JPH08102640A - Crystal oscillator - Google Patents

Abstract

PURPOSE: To improve workability and to inexpensively and automatically obtain a crystal oscillator by molding an oscillation circuit element with resin to form a circuit base, extending terminal plates and holding plates from the circuit base and fixing crystal chips to the holding plates. CONSTITUTION: The crystal oscillator consists of four parts, i.e., a metallic base 1, a circuit base 11, crystal chips, and a cover. The base 11 is formed of an IC chip, terminal plates 12 and holding plates 13 by molding a resin body 14. Respective terminal plates 12 have one end parts connected to an electrode land by wire bonding and are symmetrically extended from both the opposed sides of one side of the resin body 14 as L shaped and reversely L shaped parts. Through holes 16 are formed on respective extended end parts to be the corner parts of quadrangles. The holding plates 13 are extended from both the opposed sides of the other side of the body 14 and have bent holding parts on their extended end parts. The tip parts of lead terminals 7 are inserted into the through holes 16 of the terminal plates 12 and the circuit base 11 is directly fixed to the surface of the metallic base 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field of application of a crystal oscillator in which a crystal blank and an oscillator circuit element are sealed in a single container and miniaturized. In particular, a resin-molded circuit base of the oscillator circuit element is used. Related to the crystal oscillator.

[0002]

BACKGROUND OF THE INVENTION Crystal oscillators are widely used in various electronic devices because of their stable oscillation frequency. One of such devices is an inverter oscillator circuit using a CMOS-IC, which is useful as a reference clock source in, for example, computers and their peripheral devices. In recent years, for the purpose of miniaturization of this kind of equipment, for example, a small crystal oscillator in which a quartz piece is held on a ceramic substrate on which an IC having a CMOS and a circuit element integrated into one chip is held and hermetically sealed in a metal container is mainstream. (For example, Japanese Patent Application No. 61
227503).

[0003]

2. Description of the Related Art FIGS. 4 and 5 are views of a crystal oscillator for explaining a conventional example of this kind. FIG. 4 is an exploded view and FIG. 5 is a sectional view. The crystal oscillator includes a metal base 1, a ceramic substrate 2, an IC chip 3, a crystal piece 4, a holder 5 and a cover 6. The metal base 1 has lead terminals 7 that are hermetically sealed at the four corners of the surface and have their tips protruding. The ceramic substrate 2 has holes 8 at its four corners, and is inserted into the tip portions of the lead terminals 7 and fixed on the metal base. The IC chip 3 has a conductive pattern (not shown) connected to each lead terminal 7 and constitutes an inverter oscillation circuit (see FIG. 6).
Equipped with. The terminals (not shown) of the IC chip 3 are
After connection with the conductive pattern by, for example, wire bonding 9, it is covered with resin 10. The crystal piece 4 has the excitation electrodes 11 on both main surfaces and extends the extraction electrodes 12 on the outer peripheral portions of both ends. The holder 5 has a Z shape with an upper end portion having an arcuate arm. Then, the outer peripheral portions of both ends of the crystal piece 4 are fixed to the upper ends (arc-shaped arms), and the lower end portions are fixed to the ceramic substrate 2. The cover 6 is joined (sealed) to the metal base 1 by, for example, resistance welding, and the crystal piece 4 is hermetically sealed.

[0004]

However, in the structure described above, the IC chip 3 is mounted on the ceramic substrate 2 and coated with resin, and then the holder 5 is further fixed and the crystal piece 4 is mounted (or the crystal piece 4). (Fix the holder 5 that has been attached)
Therefore, there is a problem that the man-hours are large and workability is poor. In addition to these, the ceramic substrate 2 is also expensive, and it is necessary to form a conductive pattern. Furthermore, since the ceramic substrate 2 is formed by firing, the holes 8 formed at the four corners, for example, have poor positional accuracy and cannot be smoothly mounted on the metal base 1, which also impedes automation.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a crystal oscillator which has good workability and is inexpensive and suitable for automation.

[0006]

According to the present invention, each oscillating circuit element is resin-molded to form a circuit base, and a terminal plate and a holding plate are extended from the circuit base, and the terminal plate is connected to a lead terminal. The basic solution is to fix the crystal piece to the.
That is, by integrating the parts other than the crystal piece into the circuit board,
It is characterized in that it is configured without using a ceramic substrate. An embodiment of the present invention will be described below.

