JPS59212015A - Piezoelectric filter and its manufacture - Google Patents

Abstract

PURPOSE:To reduce the size of a piezoelectric filter and to facilitate its manufacture by holding a ceramic oscillator on a base in three dimensions. CONSTITUTION:Two blocks 20A and 20B are used in combination to form the base; and surfaces 38 and 45 for leading out earth lines are provided at symmetrical positions on a separation-line side, and an input lead-out surface 33 and an output lead-out surface 48 are provided outside surfaces of the blocks 27 and 28. Respective lead-out surfaces are parts of lead-out electrodes 25B, 23, and 24. The respective lead-out electrodes are formed of a lead frame 65 expanded in plane during manufacture, both blocks 20A and 20B are positioned thereupon, and the ceramic oscillator 21 to which a coupling line 40 and a lead line 36 are soldered is mounted on them and soldered to respective lead-out electrodes 38, 46, 33, and 48. Then, the lead frame is bent at the center part, and a frame part 60 is cut away. Further, a link part 26 has a groove 66, which facilitates the bending.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piezoelectric filter that is small and easy to assemble using a rectangular piezoelectric vibrator, and a method for manufacturing the same.

A conventional piezoelectric filter of this type having a 1 νU is shown in plan view in FIG. An input derivation tm and an output derivation electrode are provided on one side of a flat insulating frame 10 provided with a punched portion 2, and an earth derivation electrode 3 is provided on the curved surface, and in the punched portion 2 of this frame 1, Two short fence-shaped seven-arm vibrators 4 are arranged side by side, and one electrode of each ceramic vibrator 5 is connected to an input lead-out electrode and an output lead-out electrode by a reed cape 5, respectively. A connector wire 7 in which the vibrator 40 and the Ikegata electrode 6 are connected to the shearth deriving electrode 3 across the punched portion 2
They are fixed and connected to each other on top.

Reference numerals 8, 9, and 10 are external connection terminals connected to respective electrodes of the frame body 1 through the handles 11.

In FIG. 1, an input derivation electrode and a neutral force derivation electrode are provided on the back surface of the frame and body 1. Furthermore, the ceramic vibrator 4 is of a two-terminal type, and electrodes 6 are provided on the front and back surfaces, and performs longitudinal vibration. Furthermore, the coupler wire 7 serves to fix the ceramic vibrator 4 and to transmit the s'''1m motion.

However, this type of piezoelectric filter has a flat shape, and since the frame 1 must be provided with a punched portion 2 to hold the ceramic vibrator 4 in the same plane as the frame 1, it has the disadvantage that the shape becomes large in plane. There is.

An object of the present invention is to provide a piezoelectric filter having a structure for three-dimensionally holding a piezoelectric vibrator and a method for manufacturing the same, and to solve the conventional drawbacks.

In the present invention, two rectangular blocks of synthetic resin whose bases are separable are put together, and each block is grounded at a symmetrical position on either the side surface on the separation line side or the side surface on the side opposite to the separation line. Derivation electrodes, input and output derivation electrodes are buried in blocks and exposed at symmetrical positions on the remaining side surfaces, and multiple strip-shaped piezoelectric vibrators bend one electrode into a U-shape. It is fixed on the base by connecting both ends of the coupler wire to the earth lead-out electrode, and the electrodes of the piezoelectric vibrator on the input and output sides are connected to the input and output lead-out electrodes. The invention provides a piezoelectric filter and a method for manufacturing the same, characterized in that the filters are connected to each other by lead wires.

The following are figures 2 to 7 showing embodiments of the piezoelectric filter of the present invention.
This will be explained with reference to the figures. Figure 2 is an exploded perspective view.
Figures 3 and 4 are exploded perspective views of the base, Figures 5 and 6,
FIG. 7 is an assembly plan view and an assembly front view V1 assembly side view, respectively. In FIGS. 5 to 7, only the case is shown in cross-section. In Figures 2 to 7, 20 is the base, 2
1 is a rectangular ceramic resonator, 22 is a synthetic resin case, '23 is an input lead-out electrode, 24 is an output lead-out electrode,
25A and 25B are ground lead-out electrodes.

The base body 20 is constructed by combining two square blocks 20A and 20B made of synthetic resin.
Reference numeral 26 denotes a connecting portion that is integrally formed across the separation line 29 between the upper surface 27 of the block 2OA and the upper surface 28 of the block 20B. In FIGS. 3 and 4, connecting parts are omitted for ease of understanding, but the base body 20 is shown in a separated state from different viewing directions.

