JP2650157B2 - Crystal oscillator - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention relates to a highly reliable quartz resonator which is free from cracks and oscillation failures and has excellent durability.

(Prior art) A crystal unit is assembled by attaching a metal electrode to a thin crystal blank formed by cutting a quartz crystal at a predetermined angle, and bonding the metal electrode and a lead conductor drawn out from a cover plate of a case. , Cover the assembled crystal piece and seal it,
Widely used for oscillation and the like. A conductive adhesive is used between the electrode of the crystal unit and the lead conductor or between the pad and the lead conductor of the semiconductor device to maintain the mechanical connection between the two while making the electrical connection. . As this conductive adhesive, a two-part epoxy adhesive has been conventionally used.

However, satisfactory properties have not been obtained with conventional conductive adhesives. For example, if a high-frequency thin quartz crystal piece is bonded with a two-component epoxy-based conductive adhesive, the conductive adhesive covering the crystal piece will cause cracks in the crystal piece after curing, There were drawbacks such as the occurrence of non-oscillation in the drop test. Further, the adhesive has two drawbacks, such that the pot life after mixing the two packs is short, and the amount of outgas generated is large, so that the adhesiveness is reduced and other effects are caused. In the case of thin quartz pieces, if a conductive adhesive made of a flexible resin such as polyester or polybutadiene is used, problems such as crack generation and oscillation failure due to a drop test will not occur. However, there is a disadvantage that oscillation failure still occurs depending on the hardness of the sample, the number of drops in a drop test, and the like.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned drawbacks, and has no cracks even when a thick crystal piece is used, and has no oscillation failure even in a severe drop test. It is an object of the present invention to provide a highly reliable quartz oscillator having excellent durability.

[Constitution of the Invention] (Means for Solving the Problems) The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have achieved the above object by using a conductive adhesive described later. We have found what we can do and completed the present invention.

That is, the present invention relates to: (A) an organic resin having two or more carboxyl groups in a molecular side chain or a molecular terminal, and (B) a metal electrode provided on a crystal blank and one end of a lead conductor of an envelope. A crystal unit characterized by being bonded and fixed with an epoxy compound having an alicyclic epoxy and a glycidyl group in the same molecule and a conductive adhesive containing (C) a conductive powder as an essential component.

 Hereinafter, the present invention will be described in detail.

The quartz piece used in the present invention is a thin piece having a thickness of about 80 μm obtained by cutting a quartz crystal at a predetermined angle, and a thick piece having a thickness of about 350 μm.
m. The cross section of the crystal piece may be any of a circular shape, an elliptical shape, and a polygonal shape, and is not particularly limited. Also, the size of the crystal piece is not particularly limited.

The lead conductor of the present invention is drawn out from a case cover plate or the like, and is not particularly limited.

In the present invention, (A) 2
Examples of the organic resin having two or more carboxyl groups include those having a long-chain alkyl group in consideration of flexibility, polyester-based, polybutadiene-based and acrylonitrile-
Resins having a butadiene system are preferred. Specific compounds include, for example, Polybd R-45MA (trade name, manufactured by Idemitsu Petrochemical Co., Ltd.), C-1000 (trade name, manufactured by Nippon Soda Co., Ltd.), CTBN-13
00 × 31, CTBN-1300 × 8, CTBN-1300 × 9, CTBN-1300 × 13
(Manufactured by Ube Industries, trade name), ELC-1, EL-2 (manufactured by Nippon Synthetic Rubber Co., Ltd.) and the like.
It can be used in combination of more than one species.

The epoxy compound (B) having an alicyclic epoxy and a glycidyl group in the same molecule used in the present invention has the following general structural formula: Or (Wherein, R represents an aliphatic or aromatic divalent group), and the viscosity thereof is preferably low,
The viscosity at 25 ° C. is desirably 100 poise or less. Specific compounds include, for example, Celloxide 300
And ERL-4206 (manufactured by Union Carbide, trade name), etc., and these can be used alone or in combination of two or more.
The mixing ratio of the epoxy compound (B) is preferably 5 to 150 parts by weight based on 100 parts by weight of the organic resin (A). If the compounding amount of the epoxy compound is less than 5 parts by weight, the epoxy group is less than the carboxyl group, whereby curing is not sufficiently performed, and the viscosity of the resin is increased, resulting in poor workability. On the other hand, if it exceeds 150 parts by weight, the epoxy component becomes too large, and sufficient flexibility cannot be obtained, which is not preferable. Further, a resin obtained by preliminarily subjecting the organic resin (A) and the epoxy compound (B) to a heating reaction at 150 to 170 ° C. may be used.

