol% of conductive particles
It is characterized by comprising.

The invention of claim 2 is characterized in that a polyphenylene ether having a number average molecular weight of 1,000 to 3,000 is used. The invention according to claim 3 is characterized in that conductive particles having an average particle diameter of 1 to 20 μm are used. The anisotropic conductive adhesive film according to the present invention is characterized in that the above-described anisotropic conductive adhesive resin composition is formed into a film.

[0007]

Embodiments of the present invention will be described below. As the epoxy resin constituting the adhesive resin composition in the present invention, any epoxy resin generally used as a resin for electrical insulation can be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin , Bisphenol S type epoxy resin,
Phenol novolak epoxy resin, cresol novolak epoxy resin, bisphenol A novolak epoxy resin, glycidyl etherified resin of 2,6-xylenol dimer, bisphenol F novolak epoxy resin, isocyanurate epoxy resin, hydantoin epoxy resin , Trifunctional epoxy resin or 4
Examples include polyfunctional epoxy resins such as functional epoxy resins, glycidylamine epoxy resins, glycidylated epoxy resins of diaminophenyl ether, alicyclic epoxy resins, and brominated flame-retardant epoxy resins. it can. These epoxy resins can be used alone or in combination of two or more.

In the present invention, any commercially available polyphenylene ether (PPE) can be used, or polyphenylene ether (PPE) modified with polystyrene or the like can be used. As described above, it is possible to use any commercially available polyphenylene ether. However, commercially available polyphenylene ether generally has a relatively large number average molecular weight of 15,000 to 25,000. When the resin composition is prepared, the viscosity of the composition becomes high and voids are likely to remain during film production. Therefore, when a circuit board or the like is connected using the anisotropic conductive adhesive film manufactured as described above, voids are also generated in a circuit connection portion, and connection reliability between circuits is deteriorated. Therefore, in the present invention, by using polyphenylene ether having a low molecular weight, the viscosity of the anisotropic conductive adhesive resin composition is reduced, and a void-free anisotropic conductive adhesive film can be produced. Is preferred.

However, polyphenylene ethers having a low molecular weight are not commercially available. When a commercially available polyphenylene ether is used, its molecular weight must be adjusted. To adjust the molecular weight of polyphenylene ether, refer to the Journal of organa
Nic chemistry, 34, 297-303
(1968). That is, polyphenylene ether is converted to bisphenol A under a radical initiator such as benzoyl peroxide.
And a phenolic compound such as the above, whereby the polyphenylene ether skeleton is cleaved. Benzoyl peroxide is preferably added in an amount of 3 to 10 parts by weight per 100 parts by weight of polyphenylene ether,
The addition amount of bisphenol A is also preferably 3 to 20 parts by weight. If the amount of benzoyl peroxide or bisphenol A is too large, the number average molecular weight of the polyphenylene ether is too low, and if the amount is too small, the effect of lowering the number average molecular weight of the polyphenylene ether is small. In addition,
The skeletal cleavage reaction of this polyphenylene ether is 80 to 1
The reaction is preferably performed in the range of 20 ° C., and the reaction time is 10 to
100 minutes is preferred. In this reaction, it is preferable to use an aromatic hydrocarbon-based solvent or a halogen-based solvent described below, which can dissolve these materials, in order to adjust the reactivity and the viscosity.

The number average molecular weight of the polyphenylene ether used in the present invention is preferably from 1,000 to 3,000, and when the number average molecular weight exceeds 3,000, the viscosity of the anisotropic conductive adhesive resin composition becomes high. When an anisotropic conductive adhesive film is produced, voids may be generated. Conversely, the number average molecular weight is 1
When a polyphenylene ether of less than 000 is used, the heat resistance of the cured product of the anisotropic conductive adhesive resin composition decreases,
Not preferred.

The curing agent used in the present invention is not particularly limited as long as it is involved in the curing of the epoxy resin, and is preferably an amine-based, phenol-based, or acid anhydride-based curing agent. Further, the elastomer added in the present invention may be reactive or non-reactive, and is not particularly limited, but may be SBR (styrene-butadiene rubber),
SBS (styrene-butadiene-styrene copolymer),
It is preferable to use SEBS (styrene-ethylene-butene-styrene copolymer), SIS (styrene-isoprene-styrene copolymer) or the like.

In the present invention, the conductive particles include
Although not particularly limited, for example, nickel, copper,
Metals such as iron, aluminum, gold, silver, lead and tin, metal oxides, alloys such as solder, carbon, graphite, or core materials such as plastics and ceramics coated with metal by plating Can be mentioned. The average particle size of the conductive particles is more preferably in the range of 1 to 20 μm in order to ensure high reliability of connection between circuits to be connected and ensure insulation between adjacent circuits.

