JPS6261166B2 - - Google Patents

Description

[Detailed Description of the Invention] <Object of the Invention> [Industrial Field of Application] The present invention provides a method for integrating a printed circuit board to which circuit components such as a piezoelectric oscillation circuit and a piezoelectric wave circuit are attached and a piezoelectric diaphragm into one container. This invention relates to an improvement of a piezoelectric oscillator housed in a piezoelectric oscillator.

[Conventional technology] Crystal vibrator devices that are smaller and cheaper than conventional ones have been introduced, but conventional piezoelectric vibrator devices are
It was necessary to attach circuit components to the printed circuit board and attach a support for attaching the crystal diaphragm.

The work of attaching the support for mounting the crystal diaphragm onto the printed circuit board is quite complicated, and it is necessary to improve the workability, such as determining the size and position of the support.

[Problems to be Solved by the Invention] Since attaching a support for supporting the piezoelectric diaphragm from the outside poses a problem in terms of work, the support was studied.

[Object of the present invention] The object of the present invention is to solve the above-mentioned problems, simplify the structure, reduce the size, and improve workability.
The object of the present invention is to provide a low-cost piezoelectric vibration device.

<Structure of the present invention> [Means for solving the problem] In the present invention, the support for the piezoelectric diaphragm is provided with a stepped portion in the insulating base recess at the same height as the lead terminal, and the exposed L of the lead terminal is A piezoelectric diaphragm is placed and fixed on the upper part of the letter shape.

[Operations and Examples] Examples will be described below. The plan view shown in FIG. 1 is a lead terminal frame 100, which is integrally formed from a single brass plate by pressing or etching. For brass, the thermal expansion α of the insulating base is 1.8 to 1.8.
It is 2.3×10 ^-5 /deg. This lead terminal frame 100
, one of the two lead terminals 101 and 102 is held in the common holding part 105 and the other two lead terminals 10
1 and 102 are connected by a common holding part 105, and the other two lead terminals 106 and 107 are connected by a common holding part 110.
0 are connected at the periphery surrounding the lead terminal.
Lead terminals are 101, 102 and 106, 107
One set constitutes one piezoelectric vibration device. Similarly, each of them constitutes one set, and the number of these sets may be a predetermined number, for example, 30 sets. In this example, all the lead terminals have the same shape, so
First, the connecting portion 111 with the common holding portion 105 has a relatively narrow width, similar to known IC terminals.
The next intermediate portion 112 is also wider than the connecting portion 111, similar to the terminal connecting portion 140 of the lead terminal. The protruding portion 114 formed between the intermediate portion 112 and the terminal connecting portion 140 is partially wider than the width of the intermediate portion 112 and the terminal connecting portion 140 in order to strengthen the penetration fixation with the insulating base 300, which will be described later. It stands out widely.

As shown in the perspective view of FIG.
The tip portion 127 located at the tip of the lead terminal frame 100 is bent downward from the main plane of the lead terminal frame 100 into an L-shape. Lead terminals 102, 106, 107
The tip portions 128, 129, and 130 are also bent in the same manner.

As shown in the plan view of FIG.
Recesses 201, 202, 203, 204 are formed at locations aligned with 7, 128, 129, 130, and metal films 205, 2 such as solder plating are formed around these recesses.
06, 207, 208 are formed. and,
As shown in the perspective view of FIG. 4, this printed circuit board 200 includes a pair of lead terminal tips 127,
By simply placing the recesses 201, 202, 203, and 204 of the printed circuit board 200 on the terminals 28, 129, and 130, one set of lead terminals is installed. The tips 127, 128, 129, 130 of the lead terminals are connected to the metal films 205, 206, 207, 2 of the printed circuit board.
08 respectively by soldering. Note that the printed circuit board 200 shown in FIGS. 3 and 4 does not show circuit components for the purpose of explanation, but in this example, the circuit components are components of a known crystal oscillation circuit as shown in FIG. , among these, the crystal resonator X is assembled separately. Here, Q ₁ , Q ₂ are mini-molded transistors, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ are printed resistors, and C ₁ , C ₂ , C ₃ , C ₄ are chips. Each consists of a capacitor, and these parts are shown in Figure 6A (Figure 3).
(A plan view of the printed circuit board 200 shown in the figure, seen from the back side) and Figure B (Similarly, a plan view seen from the front side)
As shown in FIG. 2, it is soldered and connected on a printed wiring board 200 at a position indicated by a broken line. Note that A and E (B) are the connection points of the crystal resonator, and E is the ground terminal, which is electrically connected to the metal films 206 and 208, respectively, in FIGS. 3 and 4, and is connected to the power supply terminal Vcc and the output. Similarly, the terminal Out is electrically connected to the metal films 205 and 207.