As the catalyst used in the present invention, a catalyst of the kaotin type is used. For example, a combination of an aluminum compound such as a combination of trismethoxyaluminum and triphenyl (methoxy) silane, a combination of trisethoxyaluminum and diphenyldimethoxysilane, and a silicon compound that generates silanol by heating, or a sulfonium salt type And a chaoline-based catalyst. Specific product names include Adeka Optomer Cp66, Cp77 (trade name, manufactured by Asahi Denka Kogyo KK), and these can be used alone or in combination of two or more.

In addition, the conductive adhesive of the present invention may be blended with a bifunctional or higher functional alicyclic epoxy resin, if necessary, to impart heat resistance.

The organic resin of (A) is reacted with the epoxy compound of (B) to form a binder, and a conductive powder of (C) described below is added as a binder to form a conductive adhesive.

As the conductive powder (C) used in the present invention, copper powder,
Examples thereof include silver powder, nickel powder, and powder having a metal layer on the surface. These may be used alone or in combination of two or more. It is desirable that these conductive powders have an average particle size of 30 μm or less. If the average particle size exceeds 30 μm, high-density filling is not possible, the paste does not form, and the printability and other coating performance deteriorate, which is not preferable. The mixing ratio of the conductive powder is 30/70 to 10/90 by weight ratio of the binder and the conductive powder.
It is desirable that If the amount of the conductive powder is less than 70 parts by weight, satisfactory conductivity cannot be obtained, and if it exceeds 90 parts by weight, workability and adhesiveness are undesirably reduced.

For the conductive adhesive used in the present invention, an organic solvent can be used as needed to adjust the viscosity. Solvents used include dioxane, hexanone, benzene, toluene, solvent naphtha, industrial gasoline, cellosolve acetate, ethyl cellosolve, butyl cellosolve, butyl cellosolve acetate, butyl carbitol acetate, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. And these can be used alone or in combination of two or more.

The conductive adhesive used in the present invention can be easily produced by blending the above-mentioned components and kneading them well with a three-roll mill or the like. Using the conductive adhesive thus produced, a metal electrode provided on the surface of a crystal blank and a lead portion of a semiconductor device pad or a component are applied, and these are adhered to each other at 150 ° C. for 6 hours.
A crystal oscillator can be manufactured by heating and curing for 0 minutes and bonding and fixing.

(Function) The quartz oscillator of the present invention is obtained by reacting a low-viscosity epoxy compound with a flexible rubber-like substance or long-chain resin,
Crack generation, oscillation failure, and durability are improved by using a conductive adhesive that uses a resin that has improved flexibility, adhesion, curing speed, and workability.

(Examples) Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 3 The components shown in Table 1 were blended and kneaded three times with three rolls to produce one-component conductive adhesives. Dispensing was applied to the electrode part of a 350 μm-thick crystal piece and the pad part of the semiconductor device using this adhesive,
After heating and curing for a minute, a quartz oscillator was manufactured. It was confirmed that the curing reaction at this time was complete, and the amount of outgas generated thereafter was small. The number of non-oscillations when this crystal resonator was cracked 100 times and dropped 100 times from above 75 cm was measured (the total number of samples n = 30). The results are shown in Table 1. The crystal resonator of the present invention had no cracks, had no oscillation failure after falling, and the remarkable effect of the present invention was recognized.

Comparative Example 1 The components shown in Table 1 were blended, a one-component conductive adhesive was produced in the same manner as in Examples 1 to 3, and a quartz oscillator was produced in the same manner as in Examples 1 to 3. In the same manner, various properties were tested, and the results are shown in Table 1.

Comparative Example 2 A quartz oscillator was manufactured in the same manner as in Examples 1 to 3 using a two-component epoxy conductive adhesive using a commercially available polyamide curing agent, and various characteristics were tested in the same manner. The results are shown in Table 1.

[Effects of the Invention] As is clear from the above description and Table 1, the quartz oscillator of the present invention uses a conductive adhesive excellent in flexibility, flexibility and adhesiveness, and therefore has a relatively large thickness. It has no cracks even in a crystal piece, and has no oscillation failure even in a severe drop test, and is extremely excellent in durability. Since the curing reaction of the conductive adhesive is complete, the occurrence of outgas and the like is small and the other characteristics are not adversely affected, so that a highly reliable quartz oscillator can be obtained.

Claims (1)

(57) [Claims] (1) A metal electrode provided on a crystal piece and one end of a lead conductor of an envelope are connected to (A) a molecular side chain or a molecular end.
Adhesively fixed by an organic resin having at least two carboxyl groups, (B) an epoxy compound having an alicyclic epoxy and a glycidyl group in the same molecule, and (C) a conductive adhesive containing conductive powder as an essential component. A quartz oscillator characterized by the following.