[0007]

1 to 3 are views for explaining an embodiment of the present invention. FIG. 1 (ab) is a front view and a side view of a crystal oscillator, and FIG. 2 is a mounting view of a circuit base. 3 is a plan view of the same. The crystal oscillator is composed of four parts: a metal base 1, a circuit board 11, a crystal piece 4, and a cover. The metal base 1, the crystal piece 4, and the cover 6 are the same as in the conventional example, and the same numbers are given and the description thereof is omitted. The circuit base is formed by molding the IC chip 3, the terminal plate 12, and the holding plate 13 with a resin body 14. The IC chip 3 is integrated with the above-mentioned oscillation circuit elements, and has electrode lands (terminals) 15 on its surface.
Have. One end of the terminal plate 12 is connected to the electrode land 15 by wire bonding 9, and the terminal plate 12 extends symmetrically as an L-shape and an inverted L-shape from both opposite side surfaces of the resin body 14. Then, the through-holes 16 are provided at the respective extending end portions which are the corners of the quadrangle. The holding plate 13 extends from the other opposite side surfaces of the resin body 14 and has a bent holding portion at the extending end. The terminal plate 12 and the holding plate 13
Is formed by pressing a metal flat plate and is integrated with the frame 17 and is then resin-molded and separated after the connection with the IC chip 3.

In such a structure, the circuit board 11 is directly fixed on the surface of the metal base 1 by inserting the through hole 16 of the terminal plate 12 into the tip portion of the lead terminal 7. Then, the outer peripheral portions of both ends of the crystal piece 4 are fixed to the holding portions of the holding plate 13. Then, the cover 6 is resistance-welded and sealed to the metal base 1.
The through hole 16 of the terminal board 12 and the lead terminal (tip portion)
Are connected by, for example, solder.

Therefore, in the crystal oscillator configured as described above, the number of parts at the time of assembly is small, and the mounting of the IC chip 3 and the holder 5 is completed when the circuit base 11 is fixed to the metal base 1. , Make workability extremely good. That is, focusing on the resin coating in the conventional example, the circuit board 11 in which the terminal plate 12 and the holding plate 13 are integrated
Since the ceramic substrate 2 is unnecessary, it is not necessary to separately fix the IC chip 3 and the holder 5, and workability is improved. Since the terminal plate 12 is made of a flat metal plate and the through hole 16 has a higher positional accuracy than ceramics, the mounting on the metal base 1 is not misaligned and is suitable for automation. Moreover, since the circuit board 11 is formed from the resin mold without using the ceramic substrate 2, the cost thereof is also low.

[0010]

[Other Matters] In the above embodiment, the through hole 16 is provided in the extended end portion of the terminal plate 12 to connect to the lead terminal 7, but it may be joined by, for example, a depression or a flat plate by laser welding or the like. , I don't care about the form. Further, the terminal plate 12 and the holding plate 13 do not necessarily need to extend from the side surface of the resin body 14, and may be the upper surface, and may have a rectangular shape in the drawing, but may have a circular shape, and the shape thereof is not limited. . Further, the holding plate 13 is formed by simply bending the extending end portion to form the holding portion, but the holding plate 13 is not limited to this form. Furthermore, for example, a hole may be provided in the embedded portion of the resin body 14 in the holding plate 13, or the inside of the resin body may be bent to increase the length and increase the holding strength. Although the IC chip 3 is embedded in the resin body 14, the effect is the same even if the individual oscillation circuit elements are embedded unless the size thereof is limited. As described above, the present invention can be modified in various ways. The point is to use the circuit base 11 in which the terminal plate 12 and the holding plate 13 are extended and the oscillation circuit element is embedded, and this is placed in a metal container. The encapsulated structure basically belongs to the technical scope of the present invention.

[0011]

According to the present invention, each oscillating circuit element is resin-molded to form a circuit board, and the terminal board and the holding board are extended from the circuit board to connect the terminal board to the airtight terminal and hold it. Since the crystal piece is fixed to the plate, it is possible to provide a crystal oscillator that does not require a ceramic substrate, has good workability, is inexpensive, and is suitable for automation.

[Brief description of drawings]

1A and 1B are diagrams illustrating an embodiment of the present invention, in which FIG. 1A is a front view and FIG. 1B is a side view.

FIG. 2 is a mounting view of a circuit board for explaining an embodiment of the present invention.

FIG. 3 is a plan view of a circuit board for explaining an embodiment of the present invention.

FIG. 4 is an exploded view of a crystal oscillator for explaining a conventional example.

FIG. 5 is a sectional view of a crystal oscillator for explaining a conventional example.

FIG. 6 is a diagram of an inverter oscillation circuit for explaining a conventional example.

[Explanation of symbols]

1 metal base, 2 ceramic substrate, 3 IC chip, 4 crystal piece, 5 holder, 6 cover, 7 lead terminal, 8 holes, 9 wire, 10 resin, 11 circuit board, 12 terminal plate, 13 holding plate, 14 Resin body, 15
Electrode land, 16 through holes, 17 frame.

Claims (1)

[Claims] 1. A metal base having a plurality of lead terminals whose tips protrude above the surface, a metal cover which is sealed by the metal base to form a closed container, and an oscillating circuit element embedded in a resin body. A circuit base having a plurality of terminal plates and a pair of holding plates extending from the resin body, the circuit base being mounted on the metal base, and extending ends of the respective terminal plates. A crystal oscillator, characterized in that it is connected to the tip of the lead terminal, and the outer peripheral portions of both ends of the crystal piece are fixed to the extended end of the holding plate.