JPH0247631Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a piezoelectric device, and particularly to the structure of a flat piezoelectric device in which a piezoelectric device chip is used with its main plane fixed horizontally.

(Prior art) Piezoelectric devices such as crystal oscillators and filters that have been conventionally used in various devices such as communication devices are based on a piezoelectric device chip 1 and a base 2, as shown in Fig. 7.
It has been common practice to firmly hold the wire at one end of the leads 3, 3 passing through the wire hermetically, and to hermetically seal the wire with a sealing tube 4.

However, in recent years, as various electronic devices have become required to be smaller and thinner, conventional rigid piezoelectric devices such as those mentioned above are mounted on printed circuit boards at a much higher position than other electronic components. As a result, there were serious defects in that not only did it significantly impair the space factor of electronic equipment, but it was also difficult to apply it to automatic mounting machines.

In order to solve these problems, a type of package in which a piezoelectric device chip 6 is horizontally sealed in a shallow dish-shaped package 5 as shown in FIG. 8 has been proposed. The disadvantages are that positioning when mounting the lead member 7 on the lead member 7 is difficult and complicated, and mass production is poor and automation is difficult.

In addition, as a product that improved mass productivity,
-86390, in which the vibrator is bonded to a flexible flat plate material called a hoop material, and positioning is ensured by bonding the hoop material to the leads. In this method, the vibrator coupled to the conductive elastic support had to be separated from the hoop material, which required a large number of man-hours, and furthermore, the shape of the package and lead was difficult to automate and mass-produce.

(Purpose of the invention) The present invention was made in order to eliminate the defects of the conventional flat type piezoelectric device as described above, and to provide a flat type piezoelectric device having a structure that requires less man-hours and is highly suitable for automatic mass production. With the goal.

(Summary of the invention) To achieve this purpose, the piezoelectric device according to the invention is a piezoelectric device sealed in a flat airtight container that has a lid bonded to the edge of the opening and a lead member that hermetically penetrates the side wall of the package. In the case where the lead member is composed of two members, an outer lead member whose main part is a part that penetrates the side wall of the package, and an inner lead member that supports and fixes the piezoelectric device chip, the outer lead The lead portion of the member is bent inside the side wall of the airtight container, and the side of the bent portion of the lead member facing the inner wall is buried in the wall,
By fitting an internal lead member whose main part is a piezoelectric device/chip fixing base into a package provided with the external lead member, and joining the fixed terminal portion of the internal lead member and the external lead member of the package. It is characterized by having been configured.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

First, the structure of the external lead member whose main part is the part where the lead member penetrates the side wall of the package will be described.

1a and 1b are a plan view and a sectional view taken along line A-A of a package 10 used in a flat piezoelectric device according to the present invention, in which an insulating material such as glass 1
Put the preform part 1 into the mold and make the lead member 1.
2 and the metal frame 13 for sealing the package opening are both baked and hardened.

In this embodiment, the lead member 12 that penetrates the wall of the package cage 10 is bent in an L-shape in the wall because the path of the lead member in the package wall is made as long as possible to ensure sufficient airtightness. The large area pad extending from the position of the lead 12 is used as an electrode for electrical sealing or grounding if necessary.

Incidentally, FIG. 2 is a sectional view showing another embodiment of the package used in the flat type piezoelectric device according to the present invention, in which glass 11 is placed in a mold and lead member 7 is inserted.
and two metal frames 13 and 1 for sealing the package opening.
3 and a package 14 which has no bottom and is baked and hardened.

In the case of this type of package, it goes without saying that after a piezoelectric device chip, which will be described later, is mounted on a lead projecting inside the package, both openings are sealed with a lid.

In order to mass-produce external lead members having such a structure, a large number of lead members 12, 12,
...and a large number of flanges 13, 13, ... arranged in a similar lead frame 19 are put into a mold together with the glass preform parts mentioned above, aligned precisely using the alignment holes 20, and then baked and hardened. This can be easily done by manufacturing a large number of packages at once.

Next, the structure of the internal lead member for supporting and fixing the piezoelectric device chip and the method of attaching the external lead member and the internal lead member will be explained.

For example, a thin metal plate having spring properties such as molybdenum, nickel, or phosphor bronze is formed into the shape shown in FIG. By bending inward, an inner lead member 31 as shown in FIG. 4d is produced.

Note that the lead 3 in the internal lead member 31
Reference numeral 2 denotes a contact lead, which is used when, for example, conductive contact with the lid is required.

The internal lead members 31 can also be manufactured all at once by arranging a large number of them on a lead frame 40 and photographing them as shown in FIG. 4B, in the same manner as in the package manufacturing method described above.

Further, the internal lead member 31 is provided with ultra-thin bridge portions 33, 33, . This is used when separating each fixed terminal 30 after attachment.

