JPS62105513A - Crystal resonator - Google Patents

Abstract

PURPOSE:To eliminate cracking and to eliminate a defect in oscillation due to a vibration test by adhering a metallic electrode to the lead-out conductor of a component with a conductive adhesive which contains an urethane prepolymer, polyhydric alcohol, etc., petroleum-based resin having a hydroxyl group, and conductive power. CONSTITUTION:The metallic electrode provided to a crystal piece obtained by cutting a crystal body at a specific angle and the lead-out conductor of the component are adhered and fixed together with the conductive adhesive which contains an urethane prepolymer, polyhydric alcohol, etc., petroleum-based resin having a hydroxyl group, and conductive powder. Then, the urethane prepolymer is formed by blocking a terminal active isocyanate group with an active hydride and the equivalent ratio (CNO/OH) of an isocyanate group NCO dissociated from the urethane prepolymer to the hydroxyl group of polyhydric alcohol and the petroleum-based resin having the hydroxyl group is 1.0-1.2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a highly reliable crystal resonator that is highly durable and free from cracks and oscillation defects.

[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 attached to the thin quartz piece. It is widely used for power generation, etc. by gluing conductors together and assembling the crystal piece, then putting a cover on the assembled crystal piece and sealing it. A conductive adhesive is used between the electrode of the crystal resonator and the lead-out conductor, or between the pad of the semiconductor device and the lead-out conductor, in order to maintain electrical conductivity and mechanical bonding between the two.

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 use is glued with a two-component epoxy conductive adhesive, the conductive adhesive covering the crystal piece may cause cracks on the crystal piece after hardening, or the crystal vibration may be affected. Drop test C had some drawbacks such as no oscillation. In addition, since the adhesive is a two-component adhesive, there are disadvantages such as a short pot life after mixing the two components, and a large amount of outgas generation, which reduces adhesion and causes other costs. . Furthermore, in the case of old quartz crystals, if a conductive adhesive made of flexible resin such as polyester or polybutadiene is used, there will be problems such as cracks and poor oscillation during drop tests (although this does not occur, it is difficult to use a thick crystal piece). In some cases, oscillation failure may occur depending on the hardness of the resin, the number of drops in the drop test, etc.

[Object of the Invention] An object of the present invention is to solve the above-mentioned drawbacks.
1, we aim to provide a highly durable and reliable crystal resonator that does not generate cracks even when using a thick crystal piece and exhibits no oscillation failure even in severe drop tests.

[Summary of the Invention] As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by using a conductive adhesive as described below. 2) and completed the present invention.

That is, in the present invention, a metal electrode provided with a crystal piece and a lead-out conductor of a component are bonded together using a conductive adhesive containing a urethane prepolymer, a polyhydric alcohol, a petroleum-based resin having 4 hydroxyl groups, and a 54-electroconductive powder. This is a crystal resonator characterized by being fixed. The urethane prepolymer is made by blocking terminal active isocyanate groups with an active hydrogen compound, and isocyanate W (
NCO) and the hydroxyl group (OH) of polyhydric alcohols and petroleum-based resins (OH), which is the hydroxyl group [NCO/O
H] is within the range of 1.0 to 1.2.

The crystal piece used in the present invention is a thin piece of about 80 um obtained by cutting a quartz crystal body at a predetermined angle, and the thickness of the crystal piece is about 350 μm. Further, the shape and size are not particularly limited.

As the urethane prepolymer used in the present invention, all types of prepolymers that form urethane can be used, but preferably a block in which one or more terminally active isocyanate groups are blocked with an active hydrogen compound. Isocyanate prepolymers are preferred.

Typical examples include polynisdel or polybutadiene having a terminal active isocyanate group, and polynisdel or polybutadiene having a terminal active isocyanate group.
] Blocked with a packing agent, specifically Desmodule AP Stable (manufactured by Bayer AG, product name)
, Kneelock Q-9062 <manufactured by Idemitsu Petrochemical Co., Ltd., trade name), etc., and these may be used alone or in a mixture of two or more. These blocked urethane prepolymers are stable at room temperature, but have the property of dissociating isocyanate groups when heated to 120° C. or higher.

Examples of the polyhydric alcohols used in the present invention include those having a long-chain alkyl group in consideration of flexibility, and polyhydric alcohols tj', t)' of the polynis type and polybutadiene type. Specifically Byron #
300 (manufactured by Nittobo Co., Ltd., trade name), R-45 (manufactured by Idemitsu Petrochemical Co., Ltd., trade name), polyethylene glycol and polypropylene glycol made by Sanyo Chemical Co., Ltd., etc., and these may be used alone or in combination of two or more kinds. use.

