JPH0155609B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chip-shaped piezoelectric vibrating component having a structure in which a piezoelectric vibrating unit is laminated so as to sandwich a piezoelectric vibrating unit between plate-shaped insulators.

[Conventional technology]

Conventionally, piezoelectric vibrating components such as resonators, oscillators, filters, and FM discriminators have been known to have various structures depending on the characteristics of the vibration mode in which the piezoelectric vibrating unit is used.

For example, ceramic filters with a relatively low frequency band of several hundred kilohertz use a case-type filter in which a piezoelectric vibrating unit is housed in an outer case made of resin or the like into a box shape. Ceramic filters for the frequency band from several MHz to several tens of MHz are of the so-called dip coating type, in which exterior resin is adhered to the area other than the vibration area of the energy confinement type piezoelectric vibration unit, or surface wave Elements that are dip-coated or have a hermetic shield case are generally known. However, all of these piezoelectric vibrating components have a structure with a dielectric terminal having a lead terminal.

[Technical problem to be solved by the invention]

In recent years, with the miniaturization of electronic devices, various efforts have been made to increase the packaging density of electronic components.
However, the above-mentioned piezoelectric vibrating components with lead terminals basically have a structure in which the piezoelectric vibrating unit is covered with an exterior member and multiple lead terminals protrude from the exterior member, so the shape is large. However, the disadvantage was that the packaging density was low.

On the other hand, in order to improve the efficiency of mounting work and increase the packaging density, it is desired that various electronic components have leadless chip-shaped structures. However, in a type of piezoelectric vibrating component that has excitation electrodes on both main surfaces of a piezoelectric substrate and needs to be electrically extracted to the outside on both main surfaces of the piezoelectric substrate,
It has been difficult to make chip parts that can be face bonded.

Therefore, an object of the present invention is to provide a piezoelectric vibrating component using a piezoelectric vibrating unit having excitation electrodes to be drawn out to the outside on both principal surfaces, which can facilitate mounting work and improve packaging density. It is in.

[Means for solving technical problems]

In the chip-shaped piezoelectric vibrating component of the present invention, notches are provided in at least two places in a plate-shaped insulator, and a conductive film is formed on each wall surface in the thickness direction of the insulator in these notches. It has at least a structure in which the piezoelectric vibrating unit is sandwiched between two objects. The lead electrode of the piezoelectric vibration unit is electrically connected to a conductive film provided on the insulator.

The piezoelectric vibration unit has a structure in which a pair of excitation electrodes are provided on the front and back surfaces of a piezoelectric substrate. and,
The excitation electrode on one side of the piezoelectric substrate electrically connects the conductive film of the plate-shaped insulator placed on the other side of the piezoelectric substrate via the electrode film provided on the side surface of the chip-shaped piezoelectric vibrating component. It is connected to the.

[Effect]

The excitation electrode provided on one side of the piezoelectric substrate is
Since it has a configuration in which it is connected to a conductive film of an insulator arranged on the other side of the piezoelectric substrate through an electrode film provided on the side surface of the vibrating component, the excitation electrode provided on the other side of the piezoelectric substrate It can be mounted on a mounting portion of a printed circuit board or the like by face bonding using the conductive film of an insulating material disposed on the other side of the piezoelectric substrate. Therefore, the mounting work is easy, and since it is a leadless type chip component, it is possible to effectively increase the mounting density.

[Explanation of Examples]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

First, the structure of the piezoelectric vibrating unit used in the piezoelectric vibrating component of this embodiment will be explained with reference to FIGS. 1 and 2.

Referring to FIG. 1, an electrode as shown is formed on one surface of a piezoelectric ceramic substrate 101. As shown in FIG. That is, the excitation electrodes 102a and 102b constitute the first energy confinement type piezoelectric ceramic filter element part 102, and the excitation electrodes 102a and 102b constitute the second energy confinement type piezoelectric ceramic filter element part 103.
Excitation electrodes 103a and 103b are formed to constitute. Note that 104 and 105 are extraction electrodes, and 106 is an electrode for forming a capacitor.

On the other hand, on the lower surface of the piezoelectric ceramic plate 101, electrodes are formed as shown in FIG. That is, the excitation electrode 102 for forming the first and second piezoelectric ceramic filter element parts
c, 103c, capacitor electrode 106 for forming a capacitor, and extraction electrode 107, 1
08 is formed.

The circuit configuration of the piezoelectric vibrating unit is shown in a circuit diagram in FIG.

In the piezoelectric vibrating component of this embodiment, a first plate-shaped insulator 109 shown in FIGS. 4 and 5 is laminated on the upper surface of the piezoelectric vibrating unit described above via an adhesive. This plate-shaped insulator 109 is made of a synthetic resin such as a glass epoxy board often used as a printed circuit board or a through-hole plated board, or a ceramic such as alumina.

