JPS62112410A - Piezoelectric resonator - Google Patents

Abstract

PURPOSE:To obtain a piezoelectric resonator where the pass band center of the amplitude characteristic and a point of phase angle 90 deg. of the phase characteristic are made coincident by adhering two pieces of three-terminal piezoelectric vibrator elements by an adhesives, forming each lead electrode properly and connecting the electrodes. CONSTITUTION:The two pieces of three-terminal piezoelectric vibrator elements 2, 2 of the energy confinement type and the thickness vibration mode are adhered by an adhesives so as to overlap electrodes to form a piezoelectric resonator 1. In this case, the lead electrode 8 of the common electrode 7 is led up to the uppermost end of each rear side, an external common lead electrode 9 is formed on the surface of one base from the uppermost end to the lower end and lead electrodes 10, 12 and 11, 13 of split electrodes 5 and 6 are formed on the surface of each base as shown in figure. Further, both the bases are adhered by applying the adhesives while the uppermost part of the rear side is left and IN, OUT terminals are connected to the lead electrodes of the one base and a GND terminal is connected to the lead electrode of the other base. Through the constitution above, the pass band center of the amplitude characteristic and the frequency of a point of the phase angle 90 deg. of the phase shift characteristic are made nearly coincident and the linearity of the phase characteristic in this case is improved.

Description

Detailed Description of the Invention (Al Technical field) This invention relates to a piezoelectric resonator used as a discriminator, etc. in an FM demodulation circuit. (b) Prior art and its drawbacks A piezoelectric resonator consisting of an energy confinement type, thickness vibration mode three-terminal piezoelectric vibrating element with two divided electrodes and a common electrode formed on the back side is used as a discriminator in an FM demodulation circuit, etc. However, with conventional piezoelectric resonators, which only have electrodes formed on both sides of a single substrate,
Since the passband center of the amplitude characteristic and the phase angle 90' point of the phase shift characteristic do not match, when the passband center of the amplitude characteristic is aligned with the reference frequency, the phase angle at this reference frequency will be 90'.
'It will deviate from that. Therefore, when using such a conventional piezoelectric resonator in a phase shift circuit in a Fordrecher type FM detection circuit, for example, by further correcting the phase angle with an RLC circuit, the phase shift angle can be adjusted at the reference frequency. It was necessary to obtain a detection characteristic of 90°. Therefore, conventional piezoelectric resonators can be used in such FM
When used in a demodulation circuit, not only is the phase shift circuit complicated and expensive, but the RI-C circuit must be selected appropriately according to the circuit constants of the FM-IF-IC used. It lacks versatility, and the detection characteristics are affected by variations in the inductance of this RLC circuit, resulting in poor temperature characteristics.

(C1 Purpose of the Invention This invention was made in view of the above circumstances, and consists of bonding two 3-terminal piezoelectric vibrating elements together with an adhesive,
The object of the present invention is to provide a piezoelectric resonator in which the center of the passband of the amplitude characteristic and the 90° phase angle point of the phase shift characteristic coincide by appropriately forming and connecting each extraction electrode.

(d1 Structure and Effect of the Invention The piezoelectric resonator of the present invention has a first divided electrode on one end side and a second divided electrode on the other end side by side formed approximately at the center of the front surface of the substrate, and a common divided electrode at approximately the center of the back surface. Energy confinement type with electrodes formed.

In a piezoelectric resonator in which two 3-terminal piezoelectric vibrating elements in thickness vibration mode are bonded together with adhesive so that their common electrode sides overlap, both plates are arranged with their back sides facing each other and connected to the common electrode. A common lead electrode is formed by drawing it out to the upper end of one end side of each back surface, and
On the surface of one substrate, an external common extraction electrode is formed from the upper end to the lower end on one end side, and a first divided electrode connected to the first divided electrode is extended to the upper end on the other end side. and further, a second electrode connected to the second divided electrode.
A split split electrode is formed by being drawn out to the lower end on the other end side, and a first split split electrode connected to the first split electrode is formed on the surface of the other substrate by being pulled out to the center lower end. A second split electrode connected to the two-split electrode is drawn out to the upper end of the other end, and the two boards are bonded together by applying adhesive, leaving only the upper end of one end on the back side. Each extraction electrode formed on the front and back surfaces of one board at the upper end of one end and the back surface of the other board is connected by a conductive means, and each lead electrode formed on the surface of both store boards at the upper end of the other end is Connect the extraction electrodes with each other using a conductive means, and connect the IN to each extraction electrode at the lower end of both ends of one board.
, the OUT terminal is connected, and the GND terminal is connected to the lead electrode at the lower end of the center of the other board.

When the piezoelectric resonator of the present invention is configured as described above, the frequency at the center of the passband of the amplitude characteristic and the 90° phase angle point of the phase shift characteristic can be made to almost match, and the linearity of the phase characteristic at this time can be It also gets better. Furthermore, by rationally arranging each extraction electrode, connection outside the substrate can be made using a simple conductive means such as a conductive paste, and the productivity of the element can be improved.

(e) Embodiment FIG. 1 is an exploded perspective view of a piezoelectric resonator used in an embodiment of the present invention, FIG. 2 is a diagram showing an adhesive application pattern on one substrate of the same piezoelectric resonator, and FIG. A front view of the piezoelectric resonator, FIG. 4 is a front view of the piezoelectric resonator after being packaged.