A substantially L-shaped output lead-out electrode 24 that also serves as a terminal is buried in the block 20A, and the terminal portion 30 thereof is exposed from top to bottom along the side surface 31 on the separation line 29 side. It protrudes from the bottom surface 62. Output derivation electrode 2
The upper side of the terminal portion 4 is bent into a crank shape within the block 2OA, as indicated by the dotted line, and forms a flat surface 33 that is different in step from the terminal portion 30. The flat surface 33 is exposed in a recess 35 formed in a side surface 34 of the block 2OA opposite to the separation line 29 side. The recess 35 is narrow at the bottom to facilitate positioning of the lead wire 36, but the flat surface 33 is exposed at the wide upper portion. Also block 20
A ground lead-out electrode 25A is buried in A, and a terminal portion 37 is exposed from top to bottom along the side surface 31, but is cut off just below the bottom surface 32. The upper side of the grounding pole 25A is also bent into a crank shape within the block 2OA to form a flat surface 38 that is different in step from the terminal portion 37. The flat surface 38 is the recess 3 formed in the side surface 31.
It is exposed within 9. The lower portion of the fourth portion 39 is also narrowed to facilitate positioning of the connector wire 40, and the flat surface 38 is exposed at the upper wide portion. flat surface 38, flat surface 56
are placed side by side with their positions shifted from each other, and the distance between the exposed surfaces is the electrode 41 on the front and back of the ceramic vibrator 210.
It is the same as the interval between. Further, although the heights of the flat surfaces 38 and 33 are lower than the height of the block 2OA, their thick portions are exposed on the upper surface 27.

An approximately L-shaped earth lead-out condolence wire [125B] which also serves as a terminal is buried in the block 20B, and the terminal portion 42 is exposed from top to bottom along the side surface 43 on the side of the separation line 29, and is further exposed from the bottom surface 44. It stands out. The upper side of the earth lead-out condolence wire 125B is a block 20 as shown by the dotted line.
The reed is bent into a crank shape within B to form a flat surface 45 that is different in step from the terminal portion 42. The flat surface 45 is exposed within a recess 46 formed in the side surface 43. Recess 4
6 is narrow at the bottom so that the connector wire 40 can be easily positioned, but the flat surface 45 is exposed at the wide upper part. Further, an input lead-out electrode 23 which also serves as a terminal is buried in the block 20B, and a terminal portion 47 is exposed halfway down along the side surface 43 and protrudes from the bottom surface 44.

The input lead-out electrode 23 is bent twice at right angles within the block 2DB, forming a flat surface that is different in step from the terminal portion 47. The flat surface 48 is the side surface 4 opposite to the side surface 43.
It is exposed in a wide part within the recess 50 formed at 9.

The flat surfaces 48 and 45 are juxtaposed with their positions shifted from each other, and the distance between the exposed surfaces is the same as the distance between the parallel surfaces. Further, the heights of the flat surfaces 48 and 45 are lower than the height of the block 20B, but their thick portions are exposed on the upper surface 28.

Then, bend the connecting portion 26 to form the base 2 as shown in FIG.
0, a recess 5 is formed at a symmetrical position along the separation line 29.
9 and a recess 46, and a recess 50 and a recess 35 are located at opposite sides of the separation line 29, that is, at symmetrical positions between the side surface 49 and the side surface 34. The terminal portions 37 and 30 that were exposed on the side surface 31 along the separation line 29, and the terminal portions 47 and 42 that were exposed on the side surface 43 are hidden within the base body 20 except for the portions protruding from the bottom surface. This 9 flat surface 3 of the base 20
8 and the flat surface 45 are connected to both ends of a U-shaped joint wire 40, and a lead wire 36 is connected to the flat surface 35 and the flat surface 4.
is connected. Further, two ceramic vibrators 21 are sandwiched between a coupler wire 40 and a lead wire 36 on both sides of the separation line 29, and their front and back electrodes 41 are connected to the coupler wire 40 and the lead wire 36, and the base 20 fixed on top.

A case 22 is placed over the base body 20, and a stepped portion 51 is formed inside the case 22.
0 end to create a space around the ceramic vibrator 21.

The case 22 serves to protect the ceramic vibrator 21 and its fixed parts and also to press the sides of the base 20 to prevent it from separating.