The epoxy resin, polyphenylene ether, and curing agent are blended, the elastomer is blended, and the conductive particles are blended to obtain the anisotropic conductive adhesive resin composition according to the present invention. You can do it. Here, the elastomer is a composition 1 comprising an epoxy resin, polyphenylene ether, and a curing agent.
It is blended in the range of 5 to 50 parts by weight with respect to 00 parts by weight. If the amount of the elastomer is less than 5 parts by weight, the anisotropic conductive adhesive resin composition becomes brittle, making it difficult to form a film and making it impossible to prepare an anisotropic conductive adhesive film. Conversely, if the amount of the elastomer exceeds 50 parts by weight, the heat resistance of the cured product of the anisotropic conductive adhesive resin composition may be impaired. The mixing ratio of the epoxy resin, the polyphenylene ether, and the curing agent was such that, based on 100 parts by weight of the epoxy resin, 20 to 100 parts by weight of the polyphenylene ether and 0.5 to 20 parts of the curing agent.
A range of parts by weight is preferred.

The amount of the conductive particles is 0.1 to 15 vol based on the resin composition containing the epoxy resin, polyphenylene ether, curing agent and elastomer.
% Is preferred. The compounding amount of the conductive particles is 0. lvo
If it is less than 1%, it is difficult to obtain stable conduction reliability between circuits to be connected, and the compounding amount of the conductive particles is 1%.
If it exceeds 5 vol%, insulation reliability between adjacent circuits may not be obtained.

Here, the anisotropic conductive adhesive resin composition of the present invention can be used after being diluted with a solvent. The solvent is not particularly limited as long as it can dissolve polyphenylene ether.Examples include aromatic hydrocarbon solvents such as toluene, benzene, and xylene, and trichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, and chloroform. Halogen-based solvents can be used. These solvents can be used alone or in combination of two or more.

On the other hand, the anisotropic conductive adhesive film of the present invention can be obtained by molding the anisotropic conductive adhesive resin composition into a film. For example, a polyester film as a film for a carrier, a polyimide film, insoluble in a solvent in the resin liquid of the anisotropic conductive adhesive resin composition such as a fluororesin-based film, and those that have been subjected to release treatment, this carrier By casting and drying the anisotropic conductive adhesive resin composition on the film, an anisotropic conductive adhesive film can be obtained.

[0017]

Next, the present invention will be described specifically with reference to examples. Example 1 Polyphenylene ether (P) having a number average molecular weight (Mn) of 20,000 manufactured by Nippon GE Plastics Co., Ltd.
PE) was mixed with benzoyl peroxide (BPO), bisphenol A (BPA) and toluene in the proportions shown in Table 1, and the resulting mixture was stirred at 90 ° C. for 60 minutes to react. Table 1 shows the number average molecular weight of this product. The number average molecular weight of PPE was measured by gel permeation chromatography (column structure: TSKge manufactured by Tosoh Corporation).
l SuperHM-M (one) + SuperHM-H
(1 piece)) to determine the molecular weight distribution.

The number average molecular weight of 130 obtained as described above
64 parts by weight of a toluene solution of polyphenylene ether of No. 0 and SBS (Asahi Kasei Corporation) as an elastomer component
40% by weight of “Tuffrene A” manufactured by
The mixture was stirred for 0 minutes and then cooled to room temperature. Next,
80 parts by weight of a brominated bisphenol A type epoxy resin ("YDB-500" manufactured by Toto Kasei Co., Ltd., having a nonvolatile content of 80% by weight with toluene), 1 part by weight of diaminodiphenylmethane (DDM) as a curing agent, 2-ethyl 5 parts by weight of -4-methylimidazole (2E4MZ) were added, and nickel particles having an average particle size of 2 μm were further added in 10 vol.
% And uniformly stirred to prepare an anisotropic conductive adhesive resin composition.

Then, the anisotropic conductive adhesive resin composition is applied on a release-treated polyethylene terephthalate film using a bar coater, and is dried by blowing at 80 ° C. to give a 25 μm thick anisotropic conductive adhesive resin composition. A conductive adhesive film was obtained. (Example 2) An anisotropic conductive adhesive resin composition was prepared in the same manner as in Example 1 except that the blending amount of SBS was 45 parts by weight and nickel particles having an average particle size of 5 µm were added at 8 vol%. The anisotropic conductive adhesive film having a thickness of 25 μm was prepared in the same manner as in Example 1 using the prepared anisotropic conductive adhesive resin composition.

