JPH07273580A - Manufacture of composite piezoelectric component - Google Patents

Abstract

PURPOSE:To obtain the manufacture method of composite piezoelectric components in which both the low height and the thin profile processing are attained with high mass-productivity. CONSTITUTION:A paper-tablet piezoelectric oscillator element base material 12a being a base material of a piezoelectric oscillating element 12 and a paper- tablet capacitor base material 13a being a base material of a capacitor 13 are prepared (A-D), and the both are adhered by a conductive adhesives 17 with a gap 18 inbetween (E). Then plural locations of the adhered materials are cut simultaneously at a prescribed width as shown in the arrow A to obtain plural chips each comprising the adhered piezoelectric oscillating element 12 and capacitor 13 (E). Then terminals 14-16 are bonded to each chip with electrical continuity (F) and each chip is coated by an insulating outer package resin so as to leave a space at least around a vibration part of the piezoelectric oscillating element 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a composite piezoelectric component, such as a piezoelectric oscillator having a built-in load capacitance, which has a piezoelectric element and a capacitor built therein.

[0002]

2. Description of the Related Art A conventional example of this type of composite piezoelectric component is shown in FIG.
And shown in FIG.

All of these are examples of a piezoelectric oscillator having a built-in load capacitance, but the example of FIG. 3 is a small strip-shaped piezoelectric substrate 2.
The piezoelectric oscillation element 2 in which two electrodes 22 and 23 are formed so as to face each other on the front and back main surfaces of 1 and the electrodes 32 and 33 are provided near both ends of one main surface of the dielectric substrate 31. ,
A capacitor 3 having electrodes 34 formed in the vicinity of the center of the other main surface is fixed to the semi-cylindrical tips of the terminals 4 and 5 on the same plane.

On the other hand, in the example of FIG. 4, the piezoelectric oscillating element 2 and the capacitor 3 having substantially the same structure as the above are arranged by placing the former inside the tip portions of the terminals 4 and 5 and the latter outside the tip portions. The terminals 4 and 5 are fixed in parallel with each other with a certain gap therebetween. The gap between the piezoelectric oscillation element 2 and the capacitor 3 is provided to some extent by the vibrating portion of the piezoelectric oscillation element 2 (electrodes 22 and 23 sandwiching the piezoelectric substrate 21).
This is because a cavity for securing a vibration space is formed between the outer resin described later by a wax drip or the like.

In any of the examples, more specifically, the electrode 23 of the piezoelectric oscillation element 2 and the electrode 32 of the capacitor 3 are connected to the terminal 4, and the electrode 22 of the piezoelectric oscillation element 2 and the electrode 33 of the capacitor 3 are connected to the terminal 5, respectively. Soldering. Furthermore,
The terminal 6 is soldered to the electrode 34 of the capacitor 3 (however, solder is not shown). Further, finally, the piezoelectric oscillation element 2 and the capacitor 3 and the like are surrounded by the piezoelectric oscillation element 2
Although a hollow portion is left around the vibrating portion, it is covered with an insulating exterior resin, but the illustration thereof is omitted here.

In the capacitor 3, capacitance is formed between the electrodes 32 and 33 on the one main surface side and the electrode 34 on the other main surface side. The equivalent circuit of the parts is as shown in FIG. Therefore, such a composite type piezoelectric component is suitable for use in, for example, a Colpitts type oscillation circuit.

[0007]

However, in the conventional example shown in FIG. 3, since the piezoelectric oscillation element 2 and the capacitor 3 are arranged in the same plane in the vertical direction, the exterior of the vibrating portion of the piezoelectric oscillation element 2 is covered. Although it is easy to form the cavity with the resin, there is a problem that it is difficult to reduce the height (to reduce the height of the back).

On the other hand, in the case of the conventional example of FIG. 4, since the piezoelectric oscillation element 2 and the capacitor 3 are arranged in parallel, it is possible to reduce the height, but both the piezoelectric oscillation element 2 and the capacitor 3 are arranged. Since the terminals 4 and 5 are fixed to the inside and outside of the semi-cylindrical tip end portions so that there is a certain gap between them, there is a problem that it is difficult to reduce the thickness.

Therefore, the main object of the present invention is to provide a method of manufacturing a composite piezoelectric component which is both low-profile and thin, with high productivity.

