JPS6163106A - Package of crystal resonator - Google Patents

Abstract

PURPOSE:To improve characteristics by arranging a cylinder to the inside of an outer tube to prevent contact with a lead wire or the resonator at generation of a whisker. CONSTITUTION:The crystal resonator 5 is bonded to the lead 3 by solder 6, a cylindrical cylinder 11 is bonded to glass 4 of an airtight terminal or a cylindrical metallic tube 2 by an adhesives 12, the airtight terminal is pressed from an opening 7 of the outer tube 1 under vacuum or inactive gas and sealed. A stress is produced at sealing near the boundary 9 of the bonding part 8 between the outer tube 1 and the tube 2. Even when a whisker 10 is generated and grown, it does to reach the resonator 5 and the lead wire 3 by disturbance of the cylinder 11 and no electric short-circuit is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a container for enclosing a crystal resonator.

[Background of the invention]

It is well known that with the development of electronics, crystal oscillators are being used as electrical signal sources in various electrical products. Crystal resonators used in crystal oscillators, like other electronic components, are becoming smaller, more sophisticated, and less expensive.

Incidentally, when compared with a ceramic resonator, a crystal resonator has a very high Q value and long-term stability in oscillation frequency and equal series resistance value. Therefore, crystal resonators have excellent characteristics as sources of stable vibration frequencies.

However, in order to obtain a stable frequency, it is necessary to avoid the influence of the outside world, so the crystal resonator must be placed in an airtight container, and should not come in contact with the outside air or water vapor. stored in gas.

[Conventional technology and problems]

Next, conventionally used containers will be explained.

FIG. 1 is a perspective view showing the appearance of a container for a crystal resonator. FIG. 2 is a perspective view of the quartz crystal resonator, which has been disassembled to show the inside of the container. (a) shows the L outer tube, and (b) shows the inside of the airtight terminal. 1 is an outer tube, 2 is a cylindrical metal tube as an airtight terminal, 3 is a lead wire, 4 is a glass airtight terminal, and 5 is a vibrator. Note that the electrodes of the vibrator 5 are not shown.

The lead wire 3 is made of Kovar metal, is bonded to an electrode (not shown) of the vibrator 50 with solder or adhesive 6, and is used to extract the vibration voltage of the vibrator 5 to the outside.

The outer tube 1 is made of nickel silver or Kovar metal, and is made of 5n-Pb
No-Noda plated. Cylindrical metal tube 2 with airtight terminal
is made of Kovar metal, Au or Sn-P
B-plated.

After the vibrator 5 is bonded to the lead wire B with a solder or adhesive 6, sealing is performed by press-fitting an airtight terminal into the inner wall of the outer tube 1 in a vacuum or an inert gas. During press-fitting, the inner wall of the outer tube 1 and the outer wall of the cylindrical metal tube 2 of the airtight terminal are rubbed together, joining of soft metals such as Sn-Pb or Au is performed, and air or water vapor inside and outside the container is removed. Cut off the gas flow.

However, whiskers are often generated from the S n -P b plating layer and come into contact with the lead wire 3 or the vibrator 5, causing an electrical short circuit and causing an accident in which oscillation stops. To date, much research has been carried out to clarify the causes of whiskers in order to take measures to prevent their occurrence, but no complete countermeasures have been established yet.

A whisker is a single crystal of metal, with dimensions of 1 to 2 microns in thickness and 0.1 to 300 microns in length, and a cross-sectional shape such as circular, square, or star-shaped.

Although various factors have been discussed as to why whiskers occur, stress seems to play an important role. In FIG. 2, when the airtight terminal is press-fitted into the outer tube 1, the vicinity of the opening 7 of the outer tube 1 is widened, deformed, and residual stress is generated. In order to explain the inside of the outer tube 1, FIG.
FIG. 2 is a cross-sectional perspective view showing a part of the outer tube 1 cut away. 7 is the opening, 8 is the inner wall of the outer tube 1, and S n -P
This is a joint portion that is plated with gold or gold, and is joined by rubbing against the outer wall of the cylindrical metal tube 2 of the airtight terminal when the airtight terminal is press-fitted. 9 is the boundary of the joint 8, 5n-Pb
Or Au is raised. This portion is where the stress is maximum and where whiskers 10 are most likely to occur.

[Purpose of the invention]

An object of the present invention is to improve characteristics and yield by preventing whiskers from coming into contact with lead wires or vibrators even if they occur.

[Structure of the invention]

The configuration of the present invention is that a cylindrical body is disposed inside the outer tube.

[Embodiments of the invention]

Next, one embodiment of the present invention will be described based on the drawings. FIG. 4 is a sectional view of a hermetic terminal showing a first embodiment of the present invention. 2 is a cylindrical metal tube of an airtight terminal, 3 is a lead wire, 4 is glass, 11 is a cylindrical body, and 12 is an adhesive.

FIG. 5 shows a cross-sectional view of a completed crystal camera incorporating a cylindrical body, in which the crystal oscillator 5 is bonded to the lead wire B with conductive adhesive or solder 6, and the cylindrical body 11 is bonded. Adhere to the glass 4 of the airtight terminal or the cylindrical metal tube 2 of the airtight terminal with adhesive 12,
FIG. 2 is a cross-sectional view showing the periphery of the airtight terminal of the vibrator whose press-in port is sealed from the opening 7 side of the outer tube 1 in a vacuum or inert gas atmosphere.

