JPS63187908A - Composite trap - Google Patents

Abstract

PURPOSE:To curtail a work man-hour, to obviate a problem of electric conduction deficiency, and also, to miniaturize the titled trap, and to improve the work efficiency by placing in parallel a trap element which has been constituted by forming an electrode on a strip-like substrate. CONSTITUTION:A composite trap 1 is constituted of a first and a second trap elements f5, f6, and a strip-like piezoelectric vibration substrate 2 consisting of ceramics. On both end parts of the surface of the substrate 2, a lead electrode 3 is formed, and on the inside in the longitudinal direction of the substrate 2 from the electrode 3, a pair of the first vibration electrodes 4 are formed, and between the electrode 4 and the electrode 3, a lead wire part 5a for connecting both of them is formed. Also, in about the center part of the reverse side of the substrate 2, an earth electrode 6 is formed, and in a position opposed to the electrode 4 by placing the substrate 2 between, a pair of the second vibration electrodes 7 are formed, and between the electrode 7 and the electrode 6, a lead wire part 5b for connecting both of them is formed. In such a way, since the trap elements are provided in parallel, each trap element does not come into contact with each other, and a problem of electric conduction deficiency which has been caused by superposing them up to the present can be obviated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a composite trap that functions as a band elimination filter, and in particular can be miniaturized, easy to manufacture, and avoid low yield due to conductive defects. This paper relates to the structure of such a composite trap.

[Conventional technology]

Generally, a composite trap has a function of canting and not outputting only two target trap frequencies, for example, 4°5 MHz and 5.5 MHz, from the input frequency range. It is used as an electronic component to prevent audio signals from being mixed in.

Conventionally, as such a composite trap, for example, there is one shown in FIG. 7. In FIG. 0, reference numeral 20 is a composite trap. A pair of resonators f, , f, and electrodes formed on both ends of the resonators f and ti4 fa printed on the substrate 21 are arranged.
An external lead 23 is connected to the lead attachment electrode 22 at the bottom of the substrate 21 by solder 24, and the external lead 23 is made to protrude outward. It is constructed by covering parts with resin (not shown).

Further, as another conventional example, there is a composite trap as shown in FIG. This composite trap 30 has lead electrodes 32 formed on both edges of the surface of a substrate 3I, and the lead electrodes 32
A pair of first vibrating electric scrapers 33 are formed extending inward from the ground electrode 34, and a ground electrode 34 is formed at the upper center edge of the back surface (see FIG. 6). A trap element formed by forming a pair of second vibrating electrodes 35 extending to opposite positions with the substrate 31 in between! ,
, r, are arranged facing each other so that their ground electrodes 34 are close to each other.

Then, an external lead 36 is connected to both lead electrodes 32 of the trap element f by solder 37, an external lead 38 is connected to the ground electrode 34 on the back side, and the upper end of the trap element f, f is connected to the external lead 36. Both lead electrodes 32
They are connected to each other by a conductive paste 39, and both ground electrodes 34 are connected to each other by a conductive paste 40.

[Problem that the invention seeks to solve]

However, in the composite trap 20 shown in FIG. 7, four resonators f + and fx are arranged on the upper surface of the substrate 21.

In addition to requiring complicated assembly work to connect,
Soldering requires a large number of man-hours because there are 11 parts, and there is a problem in that production efficiency is low.

On the other hand, in the composite trap 30 shown in FIG.
A trap element r formed by forming.

Since f4 is configured to face each other, the complicated arrangement work as in the case of FIG. 7 can be omitted, and the number of soldering points can be reduced to approximately half, so productivity can be improved by reducing the number of man-hours.

However, in the composite trap 30 shown in FIG. 6, it is necessary to secure a portion to which the conductive paste is applied, and due to its structure, the substrate becomes large, and there is a problem that it cannot meet the recent demands for miniaturization.

