JPH0251905A - Manufacture of piezoelectric resonator - Google Patents

Abstract

PURPOSE:To coat a space forming material such as wax accurately only to part of a vibrating electrode by coating the space forming material such as wax delivered from a dispenser onto the vibrating electrode. CONSTITUTION:After an accessory component element 4 is mounted to a piezoelectric vibrator element 3, a thin tip of the dispenser 5 is approached to a part of the vibration electrode 2 and a prescribed quantity of the molten wax 8 is jetted from the tip of the dispenser 5 and the vibrating electrode 2 is coated by the wax 8 by dropping the wax to the vibration electrode 2. Thus, the space forming material is coated accurately only to the vibration electrode 2 of the piezoelectric vibration element, no space is caused to the ceiling in the outer package of the piezoelectric resonator and no end face reflection of the vibration is caused, then spurious vibration is suppressed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to the manufacturing process of a low-profile piezoelectric resonator in which an additional component element such as a capacitor is integrally attached so as to overlap with a piezoelectric vibrating element. The present invention relates to a method for applying a space-forming material for forming a vibration space on a vibrating electrode.

[Background technology]

In a low-profile piezoelectric resonator consisting of a piezoelectric vibrating element 3 and an additional component element 4 such as a capacitor, the piezoelectric vibrating element 3 and the additional component element 4 are arranged to face each other in order to reduce the height of the component. They are integrated in a stacked state.

In this way, in the low-profile piezoelectric resonator, the additional component element 4 is attached in parallel to the piezoelectric vibrating element 3, and a portion of the vibrating electrode 2 is covered by the additional component element 4. Therefore, when applying the wax 6 to the piezoelectric vibrating element 3, the additional component element 4 gets in the way, making it difficult to apply the wax 6.

For this reason, in the conventional manufacturing process of a low-profile piezoelectric resonator, as shown in FIG. The wax 6 (space forming material) attached to the tip of the piezoelectric vibrating element 3 is applied by dripping it onto the vibrating electrode 2. Then, as shown in FIG. 7, wax 6 is applied to the piezoelectric vibrating element 3 so as to cover the vibrating electrode 2, and then this piezoelectric resonator is immersed in an epoxy resin with wax-absorbing properties. An exterior portion 15 is formed. During this exterior molding, the wax 6 melted by heat is absorbed into the wax-absorbing epoxy resin, so the wax 6 is first
The area where was applied becomes a hollow vibration space 17 as shown in FIG. 8, which reduces the vibration load on the vibrating electrode 2.

[Problem to be solved by the invention]

In the conventional manufacturing process of a low-profile piezoelectric resonator, as described above, the plate-shaped iron 20 is laid down and inserted into the gap between the piezoelectric vibrating element 3 and the additional component element 4 from the top surface 19 side. However, since the wax 6 attached to the tip of the iron 20 was dripped onto the electrode 2 using vibration, it was difficult to accurately apply the wax 6 only to the vibrating electrode 2. In particular, since the soldering iron 20 with wax 6 is brought close to the top surface 19 side, the soldering iron 20 is placed close to the vibrating electrode 20.
The wax 6 tends to adhere to the top surface 19 when approaching the soldering iron 20, and it is difficult to apply a certain amount of wax 6 to the iron 20. Therefore, if there is too much wax 6, the wax 6 tends to adhere to the top surface 19 as shown by the broken line in FIG. spreads easily (if there is less wax 6, the vibrating electrode 2 is exposed from the wax 6), and as a result, as shown in FIG.
Wax 6 also often adhered to the surface. Therefore, when the exterior part 15 is subsequently molded using wax-absorbing epoxy resin, there is a space 18 in the exterior part 15 not only at the vibrating electrode 2 but also at the top surface 19, as shown in FIG.
was occurring.

As a result, a part of the top surface 19 of the piezoelectric vibrating element 3 is not gripped by the exterior part, and vibrations are not damped in this part, and vibrations leaking from between the vibrating electrodes 2 are reflected at the top surface 19 at the end surface. This caused standing waves and spurious vibrations. Furthermore, since the space 18 is created in the top surface 19, there is a risk that the exterior portion 15 will be damaged if an impact is applied to the upper end of the exterior portion 15, and there was a problem in terms of durability when performing a top surface impact test.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to enable wax to be applied accurately only to the vibrating electrodes of a piezoelectric resonator. In particular, the purpose is to eliminate wax adhesion to the top surface.

[Means to solve the problem]

For this reason, the method for manufacturing a piezoelectric resonator of the present invention includes: forming a piezoelectric vibrating element by providing a vibrating electrode on the surface of a piezoelectric substrate; attaching an additional component element to the piezoelectric vibrating element so as to face the surface; It is characterized in that a space-forming material such as wax discharged from a dispenser is applied to the vibrating electrode.

[Effect]

In the present invention, since a space forming material such as wax is applied to the vibrating electrode using a dispenser,
The space-forming material can be discharged from the tip of the dispenser after the tip of the dispenser is brought close to the vibrating electrode, and the space-forming material does not adhere to parts other than the vibrating electrode when the dispenser is brought close to the vibrating electrode. Moreover, since a fixed amount of space-forming material can be discharged from the dispenser, too much space-forming material may spread to areas other than the vibrating electrode (especially the top surface, etc.).
There is no possibility that the space-forming material is too small and the vibrating electrode is exposed from the space-forming material.

