JPS6340906Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a crystal resonator, and particularly to a crystal resonator using an aluminum electrode as an excitation electrode.

In general, a quartz resonator is made by processing a quartz crystal into a predetermined shape, forming metal electrodes of silver, gold, aluminum, etc. on both sides by vapor deposition, and then implanting the quartz crystal piece with the electrodes on a base. The metal electrode is held in a conductive holding member such as a wire clip that is connected to the external lead-out terminal, and a conductive adhesive is applied to the holding part to mechanically and electrically connect the metal electrode and the holding member. , a metal case was attached to the base.

By the way, if silver or gold is used as the metal electrode in the above-mentioned crystal oscillator, both of them are very expensive, which not only causes an increase in cost, but also because both have relatively high specific gravity. It has been difficult to obtain a crystal resonator with a high temperature.

In order to solve the above-mentioned problems, in recent years aluminum, which is cheaper than silver, gold, etc. and has a lighter specific gravity, has been used as electrodes. However, in the case of aluminum electrodes, a thin oxide film forms on the surface in the atmosphere. When a holding member is connected with a conductive adhesive to an aluminum electrode on which a thin oxide film has been formed, conventional conductive adhesives have an epoxy resin as a base material and harden into the base material. Because it contains adhesive and metal powder such as silver powder, if used for a long time, an oxide film will be formed on the surface of the aluminum electrode and the metal powder in the conductive adhesive, causing the frequency shown in Figure 5 to increase. As is clear from the relationship between the characteristics and changes over time, not only the frequency variation becomes large, but also the crystal impedance characteristics have a large variation as shown in FIG. 6.

In view of the above points, the present invention provides a crystal resonator using aluminum electrodes that has less variation in frequency characteristics and crystal impedance characteristics and is inexpensive by improving the characteristics of conductive adhesive. The purpose is to

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a front view of the crystal resonator 1, and FIG. 2 is a side view of the same. In the figure, 2 is a crystal piece obtained by processing a crystal body into a predetermined shape, 3, 3 (one not shown) is an aluminum electrode formed on both sides of the crystal piece 2 by vacuum deposition, 4 is a base, 5, 5 are external lead-out terminals planted in the base 4, 6, 6 are conductive holding members such as wire clips wrapped around the external lead-out terminals 5, 5, and the ends thereof have an arc-shaped holding member. Sections 7, 7 are provided, and the crystal piece 2 is held between the holding sections 7, 7. At this time, parts of the aluminum electrodes 3, 3 are also held together.
After that, the holding parts 7, 7 and the aluminum electrodes 3, 3
and are electrically connected using conductive adhesives 8, 8, which will be described later. 9 is a case attached to the base 4. The inside of the case 9 is in a vacuum or an inert gas atmosphere such as nitrogen, argon, helium, etc., or a mixed gas atmosphere thereof.

Next, the conductive adhesive 8 will be described in detail. The conductive adhesive 8 is, for example, a polycondensation type adhesive in which an epoxy resin is mixed with a curing agent and then cured. In order to impart electrical conductivity to the adhesive, 30 to 30% of fine silver powder is added to the uncured epoxy resin.
Mix about 90%.

Furthermore, a substance containing at least one of platinum, platinum black, palladium, palladium black, rhodium, rhodium black, and zirconium is added to the uncured epoxy resin imparted with conductivity.
It is a mixture of about 0.1 to 60 [%].

Examples and experimental results will be explained below. A hardening agent is mixed into a liquid epoxy resin containing 70% of fine silver powder, and at the same time, 1% of palladium black is mixed in. When stirred, a conductive adhesive is created. This adhesive may be applied to the holding parts 7, 7 of the crystal resonator 1 and the aluminum electrodes 3, 3, and the epoxy resin may be cured.

Figure 3 shows the measurement of the change over time in the frequency characteristics of the crystal resonator 1 after it has been completely cured.
Figure 4 shows the measured changes in the impedance characteristics of the crystal over time. As is clear from each figure, this may be because the oxidizing power of the metal (silver) in the aluminum electrodes 3 and the conductive adhesive 8 is suppressed.
The reason for this is not necessarily clear, but the variation in frequency characteristics and crystal impedance characteristics can be significantly reduced compared to conventional examples, and changes over time are extremely small and can be maintained stably. Note that in the present invention, the electrode is made of aluminum, and is mixed together with metal fine powder that imparts conductivity. Platinum, platinum black, palladium, palladium black,
Due to the difference in ionization tendency between rhodium, rhodium black, zirconium, and aluminum, a potential difference is formed between them, which acts so that the thin oxide film that is always on the surface of the aluminum electrode is always reduced to metallic aluminum. It is certain that you will receive it.

Although epoxy resin was used as the base material of the conductive adhesive 8 in the above embodiment, it is not necessarily limited to epoxy resin, and any adhesive resin may be used.

Further, in the above embodiment, a wire clip type was used as the holding member 6, but various types other than the wire clip type are possible, such as a metal ribbon type.

As explained above in detail, the present invention forms aluminum electrodes 3, 3 on both sides of the crystal piece 2 processed into a predetermined shape, and holds and holds the crystal piece 2 with conductive holding members 6, 6. A conductive adhesive 8 is applied to the parts 7, 7, and the aluminum electrodes 3, 3
and the holding members 6, 6 are electrically connected, a metal fine powder that imparts conductivity to the conductive adhesive, and one of platinum, platinum black, palladium, palladium black, rhodium, rhodium black, and zirconium is used. Because at least one type of ingredient was mixed in,
Perhaps because the oxidizing power of the metal in the aluminum electrodes 3, 3 and the conductive adhesive 8 is suppressed, variations in frequency characteristics and crystal impedance characteristics are small, and highly reliable products can be manufactured at low cost.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
Fig. 1 is a front view, Fig. 2 is a side view, Fig. 3 is a graph showing changes over time in the frequency characteristics of the present invention, Fig. 4 is a graph showing changes over time in the crystal impedance characteristics of the invention, Fig. 5 is a graph showing the change over time in the frequency characteristic of the conventional example, and FIG. 6 is a graph showing the change over time in the crystal impedance characteristic in the conventional example. 1...Crystal resonator, 2...Crystal piece, 3,3...
Aluminum electrode, 4... Base, 6, 6... Holding member, 7, 7... Holding part, 8... Conductive adhesive.

Claims (1)

[Scope of utility model registration request] A crystal resonator in which aluminum electrodes are formed on both sides of a crystal piece processed into a predetermined shape, the crystal piece is held by a conductive holding member, and the aluminum electrode and the holding member are fixed with a conductive adhesive, The conductive adhesive is characterized in that it contains a metal fine powder that imparts conductivity and at least one of platinum, platinum black, palladium, palladium black, rhodium, rhodium black, and zirconium as components. Crystal oscillator.