JPH0325802A - Electrode connecting material - Google Patents

Abstract

PURPOSE:To obtain the electrode connecting conductive material for electronic parts which is soft after hardening and having the fine heat stability for a long term by forming the electrode connecting material with polyether resin, isocyanate compound and conductive filler. CONSTITUTION:Desirable polyether resin is a diglycidyl ether polymer of 2.2-bis (4-hydroxyphenyl) propane to be obtained by reaction of diglycidyl ether made of dihydric phenol having epoxy group not exceeding two per one molecular on the average and 1.1.1-tri (hydroxymethyl) propane. As isocyanate including component which performs crosslinking reaction with the polyether resin, diisocyanate and polyisocyanate compound is used. As conductive filler, more than one or two hinds of plastic powder, rubber powder, ceramic powder, glass powder to which metal plating is performed, carbon powder, conductive rubber powder and metal powder are used in combination.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to electrode connections of electronic components such as crystal resonators, ceramic resonators, and filters. In particular, it relates to conductive connecting materials with flexibility and long-term thermal stability.

Conventional technology Generally, the conductive adhesive used to connect the electrodes of crystal units, etc., is a hard conductive adhesive made by mixing a conductive filler with a thermosetting resin such as epoxy resin, phenol resin, or polyimide resin. be done. However, the coating film of these conductive adhesives is hard after curing, and this is especially true when connecting crystal resonators made of crystal pieces, which have become thinner in recent years, due to shrinkage during curing of the adhesive. The crystal piece is broken. Even if it doesn't lead to rupture. There is a problem in that the frequency of the υ crystal resonator changes over time due to residual stress after curing.

1. In order to solve these problems, soft conductive adhesives using polyurethane as a binder made by reacting block polyisocyanates and polyhydric alcohols have recently been used; however, these soft conductive adhesives 6 has the advantage of alleviating the stress during curing and shrinkage mentioned above. For example, during long-term thermal aging at a high temperature of 120°C or higher, the urethane bond is destroyed [the mechanical bonding force at the electrode connection decreases to the edge, which causes non-oscillation and crystal vibration. There is a risk that the child's functions will be severely impaired.

(Objective of the invention) The object of the invention is. In order to solve the above-mentioned problems, the present invention relates to a conductive electroplated connecting material for electronic components which is soft after hardening and has excellent long-term thermal stability.

<Detailed Description of the Invention> The polyether resin used in the present invention is composed of diglycidyl ether of dihydric phenol having an average of 1 to 2 epoxy groups per molecule, and 1. 1. ．． 1? }Product obtained by reaction with di(hydroxymethyl)propane
L<a2. ? - diglycidyl ether of bis(4-hydroxyphenyl)propane.

This type of glycidyl ether is represented by the following general formula, where Q represents two groups obtained by removing two H atoms from the OH group in dihydric phenol. and n has an average value in the range of 0 to 30.

More specifically, the polyether resin used in the present invention is Epicor T}l-72HX40 manufactured by Yuka Ciel Epoxy Co., Ltd.
Or Ebihut T)

1. The incyanate-containing composition that crosslinks with these polyether resins is... , diisocyanate and polyisocyanate compounds, block type polyisocyanate compounds, and isocyanate prepolymers, or a combination of two or more thereof may be used. The medium-block type polyincyanate compound', a brepolymer of incyanate, is most preferable from the standpoint of forming a conductive III adhesive into a single component. To explain these more specifically, block type polyisocyanate compounds are manufactured by BI, IIOQ (Sumitomo Bayer Urethane Co., Ltd.), Coronae} 2507. tsk13
．． 2515 (manufactured by Nippon Polyurethane Industry Co., Ltd.), etc. 1. As an isocyanate prepolymer. Desmo bottle 1
1 (Sumitomo Bayer Urethane Stock! #) 2 is mentioned.

Furthermore, the binder costs 1K! For the purpose of imparting properties, styrene-butadiene rubber, styrene-butadiene-styrene block copolymer mononitrile rubber, acrylic rubber, butadiene rubber. Synthetic rubber such as urethane rubber can be added.

The conductive filler used in the present invention includes (a) gold, wood powder, rubber powder, ceramic powder, plating powder obtained by plating glass powder with metal, f) carbon powder, graphite powder, and (d)
Type 1 of conductive rubber powder obtained by pulverizing conductive rubber powder
Or use two or more types together.

The content of the conductive powder relative to the binder may range from 50 to 90% by weight, but preferably from 70 to 90% by weight. If the content is less than 70% by weight, the conductivity tends to fluctuate, and if the content is more than 90% by weight, the connection strength decreases.

1) The particle size of the conductive filler is preferably 50 μm or less tL<50
A particle size of .mu.m or more has the disadvantage that filler sedimentation increases during storage.

The connecting material used in this invention is. In addition, for the purpose of adjusting viscosity. Toluene, isophorone. A general-purpose solvent such as cellosolve acetate may be mixed with an inorganic powder such as Si-5-silica powder, and a plastic powder or rubber powder such as silicone resin, epoxy resin, or phenol resin.

Furthermore, the present invention can be used as an antifoaming agent, a leveling agent, and an adhesion improver depending on the purpose of use. Various additives such as antioxidants and rust preventives can be added.

You can practice mixed manners.

<Examples of the invention> Examples 1 to 4 A certain amount of each of the ingredients shown in Table 1 was prepared. After kneading with three rolls, a predetermined connecting material was obtained.

0 Conductivity 1 The connecting material shown in Table 1 was coated on a ceramic plate to a thickness of 30 μm and cured at 150° C. for 30 minutes, and then the conductivity of the coating film was measured.

0 Pencil hardness At the same time as above, place the connecting material on the steel plate at a thickness of 30 μm! After the coating, the resin was cured by heating at 150° C. for 30 minutes to obtain a cypress membrane. Set the obtained lead m x 3 m' steel pieces 11k
The steel pieces were bonded together by heating and curing at 1 inch° C. for 30 minutes. After gluing. The falling strength of the steel pieces was measured using a cage.

Comparative Examples 1 to 2 0 Comparative Example 1 Table 1 shows the results of urethane-based conductive connecting materials obtained by crosslinking block incyanate and polyhydric alcohol (triol with a molecular weight of 149).

0 Comparative Example 2 Table 1 shows the results of an epoxy conductive adhesive using a polyamide curing agent.

<Effects of the Invention> As shown above, the conductive connecting material according to the present invention has unprecedented properties in that the coating film after curing is flexible and has excellent long-term thermal stability. Therefore, in response to the recent trend towards miniaturization of crystal resonators, which requires thinner crystal pieces and lower distortion, as well as demands for stability during high-temperature thermal aging, the connecting material (7) has excellent properties.

Claims (2)

[Claims] (1) An electrode connecting material characterized by being composed of a polyether resin, an isocyanate compound, and a conductive filler. (2) An electrode connecting material characterized in that the polyether resin according to claim 1 is a diglycidyl ether of 2,2-bis(4-hydroxyphenyl)propane having the following general formula. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Here, Q is the 2 H from the OH group in divalent phenol.
Indicates two groups obtained by removing atoms, and n is 0 to 3
It has an average value in the range of 0.