Further, although the substrates are placed close to each other, it is difficult to accurately maintain this gap within a certain range, and in some cases, there is a problem that they may come into contact with each other due to mechanical vibration, resulting in poor conductivity.

An object of the present invention is to provide a composite trap that can be easily assembled in the dark, can meet the demand for miniaturization by having a structure that allows the trap element to be downsized, and can also solve the problem of poor conductivity. There is a particular thing.

[Means for solving problems]

The inventor of the present invention conducted intensive research to solve the above-mentioned conventional problems, and succeeded in developing a trap element in which electrodes are formed on a narrow strip-shaped substrate while maintaining the specified characteristics. did. That is, we have come up with the idea that by adopting this trap element, we can meet the above-mentioned demand for miniaturization, and if we arrange the trap elements in parallel, the elements do not touch each other, so that the above-mentioned conventional problems can be solved,
This invention has been made.

Therefore, in the present invention, lead electrodes are formed at both ends of the front surface of a rectangular piezoelectric vibrating substrate, and a pair of first vibrating electrodes are formed inside the lead electrodes in the longitudinal direction, and approximately at the center of the back surface of the substrate. A ground electrode is formed at the top of the trap element, and a pair of second vibrating electrodes are formed at a position facing the first vibrating electrode, and first and second trap elements are arranged in parallel with their respective surfaces facing the same side. However, the above 1. This composite trap is characterized in that a common external lead terminal and a common ground terminal are connected to each lead electrode and ground electrode of the second trap element, respectively.

[Effect]

According to the composite trap according to the present invention, since the trap elements each having an electrode formed on a strip-shaped substrate are arranged in parallel,
The elements do not come into contact with each other due to vibration, and the problem of poor electrical conductivity caused by conventional overlapping with gaps can be solved.

In addition, the trap elements were arranged in parallel, but the substrate itself was narrow strip-shaped, so it was different from the conventional one in which four elements are arranged in parallel as shown in Fig. 7, or the one in which the substrate itself is large as shown in Fig. 6. Compared to the case where they are stacked one on top of the other, it is possible to meet the demand for smaller size.

Furthermore, since it is only necessary to arrange the boards in parallel and connect each terminal, the soldering process requires less man-hours compared to the one shown in Fig. 7, and the required gap can be secured as in the one shown in Fig. 6. Difficult assembly work is not required, and as a result, work efficiency can be improved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

4 and 5 show a composite trap according to an embodiment of the present invention, in which f and f are the first and second parts of the composite trap of this embodiment. a second trap element,
2 is a rectangular piezoelectric vibrating substrate made of ceramics, for example. Lead electrodes 3 are formed at both ends of the surface of the substrate 2 (see FIG. 2 ia+), and a pair of first vibrating electrodes 4 are formed inside the lead electrodes 3 in the longitudinal direction of the substrate 2. A lead wire portion 5a is formed between the first vibrating electric scraper 4 and the lead electrode 3 to connect them.

A ground electrode 6 is formed approximately at the center of the back surface of the substrate 2 (see FIG. 2), and a pair of second vibration electrodes are formed at positions facing the first vibration electrode 4 with the substrate 2 in between. Electrode 7
A lead wire portion 5b is formed between the second vibrating electrode 7 and the ground electrode 6 to connect them.

In addition, the first one having the above configuration. Second trap element fs=
The pixel elements fh are arranged in parallel so that the surfaces of the pixel elements fs and fi are on the same plane, and a slight gap is provided between the elements fs and fa.

Furthermore, the above 1. A common lead terminal 8 is connected to each of the left and right lead electrodes 3 of the second trap elements fs, fh by solder 10, and a common ground terminal 9 is connected to each ground electrode 6 by solder 10. connected by.

Furthermore, the above 1. The second trap element f5°fh portion is covered with elastic silicone rubber 12 with each terminal 8.9 protruding, and the silicone rubber 12 is covered with exterior resin 11.

Next, the effects of this embodiment will be explained.

