JP2536627B2 - Chip-shaped piezoelectric component - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a chip-shaped piezoelectric component used for a filter circuit, a trap circuit, a frequency demodulation circuit, or the like in various electronic devices.

(Prior Art) An exploded perspective view, an external perspective view and a longitudinal sectional view of an example of a conventional chip-shaped piezoelectric component are shown in FIG. 6, FIG. 7 and FIG. 8, respectively.

The chip-shaped piezoelectric component is a piezoelectric resonator using energy trap type thickness longitudinal vibration of a ceramic piezoelectric substrate 1, which is formed into a chip. A first protective substrate 3 and a second protective substrate 4, which are adhered to one main surface and the other main surface of the piezoelectric substrate 1 of the element 2, respectively;
It is composed of the element 2 and a first external terminal electrode 5 and a second external terminal electrode 6 formed on the end faces of the protective substrates 3 and 4.

The element 2 has one oscillating electrode 7 and the other oscillating electrode 8 of the resonator, which are respectively formed in the central portions of one main surface and the other main surface of the piezoelectric substrate 1 made of ceramic. Then, the one vibrating electrode 7 is led out by the lead electrode 9 to a lead terminal 10 formed on one side of one main surface of the piezoelectric substrate 1. In addition, the other vibrating electrode 8
Is drawn out to the lead-out terminal 12 formed on one side of the other main surface of the piezoelectric substrate 1 by the lead-out electrode 11. The lead terminal 10 and the lead terminal 12 are
Located on opposite sides of each other. The piezoelectric substrate 1 performs energy trap type thickness longitudinal vibration between the vibrating electrodes 7 and 8 and in the vicinity thereof.

On the other hand, both the first protective substrate 3 and the second protective substrate 4 are made of an organic or inorganic insulating material. On the surfaces of the first protective substrate 3 and the second protective substrate 4 facing the elements, circular recesses are formed in the central portions thereof in order to form a gap for allowing the vibration of the vibrating portion 15 of the piezoelectric substrate 1, respectively. C is provided.

The first protective substrate 3 is adhered to one main surface of the piezoelectric substrate 1 by an adhesive 13 applied to one main surface of the piezoelectric substrate 1 of the element 2 on the surface where the circular recess C is formed. To be done. Further, the second protective substrate 4 is also adhered to the other main surface of the piezoelectric substrate 1 by the adhesive 14 applied to the other main surface of the piezoelectric substrate 1 of the element 2 in the same manner as described above. .

The first external terminal electrode 5 is the lead electrode.
10 is formed by covering the solder on the primary metal film Sp formed by sputtering or the like on one end face side of the element 2 and the protective substrates 3 and 4 which are bonded to one side of each formed side, It is electrically connected to the extraction electrode 10. The second external terminal electrode 6 is formed by sputtering or the like on one end face side of the element 2 and the protective substrates 3 and 4 which are bonded to each other on one side where the extraction electrode 12 is formed. It is formed by covering the solder on the primary metal film Sp and is electrically connected to the extraction electrode 12.

(Problems to be Solved by the Invention) In the conventional chip-shaped piezoelectric component having the above-described structure, it is generally made of one insulating substrate S provided with a large number of circular recesses C as shown in FIG. Separated mother boards are used for the first and second protective boards 3 and 4.

This mother substrate is manufactured by pressing and firing with a predetermined die having a pattern corresponding to the circular recess C. However, it is unavoidable that the circular recesses shrink a little during the firing stage, and the pitch, size, position, and depth of the circular recesses C change variously, and the degree of change is not uniform. However, since it becomes a problem in accuracy when assembling the piezoelectric parts, and particularly the necessary vibration is damped, it is difficult to mass-produce the piezoelectric parts without variations in characteristics.

Furthermore, when changing the shape and size of the circular recess C, another mold is required, which also increases the manufacturing cost.

The present invention has been made to solve the above problems, and in the manufacturing stage, it is possible to easily provide a concave portion stably at a predetermined position of the protective substrate, and even with respect to the pattern change of the concave portion. An object of the present invention is to provide a chip-shaped piezoelectric component that does not require a large number of molds.

(Means for Solving the Problems) In order to achieve the above object, in a chip-shaped piezoelectric component according to the present invention, a piezoelectric substrate has a vibrating electrode, and an element that performs energy trapping type vibration at the vibrating electrode portion is provided. In a chip-shaped piezoelectric component in which the element is sandwiched between a pair of protective substrates and the vibrating electrode is pulled out to an end face of the element, the protective substrate is a recess that allows the vibrating portion of the piezoelectric substrate to vibrate. An insulating paste is printed on one main surface so that it is formed at a position facing the vibrating electrode and is baked, and the protective substrate and the element are sandwiched between the insulating paste to form an adhesive agent. It is characterized by being bonded by.

