JPS632410A - Manufacture of piezo-resonator - Google Patents

Abstract

PURPOSE:To efficiently manufacture a piezo-resonator, by forming solder layers on the surface of the 1st and 2nd drawn-out sections of plural chips and respectively connecting a pair of divided electrodes with a pair of 1st terminals and a common electrode with the 2nd terminal. CONSTITUTION:On one main surface of a master substrate 13 plural 1st drawn- out sections 20a and 20b are formed in such a state that they are respectively extended outward from divided electrodes 16a and 16b and, on the other main surface, plural drawn-out sections 22a and 22b are formed from a common electrode 18 to the vicinity of the end sections of the base plate 13 in its width direction. Then solder layers 21a and 21b and 23a and 23b are respectively formed on the surfaces of the wide width sections of the drawn-out sections 20a and 20b and 22a and 22b. Therefore, when the solder layer of each drawn- out section is heated, the pair of divided electrodes 16a and 16b are electrically connected with the pair of 1st terminals 24 and 26 and the common electrode 18 with the 2nd terminal 28, respectively. When the solder layers are formed on the surfaced of the drawn-out sections before connecting the filter elements to the terminals in such way, a piezo-resonator can be manufactured efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method of manufacturing a piezoelectric resonator, and particularly to a method for manufacturing a piezoelectric resonator, for example, a filter having a tanzag-shaped piezoelectric substrate.

The present invention relates to a method of manufacturing a piezoelectric resonator used as an oscillator, a discriminator for an FM detection circuit, etc.

(Prior Art) An example of a conventional filter that forms the background of the present invention is disclosed in, for example, Japanese Utility Model Application Publication No. 180132/1983.

The filter disclosed in this publication is manufactured by first preparing a terminal and a filter element that are integrally molded in a case, and then connecting the drawer part of the filter element to the terminal with a conductive bonding material. be done.

(Problems to be Solved by the Invention) In such conventional methods, since the drawn-out portion of the prepared filter element is a minute portion, it is necessary to apply a conductive bonding material such as conductive paste to that portion. Soldering was difficult and complicated, and mass production was poor.

Therefore, the main object of the present invention is to provide a method for manufacturing a piezoelectric resonator that can efficiently manufacture a piezoelectric resonator.

(Means for Solving the Problems) This invention provides a step (a) of preparing a rectangular piezoelectric substrate.
), a step (b) of forming a pair of parallel divisions spaced apart from each other from one end to the other end of one main surface of the piezoelectric substrate; Step (C) of forming a plurality of first lead-out portions extending outward from the electrode, and Step (d) of forming a common electrode facing the pair of divided electrodes on the other main surface of the piezoelectric substrate.
), and each of them is spaced apart from the common electrode to the first
(e) forming a plurality of second lead-out parts extending in the same direction as the lead-out parts; and forming a solder layer on the surface of each of the plurality of first lead-out parts and each of the plurality of second lead-out parts; step (f) of separating the piezoelectric substrate into a plurality of chips such that each chip includes a pair of corresponding first draw-out portions and a corresponding one second draw-out portion; step (g) of preparing a pair of first terminals to be connected to the pair of split electrodes and a second terminal to be connected to the common electrode; The method for manufacturing a piezoelectric resonator includes a step (i) of connecting a pair of first terminals and a second terminal to a pair of divided electrodes and a common electrode of a chip, respectively.

(Function) A solder layer is formed on the surfaces of the first lead-out portion and the second lead-out portion of the plurality of chips at once. Furthermore, this solder layer connects a pair of divided electrodes and a common electrode to a pair of first and second electrodes.
and the second terminal are respectively connected.

(Effects of the Invention) According to the present invention, a solder layer is formed on the surfaces of the first lead-out part and the second lead-out part of a plurality of chips at once, and the solder layer forms a pair of divided electrodes and a common electrode. and 1
Since the first and second terminals of the pair are connected to each other, a conductive bonding material such as a conductive paste is individually applied to the lead-out portions of the divided electrodes and the common electrode of each chip. There is no need for soldering or soldering using a soldering iron, so piezoelectric resonators can be manufactured efficiently.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Embodiment) FIGS. 1A to 1C are perspective views showing steps of an embodiment of the present invention. In this embodiment, a method for manufacturing a filter as an example of a piezoelectric resonator will be described in particular, but it should be pointed out in advance that the present invention can also be applied to a method for manufacturing other piezoelectric resonators such as an oscillator.