The cylindrical body 11 is made of a metal that does not easily generate whiskers, such as nickel, Kovar, or stainless steel, or of glass, ceramic, or the like.

FIG. 6 is a cross-sectional view of the airtight terminal viewed from plane AA in FIG. 5. Joint part 8 between outer tube 1 and cylindrical metal tube 2 of airtight terminal
Stress is generated near the boundary 9 during sealing. Generally, heat treatment is performed to remove stress, but since solder is used in the case of the resonator container, high temperature heating is not possible, and the process is usually around 100°C, so residual stress remains. .

Stress is an important factor in the generation and growth of whiskers.

Therefore, whiskers 10 are generated near the boundary 9 of the joint. However, since the cylindrical body 11 is arranged inside the outer tube 1, even if the whiskers 10 develop and grow, they are protected by the cylindrical body 11 and cannot reach the vibrator 5 and the lead wire 6, resulting in electrical It will not cause a short circuit.

In this embodiment, a cylindrical object was used as the cylindrical object to prevent an electrical short circuit caused by a whisker, but it goes without saying that the shape is not limited to a cylinder as long as it meets the purpose of the present invention. .

FIG. 7 is a sectional view for explaining the second embodiment of the present invention, and FIG. 8 (Al) is an exploded perspective view of the cylindrical body viewed from diagonally above. 16.14 is a cylindrical body with a semicircular cross section, and is disposed inside the combined outer tube 1 with its ends joined together to prevent electrical short circuits due to contact with whiskers.

That is, the tip 16 of the cylindrical body 13 and the tip 17 of the other cylindrical body 14 are joined. Similarly, the other tips 15 and 18 are joined and assembled. FIG. 9 is a sectional view showing a third embodiment of the present invention, and is a view of the airtight terminal viewed from the tip of the vibrator 5. 19 is a cylindrical body having a rectangular cross section.

FIG. 10 is a sectional view showing a fourth embodiment of the present invention.

The outer diameter of one end 24 of the cylindrical metal tube of the airtight terminal is smaller than the outer diameter of the other end 25. It is pushed into one end 25 of the tube and adhered with adhesive 24. Holes 22 and 23 are made in the bottom of the teapot-shaped cylindrical tube 20 in order to vent the air inside when sealing.

〔Effect of the invention〕

According to the present invention, even if whiskers occur, the cylindrical body is disposed inside the outer tube (therefore, the whiskers do not come into contact with the electrodes or lead wires of the vibrator, which may cause an electrical short circuit. Since this can be prevented, improvements in characteristics and yield can be obtained.

Although the present invention has been described with respect to a container for enclosing a quartz crystal, it goes without saying that it can also be applied to containers for enclosing other electronics and components in order to prevent electrical short circuit accidents caused by whiskers.

[Brief explanation of the drawings] Fig. 1 is a diagram showing the external appearance of the transducer container, Fig. 2 is an exploded perspective view showing the inside of the conventional transducer container, and Fig. 3 is a partially cut away outer tube. FIG. 4 is a sectional view of the airtight terminal showing the first embodiment of the present invention, FIG. 5 is a sectional view of the vibrator, and FIG. 6 is an AA sectional view of the airtight terminal seen from the tip of the vibrator. , FIG. 7 is a sectional view showing a second embodiment of the present invention, FIG. 8 is a perspective view of a cylindrical body having a semicircular cross section, and FIG. 9 is a third embodiment of the present invention.
Embodiment FIG. 10 is a sectional view showing a fourth embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Outer tube, 2... Cylindrical metal tube with airtight terminal, 5... Vibrator, 8... Joint surface, 10... ...whisker, 11...tubular body, 16.14...tubular body, 19...tubular body with a rectangular cross section, 20...
...Tea caddy shaped body. Patent applicant Citizen Watch Co., Ltd. Figure 1 (b) 5 4Z j Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (5)

[Claims] (1) A lead wire for fixing the crystal resonator and establishing electrical continuity with the electrodes of the crystal resonator, an airtight terminal for hermetically sealing the lead wire, and an airtight terminal that is engaged with the airtight terminal and is connected to the crystal resonator. In a crystal resonator container consisting of an outer tube that seals the resonator in a vacuum or an inert gas, a cylindrical body is disposed inside the outer tube and at a position surrounding the crystal resonator. A distinctive crystal oscillator container. (2) A container for a crystal resonator, characterized in that the cylindrical body according to claim 1 is a cylindrical object. (3) A container for a crystal resonator, wherein the cylindrical body according to claim 1 has a shape obtained by combining two objects each having a semicircular cross section. (4) A container for a crystal resonator, wherein the cylindrical body according to claim 1 has a rectangular cross section. (5) The cylindrical body according to claim 1 is a tea-shaped cylinder having a hole at the bottom, and an opening of the cylindrical body at one end of the cylindrical metal tube of the airtight terminal whose outer diameter is smaller than the other end. A crystal oscillator container characterized by having parts glued together.