(Example 3) Benzoyl peroxide and bisphenol A were blended in the ratio shown in Table 1 with polyphenylene ether having a number average molecular weight of 20,000, and a number average molecular weight of 230 was obtained by reacting in the same manner as in Example 1.
Except that the amount of SBS was 30 parts by weight, the amount of diaminodiphenylmethane was 0.8 part by weight, and nickel particles having an average particle size of 15 μm were added at 5 vol% using polyphenylene ether of 0. An anisotropic conductive adhesive resin composition was prepared in the same manner as in Example 1. Further, using this anisotropic conductive adhesive resin composition, an anisotropic conductive adhesive film having a thickness of 25 μm was obtained in the same manner as in Example 1. I got

Example 4 Using polyphenylene ether having a number average molecular weight of 2300 obtained in the same manner as in Example 3,
Except that the amount of SBS was 20 parts by weight, the amount of diaminodiphenylmethane was 0.6 parts by weight, and nickel particles having an average particle diameter of 5 μm were added at 15 vol%,
An anisotropic conductive adhesive resin composition was prepared in the same manner as in Example 1, and the anisotropic conductive adhesive resin composition having a thickness of 25 μm was prepared in the same manner as in Example 1 by using this anisotropic conductive adhesive resin composition. An adhesive film was obtained.

(Example 5) A polyphenylene ether having a number average molecular weight of 20,000 was mixed with benzoyl peroxide and bisphenol A at the ratio shown in Table 1 and reacted in the same manner as in Example 1 to obtain a number average molecular weight of 280.
Except that polyphenylene ether of 0 was used, the compounding amount of SBS was 7 parts by weight, the compounding amount of diaminodiphenylmethane was 0.6 parts by weight, and 1 vol% of nickel particles having an average particle size of 18 μm were added. An anisotropic conductive adhesive resin composition was prepared in the same manner as in Example 1. Further, using this anisotropic conductive adhesive resin composition, an anisotropic conductive adhesive film having a thickness of 25 μm was obtained in the same manner as in Example 1. I got

Example 6 A polyphenylene ether having a number average molecular weight of 20,000 was mixed with benzoyl peroxide and bisphenol A at the ratios shown in Table 1 and reacted in the same manner as in Example 1 to obtain a number average molecular weight of 700.
Anisotropic conductive adhesive was prepared in the same manner as in Example 1 except that the polyphenylene ether was used, the amount of diaminodiphenylmethane was 1.2 parts by weight, and nickel particles having an average particle size of 5 μm were added at 3 vol%. Prepare a resin composition, further using this anisotropic conductive adhesive resin composition,
An anisotropic conductive adhesive film having a thickness of 25 μm was obtained in the same manner as in Example 1.

(Example 7) Benzoyl peroxide and bisphenol A were blended at the ratio shown in Table 1 with polyphenylene ether having a number average molecular weight of 20,000, and the number average molecular weight obtained by reacting in the same manner as in Example 1 was 340.
0 polyphenylene ether, the amount of diaminodiphenylmethane was adjusted to 1.5 parts by weight, and the average particle diameter was 12 μm.
Except that 5 vol% of nickel particles of m was added, an anisotropic conductive adhesive resin composition was prepared in the same manner as in Example 1, and further using this anisotropic conductive adhesive resin composition, An anisotropic conductive adhesive film having a thickness of 25 μm was obtained in the same manner as in Example 1.

Comparative Example 1 An anisotropic conductive adhesive resin composition was prepared in the same manner as in Example 1 except that the elastomer component was not blended. A film-like product could not be formed from this anisotropic conductive adhesive resin composition, and an anisotropic conductive adhesive film could not be obtained.

Comparative Example 2 An anisotropic conductive adhesive resin composition was prepared in the same manner as in Example 1 except that 18 vol% of nickel particles having an average particle size of 5 μm were added. Example 1 using a conductive adhesive resin composition
In the same manner as in the above, an anisotropic conductive adhesive film having a thickness of 25 μm was obtained.

Comparative Example 3 Example 1 was repeated except that 18 vol% of nickel particles having an average particle size of 25 μm were added.
An anisotropic conductive adhesive resin composition was prepared in the same manner as in Example 1. Further, using this anisotropic conductive adhesive resin composition, an anisotropic conductive adhesive film having a thickness of 25 μm was formed in the same manner as in Example 1. Obtained.