The piezoelectric resonator 1 of this embodiment is constructed by bonding two three-terminal piezoelectric vibrators 2.2 together with an adhesive 3. The three-terminal piezoelectric vibrator 2.2 has a first divided electrode 5 on one end (left side in FIG. 1) and a second divided electrode 6 on the other end approximately in the center of a substrate 4 made of piezoelectric ceramics.
are formed side by side, and a common electrode 7 is formed in the center of the back side.
This is an energy trapping type, thickness vibration mode piezoelectric vibrating element. The piezoelectric resonator 1 of this embodiment is a three-terminal piezoelectric vibrating element 2 in which each electrode 5, 6.7 is formed in this way.
, 2 are arranged so that their back surfaces face each other, and common lead-out electrodes 8, 8 connected to the common electrodes 7, 7 are each drawn out to the upper end of one end side of each back surface. Further, on the surface of one substrate (the substrate on the back side in FIG. 1) 4, an external common extraction electrode 9 is formed between the upper end and the lower end on one end side. On the surface of one of the substrates 4, a first splitting electrode 10 connected to the first splitting electrode 5 is formed extending all the way to the upper end on the other end side, and a second splitting electrode 10 is formed on the surface of the one substrate 4.
The second divided electrode 11 connected to the divided electrode 6 is formed by being drawn out to the lower end on the other end side. On the surface of the other substrate 4, a first divided electrode 12 connected to the first divided electrode 5 is formed by extending it to the lower end of the center, and a second divided electrode 13 connected to the second divided electrode 6 is formed. is formed by pulling it out all the way to the upper end of the other end.

As shown in FIG. 2, both substrates 4.4 on which each electrode pattern has been formed in this manner are coated with adhesive 3 and bonded together, leaving only the upper end on one end side of the back surface. (
However, FIG. 2 shows only the case of one substrate 4. The other substrate 4 is laterally symmetrical with respect to this. ) Both substrates 4.4 bonded together in this way have a conductive paste (conducting means) 14 on the upper end of one end, as shown in FIG.
By applying the adhesive, it enters the part between the back surfaces of each substrate 4, 4 where the adhesive 3 is not applied, and the common extraction electrode 8
．． 8 becomes conductive. Further, the conductive base 1-14 simultaneously connects these common extraction electrodes 8.8 with an external common extraction electrode 9 formed on the surface of one of the substrates 4. Also, conductive paste 1 was applied to the upper end of the other end of both substrates 4゜4.
4 and connect the first splitting electrode 10 and the first splitting electrode I3 formed on the surfaces of both substrates 4, 4, respectively. Among the lead-out electrodes connected in this way, the external common lead-out electrode 9 of one of the substrates 4 is connected to the IN terminal 15 by solder at the lower end of one end side, thereby forming an input terminal. Also, a second substrate 4 formed on the surface of one substrate 4
The split electrode 11 has an OUT terminal 1 at the lower end on the other end side.
6 with solder to form an output terminal. Furthermore, the first splitting electrode 12 formed on the surface of the other substrate 4 is
At the lower end of the center, it is connected to the GND terminal 17 with solder 19 to constitute a ground terminal. As shown in FIG. 4, the piezoelectric resonator 1 of this embodiment constructed in this manner has the entire substrate 4.4 covered with an exterior material 18 to become an element component.

The piezoelectric resonator 1 of this embodiment configured as described above is as follows:
Since the frequencies at the center of the passband of the amplitude characteristic and the 90° phase angle point of the phase shift characteristic almost match, by aligning the center of the passband of the amplitude characteristic with the fundamental frequency, the phase angle at this fundamental frequency can also be set to 90'. It can be done. Therefore, when used as a discriminator of an FM demodulation circuit, good detection characteristics can be obtained by itself.

Moreover, the piezoelectric resonator 1 of this embodiment has each extraction electrode 8 to 1.
Since the pattern No. 3 is rationally formed, a desired connection can be obtained by simply applying the conductive paste 14 at two locations, contributing to an improvement in device productivity.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a piezoelectric resonator used in an embodiment of the present invention, Fig. 2 is a diagram showing an adhesive coating pattern on one substrate of the piezoelectric resonator, and Fig. 3 is a front view of the piezoelectric resonator. 4 are front views of the same piezoelectric resonator after being packaged. 1-piezoelectric resonator, 2-3-terminal piezoelectric vibration element, 3-adhesive, 4-substrate, 5-first divided electrode, 6-second divided electrode, 7-common electrode,
8-Common extraction electrode, 9-External common extraction electrode, 10.12-First division extraction electrode, 11.13-Second division extraction electrode, 14-Conductive paste (conducting means), 15 IN terminal, 16-OUT terminal , 17-GND terminal.

Claims (1)

[Claims] (1) Forming a first divided electrode on one end side and a second divided electrode on the other end side by side approximately at the center of the surface of the substrate,
In a piezoelectric resonator, two 3-terminal energy confinement type, thickness vibration mode, 3-terminal piezoelectric vibrating elements with a common electrode formed almost in the center of the back surface are bonded together with adhesive so that the common electrode sides overlap. They are arranged so that they face each other, and a common extraction electrode connected to the common electrode is drawn out to the upper end of one end side of each back surface. A first electrode forming an external common extraction electrode and connected to the first divided electrode.
A split splitting electrode is formed by being drawn out to the upper end of the other end side, and a second splitting splitting electrode connected to the second split electrode is further drawn out to the lower end of the other end side, and on the surface of the other substrate, A first split electrode connected to the first split electrode is formed by being drawn out to the lower end of the center, and a second split electrode connected to the second split electrode is drawn out to the upper end of the other end. , Moreover, the two substrates are bonded together by applying adhesive, leaving only the top end of one end of the back surface, and each drawer is formed on the front and back surfaces of one board and the back surface of the other board at the top end of the one end. The electrodes are connected by a conductive means, and the lead electrodes formed on the surfaces of both substrates at the upper end of the other end are connected by the conductive means, and IN, A piezoelectric resonator characterized in that an OUT terminal is connected and a GND terminal is connected to an extraction electrode at the lower end of the center of the other substrate.