After the printed circuit board 200 with the circuit components attached thereon is connected to a set of lead terminals, the printed circuit board 200 is shown in the plan view of FIG. As shown in the BB sectional view, the insulating base 300 is fixed within the insulating base 300 by molding the insulating base 300. The material of this insulating base 300 is an insulating material that is approximately equal to the thermal expansion coefficient α of brass, which is the metal material of the lead terminal frame 100, and in this example, polycarbonate resin (thermal expansion coefficient α = 2 to 3 × ^10-5 /deg)
are using. The basic structure of the insulating base 300 is
It is a rectangular plate with a circular recess 301 formed from one main plane, and a predetermined number of step surfaces 3 are formed on the side surfaces of the recess 301 from the bottom to the top.
02, 303, 304, 305, and 306 are provided. First, the stepped surface 302 has an L-shaped upper part 113, 117, 121, 12 formed by bending the lead terminal.
5, and supports a crystal diaphragm 400, which will be described later, together with the terminal connection portion. The step surfaces 303, 304, 305, and 306 support a lid 500, which will be described later. A groove 30 is formed on the upper surface of the insulating base 300 between the peripheral upper surface 307 and the recess 301 in order to maintain airtightness with the lid 500, which will be described later.
8, and the cross-sectional shape between the side surface of this groove 308 on the recess 301 side and the upper side surfaces of the stepped surface 302 and the stepped surfaces 303 to 306 becomes thinner toward the tip, and the peripheral upper surface 307 more prominent.
The tip may have a protruding shape with a certain thickness, and the thickness is preferably about 1 to 2 mm.

Then, the printed circuit board 200 is buried near the bottom of the insulating base 300, with the board surface to which the main circuit components are attached, together with the circuit components, and the central part of the back surface of the board surface becomes the bottom surface of the recess 301 and is exposed. (This exposure is optional, and the center portion of the back surface may also be buried.) The peripheral portion of the substrate surface is buried in the insulating base 300 from the inner surface of the recess 301. In addition, the L-shaped upper part 11 of the lead terminal
The upper surfaces of 3, 117, 121, and 125 are exposed, but the bottom portions are stepped by the thickness of the stepped surface 30.
It is buried in 2. Middle part 112 of lead terminal
The protrusions 114 and the portions of the L-shaped upper parts 113, 117, 121, and 125 adjacent to these protrusions are fixed through the side surface of the insulating base 300 to the inside of the recess 301. This through-fixation is possible as long as the integrally molded lead terminal frame 100 is used.
However, if the intermediate portion 112 of the lead terminal frame 100 is bent into an L-shape or any other deformation is performed, the lead terminal frame 100 may be emitted from the bottom surface or other outer surface of the insulating base 300.

As shown in the plan view of FIG. 8A and the C-C sectional view of FIG. 402, 403 and
Extracting electrodes 404 and 405 that do not face each other from these excitation electrodes toward the periphery of the crystal diaphragm 401
is attached. These electrodes are formed by vacuum-depositing metals such as gold, silver, and aluminum. And, such a crystal diaphragm 400
As shown in the plan view of FIG.
4 and 405 are L-shaped upper parts 125 and 117, respectively.
The lead electrodes 404 and 405 are attached to the L-shaped upper part 125 and 117 with conductive adhesive 406 and 4.
07 and connect electrically and mechanically. Note that the connection between the other L-shaped upper parts 113, 121 and the crystal diaphragm 400 is optional in terms of electrical connection, but adhesives 408, 409 are applied to further strengthen the mechanical connection. It is preferable.