Also, the pads 3 at the four corners of the internal lead member 31
4, 34, . . . have dimensions such that they overlap the protruding portions of the leads 12 inside the package 10.

If the piezoelectric device chip 35 is placed on the horizontal portion of the tip of the leg 30 and the electrode lead portion and the tip of the leg are fixed with a conductive adhesive 36 or the like, the result will be as shown in FIG. 4c. The internal lead member to which the piezoelectric device chip is fixed is completed.

The internal lead member on which the piezoelectric device chip 35 is mounted and fixed in this manner is fitted into the package 10 or 14 made of the external lead member, and the lead members 12, 12, . . . and the pad 34 of the internal lead member are connected. After connecting by soldering or spot welding, etc., the pads 34, 3 at the four corners of FIG.
By applying current between the pads 4, . . . , the small area portions 33, 33 . The electrical connection between the piezoelectric device chip 35 and the piezoelectric device chip 35 fixed in the package is completed.

The opening of the package housing the piezoelectric device chip is thus covered with a metal lid 37 and the metal frame 13 provided in the opening is sealed with solder.
A flat piezoelectric device as shown in the figure is completed.

The final sealing process should generally be performed in a vacuum or inert gas, which is the same as the conventional piezoelectric device sealing process, but the sealing process in a special atmosphere as described above requires appropriate equipment. So lid 3
7 has a small hole 38 as shown in FIGS. 6a and 6b, and solder 39 is placed around it in advance. After the package opening is hermetically sealed in the atmosphere, the solder 39 is irradiated with a laser in a predetermined atmosphere. The pores may be closed by irradiation.

Finally, to explain how to adjust the frequency of a flat piezoelectric device manufactured using the method described above, it is difficult to adjust the frequency using the additive vapor deposition method for a piezoelectric device that is already housed and fixed in a package. Therefore, the frequency can be easily adjusted by using a method of removing the electrodes of the piezoelectric device using a laser or the like.

Moreover, it is desirable to carry out this operation after the piezoelectric device is completely sealed in the package. Therefore, a transparent window 41 is provided in the lid 37 as shown in FIG. The frequency can be easily adjusted by removing a desired portion of the electrode.

(Effect of the invention) Since the flat type piezoelectric device according to the present invention is constructed as described above, the production process can be significantly automated due to the characteristics of the flat type, resulting in a significant reduction in the cost of piezoelectric devices. Not only is it effective, but it also improves the impact resistance of the device chip because of the shape of the piezoelectric device chip support, the large number of device chip support points, and the flexibility of each support leg. It is also effective on

In addition, since it is easy to use an automatic mounting machine when mounting the flat piezoelectric device according to the present invention on a printed circuit board, it not only contributes to reducing the cost of various electronic devices that use this device, but also makes it easier to mount the flat piezoelectric device according to the present invention on a printed circuit board. Since printed boards have a good space factor, they are extremely effective in making various electronic devices thinner.

[Brief explanation of the drawing]

1a, b and 2 are diagrams showing the structure of the external lead member of the piezoelectric device according to the present invention, and FIGS. 3 a, b are process diagrams showing an example of the manufacturing process of the external lead member according to the present invention. , Fig. 4 a, b, c, and d are process diagrams showing an example of the structure and manufacturing process of a non-lead member without a piezoelectric device according to the present invention, and Fig. 5 is an example of an implementation of a flat type piezoelectric device according to the present invention. 6a, b, and c are a plan view and a cross-sectional view, respectively, showing an embodiment of the package opening sealing lid used in the present invention, and FIGS.
The figure is a cross-sectional view showing the structure of a conventional piezoelectric device. 10, 14...Package, 11...Insulator, 12
...Lead member, 13...Metal frame, 18, 19, 40
... Lead frame, 20 ... Hole, 30 ... Fixed terminal, 31 ... Internal lead member, 32 ... Contact lead, 33 ... Bridge part, 34 ... Pad, 35 ... Piezoelectric device chip, 36 ... Conductive adhesive, 37
...metal lid, 38...small hole, 39...solder, 41...window.

Claims (1)

[Claims for Utility Model Registration] A piezoelectric device sealed in a flat type airtight container having a lid adhered to the edge of the opening and a lead member hermetically passing through the side wall of the package, the lead member passing through the side wall of the package. In the device, the lead portion of the external lead member is located inside the side wall of the airtight container. and embedding the side facing the inner wall of the bent portion of the lead member in the wall;
By fitting an internal lead member whose main part is a piezoelectric device/chip fixing base into a package provided with the external lead member, and joining the fixed terminal portion of the internal lead member and the external lead member of the package. A flat piezoelectric device characterized by the following structure.