[0010]

In order to achieve the above object, the manufacturing method of the present invention is such that both main surfaces of a piezoelectric substrate are opposed to each other in the vicinity of the central portion and are folded back to the vicinity of the ends of the opposite main surface. A strip-shaped piezoelectric element base material formed by forming respective electrodes, and electrodes are formed near both ends of one main surface of the dielectric substrate and at least near the center of the other main surface. A step of preparing a strip-shaped capacitor base material consisting of a piezoelectric element base material and a capacitor base material, and a main surface on which electrodes are formed near both ends of the capacitor base material Side is the piezoelectric element base material side, and the step of attaching with a conductive adhesive at the opposing electrode parts, and cutting the thus-attached ones at a constant width at multiple locations at the same time. Piezoelectric element obtained A step of cutting out a plurality of chips formed by bonding together a capacitor obtained from a capacitor base material, conductively bonding the first and second terminals to both ends of each chip thus cut out, and at the center of the capacitor Of electrically connecting the third terminal to the electrode in the vicinity of the portion, and at least vibrating the piezoelectric element around the piezoelectric element, the capacitor, and the tips of the first to third terminals of the electrically conductively joined terminal in this manner. And a step of covering it with an insulating exterior resin while leaving a space around the section.

[0011]

According to the above method, the piezoelectric element is formed by forming electrodes on both main surfaces of the piezoelectric substrate that face each other in the vicinity of the central portion and are folded back to the vicinity of the ends of the opposite main surface. A capacitor, in which electrodes are formed near both ends of one main surface of the body substrate and at least near the center of the other main surface, respectively, and a gap is provided between the two, and electrodes are provided near both ends of the capacitor. With the main surface side being formed as the piezoelectric element side, a plurality of chips made by adhering opposite electrode parts with a conductive adhesive are made in a lump, and a composite piezoelectric component is manufactured using such chips. It can be manufactured.

[0012]

1 is a cross-sectional view showing an example of a composite type piezoelectric component manufactured by the manufacturing method of the present invention.

This composite type piezoelectric component is also an example in the case of a piezoelectric oscillator having a built-in load capacitance, and is a small strip-shaped piezoelectric substrate 1.
The piezoelectric oscillation element 12 is formed by forming electrodes 122 and 123, which are opposed to each other with the piezoelectric substrate 121 sandwiched therebetween in the vicinity of the central portion thereof, and are folded back to the vicinity of the end portions of the opposite principal surface, on both main surfaces of 21. is doing. A portion where the electrodes 122 and 123 face each other with the piezoelectric substrate 121 interposed therebetween is a vibrating portion due to thickness shear vibration.

In this composite piezoelectric component, electrodes 132 and 133 are provided near both ends of one main surface of the small strip-shaped dielectric substrate 131, and an electrode 134 is provided at least near the center of the other main surface. It has a capacitor 13 formed.

The piezoelectric oscillator 12 and the capacitor 13 as described above are connected to the electrodes 132, 13 of the capacitor 13.
The main surface side on which 3 is formed is used as the piezoelectric oscillation element 12 side, and a small gap 18 is provided between the two, and the electrodes are opposed to each other by a conductive adhesive 17 to bond them.

Then, the ends of the first and second terminals 14 and 15 (see also FIG. 2 (F)) having the both ends of the above-mentioned bonded pieces, respectively, have semicylindrical ends in this example. It is put in a portion and is conductively joined by soldering in this example. More specifically, the piezoelectric oscillation element 1
The second electrode 123 and the terminal 14 are soldered together, and the electrode 122 and the terminal 15 are soldered together. Reference numeral 19 indicates the solder.

The tip of the third terminal 16 is conductively joined to the electrode 134 of the capacitor 13 by, for example, soldering.

Furthermore, around the piezoelectric oscillation element 12, the capacitor 13, and the tips of the terminals 14 to 16 as described above,
The piezoelectric oscillation element 12 is covered with an insulating exterior resin 20 so as not to come into contact with at least the vibrating portion as described above. More specifically, the piezoelectric oscillator 12 and the capacitor 1
3, the gap 18 described above is left, and a cavity portion 21 is formed outside the vibrating portion of the piezoelectric oscillation element 12, so that the vibration space of the vibrating portion of the piezoelectric oscillation element 12 is formed. Is secured.

In the capacitor 13 as well, as in the case of the conventional example, capacitance is formed between the electrodes 132, 133 on one main surface side and the electrode 134 on the other main surface side, respectively. The equivalent circuit of the composite piezoelectric component of this embodiment is also as shown in FIG.

Moreover, according to the above structure, the piezoelectric oscillation element 1
Since the capacitor 2 and the capacitor 13 are bonded together, they are arranged in parallel, and unlike the case of the conventional example of FIG. 3, a large dimension in the height direction is not required, so that the height can be reduced. .

Further, the piezoelectric oscillation element 12 and the capacitor 13
Since they are bonded together with the conductive adhesive 17 without interposing other terminals or the like, the gap 18 between the two is very small unlike the case of the conventional example of FIG.

Moreover, in the conventional example of FIG. 4, if the gap between the piezoelectric oscillation element 2 and the capacitor 3 is made small, it becomes very difficult to form a cavity using a wax drip or the like, and the reliability and mass productivity of the product are improved. However, in this embodiment, the gap 18 between the piezoelectric oscillation element 12 and the capacitor 13 is inevitably very small. 18
Since there is no wraparound inside, there is no need to purposely form a cavity between the piezoelectric oscillation element 12 and the capacitor 13 using wax drip or the like. Therefore, it is possible to reduce the size of the composite piezoelectric component and improve its reliability and mass productivity.

