JPS61261913A - Crystal resonator - Google Patents

Abstract

PURPOSE:To eliminate the generation of a crack of the time of adhesion, and to eliminate the non-oscillation caused by a drop test, by sticking and fixing an electrode and a leading-out conductor of parts by a conductive adhesive agent using a urethane prepolymer having no unsaturated double coupling, and polyhydric alcohol, etc. CONSTITUTION:A metallic electrode provided on a crystal piece and a leading- out conductor of parts are stuck and fixed by a conductive adhesive agent using a urethane prepolymer A having no unsaturated double coupling and polyhydric alcohol, etc. B. The polymer A is obtained by converting an end active isocyanate base to a block by an active hydrogen compound. A ratio of the isocyanate base dissociated from the polymer A and a hydroxyl group of the alcohol, etc. B is that of a range of 1.0-1.2 equivalent. In this way, the generation of a crack of the time of adhesion is eliminated, and the non- oscillation caused by a drop test is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a crystal resonator that has excellent durability and is free from cracking and poor transmission.

[Technical background of the invention and its problems] A quartz crystal resonator is a thin quartz piece made by cutting a quartz crystal at a predetermined angle, and a metal electrode is provided on the thin quartz piece, and a drawer extending from the lid plate of the case and the metal electrode are attached. It is widely used for oscillation, etc. by gluing the conductor and putting a cover over the assembled crystal piece to seal it.

Conductive adhesive is used between the electrodes of the crystal resonator and the lead-out conductor, or between the pads of the semiconductor device and the lead-out conductor, in order to maintain the mechanical bond between them while maintaining S conductivity. . As this conductive adhesive, a two-component epoxy adhesive has conventionally been used.

However, conventional conductive adhesives do not have satisfactory properties. 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 are drawbacks such as some cases not oscillating in drop tests. In addition, since it is a two-component product, the pot life after mixing the two components is short, and there are many outgas generation ports, which reduce adhesion and affect other products. Furthermore, if a flexible resin having unsaturated double bonds such as polybutadiene is used, the above-mentioned problems of cracking of crystal pieces and failure of transmission due to drop tests will not occur in the initial stage. However, if exposed to high temperatures of 100°C or higher for a long period of time, the unsaturated double bonds in polybutadiene will be oxidized and polymerization will proceed on the surface, resulting in a loss of flexibility and the same problem as epoxy resins, which can cause cracks and poor transmission. Ta.

[Objective of the Invention] The object of the present invention was to solve the above-mentioned drawbacks, and has no cracks, no misfires in drop tests, and exhibits excellent characteristics even after being left at high temperatures. The aim is to provide a crystal resonator with good durability.

[Summary of the Invention] As a result of extensive studies to achieve the above object, the present inventors have developed a method for adhesive fixation using a conductive adhesive using a urethane prepolymer and polyhydric alcohols that do not have unsaturated double bonds. The inventors have discovered that the above object can be achieved by doing the following, and have completed the present invention.

That is, in the present invention, the metal electrode provided on the crystal piece and the lead-out conductor of the component are made of a urethane prepolymer having no unsaturated double bonds, a polyhydric alcohol having no unsaturated double bonds, and a conductive material. A conductive adhesive that contains powder as an essential ingredient.
This is a crystal resonator characterized by being fixed with adhesive. The urethane prepolymer having no unsaturated double bonds has terminal active isocyanate groups blocked with an active hydrogen compound, and isocyanate groups (N
The ratio of CO) to the hydroxyl group (OH) of polyhydric alcohols having no unsaturated double bonds (NCOloH) is 1.0 to 1.
．． 2 wins! (7) Range (7) Mo (7).

The crystal piece used in the present invention is a thin piece of about 80 μm thick obtained by cutting a crystal body at a predetermined angle, and the shape and size thereof are not particularly limited.

As the urethane prepolymer without unsaturated double bonds used in the present invention, all types of prepolymers that form urethane without unsaturated double bonds can be used, but terminally activated isocyanates are preferably used. Blocked isocyanate prepolymers whose groups are blocked with active hydrogen compounds are preferably used. Typical examples include polyesters, polyolefins, or hydrogenated polybutadienes having terminal active isocyanate groups, which are blocked with blocking agents such as acetoacetate, cyclohexanone oxime, phenol, and imidazole. Specific examples include Desmodur AP Stable (manufactured by Bayer AG, trade name), which may be used alone or in combination of two or more. Urethane prepolymers having no blocked unsaturated double bonds are stable at room temperature, but have the property of dissociating isocyanate groups when heated to 120° C. or higher.