The plate-shaped insulator 109 has a notch 1 at the corner.
10a to 110d, semicircular notches 110e and 110f are formed in the central portions of the longer sides. The wall surfaces in the thickness direction of these notches 110a to 110f and the notch 110 of the plate-shaped insulator 109
Conductive film 11 extending over both main surfaces near a to 110f
1 to 114 are formed.

The conductive film 111 is formed by continuously forming a conductive film provided in the notches 110a and 110b on the upper surface of the plate-shaped insulator 109, that is, on the outer surface not facing the piezoelectric ceramic substrate 101. The conductive film 112 has notches 110c, 1
The conductive film of the 10d portion is continuously formed. In this point, the conductive films 113 and 114 are different from those formed by ordinary through-hole electrode formation techniques.

A second plate-shaped insulator (FIG. 6 shows only the view from the lower surface) in which similar notches 110a to 110f are formed is also attached to the lower surface side of the piezoelectric ceramic substrate 109 via adhesive. It will be done. This second
Also in the plate-shaped insulator, the notches 110a to 11
Conductive films 111 to 114 extending near the notch are formed on both the main surfaces of the insulator and the wall surface in the thickness direction of 0f. However, the shape of the electrode on the lower surface of the second plate-like insulator is as shown in FIG. That is, the same conductive films 111 and 112 as shown in FIG.
The conductive film 11 is formed so as to be continuous with the conductive film formed on the wall surface of the central notch portion 10b or the notch portions 110c and 110d, and to be continuous with the conductive film formed on the wall surface of the central notch portion 110e and 110f.
6 is given to the lower center area.

Note that the upper surface side of the second plate-shaped insulator 115, that is, the side facing the piezoelectric ceramic substrate 101,
Since it is the same as the lower surface of the first plate-shaped insulator 109 (the electrode shape shown in FIG. 5), its illustration is omitted.

Note that the plate-shaped insulator 109 is the same as the plate-shaped insulator 115.
It may be configured to have the same electrode shape.

FIG. 7 shows the piezoelectric ceramic substrate 101 and the first and second plate-shaped insulators 109 and 115 bonded together. The plate-shaped insulators 109 and 115 are bonded to the top and bottom surfaces of the piezoelectric ceramic substrate 101 via an adhesive 118, respectively. At this time, it is necessary to determine the thickness and application range of the adhesive 118 so that a gap is created over the vibration area so as not to inhibit the vibration.

As shown in a schematic side view in FIG. 8, electrode films 11
7,117 is formed. This electrode film 117
conducts the conductive film 111 of the plate-like insulator 109 and the conductive film 111 of the second plate-like insulator 115,
Similarly, the conductive film 112 of the first plate-like insulator 109
and the conductive film 112 of the second plate-like insulator 115 are electrically connected.

Possible methods for forming the electrode film 117 include sputtering, vapor deposition, and ion plating, but considering the adhesion of the electrode film 117 to the formation surface, sputtering is optimal.

In addition, in order to prevent the silver eating phenomenon during soldering, we sputtered Monel metal (30% Cu, 65% Ni), which has excellent adhesion to the substrate, as the base electrode, and also Instead of sputtering, copper may be vapor-deposited and then silver may be further vapor-deposited to obtain the required electrode film thickness.

By providing the electrode film 117 as described above, a structure that can be face bonded to a printed circuit board or the like is realized. That is, Figures 7 and 8
As is clear from the figure, the piezoelectric ceramic substrate 10
Excitation electrodes 102a and 10 provided on the upper surface side of 1
3a (Fig. 1), an extraction electrode 104,
105, the conductive films 111 and 112 of the plate-shaped insulator 115 disposed on the other surface side of the piezoelectric ceramic substrate, that is, on the lower side, via the electrode film 117.
Since it is electrically connected to, it can be mounted on a printed circuit board or the like in the orientation shown in FIG. 7 by face bonding.

Note that the electrode structure of the first plate-like insulator 109 is as follows:
If it is the same as the second plate-shaped insulator 115 and an electrode film having the same function as the electrode film 117 is formed also on the extraction electrode 107, a filter without vertical and horizontal symmetry can be obtained.

Moreover, it is preferable that each electrode film and conductive film described above be soldered. Equipment (TV
Conductive films 111, 11 shown in FIG.
2, 116 are faced and soldered.
The extraction electrode 104 includes plate-shaped insulators 109 and 115.
The conductive films 111, 111 are reliably electrically connected to the electrode film 117 by the solder. Similarly,
The extraction electrode 105 is also made of plate-shaped insulators 109, 115.
The conductive films 112, 112 are reliably electrically connected to each other by the electrode film 117 and the solder.