Next, an example of a method of manufacturing the above composite piezoelectric component will be described with reference to FIG.

First, a long and narrow strip-shaped piezoelectric oscillator element base material 12a as shown in FIGS. 9A and 9B, and FIGS.
An elongated strip-shaped capacitor base material 13 as shown in (D)
a and are made respectively, and both are bonded with a conductive adhesive 17 as shown in FIG. The piezoelectric oscillation element base material 12a is a source of the piezoelectric oscillation element 12 described above, and has the same structure as that. That is, the piezoelectric substrate 121 and the electrodes 122 and 123 as described above are provided. The capacitor base material 13a is the capacitor 1 described above.
It is the source of 3 and has a similar structure. That is, the dielectric substrate 131 and the electrode 13 as described above.
2 and 133.

Next, the above laminated pieces are
As shown by an arrow A in FIG. 7E, when a plurality of parts having a constant width are cut at the same time, the piezoelectric oscillation element 1 as described above is formed.
A plurality of chips obtained by bonding the capacitor 2 and the capacitor 13 together are obtained at one time.

Next, as shown in FIG. 6F, each of the chips obtained as described above is provided with the terminal 14 as described above.
Solder each ~ 16.

Next, for example, wax is dipped in advance in order to form the above-mentioned cavity 21 around the vibrating portion outside the piezoelectric oscillation element 12, and the piezoelectric oscillation element 12, the capacitor 13, and the terminals 14 to 14 are connected. If the tip of 16 is dipped into, for example, a molten porous exterior resin 20 (see FIG. 1), the wax is absorbed in the exterior resin 20 and
A composite piezoelectric component as shown in (1) is obtained.

According to the manufacturing method as described above, a plurality of chips in which the piezoelectric oscillation element 12 and the capacitor 13 are bonded together are manufactured in a lump, which is excellent in mass productivity. Moreover,
It is possible to obtain a plurality of chips having the same characteristics.

[0029]

As described above, according to the manufacturing method of the present invention, it is possible to manufacture a composite type piezoelectric component which is formed by bonding a piezoelectric element and a capacitor to each other and which can be made thin and thin.

Moreover, since a plurality of chips formed by bonding the piezoelectric element and the capacitor together are made at once from the base material,
Excellent mass productivity. Therefore, the cost of the composite piezoelectric component can be reduced.

Further, since a plurality of chips are collectively made from the same base material, it is possible to obtain a plurality of composite piezoelectric components having the same characteristics.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a composite piezoelectric component manufactured by the manufacturing method of the present invention.

FIG. 2 shows an example of steps in the manufacturing method according to the present invention, in which (A) is a plan view of a piezoelectric oscillator element base material,
(B) is a side view thereof, (C) is a plan view of a capacitor base material, (D) is a side view thereof, (E) is a view in which a piezoelectric oscillation element and a capacitor are bonded together, and (F) is a molded outer resin. FIG.

FIG. 3 is a perspective view showing an example of a conventional composite piezoelectric component.

FIG. 4 is a perspective view showing another example of a conventional composite piezoelectric component.

5 is an equivalent circuit diagram of the composite piezoelectric component of FIGS. 1, 3 and 4. FIG.

[Explanation of symbols]

 12 Piezoelectric oscillation element (piezoelectric element) 12a Piezoelectric oscillation element base material (piezoelectric element base material) 121 Piezoelectric substrate 122,123 Electrode 13 Capacitor 13a Capacitor base material 131 Dielectric substrate 132-134 Electrode 14-16 Terminal 17 Conductive adhesive 20 Exterior resin

Claims (1)

[Claims] 1. A strip-shaped piezoelectric element base material is provided, in which electrodes are formed on both main surfaces of a piezoelectric substrate so as to face each other in the vicinity of the central portion and are folded back to near the ends of the opposite main surface. And a step of preparing a strip-shaped capacitor base material in which electrodes are formed near both ends of one main surface of the dielectric substrate and at least near the center of the other main surface, and a piezoelectric element base material And the capacitor base material, with a gap between the two, and the main surface side where electrodes are formed near both ends of the capacitor base material is the piezoelectric element base material side,
Obtaining from the piezoelectric element and capacitor base material obtained from the piezoelectric element base material by the step of attaching them with a conductive adhesive at opposite electrode parts A step of cutting out a plurality of chips formed by adhering the capacitors to each other, and the first and second chips are formed on both ends of each chip thus cut out.
And conductively bonding the terminals to each other, and conductively bonding the third terminal to the electrode near the center of the capacitor, and the piezoelectric element, the capacitor, and the first to third terminals having the terminals conductively bonded in this manner. And a step of covering the periphery of the tip of the piezoelectric element with an insulating exterior resin leaving a space around at least the vibrating portion of the piezoelectric element.