Therefore, it is possible to prevent a space from being formed in the top surface of the exterior part as in the conventional method, and also solve the problem of end face reflection and the problem of strength of the top surface of the exterior part, as in the conventional method.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the accompanying drawings.

The piezoelectric vibrating element 3 has a vibrating electrode 2 made of a metal thin film, two lead wires 7, and a terminal electrode 8 formed on both the front and back sides of a piezoelectric substrate 1 made of piezoelectric ceramics or the like using a thin film forming technique such as sputtering. The front and back vibrating electrodes 2 face each other at the center of the piezoelectric substrate 1, and the terminal chamber ri8, which performs energy trapping type mechanical vibration in the area between the vibrating electrodes 2, is located between the front and back sides of the piezoelectric substrate 1. The vibrating electrode 2 and the terminal are connected to the pole 8 by a lead wire 7. Further, both sides of the piezoelectric vibrating element 3 are held by space fittings 9 which are formed by bending a conductive metal plate into a groove shape, and both space fittings 9 are electrically connected to each terminal electrode 8 by soldering or the like. has been done. Furthermore, lead terminals 10 are extended from each of the space fittings 9.

The illustrated additional component element 4 is a capacitor element, in which thin metal film capacitor plates 12 are formed on both the front and back surfaces of a dielectric ceramic substrate 11, and metal thin film lead wires 13 are drawn out from the capacitor plate 12 on both sides. It is something that However, the additional component element 4 is not limited to a capacitor element. This additional component element 4 is placed parallel to the piezoelectric vibrating element 3 with both ends placed on the space fittings 9 as shown in FIG. The piezoelectric vibrating element 3 is arranged at both ends thereof and fixed to the space fitting 9 by solder, silver paste, etc., and a gap is formed between the additional component element 4 and the piezoelectric vibrating element 3. Furthermore, the additional component element 4 and the piezoelectric vibrating element 3 are electrically connected by soldering or the like at both ends of the additional component element 4 so as to constitute a predetermined circuit.

Furthermore, in the illustrated example, lead terminals 14 are soldered to the capacitor plate 12 of the additional component element 4.

After the additional component element 4 is attached to the piezoelectric vibrating element 3 in this way, as shown by the imaginary line in FIG.
The tapered tip of the dispenser 5 is brought close to the vibrating electrode 2, a fixed amount of melted wax 6 is discharged from the tip of the dispenser 5, and the vibrating electrode 2 is moved as shown in FIG.
The vibrating mold &2 is coated with wax 6 by dripping wax 6 onto the area. Since the wax 6 is discharged from the dispenser 5 in a fixed amount after the dispenser 5 is brought close to the vibrating electrode 2, there is no risk of the wax 6 adhering to parts other than the vibrating electrode 2, such as the part surrounded by the broken line in Fig. 3. be applied accurately. Also, the vibrating electrode 2 on the opposite side is also connected to the second
Wax 6 is applied by dispenser 5 as shown by imaginary lines in the figure. In this way, the re-vibration electrode 2 is covered with the solidified wax 6.

Next, the piezoelectric resonator 16 manufactured as described above is immersed in a wax-absorbing epoxy resin, and then the epoxy resin is thermally cured to form the exterior portion 15. The wax 6 is a space forming material, and the remelted wax 6 is absorbed into the epoxy resin, and a vibration space 17 is formed in the area where the wax 6 has been absorbed, as shown in FIG. The vibrating electrode 2 vibrates within this vibration space 17 without being damped, and since the entire outer periphery of the one-pressure type vibrating element 3 is held by the exterior part 15, end face reflection is suppressed. In addition, since there is no space around the outer circumference of the piezoelectric vibrating element 3,
It also has excellent impact resistance.

〔Effect of the invention〕

According to the present invention, the space forming material can be accurately applied only to the vibrating electrode portion of the piezoelectric vibrating element.

As a result, unlike the conventional example, there is no space at the top end of the piezoelectric resonator's exterior, and vibration reflections from the end face do not occur, making it possible to suppress spurious vibrations. Durability in impact tests is also improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention, FIGS. 2 and 3 are a schematic cross-sectional view and a plan view showing the wax attachment location according to the above method, and FIG. A cross-sectional view of a piezoelectric resonator, FIG. 5 is a perspective view of a conventional example, FIGS. 6 and 7 are a plan view and a schematic cross-sectional view showing the locations where wax is applied by the conventional method, and FIG. 8 is an exterior mold of the same as above. FIG. 7 is a cross-sectional view of the subsequent piezoelectric resonator. 1... Piezoelectric substrate 2... Vibrating electrode 3... Piezoelectric vibrating element 4... Additional component element 5... Dispenser

Claims (1)

[Claims] 1) A piezoelectric vibrating element is formed by providing a vibrating electrode on the surface of a piezoelectric substrate, and an additional component element is attached to the piezoelectric vibrating element so as to face the surface, and then a wax-like space is formed by discharging it from a dispenser. A method for manufacturing a piezoelectric resonator, characterized in that a material is attached to the vibrating electrode.