Next, the lid 500 that is placed over the insulating base 300 is attached to the stepped surfaces 303, 304, 305 of the recess 301 of the insulating base 300, as shown in the plan view of FIG. , 306, and a groove 501 is formed in its peripheral portion, and the cross-sectional shape between the outer side surface of this groove 501 and the side surface of the lid 500 is the same as that of the above-mentioned insulating base. Like the groove 308, it becomes thinner toward the tip and protrudes from the upper surface 502. Like the insulating base 300, the material of this lid 500 is polycarbonate resin, and this resin is a thermoplastic resin with characteristics such as condensation strength, adhesive strength, flexibility, and compatibility with other resins. In addition, ethylene-vinyl acetate copolymer (EVA), polyethylene-atactic polypropylene (APP), ethylene-ethyl acrylate copolymer (EEA), polyamide, polyester, polyphenylene sulfide (PPS), polyphenylene oxide ( PPO), polybutylene terephthalate (PBT), etc.

As shown in the plan view of FIG. 11A and the EE--E sectional views of FIG.
Step surface 303 in recess 301 of insulating base 300,
304, 305, and 306. Then, as shown in FIG.
The temperature is preferably 30 to 100 degrees higher than the melting points of 0 and lid 500, and in this example, it is 300 degrees Celsius. ), melt both tips. This tip portion has a relatively small heat capacity and can be easily melted, and furthermore, once melting starts, the next layer (lower layer) will be melted one after another, and the melted portion 601 Expand. This melted portion 601 is released from the hot plate 600 and left to stand at room temperature to be fixed. Note that the hot plate 600 during melting
In order to prevent the heat plate 600 from sticking, it is effective to coat the abutting part of the hot plate 600 with a heat-resistant fluororesin, or to interpose a heat-resistant non-adhesive sheet such as a fluororesin between the two. be.

The crystal vibrating device obtained in this way has the first
As shown in the plan view of FIG. 2, a predetermined number of terminals can be manufactured in a state where they are supported by the lead terminal frame 100.

In the above embodiments, a crystal diaphragm was used as an example of the piezoelectric diaphragm, but other materials such as lithium tantalate or piezoelectric ceramic may also be used, and the shape thereof is not limited to a flat disk, but may be square, rectangular, or any other arbitrary shape. In that case, the planar shape of the recess naturally changes depending on the planar shape of the piezoelectric diaphragm.

<Effects of the present invention> According to the present invention, the dimensions of the insulating base, which is the main body shape, are 13 mm, 13 mm, and 5 mm in length, width, and height, respectively.
We were able to successfully achieve miniaturization by achieving a model with a margin of 1 mm. Since assembly work is extremely easy, automation is also possible, and we have succeeded in significantly reducing manufacturing costs.

In addition, in the present invention, there is no need to attach a support for attaching the crystal diaphragm to the printed circuit board, and when the insulating base is molded, the L-shaped upper part, which is the connection part, is automatically exposed in the recess, and the crystal diaphragm is placed there. It has a structure that can be easily fixed by placing it.

[Brief explanation of the drawing]

Figure 1 is a plan view showing the lead terminal frame, Figure 2 is a perspective view showing the L-shaped tip of the lead terminal, Figure 3 is a plan view showing the printed circuit board, and Figure 4 is the printed circuit board. FIG. 5 is a perspective view showing the state in which the board is installed on the lead terminals, FIG. 5 is a diagram of the crystal oscillation circuit attached to the printed board, and FIGS. 7A is a plan view showing the printed circuit board embedded in the insulating base; FIG. A is a plan view showing the crystal diaphragm, B is a sectional view along C-C, FIG. 9 is a plan view showing the crystal diaphragm installed in the recess of the insulating base, and FIG. The plan view and FIG.
FIG.
The figure is a plan view showing the crystal vibrating device after assembly. 101, 102, 106, 107... Lead terminal, 113, 117, 121, 125... L-shaped upper part, 200... Printed circuit board, 300 Insulating base, 301... Recess, 400... Crystal diaphragm.

Claims (1)

[Claims] 1. In a piezoelectric vibrating device in which a printed circuit board and a piezoelectric diaphragm with circuit components attached are buried in a recess of an insulating base and hermetically sealed with a lid, the printed circuit board with the circuit components attached to the bottom of the recess of the insulating base is buried, the tips of a plurality of lead terminals are bent into an L-shape and electrically connected to the printed circuit board, the L-shaped portions of the lead terminals are exposed within the recess, and the upper part of the L-shape is buried. A piezoelectric vibrating device, characterized in that the piezoelectric vibrating plate is placed and fixed on.