In this way, the configuration of the piezoelectric filter of the present invention as shown in FIGS. 5, 6, and 7 in which the piezoelectric vibrator 21 is three-dimensionally supported on the base 20 can be obtained.

Next, the eighth example shows the method for manufacturing a piezoelectric filter of the present invention.
This will be explained with reference to the plan views shown in FIGS.

First, as shown in Fig. 8, the flat surface 38 and the flat surface 5' are
5. A lead frame 65 is prepared, which is formed by forming a set of leads 61, 62, 63, and 64, each of which has a flat surface 45 and a flat surface 48 parallel to the frame 60. The leads 61 and 62 are a pair and extend from the frame 60 on one side to the center of the lead frame 65, and the flat surfaces 38 and 33 are arranged side by side with their positions shifted from each other. Lead 6! I and the lead 64 are another pair and extend from the opposing frame 60 to the center of the lead frame 65.
The plane 45 and the flat surface 48 are arranged side by side with their positions shifted from each other. The flat surface 38 and the flat surface 45 and the flat surface 63 and the flat surface 48 face each other at the same height.

Next, as shown in Fig. 9, lead 61, lead 62, lead 6
5 and lead 64 are molded in pairs as a pro, a block 2OA, and a block 20B.

The side of each lead that connects to the frame 60 is protruded from the block 2OA, the flat side is the block 2OA, and the flat side is the block 2OA.
A and buried in block 20B. However, the flat surface 33
' and the flat surface 48 are scattered within the concave portion 35 and the concave portion 50°, respectively, and the flat surface 38 and the flat surface 45 are also not visible, but are exposed within the concave portion 39 and the concave portion 46 on the opposite side by 5°, respectively. Also, a connecting portion 26 connects block 2OA and block 20B at the center.
is also formed at the same time. Although this connecting portion 26 is not essential to the present invention, if it is designed to form this connecting portion 26, it is sufficient to provide only one gate in the mold for injecting synthetic resin during molding. This is convenient because there is no need to provide a separate one for 20B. A groove 66 is formed in the center of the connecting portion 26, which makes it easy to bend the connecting portion 26.

Furthermore, as shown in FIG. 10, two ceramic vibrators 21 are placed between the blocks 20A and 20B, and the electrodes 41 on the front and back are connected to each lead via the straight connector wire 40 and the lead wire 36. Connecting. Specifically, the recess 3 that is not visible when the lead frame 65 is turned over.
9 and the recess 46 and soldered to the flat surfaces 38 and 45. Furthermore, the connector wire 40 is also soldered to the electrode 41 of the ceramic resonator 210. Next, as shown in FIG. 10, with the lead frame 65 facing up, the two lead wires 36 are soldered to the flat surface 48 and the electrode 41, and to the flat surface 33 and the electrode 41, respectively. Here, lead 61 and lead 63
will later become electrode 25A for grounding (b) and electrode 25B for grounding, but the base 2
Lead 6 because only one side needs to actually protrude outside of 0.
1 should be cut short along the dotted line. Then, the base body 20 is formed by bending the lead frame 65 around the dotted line in the center until the side surfaces of the blocks 20A and 20B come into contact with each other as shown in FIG. At this time, the connector wire 40 is also bent into a U-shape. Then, after covering and fixing the case 22 as shown by the dashed line in FIG. The piezoelectric filter is completed.