Petroleum-based resins having hydroxyl groups used in the present invention include:
For example, a typical example is a compound that has a promising norbornene ring formed by polymerizing a C6 fraction, and specifically, Finton 1700
(manufactured by Nippon Zeon Co., Ltd., trade name). This water!
! The petroleum-based resin having groups is used in combination with the above-mentioned polyhydric alcohol, and becomes a hydrous M single component that reacts with the isocyanate groups dissociated from the urethane prepolymer. Of the 100 parts by weight of the hydrous acid group component, 5 to 90 parts by weight of the petroleum resin having water M groups, preferably 20"-80 parts by weight.
Part number list. If the amount is less than 5 parts by weight, sufficient contact force cannot be exerted, and if it exceeds 90 parts by weight, sufficient flexibility cannot be obtained, both of which are unfavorable.

The petroleum resin having a water M group is mixed with the above-mentioned polyhydric alcohol and reacted with the isocyanate L group dissociated from the urethane prepolymer to form a binder for the adhesive. Dialkyltin dilaurate or the like is generally used as a catalyst to promote this reaction system. The blending ratio of the urethane prepolymer and the hydrous acid group component is based on the isocyanate group (
NCO) and the hydroxyl group (OH) of the hydrated acid group component [
NGO10H] is preferably within the range of 1.0 to 1.2. If this ratio is less than 1.0 or more than 1.2, the desired characteristics cannot be obtained.

The conductive powder used in the present invention includes silver powder, copper powder,
Examples include nickel powder and powder having four layers of gold Wf on the surface, and these may be used alone or in a mixture of two or more. These conductive powders all have an average particle size of 30μ
It is preferable that it is below m. This is because if the average particle size exceeds 30 μm, high-density packing becomes impossible and the coating performance deteriorates without forming a paste-like form, which is not preferable.

The blending ratio of the binder and the conductive powder is preferably 30 nia 0 to 10:90 in terms of gravity omega ratio. If the conductive powder is less than 70 parts by mass, satisfactory conductivity cannot be obtained, and if it exceeds 90 parts by mass, workability and adhesion will deteriorate, which is not preferable. Therefore, it is limited 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.

Examples of these solvents include dioxane, hexanone, benzene, toluene, solvent naphtha, industrial gasoline, cellosolve acetate, ethyl cellosolve, butyl cellosolve, butyl cellosolve acetate, butyl carpitol acetate formamide, dimethyl acetamide, N-methyl birolidine, etc. It will be done.

The conductive adhesive of the present invention contains a urethane prepolymer, a polyhydric alcohol, a petroleum-based resin having a hydroxyl group, and a conductive powder, but other components may be blended as necessary as long as they do not contradict the purpose of the present invention. You may. The conductive adhesive of the present invention is produced 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 the adhesive thus obtained on the electrode part of a 350 μm thick crystal piece and the pad part of the semiconductor device,
A crystal resonator was manufactured by heating and curing at 50° C. for 30 minutes. It was observed that the curing reaction at this time was complete, and that there were few outgassing chambers after that. For this resonator, we measured the number of crystal blank cracks and non-oscillations when it was dropped 100 times from 75 cm above (total number of samples n = 30>
Shita.

These results are shown in Table 1, and the crystal resonator of the present invention did not generate any cracks and had zero oscillation failures after being dropped, demonstrating the remarkable effects of the present invention.

Comparative Example 1 A one-component conductive adhesive was obtained using each component shown in Table 1 in the same manner as in Examples 1 to 3, and crystal (Chinese crystal) was produced in the same manner, and its properties were determined in the same manner. The results are summarized in Table 1.

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 commercially available polyamide curing agent, and its characteristics were measured in the same manner. It is shown in Table 1.

Table 1 *1: Manufactured by Nippon Soda Co., Ltd., isocyanate prepolymer made of phenol-blocked polybutadiene with hydrogenated terminal hydroxyl groups *2: Manufactured by Nippon Soda Co., Ltd., polybutadiene with hydrogenated terminal hydroxyl groups *3: Manufactured by Nippon Zeon Co., Ltd., with terminal hydroxyl group hydrogenated polybutadiene Petroleum-based resin *4: The occurrence of cracks is expressed as the number of defective samples/total number of samples [Effect 1 of the invention The crystal resonator of the present invention has excellent flexibility, softness, I, and adhesiveness. Because it uses a conductive adhesive, even thick crystal pieces do not develop cracks, and even in severe drop tests, there were no liftoff defects, making it extremely durable.

Since the curing reaction of the adhesive is complete, there is little generation of outgas, etc., and other properties are not adversely affected, so a highly reliable crystal resonator can be obtained.

Claims (1)

[Claims] 1. The metal electrode provided on the crystal piece and the lead-out conductor of the component are adhesively fixed with a conductive adhesive containing urethane prepolymer, polyhydric alcohol, petroleum resin having a hydroxyl group, and conductive powder. A crystal oscillator characterized by: 2. The crystal resonator according to claim 1, wherein the urethane prepolymer has terminal active isocyanate groups blocked with an active hydrogen compound. 3 The equivalent ratio [NCO/OH] between isocyanate groups (NCO) dissociated from the urethane prepolymer and the hydroxyl groups (OH) of the petroleum resin having polyhydric alcohols and hydroxyl groups is 1.0 to 1.2.
A crystal resonator according to claim 1 or 2, which falls within the scope of claim 1 or 2.