First, as shown in FIG. 1A, a rectangular parent substrate 13 made of, for example, piezoelectric ceramic and to serve as a piezoelectric substrate for a plurality of filter elements is prepared. This parent board 13 has a rectangular shape with a short side and a long side, the short side having approximately the same length as the length in the longitudinal direction of the filter element, and the long side in the width direction of the filter element. For example, it has a length several times to several tens of times the length.

On one main surface of the parent substrate 13, as shown in FIG. 1B, a pair of divided electrodes 16a and 16b are formed in parallel and spaced apart from one end to the other. In this case, a pair of divided electrodes 16a and 16
b is formed at the center portion of the parent substrate 13 in the width direction.

Furthermore, a plurality of first lead-out portions 20a and 20b are formed on one main surface of the parent substrate 13, extending outward from the divided electrodes 16a and 16b, respectively. In this case, the plurality of first lead-out portions 20a and 20b are formed to be spaced apart from each other in the longitudinal direction of the parent substrate 13 by a length that is approximately the same as the length in the width direction of the filter element. Moreover, each first drawer part 20a and each first drawer part 20b are formed on the same straight line. Note that the ends of each of the first drawer portions 20a and 20b are wide, respectively!
! It is formed to extend continuously at the width direction end portion of the substrate 13.

Further, on the other main surface of this parent substrate 13, as shown in FIG. 1C, a common electrode 18 is provided with divided electrodes 16a and 16.
It is formed so as to be opposed at the same time as b. That is, the common electrode 18 is formed at the center in the width direction on one main surface of the parent substrate 13 from one end to the other end.

Furthermore, a plurality of second lead-out portions 22a and 22b are formed on the other main surface of the parent substrate 13, each extending from the common electrode 18 to near the end of the parent substrate 13 in the width direction. In this case, the respective second drawer portions 22a and 2
2b are formed at intervals of the same length as the length in the width direction of the filter element, and are shifted in the longitudinal direction of the main board 13 from the first pull-out parts 20a and 20b when viewed from above. It is formed. Furthermore, each of the second pull-out portions 22a and each of the second pull-out portions 22b are formed on the same straight line. In addition, each second drawer part 2
The end portions of the second pull-out portion 2a and the second pull-out portion 22b are each formed to extend in a wide series.

Solder layers 21a and 21b and 23a and 23b are formed on the surfaces of the wide portions of the first lead-out parts 20a and 20b and the second lead-out parts 22a and 22b, respectively. In this case, solder layers 21a, 21b,
23a and 23b are the drawer parts 20a, 20b, 22a
It is formed by applying, for example, paste solder or cream solder to the wide portions of 22b and 22b, and then heating and melting the cream solder.

Then, the parent board 13, for example in FIG.
A plurality of chips, that is, filter elements 12 (FIGS. 2A and 2B) are separated by a portion indicated by line A-A in FIG. (as shown in the figure).

This filter element 12, as shown in particular in FIGS. 2A and 2B, includes a tanzaku-shaped piezoelectric substrate 14 made of, for example, piezoelectric ceramic. A pair of divided electrodes 16a and 16b are formed at intervals in the direction, and a common electrode 18 is formed on the other main surface simultaneously facing the divided electrodes 16a and 16b.

Further, on one main surface of the piezoelectric substrate 14, a negative first lead-out portion 20a is formed extending from the divided electrode 16a to one end in the longitudinal direction of the piezoelectric substrate, and the other first lead-out portion 20b is formed as a divided portion. It is formed extending from the electrode 16b to the other end in the longitudinal direction of the piezoelectric substrate. Note that these first lead-out portions 20a and 20b are formed wide at the ends of the piezoelectric substrate 14. Further, the narrow width portions of the first lead-out portions 20a and 20b are formed near one end of the piezoelectric substrate 14 in the width direction.

Further, on the other main surface of the piezoelectric substrate 14, as shown in FIG. 2B, two second lead-out portions 22a and 22b are provided.
They are formed extending from both ends of the common electrode 18 to both ends of the piezoelectric substrate 14 in the longitudinal direction. It should be noted that these second pull-out parts 22a and 22b are disposed between the widths of the first pull-out parts 20a and 20b when viewed in plan, and have wide end portions. In addition, the second drawer section 22
The narrow width portions a and 22b are formed near the other end of the piezoelectric substrate 14 in the width direction.