The polyhydric alcohols without unsaturated double bonds used in the present invention include those with long-chain alkyl groups, polyester-based, olefin-based, and hydrogenated alcohols in consideration of the flexibility and pliability of the adhesive. Examples include polybutadiene-based polyhydric alcohols that do not have unsaturated double bonds. Byron #303. #200 (manufactured by Nittobo Co., Ltd., product name), GI 1000. G I 2000. G
l3000 (manufactured by Nippon Soda Co., Ltd., product name), Polytail I
-IA (manufactured by Mitsubishi Kasei Corporation, trade name), polyethylene glycol, polypropylene glycol (manufactured by Mitsubishi Kasei Corporation), etc., and these may be used alone or in combination of two or more. These polyhydric alcohols having no unsaturated double bonds are reacted with the isocyanate groups dissociated from the urethane prepolymer having no unsaturated double bonds to form a binder. Dialkyltin dilaurate or the like is generally used as a catalyst to promote this reaction system. The blending ratio of urethane prepolymer having no unsaturated double bonds and polyhydric alcohol having no unsaturated double bonds is as follows:
Water ill of dissociated isocyanate groups (NCO) and polyhydric alcohols! The equivalence ratio (NCOloH) with (OH) is 1.
It is preferably in the range of 0 to 1.2. This ratio is 1
．． If it is less than 0 or more than 1.2, the desired characteristics cannot be obtained, which is not preferable. Therefore, it is better to limit it within the above range.

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 the conductive powder has an average particle size of 30 μm or less. If the average particle size exceeds 30 μm, it is not preferable because high-density packing becomes impossible and the paste does not form, and the coating performance deteriorates. The blending ratio of the above-mentioned binder and conductive powder is 30/70 to 10/
Preferably, it is 90. If the amount of conductive powder is less than 70 parts by weight, satisfactory conductivity cannot be obtained, and if it exceeds 90 parts by weight, workability and adhesion will deteriorate, which is not preferable.

Therefore, it is limited to 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 dioquinane, hexanone, benzene,
Toluene, solvent naphtha, industrial gasoline, cellosolve acetate, ethyl cellosolve, butyl cellosolve, butyl cellosolve acetate, buty J recarbitol acetate, dimethylformamide, dimethylacetamide,
Examples include N-methylpyrrolidone.

The conductive adhesive is manufactured by thoroughly kneading the above-mentioned components using a three-roll roll or the like.

[Embodiments of the invention] Next, examples of the present invention will be described.

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 crystal piece with a thickness of 80 μm and the pad part of a semiconductor device,
A crystal resonator was manufactured by heating and curing at ℃ for 30 minutes.
The reaction at this time was complete, and it was recognized that the amount of outgas generated was small. Regarding this vibrator, cracks in the crystal piece and the number of samples that failed to emit when dropped 10 times from 75 cm above were measured (total number of samples n-30), and the results are shown in Table 1.

Comparative Example 1 A one-component conductive adhesive was manufactured using each component shown in Table 1 in the same manner as in Examples 1 to 3, a water crystal sensor was manufactured in the same manner, and the characteristics were determined in the same manner. The results are shown in Table 1.

In addition, as Comparative Example 2, a crystal resonator was manufactured in the same manner as in Examples 1 to 3 using a two-component epoxy conductive adhesive using a polyamide curing agent, and the characteristics were similarly measured. Shown in the table.

Table 1 *1: Nippon Soda Co., Ltd., hydrogenated polybutadiene-based phenol-blocked isocyanate prepolymer *2: Idemitsu Petrochemical Co., Ltd., 50% butylcarpitol solution of polybutadiene-based phenol-blocked isocyanate prepolymer *3: Nippon Soda manufactured by Idemitsu Petrochemical Co., Ltd., terminal hydroxyl group hydrogenated polybutadiene *4: manufactured by Idemitsu Petrochemical Co., Ltd., terminal hydroxyl group polybutadiene Because of this, there are no cracks during adhesion, no failures in drop tests, and it is extremely durable.Also, because the curing reaction is complete, the amount of outgas generated is small and has no negative impact on other properties. We were able to obtain an extremely reliable crystal oscillator without giving any damage.

Claims (1)

[Claims] 1. The metal electrode provided on the crystal piece and the lead-out conductor of the component are made of a urethane prepolymer having no unsaturated double bonds,
A crystal resonator characterized in that it is adhesively fixed with a conductive adhesive containing a polyhydric alcohol having no unsaturated double bonds and a conductive powder as essential components. 2. The crystal resonator according to claim 1, wherein the urethane prepolymer having no unsaturated double bonds has terminal active isocyanate groups blocked with an active hydrogen compound. 3. The ratio (NCO/OH) of the isocyanate groups (NCO) dissociated from the urethane prepolymer having no unsaturated double bonds to the hydroxyl groups (OH) of the polyhydric alcohol having no unsaturated double bonds is 1. The crystal resonator according to claim 1 or 2, wherein the amount is in the range of 0 to 1.2 equivalents.