Comparative Example 4 50 parts by weight of acrylonitrile butadiene rubber having a carboxyl group terminal (“CTBN” manufactured by Ube Industries, Ltd.) as an elastomer component, and a brominated bisphenol A type epoxy resin (“Y” manufactured by Toto Kasei Co., Ltd.)
DB-500 "(to a nonvolatile content of 80% by weight with toluene), 125 parts by weight, 1.7 parts by weight of diaminodiphenylmethane as a curing agent, and 8.3 parts by weight of 2-ethyl-4-methylimidazole. Furthermore, average particle size 2
8 vol% of nickel particles of μm were added and uniformly stirred to prepare an anisotropic conductive adhesive resin composition. Further, using this anisotropic conductive adhesive resin composition, an anisotropic conductive adhesive film having a thickness of 25 μm was obtained in the same manner as in Example 1.

[0029]

[Table 1]

Examples 1 to 7 and Comparative Example 2 as described above
Using the anisotropic conductive adhesive film obtained in (1) to (4), sandwiching the anisotropic conductive adhesive film between the evaluation IC chip provided with bumps of 50 μm pitch and the evaluation substrate provided with a wiring pattern of 50 μm pitch, 190 ° C, 20 kg / cm ² , 3
The bumps of the evaluation IC chip were electrically connected to the wiring patterns of the evaluation substrate by pressure bonding under the condition of 0 second. Regarding the connection resistance between the circuit of the evaluation IC chip and the circuit of the evaluation board and the insulation resistance between the adjacent circuits of the evaluation board, the initial value and the value after the reliability test left at 85 ° C.-95% RH for 1000 hours are shown. It was measured. The results are shown in Tables 2 and 3. The measurement of the connection resistance is performed using the four-terminal method.
A sample within 10 mΩ was evaluated as “good”, and a sample exceeding 10 mΩ was evaluated as unacceptable “x”. The measurement of the insulation resistance is performed using an insulation resistance meter, pass "○" for more than 10 ⁸ Ω, 10 ⁸ Ω
Less than "poor" was judged as unacceptable.

Further, the anisotropic conductive adhesive films obtained in Examples 1 to 7 and Comparative Examples 2 to 4 were heated at a temperature of 90 ° C. for a time of 30 seconds.
T of cured product cured under the condition of pressure 20 kgf / cm ²
g was measured by the DMA method (dynamic viscoelasticity method). The results are shown in Tables 2 and 3.

[0032]

[Table 2]

[0033]

[Table 3]

As shown in Tables 2 and 3, Examples 1 to 7
The sample showed good electrical characteristics even after the reliability test. On the other hand, Comparative Example 1 in which no elastomer was added
Could not be made into a film. In Comparative Example 2 in which 18 vol% of conductive particles were added and in Comparative Example 3 in which conductive particles having an average particle size of 25 μm were added, the initial insulation resistance was poor, and so-called resolution was not obtained. Furthermore, in the case of Comparative Example 4 in which no polyphenylene ether was added, no satisfactory electrical characteristics were obtained after the reliability test. This is considered to be due to low heat resistance as seen in a low Tg.

[0035]

As described above, the present invention provides an epoxy resin,
Composition 100 comprising polyphenylene ether and curing agent
In a resin composition containing 5 to 50 parts by weight of an elastomer and 5 to 50 parts by weight of a elastomer as a main component, the conductive particles are added in an amount of 0.1%.
Since the anisotropic conductive adhesive resin composition is prepared by containing 1 to 15 vol%, the heat resistance of the cured product of the anisotropic conductive adhesive resin composition can be increased by blending polyphenylene ether. Even after a reliability test, it is possible to obtain high connection reliability between circuits to be connected and insulation reliability between adjacent circuits.
Moreover, the anisotropic conductive adhesive resin composition can be easily formed into a film by blending the elastomer, and the molding of the anisotropic conductive adhesive film becomes easy.

According to the second aspect of the present invention, since the polyphenylene ether having a number average molecular weight of 1,000 to 3,000 is used, an anisotropic conductive adhesive film having a small number of voids without lowering heat resistance is produced. Is what you can do. According to the third aspect of the present invention, since the conductive particles having an average particle size of 1 to 20 μm are used, high reliability of connection between circuits to be connected is ensured, and insulation between adjacent circuits is ensured. It can secure the property.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09J 171: 12 121: 00)

Claims (4)

[Claims] 1. A resin composition mainly composed of 100 parts by weight of an epoxy resin, polyphenylene ether, and a curing agent and 5 to 50 parts by weight of an elastomer. An anisotropic conductive adhesive resin composition comprising 15 vol%. 2. The anisotropic conductive adhesive resin composition according to claim 1, wherein a polyphenylene ether having a number average molecular weight of 1,000 to 3,000 is used. 3. The conductive particles have an average particle size of 1 to 20 μm.
The anisotropic conductive adhesive resin composition according to claim 1 or 2, wherein m is used. 4. An anisotropic conductive adhesive film formed by molding the anisotropic conductive adhesive resin composition according to claim 1 into a film.