Further, the extraction electrode 107 is connected to the conductive films 113 and 11.
4, conduction is ensured by solder.

Note that the present invention is not limited to being applied only to the above-mentioned two-stage filter, but can also be applied to two-terminal or three-terminal resonators (oscillators), FM discriminator units, etc. . Further, even in the case of a filter, the number of stages is arbitrary. Similarly, a coupling capacitor may not necessarily be provided.

The structure of the energy confinement type resonator (filter) is not limited to the embodiments, but may be the one published in Japanese Patent Application Laid-Open No. 55-149520 or the one published in Utility Model Application Publication No. 56-157829. may also be applied.

In the case of a two-terminal type resonator (filter), it is not necessary to form the cutouts 110e and 110f.

Conductive films 111, 112, 113, 114, 11
An example of the method for forming No. 6 will be explained. First, prepare a plate-shaped insulator base material, and form, for example, a round hole or a semi-circular hole at the edge of the base material at a position equal to the width and length of the unit plate-shaped insulator to be manufactured, and then By a hole plating method, a conductive film is formed on the inner wall surfaces of the round hole and semi-round hole and on the peripheral edges of both opening end surfaces thereof. Next, by cutting the insulating base material, the first and second plate-shaped insulators as described above can be efficiently mass-produced from the insulating base material.

Note that the conductive films 111, 112, 1 of the above embodiment
16, a conductive film is applied to the entire surface of the plate-shaped insulators 109 and 115, and when etching, between the notched portions 110a and 110b, between 110c and 110d,
It can be formed by leaving the conductive film on one side between 110e and 110f.

〔Effect of the invention〕

As described above, in the present invention, plate-shaped insulators having at least two notches and conductive films formed thereon are laminated above and below a piezoelectric vibrating unit.
Although the piezoelectric vibration unit has a structure in which the extraction electrode is electrically connected to the conductive film, and the piezoelectric vibration unit has a pair of excitation electrodes on the front and back sides of the piezoelectric substrate, the excitation electrode on one side is chip-shaped. The piezoelectric vibrating component is connected to a conductive film of a plate-shaped insulator on the other side of the piezoelectric substrate via an electrode film provided on the side surface of the piezoelectric vibrating component, making it a chip component that can be face bonded. Therefore, mounting on a mounting portion such as a printed circuit board is extremely easy, and the mounting density can be effectively increased.

In addition, since the plate-shaped insulator has a structure in which a notch is provided and a conductive film is formed on the wall surface in the thickness direction of the notch, it can be relatively easily mass-produced from an insulating base material. It is also possible to stack it on the piezoelectric vibrating unit base material and then cut it. Therefore, it is possible to easily mass-produce a large number of piezoelectric vibrating components. Therefore, it is possible to obtain a piezoelectric vibrating component that is inexpensive and highly reliable with a low incidence of defective products.

[Brief explanation of drawings]

FIG. 1 is a plan view of a piezoelectric ceramic substrate used in an embodiment of the present invention, FIG. 2 is a bottom view of the piezoelectric substrate, FIG. 3 is a diagram showing the circuit configuration of the piezoelectric substrate, and FIG.
FIG. 5 is a plan view of the first plate-shaped insulator, showing the side facing the top surface of the piezoelectric ceramic substrate, and FIG. 6 is a plan view of the first plate-shaped insulator. FIG. 7 is a bottom view of the object, FIG. 7 is a side view showing the state before applying the electrode film in one embodiment of the present invention, and FIG. 8 is a diagram for explaining the function of the electrode film in one embodiment of the present invention. FIG. 3 is a schematic side view. In the figure, 101 is a piezoelectric ceramic substrate;
02a, 102b, 103a, 103b, 102
c, 103c are excitation electrodes, 104, 105, 10
7 is an extraction electrode, 109 is a first plate-shaped insulator, 1
10a to 110f are notches, 111, 112, 1
13 and 114 are conductive films, 115 is a second plate-shaped insulator, and 117 is an electrode film.

Claims (1)

[Claims] 1. Cutouts are provided in at least two places on a plate-shaped insulator, a conductive film is formed on each wall surface of the cutout in the thickness direction of the insulator, and the piezoelectric vibration unit is sandwiched between the two pieces of the insulator. A chip-shaped piezoelectric vibrating component having at least a laminated structure as shown in FIG. The excitation electrode on one side of the piezoelectric substrate is connected to the plate-shaped excitation electrode placed on the other side of the piezoelectric substrate via an electrode film provided on the side surface of the chip-shaped piezoelectric vibrating component. A chip-shaped piezoelectric vibrating component characterized by being electrically connected to a conductive film of an insulating material.