FIG. 4 shows an example of a measurement circuit for measuring the output characteristics of the composite trap 1 of this embodiment, and FIG. 5 shows the frequency and frequency of the composite trap 1 of this embodiment measured with the circuit of FIG. 4. It is a characteristic diagram showing the relationship with the amount of attenuation, and as is clear from the figure, when the predetermined trap frequency is 4.5 MHz and 5.5 MHz.
It can be seen that only 5MlI2 is canted.

The composite trap 1 according to this embodiment can ensure the above-mentioned output characteristics, and the lead 1i pole 3. Since the trap elements fs and h formed by the vibrating electrode 4.7 and the ground electrode 6 are arranged in parallel, the trap elements fs and fb do not come into contact with each other, which eliminates the conductive defects caused by conventional overlapping. can solve the problem.

In addition, since the trap elements r s and fh are formed by using a strip-shaped substrate 2 and have a narrow width, even if they are arranged in parallel, it is different from the conventional arrangement of four elements in parallel, and the substrate itself is large. The overall size is smaller than when elements are stacked one on top of the other, and the demand for miniaturization can be met accordingly.

Furthermore, two playing card elements fs and h are arranged in parallel, and a common lead terminal 8. Since it is only necessary to connect the ground terminal 9, the number of soldering points is smaller than when four trap elements are arranged in parallel, and the gap can be kept at a constant value as when two trap elements are placed one on top of the other. There is no need for the difficult work of holding it, which requires fewer man-hours and is easy to assemble.
Work efficiency can be improved as well.

〔Effect of the invention〕

As described above, according to the composite trap according to the present invention, the first and second traps each have a lead electrode, a first vibrating electrode, a second vibrating electrode, and a ground electrode formed on the front and back surfaces of a rectangular piezoelectric vibrating substrate, respectively. The second trap element is arranged in parallel, and the lead terminal for external extraction and the ground terminal are connected to the two side electrodes and the ground electrode of both trap elements, respectively, which reduces the number of work steps and prevents conductive defects. It can solve the problem, can be made smaller, and has the effect of improving work efficiency6.

[Brief explanation of the drawing]

1 to 5 are for explaining a composite trap according to an embodiment of the present invention, FIG. 1 is a perspective view showing the composite trap, and FIG. 2 (al is a plane showing the surface of the trap element. Fig. 2 (bl is a plan view showing the back side of the trap, Fig. 3 is a partial cross-sectional view of the composite trap covered with resin, Fig. 4
The figure shows a measurement circuit diagram of the composite trap, FIG. 5 is a characteristic diagram showing the relationship between frequency and attenuation, FIGS. 6 and 7 show a conventional composite trap, and FIG. 6 ta+ is a perspective view thereof. Fig. 6 (bl is a plan view of the back side, Fig. 7 is a plan view thereof. In the figure, ■ is a composite trap, 2 is a piezoelectric vibrating substrate, 3
is the lead electrode, 4.7 is the first. 2nd vibrating electrode, 6 is a ground electrode, 8 is a lead terminal, 9 is a ground terminal, fs, fi
is the first. This is a second trap element. Patent applicant: Zaida Seisakusho Co., Ltd. Agent: Patent attorney Tsutomu Figure 1, Figure 2, fs 5b627

Claims (1)

[Claims] (1) Lead electrodes are formed at both ends of the front surface of a rectangular piezoelectric vibrating substrate, and a pair of first vibrating electrodes are formed longitudinally inward from the lead electrodes on the surface, and approximately at the center of the back surface of the substrate. a ground electrode is formed on the back surface of the trap element, and a pair of second vibrating electrodes are formed on the back surface of the trap element at a position opposite to the first vibrating electrode. , and arranged in parallel, the first,
A composite trap characterized in that a common lead terminal for external extraction and a common ground terminal are connected to each lead electrode and ground electrode of the second trap element, respectively.