JPH03150907A - Crystal oscillator - Google Patents

Abstract

PURPOSE:To attain small size and thin profile of the entire oscillator by using a vibrator unit sealing a piezoelectric vibrator chip in a case made of an insulation material. CONSTITUTION:A vibrator unit 1 is connected directly onto a lead frame. The vibrator unit 1 is formed by mounting a crystal vibrator chip in a case which is formed by baking a ceramic as a box shape and has electrodes at both ends and sealing the case with glass cap. The thickness t of the crystal vibrator unit 1 is nearly 1mm, and since the thickness of a mold resin 4 at the upper and the lower place requires nearly 0.5mm when the vibrator unit 1 is mounted on the lead frame and the resin mold is applied, the thickness of the entire oscillator including the thickness of the lead frame is formed to be 2.5mm or below. Thus, the small sized and thin profile oscillator is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a resin molded oscillator in which a crystal resonator is mounted on a lead frame.

[Summary of the invention]

In the present invention, instead of the conventional piezoelectric vibrator sealed in a metal cylindrical tube, the piezoelectric vibrator is sealed in a case made of an insulating material.
By using a vibrator unit in which a piezoelectric vibrating piece is sealed, the overall thickness of the oscillator can be reduced, the design of the lead frame can be simplified, and a crystal oscillator with a small mounting area can be provided.

[Conventional technology]

An example of a resin molded crystal oscillator using a conventional lead frame is shown in the plan view of FIG. In the figure, 6 is a lead frame, and 3 is a driving IC chip for driving a crystal resonator.

The periphery of this oscillator is hardened with resin No. 4. Reference numeral 5 denotes a crystal resonator unit, in which a crystal resonator piece is sealed in a metallic cylindrical tube. Crystal resonator piece 7
Although it is in the form of a single plate, a cylindrical one must be used due to the manufacturing method of the case and the sealing characteristics. Therefore, when mounting this resonator unit 5 on the lead frame 6, since the terminals 9 are drawn out almost from the center, - numerically, a space is provided in a part of the lead frame, and the resonator unit 5 is mounted on the lead frame 6. I'm trying to include Unit 5.

[Problem to be solved by the invention]

In this way, in a resin-molded crystal oscillator using a conventional cylindrical crystal resonator unit, the height of the oscillator itself is restricted by the external diameter of the resonator unit, even if the mounting is devised. Cannot be made thinner. Also,
Cylindrical crystal resonator units come in metal cases, so avoid contact with the lead frame or
The parts that come into contact must be at the same potential. Therefore, the lead frame must be placed so as to wrap around the outside of the vibrator unit. Furthermore, when mounting a cylindrical resonator unit on a lead frame, as mentioned above, the terminals are drawn out from almost the center, so a space must be provided in a part of the lead frame for the resonator unit to fit. .

When using a cylindrical vibrator unit in this way, there are many restrictions when designing a lead frame, which causes an increase in planar area.

[Means to solve the problem]

In order to solve the above-mentioned problems, in the present invention, instead of a cylindrical crystal resonator unit mounted on the lead frame of a molded resin type crystal oscillator, a conductive resonator element is placed inside a case made of an insulating material. A thin crystal resonator unit fixed with an adhesive or the like and sealed with a glass cap or the like as shown in Japanese Patent Application No. 62-284620, for example, is mounted on a lead frame. Furthermore, the pattern of the lead frame is simplified by utilizing the fact that the case material is an insulating material. For example, the problem can be solved by arranging a lead frame pattern under the vibrator unit to shorten and simplify the wiring.

[Effect]

By mounting a thin crystal resonator unit as described above in a molded oscillator, the overall thickness of the crystal oscillator can be reduced. This is because in the case of conventional cylindrical resonators, even though the crystal resonator piece is plate-shaped and thin like resonator 7 in Figure 4, there is an extra space between it and the metal cylindrical tube. This is because the space was reduced to the minimum necessary.

In addition, when designing a lead frame, it is possible to pass the pattern wiring through the bottom part of the resonator unit, making the design easier and simplifying the pattern.The pattern area of the lead frame can be reduced, which significantly reduces the overall oscillator size. This makes it possible to achieve a smaller size.

〔Example〕

Next, a specific embodiment of the present invention is shown in FIG.

FIG. 1 is a plan view showing the internal structure of a resin molded crystal oscillator according to the present invention. In the figure, the vibrator unit 1 is directly connected onto the lead frame 6. This resonator unit 1 is made by sintering ceramic into a box shape, mounting a crystal resonator piece in a case provided with electrodes at both ends, and sealing the case with a glass cap. As shown in a perspective view of its outer shape in FIG. 2, the crystal resonator unit 1 is thinner than a conventional cylindrical resonator unit, and the thickness t is about 1 mm. When this resonator unit 1 is mounted on the lead frame 6 and then resin molded, the thickness of the mold must be 0.5 mm on the top and bottom, so the thickness of the entire oscillator including the thickness of the lead frame 6 must be 2.5 mm or less. I'm coming. Further, since the vibrator unit 1 is a ceramic container, the lead portion of the lead frame 6 can be passed under the case, and furthermore, the vibrator terminals come out from both ends. This is because in the case of the conventional tube type, the leads come out from one side, so the wiring pattern goes under the leads as shown in Figure 3. However, as described above, since the wiring pattern can be passed under the vibrator, this problem is eliminated and wiring can be done over the shortest distance. This can reduce stray capacitance and cage inductance between lead frames, and is also effective in reducing the influence on characteristics. Furthermore, a feature of this method of mounting a resonator with such a shape on a lead frame is that, in the case of conventional cylindrical resonators, the leads are connected by fixing the resonator in some way (currently, the resonator is not attached to the lead frame). This simplifies the mounting process by simply placing the components on the lead frame, which previously would have been required (by attaching them to the lead frame or fixing them with adhesive).

〔Effect of the invention〕

As described above, the resin molded oscillator of the present invention can be made smaller and thinner. Furthermore, since the mounting method is the same as that for other chip components, it is possible to use common mounting machines, and it also contributes to a significant reduction in man-hours.

In addition, the deterioration of the solder heat resistance of these resin molded oscillators is generally thought to be caused by the adhesive of the crystal resonator piece, leakage of sealing from the metal case, or the influence of the plating material, but it is not possible to use a ceramic case. Of these causes,
Problems related to the case have been eliminated, and reliability has also been improved.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the internal structure of a resin molded crystal oscillator according to the present invention, Fig. 2 is a perspective view showing the external shape of a crystal resonator unit used in the invention, and Fig. 3 is a conventional resin molded crystal oscillator. FIG. 4 is a plan view showing the internal structure of a crystal oscillator, and FIG. 4 is a cross-sectional view showing the internal structure of a cylindrical crystal resonator unit used in a conventional resin-molded crystal oscillator. 1...Crystal resonator unit used in the present invention 2...Chip capacitor 3...Drive IC 4...Mold resin 5...Cylindrical crystal resonator unit 6...Lead frame 7. ...Crystal resonator piece 9...Terminal or more

Claims (1)

[Claims] In a crystal oscillator molded with resin, the crystal oscillator includes a lead frame, a crystal oscillator unit, and an oscillation circuit IC for driving the same, and the crystal oscillator unit includes:
1. A crystal oscillator comprising a crystal resonator piece housed and sealed in a case made of an insulating material, the crystal resonator unit being mounted on the lead frame and constructed using a resin mold.