In addition, solder layers 21a, 21b are provided on the surfaces of the wide portions of the respective lead-out portions 20a, 20b, 22a, and 22b.
, 23a and 23b are formed, respectively.

Furthermore, the divided electrode 16a of this filter element 12
and the first terminals 24 and 2 to be connected to 16b
6 and a second terminal 28 to be connected to its common electrode 18
is prepared. In this case, the first terminals 24 and 26
and second terminal 28 are prepared, for example, by preparing a lead frame 30 as shown in FIG. This lead frame 30 includes a second terminal 28,
The second terminal 28 includes a planar rTJ-shaped lead portion 28a. Both ends of this lead portion 28a are formed as bent portions 28b and 28c. In addition, these bent portions 28
b and 28c are formed to face each other with substantially the same distance as the wide portion of the second drawer portions 22a and 22b. This second terminal 28 is formed extending upwardly from the metal frame 32.

Furthermore, the first terminals 24 and 26 are connected to the second terminal 28
The metal frame 32 is formed to extend upward from the metal frame 32 in parallel at a predetermined interval on both sides of the metal frame 32 . Accordingly, the first terminals 24 and 26 and the second terminal 28 are integrally formed extending from the metal frame 32 and configured as a lead frame 30.

The - side first terminal 24 includes a tanzaku-shaped lead portion 24a, and a bent piece 24b is formed extending from the tip side of the lead portion 24a in a direction perpendicular to the main surface of the lead portion 24a. . Similarly, the other first terminal 26 includes a tanzaku-shaped lead portion 26a, and a bent piece 26b is formed extending from the tip side in a direction perpendicular to the main surface of the lead portion 26a. . In this case, the bent portions 24b and 26b are formed on the outside of the first terminals 24 and 26 so as to face each other with an interval substantially the same as the length of the piezoelectric substrate 14 in the longitudinal direction.

This lead frame 30 is formed, for example, by punching out a single metal plate and then bending the necessary portions.

As shown in FIGS. 4A to 4C, the filter element 12 is attached to the lead frame 30 in the thickness direction by the elastic force of the first terminals 24 and 26 and the second terminal 28. The first terminals 24 and 26 are sandwiched between the bent pieces 24b and 26b of the first terminals 24 and 26 in the longitudinal direction. In this case, the first terminals 24 and 26 are connected to the solder layers 21a and 21b of the first lead-out parts 20a and 20b, and the bent parts 28b and 28c of the second terminal 28 are connected to the solder layers 21a and 21b of the two second lead-out parts 22a and 22b. are arranged so as to be in contact with the solder layers 23a and 23b, respectively.

Further, in this case, the second terminal 28 is arranged to straddle the common electrode 18. Therefore, in this state, the first terminals 24 and 26 and the second terminal 28 are positioned relative to the filter element 12 or the piezoelectric substrate 14. Note that if the two bent portions 28b and 28c of the second terminal 2 are formed close to the first terminals 24 and 26, respectively, the first terminals 24 and 26 and the second terminals provided to the filter element 12 are connected to each other. The stress caused by the second terminal 28 can be reduced. Therefore, even if the elastic force between the first terminals 24 and 26 and the second terminal 28 becomes large, the filter nimber 12 does not easily break.

Furthermore, by heating the solder layers 21a and 21b and 23a and 23b of the filter element 12, the lead portions 24a and 26a of the first terminals 24 and 26 are attached to the wide portions of the first lead-out portions 2°a and 20b. , the bent portions 28b and 28c of the second terminal 28 are connected to the two second lead-out portions 22a and 22b, respectively.

Thereby, the first terminals 24 and 26 and the second terminal 28 are connected to the divided electrodes 16a and 16b and the common electrode 18.
are electrically connected to each other and fixed to the filter element 12. In this case, each terminal 24.
Since 26 and 28 are positioned relative to the filter element 12, they will not be misaligned. Moreover, the drawer portions 20a, 20b of the filter element 12,
A solder layer 21a, 21 is applied on the surface of 22a and 22b in advance.
b, 23a and 23b are formed, so a conductive bonding material such as a conductive paste or the like is applied to the parts of the drawn-out parts 20a, 20b, 22a and 22b to be connected, or soldering is performed with a soldering iron. There's no need.