(Examples) Examples of the present invention will be described below with reference to the accompanying drawings.

An exploded perspective view, an external perspective view and a longitudinal sectional view of an embodiment of the chip-shaped piezoelectric component according to the present invention are respectively shown in FIG. 2 and FIG.
Shown in Figures and FIG.

The structure of this chip-shaped piezoelectric component is the same as that of the conventional one shown in FIGS. 6 to 8, and therefore detailed description thereof will be omitted.

FIG. 1 is a view showing a mother substrate lowered onto a protective substrate used for the chip-shaped piezoelectric component of the present invention. This mother substrate is composed of a flat insulating substrate S that has been fired in advance, and an insulating base P applied on one surface of the flat insulating substrate S in a predetermined pattern, in this embodiment, a circular pattern.

The flat plate insulating substrate S is preferably made of a material such as alumina which is light and has excellent insulating properties and strength. In addition, the insulating paste P is also glass or the like having excellent insulating properties. The insulating paste P is applied by a printing technique such as screen printing so as to form the circular concave portions C and then baked, so that the mother substrate is Complete. Then, this mother substrate is cut and processed into the first and second protective substrates 3 and 4.

As described above, since the insulating paste P is applied by printing on the already baked insulating substrate S to form the recesses C in a predetermined pattern, the position, size, and depth of the recesses C depend only on the printing accuracy. It is possible to manufacture a protective substrate that is not affected by variations and is stable.

Further, if the mother protective substrate having the concave portion C already formed and the mother piezoelectric substrate having the vibrating electrode and the like are attached and then cut, the assembly of the product becomes easier.

Although the chip-shaped piezoelectric component using one element has been described in the above embodiments, the present invention is not limited to this.
The present invention can also be applied to a chip-shaped piezoelectric component having a laminated structure in which elements and protective substrates are alternately stacked, such as protective substrate / element / protective substrate. In this case, the protective substrate sandwiched between the elements is provided with recesses C on both sides by printing.

(Effect of the Invention) According to the present invention, since the position and size of the concave portion provided in the protective substrate are determined only by the printing accuracy of the insulating paste, the concave portion can be provided with high precision without considering shrinkage during firing of the insulating substrate. You can

Further, since it is not necessary to intentionally select an expensive material having a low shrinkage during firing for the insulating substrate, the manufacturing cost is reduced.

Even if you want to change the shape, position, and depth of the recess, you only have to change the printing pattern and the number of times of printing the insulating paste, and there is no need to prepare many types of molds for insulating substrates, as in the past. From this aspect as well, a reduction in manufacturing cost can be expected.

[Brief description of drawings]

FIG. 1 is a mother substrate processed into first and second protective substrates of the chip-shaped piezoelectric component according to the present invention. FIG. 2 is an exploded perspective view of a chip-shaped piezoelectric component according to an embodiment of the present invention. FIG. 3 is an external perspective view of a chip-shaped piezoelectric component according to an embodiment of the present invention. FIG. 4 is a vertical sectional view of a chip-shaped piezoelectric component according to an embodiment of the present invention. FIG. 5 shows a mother substrate which is processed into the first and second protective substrates of the piezoelectric substrate of the conventional chip-shaped piezoelectric component, which is pressed by the die and fired. FIG. 6 is an exploded perspective view of a conventional chip-shaped piezoelectric component. FIG. 7 is an external perspective view of a conventional chip-shaped piezoelectric component. FIG. 8 is a vertical sectional view of a conventional chip-shaped piezoelectric component. 1 ... Piezoelectric substrate, 2 ... Element, 3,4 ... Protective substrate, 5, 6 ...
Terminal electrode, 7,8 ... Vibration electrode, 9,11 ... Extraction electrode, 10,12 ... Extraction terminal, 13,14 ... Adhesive agent, 15 ... Vibrating part, C ... Recess, S
Insulating substrate, P ... Insulating paste.

Claims (1)

(57) [Claims] 1. A piezoelectric substrate has a vibrating electrode, and an element that vibrates in an energy trapping type is provided at the vibrating electrode portion. The element is sandwiched between a pair of protective substrates, and the vibrating electrode is formed of the element. In the chip-shaped piezoelectric component drawn out to the end face, the protective substrate has one insulating paste so that a concave portion for allowing the vibration of the vibrating portion of the piezoelectric substrate is formed at a position facing the vibrating electrode. A chip-shaped piezoelectric component comprising a flat insulating substrate printed and burned on, wherein the protective substrate and the element are adhered by an adhesive with the insulating paste interposed therebetween.