JPS63124610A - Crystal resonator - Google Patents

Abstract

PURPOSE:To prevent the production of defective oscillation at a drop test and of cracks in using a thick crystal chip by adhering a metallic electrode of a crystal resonator provided to a crystal chip and an external lead conductor by a conductive adhesives including an epoxy resin, polybutadiene group liquid resin, petroleum group resin and conductive powder. CONSTITUTION:The conductive adhesives includes the epoxy resin, polybutadiene group liquid resin, petroleum group resin and conductive powder. Each component is kneaded by three-roll or the like to manufacture an adhesives. In applying dispense coating the conductive adhesives between the electrode of crystal chip and the pad of the lead conductor, the result is heated and cured for 30min at 150 deg.C to adhere both and the crystal resonator is manufactured with other assembling.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a crystal resonator, and particularly relates to a highly durable and reliable assembly technique that is free from cracks and oscillation defects. This is related.

(Prior Art) A crystal camera is a thin crystal piece made by cutting a crystal body at a predetermined angle, and a metal electrode is provided on the thin crystal piece. The electrode and the lead-out conductor drawn out from the cover plate of the case are glued together, the cover is placed over the cover plate on which the crystal piece is mounted, and this is sealed and assembled, and it is widely used for oscillation. Conductive adhesive is used between the crystal piece electrode of a crystal resonator and the lead-out conductor, or in a similar example, between the pad of a semiconductor device and the lead-out conductor, in order to mechanically connect the two while maintaining conductivity. is used. As such conductive adhesives, two-component epoxy adhesives have conventionally been widely used.

However, conventional conductive adhesives have not provided satisfactory results. For example, if a thin crystal piece for high frequency is glued with a two-component epoxy-based conductive adhesive, the conductive adhesive covering the crystal piece may cause cracks on the crystal piece after hardening, or the crystal unit may become damaged. There were problems such as oscillation failure during drop tests. In addition, since the adhesive is a two-component adhesive, there are disadvantages such as a short pot life after mixing the two components, a large amount of outgassing, a decrease in adhesion, and an impact on other properties. Ta.

Note that when using a conductive adhesive made of resin such as polyester or polybutadiene, which is more flexible than an epoxy-based conductive adhesive, if the crystal piece is thin, problems such as cracking and failure of oscillation in drop tests will occur. It disappears, but
When the crystal piece is thick, there is a problem in that oscillation failure occurs depending on the number of drops in the drop test.

(Problems to be Solved by the Invention) The present invention was made to solve the above-mentioned problems, and it does not cause cracks even when using thick crystal pieces, and does not oscillate even in severe drop tests. No defects,
The aim is to provide a highly reliable crystal resonator with excellent durability.

[Structure of the Invention] (Means and Effects for Solving the Problems) As a result of intensive research to achieve the above object, the present inventor has discovered that cracks can be prevented by using a conductive adhesive, which will be described later. The present invention was completed based on the discovery that a crystal resonator with excellent durability and no defective shooting could be obtained. That is, in the present invention, a metal electrode provided on a crystal piece and a lead-out conductor to the outside are bonded together using a conductive adhesive containing an epoxy resin, a polybutadiene liquid resin, a petroleum resin, and a conductive powder. This is a crystal resonator characterized by being fixed. The crystal resonator uses a conductive adhesive in which the polybutadiene-based liquid resin used as the conductive adhesive has an acrylonitrile group at the end, and the petroleum-based resin has a hydroxyl group.

The crystal piece used in the present invention is a thin piece of about 80 μm obtained by cutting a crystal body at a predetermined angle, and the thicker one is 350 μm thick.
It is of a certain degree. There are no particular limitations on the cross-sectional shape or size of the crystal piece, and any type can be used.

As the epoxy resin used in the present invention, all kinds of resins having a glycidyl group can be used, such as bisphenol type epoxy resin, 〇-cresol novolac type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, etc. These can be used alone or in combination of two or more.

The polybutadiene liquid resin used in the present invention is preferably one having an acrylonitrile group at the end in consideration of flexibility, flexibility and solubility. in particular,
For example, the CTBN series (manufactured by Ube Industries, Ltd., trade name) may be mentioned, and these may be used alone or in combination of two or more.