Further, the filter element 12 to which the terminals 24, 26 and 28 are attached is provided with a sheathing material (not shown), for example, by resin dipping or casing. and terminals 24, 26 and 2
8 is separated from the metal frame 32 to complete the filter 10.

The height of the completed filter 10 is, for example, 4 to 5.
It was formed relatively thin as fl. This is terminal 24.
This is because no other parts are used for positioning 26 and 2, so the structure can be made simple. In this way, this embodiment allows for reduction in height and size. Moreover, since no other parts are used when positioning the terminals, costs can be reduced.

Note that in this filter 10, a solder layer is formed in advance on the surfaces of the first and second lead-out parts of the filter element, and then the lead-out parts (electrodes) and the terminals are connected by this solder layer. With conventional filters, the width of the part to be connected had to be made relatively large (1.511 mm) in order to apply conductive paste or solder after preparing the filter element. However, it can be formed very small, for example, 0.2 fl. Therefore, in order to stabilize the electrical characteristics of the filter, the parts of the drawer that should be connected are
It can be formed at a position sufficiently separated from the divided electrodes and the common electrode.

In addition, in this filter 10, the second terminal 28 has two bent portions 28b and 28c connected to the two second lead-out portions 22.
a and 22b, the common electrode 1
It will be connected to 8.

Therefore, even if one of the two bent portions 28b and 28c of the second terminal 28 is disconnected, the second terminal 28 remains connected to the common electrode 18 by the other connection. be able to.

Therefore, in this filter 10, the connection reliability of the terminal can be improved compared to a filter in which the terminal and the common electrode are connected only at one place. Therefore, processing yield can be improved.

Furthermore, in this filter 10, since the divided electrodes 16a and 16b of the filter element 12 and the common electrode 18 are formed symmetrically, the three terminals 24, 26
The same characteristics can be obtained no matter which side of the width direction the filter element 12 and 28 are drawn out from. Therefore,
In this filter 10, when positioning the filter element 12, there is no need to worry about its direction.

In addition, in the above-mentioned embodiment, the first drawer part 20a on one side and the first drawer part 20b on the other side of the filter element 12 are replaced by the second drawer part 22a on the negative side and the second drawer part 2 on the other side.
2b are respectively formed on a straight line, but in this invention, as shown in FIGS. 5A and 5B to 6A and 6B, for example, the , the second drawer portions 22a and 22b may be formed in a staggered manner.

5A and 5B respectively show modifications of the filter element shown in FIGS. 2A and 2B,
FIG. 5A is its top view, and FIG. 5B is its back view. In this filter element 12, in particular, the narrow portion of the first lead-out portion 20a on the negative side is formed near the other end in the width direction of the piezoelectric substrate 14, and the second lead-out portion 20a on the negative side is formed near the other end in the width direction of the piezoelectric substrate
A narrow portion 2a is formed near one end thereof, and the overall shape is rotationally symmetrical by 180 degrees. Therefore, this filter element 12 can be attached to a lead frame 30, for example.
(Fig. 3), the direction does not matter.

6A and 6B show other modifications of the filter element shown in FIGS. 2A and 2B, respectively, with FIG. 6A being a top view thereof and FIG. 6B being a back view thereof. . In particular, in this filter element 12, the narrow width portion of the other first drawer portion 20b is formed near the other end in the width direction of the pressure 1 substrate 14, and further, the narrow width portion of the other second drawer portion 22b is formed near the other end in the width direction of the pressure 1 substrate 14. is formed near one end thereof, and is formed in a 180 degree rotationally symmetrical shape as a whole.

In order to manufacture an element as shown in FIGS. 5A and 5B to 6A and 6B, for example, in the method for manufacturing a filter element shown in FIGS. 1A to 1C, the first drawer What is necessary is just to form 20a and 20b and the 2nd pull-out part 22a and 22b in a shape shifted, respectively, instead of being formed on a - straight line.

In this way, the narrow width portion of the drawer portion of the filter element 12 may be formed by changing its position.

Further, in the above-described embodiment, the bending portion 28 is provided on the second terminal 28.
b and 28c, but as shown in FIGS. 7A and 7B, for example, the second terminal 28 has a bent portion 2.
8b and 28c may not be formed.