As described above, the piezoelectric filter of the present invention is configured such that the ceramic vibrator 21 is held three-dimensionally on the base 20. It is sufficient that the base body 20 has a height sufficient to position the ceramic vibrator 21 to such an extent that its vibrations are not inhibited, and the terminal portions of the electrodes protrude perpendicularly to the length direction of the ceramic vibrator 21 on the lower side. . The planar spacing between the ceramic vibrators 21 is determined by the degree of curvature of the U-shaped curved portion of the connector wire 40, but the spacing between both ends of the connector m40 is determined by curving the ceramic vibrator 21 largely to the extent that vibration transmission is not inhibited. By narrowing the distance between the flat surfaces 38 and 450, the two-dimensional distance between the ceramic vibrators 21 can be narrowed. Therefore, the terminals are located parallel to the ceramic vibrator, and the piezoelectric filter is much smaller than the conventional piezoelectric filter, which has a large planar width. Furthermore, in the piezoelectric filter of the present invention, the base 2o
is constructed by combining two blocks 2OA and 20B. Each electrode also serves as a terminal and is buried therein. Therefore, it can be easily manufactured using the lead frame 65 as described in the manufacturing method. In particular, the connector wire 40 and the lead wire 36 are connected with the lead frame 65 placed on a flat surface as shown in FIG. 36 is also straight when connected, and the connection work is easy. There is no need to connect thermal terminals. The present invention, which has many excellent effects as described above, is not limited to the examples. For example, the case where only two ceramic vibrators 21 are used has been described, but when connecting a vibrator other than the input side and output side vibrators, connect only one electrode of the vibrator to the coupler wire 40 and connect it to the input side. It may be held horizontally above the transducer on the output side. The terminal portions 37, 30 and 42, 47 of the electrodes are connected to the side surface 31 of the block 20A on the separating line side and the block 20, respectively.
Of course, the block 2O is exposed on the side surface 43 on the separation line side of B, and the thick part of the electrode is exposed on the top surface 27 and the top surface 2.
A and block 20B. Moreover, the flat surface 38 and the flat surface 45 of the earth lead-out electrode are respectively connected to the block 2OA.
The side surface 31 on the separation line side of block 20B and the side surface 43 on the separation line side of block 20B have fins, and the flat surface 36 of the output derivation electrode and the flat surface 48 of the input derivation electrode are respectively opposite to the separation line side of block 2OA. Although the ground lead-out electrode is exposed on the side surface 34 of the block 20B and the side surface 49 opposite to the separation line side, the ground lead-out electrode may be exposed on the side surface 34 and side surface 49 opposite to the separation line side. None of these depart from the scope of the present invention.

[Brief Description of the Drawings] Fig. 1: A plan view showing a conventional piezoelectric filter, Fig. 2: An exploded perspective view showing an embodiment of the piezoelectric filter of the present invention, Figs. Disassembled perspective view, Fig. 5g Assembly component side view, Fig. 6: Assembly front view, Fig. 7: Assembly side view, Fig. 8, Fig. 9,
FIGS. 10 and 11: Plan view showing an embodiment of the manufacturing method of the present invention 20: Substrate, 20A and 20B: Block. 21: Ceramic resonator, 22; Case. 23: Input derivation electrode, 24 + output derivation electrode,
25A/25B = Earth lead-out electrode. 26: Connecting part, 27/28: Top surface, 29: Separation part,
30・37・42・47; Terminal part. 31, 34, 43, 49: Side, 32, 44: Bottom,
63.38.45-48: Flat surface. 35, 39, 46, 50: Concave, 66: Reed gentleman,
40B conjugate wire, 41: Electrode. 51: Step part, 60; Frame, 61, 62, 63, 64
: Lead, 65: Lead frame. 66: Groove Patent applicant Toko Co., Ltd. Haku 2
Figure 4 RO 6 Figure 7 Figure 6U Figure 8 5 (C. 2 0A36B 8 6υ Figure 9 II II Ml QT I 1%
10 Figure

Claims (2)

[Claims] (1) The base is made up of two square blocks of synthetic resin that can be separated and is grounded at a symmetrical position on either the side of each block on the side of the separation line or the side of the side opposite to the separation line. Derivation electrodes, input and output derivation electrodes are buried in blocks and exposed at symmetrical positions on the sides of the remaining board, and a plurality of strip-shaped piezoelectric vibrators are one of them.
One electrode is connected to a U-shaped coupler wire, and both ends of the coupler wire are connected to ground lead-out electrodes, thereby fixing the piezoelectric vibrator on the input and output sides. A piezoelectric filter characterized in that the other electrode is connected to the input and output deriving electrodes by lead wires, respectively. (2) preparing a lead frame in which two pairs of leads extend toward the center from the opposing frame, each having a pair of leads having different levels of surfaces parallel to the frame and the surfaces juxtaposed to each other;
The sides connected to the frame of the leads are made to protrude, and at least the surfaces with different steps are exposed, and each pair of leads is molded with the two pairs of leads connected at the center, and a plurality of strip-shaped piezoelectric vibrations are produced. After positioning the lead frame between the molded bodies and connecting the front and back electrodes to different surfaces using the connector wire and the lead wire, bend the lead frame and bend the connector wire together with the connecting part into a U shape. A method for manufacturing a piezoelectric filter, which comprises bringing one side of the molded body into contact with each other, placing a case over the molded body, and then cutting and separating the leads from the frame.