The petroleum-based resin used in the present invention is typically a petroleum-based resin having a hydroxyl group, such as a compound having a norbornene ring obtained by polymerizing a C5 fraction. , trade name), etc., and can be used alone or in combination. The petroleum resin is blended with the above-mentioned polybutadiene liquid resin, and both have the effect of making the epoxy resin flexible and improving its adhesion to metals.

The conductive powder used in the present invention includes silver powder, copper powder,
Examples include nickel powder and powder having a metal layer on the surface, and these may be used alone or in combination of two or more.

It is preferable that all of these conductive powders have an average particle size of 30 μm or less. This is because if the average particle size exceeds 30 μm, high-density filling becomes impossible and the coating performance deteriorates, which is not preferable. This conductive powder is mixed with a binder made of the above-mentioned epoxy resin, polybutadiene liquid resin, and petroleum resin. The blending ratio of the binder and the conductive powder is 30 m
The ratio of near 0 to 10 is preferably 90.

If the conductive powder is less than 70, satisfactory conductivity cannot be obtained, and if it exceeds 90, workability and adhesion will deteriorate, which is not preferable. Therefore, it is preferable to limit it within the above range.

For the conductive adhesive used in the present invention, an organic solvent can be used as necessary to adjust the viscosity.

These solvents include dioxane, hexanone, benzene, toluene, solvent naphtha, industrial gasoline, cellosolve acetate, ethyl cellosolve, butyl cellosolve, ethyl cellosolve acetate, butyl carpitol acetate formamide, dimethyl acetamide, N-methyl biU
Examples include Lydon and the like. Further, it is preferable to add a curing catalyst to the conductive adhesive used in the present invention for the purpose of accelerating its curing, and an imidazole-based catalyst is generally used.

The conductive adhesive used in the present invention contains an epoxy resin, a polybutadiene-based liquid resin, a petroleum-based resin, and a conductive powder, but other components may be blended as necessary unless it contradicts the purpose of the present invention. The adhesive can be easily produced by thoroughly kneading these components using three rolls or the like. After dispensing and applying this conductive adhesive between the electrode part of the crystal piece and the pad part of the lead-out conductor, the adhesive is cured by heating at 150°C for 30 minutes to fix them together, and the other parts are assembled to form the crystal resonator. Manufacture.

(Example) Next, the present invention will be explained by examples.

Examples 1 to 3 Each component shown in Table 1 was kneaded three times using three rolls to produce one-component conductive adhesives. After dispensing and applying the adhesive thus obtained to the electrode part of a 350 μm thick crystal piece and the pad part of the lead-out conductor,
The mixture was cured by heating at 0° C. for 30 minutes, and a crystal resonator was manufactured. It was observed that the curing reaction at this time was complete, and that the amount of outgas generated thereafter was small. Regarding this camera element, there is a crack in the crystal piece and 10cm from 75cm above.
I wanted to find out the number of samples that failed to oscillate (defective oscillation) when dropped 0 times (total number of samples n = 30). These results are shown in Table 1, and the crystal resonator according to the present invention had no cracks and no oscillation failures after being dropped, demonstrating the remarkable effects of the present invention.

Comparative Example 1 In the same manner as in Example 1, a one-component conductive adhesive was obtained from each component shown in Table 1, a crystal resonator was manufactured, and its characteristics were tested. Shown in the table.

Comparative Example 2 A crystal resonator was manufactured in the same manner as in the example using a two-component epoxy conductive adhesive using a commercially available polyamide curing agent, and its characteristics were tested. The results are shown in Table 1. Ta.

[Effects of the Invention] As is clear from the above explanation and Table 1, the crystal resonator of the present invention uses a conductive adhesive with excellent flexibility, flexibility, and adhesiveness, so There are no cracks even in crystal blanks, there are no defects even in severe drop tests, and the product is extremely durable. Furthermore, since the curing reaction of the conductive adhesive is complete, there is little generation of outgas, etc., and as a result, the characteristics are not adversely affected, making it possible to obtain a highly reliable crystal resonator.

Claims (1)

[Claims] 1. A metal electrode provided on a crystal piece and a lead-out conductor to the outside,
A crystal resonator characterized by being adhesively fixed with a conductive adhesive containing epoxy resin, polybutadiene liquid resin, petroleum resin, and conductive powder. 2. The crystal resonator according to claim 1, wherein the polybutadiene liquid resin has an acrylonitrile group at the end. 3. The crystal resonator according to claim 1 or 2, wherein the petroleum-based resin has a hydroxyl group.