7a and 7B respectively show modifications of the main parts of the filter shown in FIGS. 4A to 4C;
Figure A is a perspective view thereof, and Figure 7B is an illustrative view thereof. In this filter 10, in particular, FIGS. 5A and 5B
The filter element 12 shown in the figure is used, and further,
Bent parts 28b and 28C on the second terminal 28 (Fig. 3)
is not formed. This second terminal 28 is
It is suspended from the common electrode 18 so as to straddle the common electrode 18, and its both ends are connected to the second lead-out parts 22a and 22b by solders N23a and 23b, respectively. In this way, if the bent portions 28b and 28C (FIG. 3) are not formed on the second terminal 28, the second terminal 28
The manufacturing process of the terminal 28 can be simplified.

In each of the above-mentioned examples, a solder layer was formed only on the surface of the lead-out part of the filter element before connecting the filter element and the terminal, but another solder layer was also formed on the surface of the part of the terminal to be connected. A layer may be formed in advance. By forming another solder layer in this manner, the terminal and the filter element can be connected more reliably.

[Brief explanation of the drawing]

FIGS. 1A to 1C are perspective views showing the steps of an embodiment of the present invention. 2A and 2B show filter elements manufactured by the steps shown in FIGS. 1A to 1C, respectively; FIG. 2A is a top view thereof, and FIG. 2B is a back view thereof. . FIG. 3 is a perspective view showing an example of a lead frame for manufacturing a filter using the lead frame and the filter elements shown in FIGS. 2A and 2B. 4A to 4C show the main parts of a filter manufactured using the filter element shown in FIGS. 2A and 2B and the lead frame shown in FIG. 3, respectively.
Figure A is its plan view, and Figure 4B is the line ■B of Figure 4A.
Fig. 4C is a perspective view showing the upside down state. 5A and 5B respectively show modifications of the filter element shown in FIGS. 2A and 2B,
FIG. 5A is its top view, and FIG. 5B is its back view. 6A and 6B show other modifications of the filter element shown in FIGS. 2A and 2B, respectively, with FIG. 6A being a top view thereof and FIG. 6B being a back view thereof. . 7A and 7B respectively show modifications of the main parts of the filter shown in FIGS. 4A to 4C, and FIG.
The figure is a perspective view thereof, and FIG. 7B is an illustrative view thereof. In the figure, 10 is a filter, 12 is a filter element, 13 is a parent board, 14 is a piezoelectric substrate, 16a and 16
b is a divided electrode, 18 is a common electrode, 20a and 20b are first lead-out parts, 22a and 22b are second lead-out parts, 2
1a, 21b, 23a and 23b are solder layers, 24 and 26 are first terminals, 2nd are second terminals, 24a, 2
6a and 28a are lead parts, 24b and 26b are bent pieces, and 28b and 28c are bent parts. Patent Applicant Murata Manufacturing Co., Ltd. Agent Patent Attorney Oka 1) Zenkei (one idiot) Figure 1A Figure 4B Figure 4C Figure 5A No. ja 23b No. 7
B trap

Claims (3)

[Claims] (1) (a) a step of preparing a rectangular piezoelectric substrate; (b) a step of forming a pair of divided electrodes in parallel at intervals from one end to the other end of one main surface of the piezoelectric substrate; (c) forming a plurality of first lead-out portions spaced apart from each other and each extending outward from the pair of divided electrodes; (d) forming the pair of divided electrodes on the other main surface of the piezoelectric substrate; (e) forming a plurality of second lead-out portions spaced apart from each other and each extending from the common electrode in the same direction as the first lead-out portion; f) forming a solder layer on the surface of each of the plurality of first lead-out parts and each of the plurality of second lead-out parts; (g) forming a solder layer on the surface of each of the plurality of first lead-out parts; (h) dividing the piezoelectric substrate into a plurality of chips so as to include one lead-out part and one second lead-out part corresponding thereto; (h) one chip to be connected to the pair of divided electrodes; the first of the pair
and a second terminal to be connected to the common electrode, and (i) the solder layer connects the pair of divided electrodes and the common electrode of the chip to A method of manufacturing a piezoelectric resonator, the method comprising: respectively connecting a first terminal and a second terminal of the piezoelectric resonator. (2) The piezoelectric resonance according to claim 1, wherein the step (f) includes a step of applying solder paste to the surfaces of the plurality of first lead-out parts and the plurality of second lead-out parts. Method of producing children. (3) The step (h) includes the step of preparing a lead frame in which the pair of first terminals and the second terminal are integrally formed on the frame. Or the method for manufacturing a piezoelectric resonator according to item 2.