JP2888547B2 - Electronic component equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICABILITY The present invention relates to a surface acoustic wave (hereinafter referred to as SA) used for a demodulation unit of a satellite broadcasting indoor receiver as shown in the block diagram of FIG.
(Referred to as “W”).

2. Description of the Related Art First, a brief description of a SAW filter will be given. 4th
As shown in the figure, a SAW filter chip 1 has an input-side metal electrode 3 and an output-side metal electrode 4 in the form of a screen, which are opposed to each other for input and output, on a surface of a crystal plate 2 made of a piezoelectric material. It is formed. The input signal is supplied to the input-side metal electrode 3 and converted into SAW, propagates on the surface of the crystal plate 2, reaches the output-side metal electrode 4, is converted into an electric signal, and becomes an output signal. Such a SAW filter chip 1 is housed in a predetermined package to form a SAW filter 5 as an electronic component as shown in FIG. That is, SAW
The filter 5 includes a chip 1, a stem 6 on which the chip 1 is mounted, and a case 7 for closing the stem 6.
And a pair of input / output leads 8 and ground leads 9 each protruding from the stem portion 6. Since the SAW filter 5 can be downsized and can be adjusted without a circuit, it is expected to be applied and developed to various electronic devices such as a TV receiver.

Next, a conventional electronic component device using the SAW filter 5 as described above will be described with reference to the drawings. As shown in the exploded perspective view of FIG. 6, the SAW filter 5 is
After inserting the input / output lead 8 and the ground lead 9 into the lead hole 11 of the board 10 and mounting it, mount it on the frame 12 and move it in the direction of arrow N.
Perform DIP soldering. After the assembly is completed, the DIP soldering surface (the back side of the substrate 10 on which the SAW filter 5 is attached)
As shown in the figure, the input / output lead 8 is connected to the front and rear circuits by a pattern 13a, and the ground lead 9 is routed by a pattern 13b and connected to the frame 12 at the soldering portion 14 and grounded.

Problems to be Solved by the Invention When the SAW filter 5 as described above is used in the UHF band such as a demodulator of an indoor receiver for satellite broadcasting as shown in the block diagram of FIG. (1) The ground lead 9 is connected to the frame 12 having the reference ground potential via a pattern 13b having a length 1 as shown in FIG. As a result, the ground lead 9 has a potential different from the reference ground potential of the frame 12.

(2) Since capacitive coupling is provided between the input / output leads 8, there is a disadvantage that it is difficult to achieve a target state from the conventional state with respect to the ripple and attenuation characteristics as shown in FIG.

SUMMARY OF THE INVENTION The present invention solves the above-described problem by making the ground potential of the SAW filter housing at the root of the ground lead as close as possible to the reference ground potential of the frame, and further minimizing capacitive coupling between the input and output leads. It is an object of the present invention to provide an electronic component device capable of performing the following.

Means for Solving the Problems To solve the above problems, an electronic component device of the present invention includes a surface acoustic wave filter, a board on which the surface acoustic wave filter is mounted, and a metal frame on which the board is mounted. Wherein the stem portion of the surface acoustic wave filter has an opposing portion substantially opposing the frame, and the opposing portion and the frame are electrically connected and grounded by soldering.

According to the present invention, since the stem portion of the surface acoustic wave (SAW) filter is electrically connected directly to the frame and grounded by the above-described configuration, the ground potential of the stem portion of the SAW filter approaches the reference ground potential of the frame. Can, and even more
Since the partition is provided between the two input / output leads of the SAW filter by the partition provided on the stem having a potential close to the reference ground potential, capacitive coupling between the input / output leads can be suppressed.

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

FIG. 1 is an exploded perspective view of a main part in an electronic component device according to one embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. In FIG. 1 and FIG. 2, the SAW filter 21
The chip of the SAW filter as shown in FIG. 4 is built in a housing composed of a stem portion 22 and a case portion 23, and the stem portion 22 is integrally formed by sheet metal press working, and has a square shape as a whole. A pair of opposite side edges are bent downward to form bent pieces 24A, 24B, and along one of the bent curves 22a, 22b of the bent pieces 24A, 24B, the case 23 is bent from one side end. And cut the bent ends of the bent pieces 24A and 24B below the case part 23 to form partition pieces 25A and 25B, and further from the back side of the stem part 22 at the position of the case part 22. One lead-in / out lead 26A, 26B protrudes downward with the partition pieces 25A, 25B therebetween. The outside of the partition pieces 25A, 25B on the back side of the stem portion 22 can be attached by inserting the input / output leads 26A into the lead holes 28A in the board 27A, and the bent pieces on the back side of the stem portion 22 can be attached. 24A, 24B and partition 25A, 2
The portion surrounded by 5B can be attached in a state where the input / output lead 26B is inserted into the lead hole 28B of the substrate 27B and fitted. If the SAW filter 21 having such a structure is attached to the substrates 27A and 27B as described above, the substrates 27A and 27B
, That is, between the input / output lead 26A and the input / output lead 26B, the partition 25 is provided by partitioning pieces 25A and 25B formed by a part of the stem portion 22 to perform partitioning. The stem portion 22 can be mounted between the metal frames 29A and 29B, and directly electrically connected between the bent piece 24A and the frames 29A, 24B and 29B by soldering or the like.

The above-mentioned electronic component device is assembled as follows. That is, as shown in FIG. 1, the SAW filter is inserted into the lead hole 28A with the input / output lead 26A projecting downward from the stem portion 22 integrally formed by sheet metal pressing, and the input / output lead 26B is It is mounted on the board 27A and the board 27B while being inserted into the lead hole 28B. At this time, the substrate 27
The portion surrounded by the bent pieces 24A and 24B and the partition pieces 25A and 25B is attached to B as described above. Next, by assembling between the frame 29A and the frame 29B and dip-soldering in the direction of arrow M, as shown in FIG. 2, the bent piece 24A and the frame 29A of the stem portion 22, and the bent piece 24B and the frame 29B are The connection is made by the soldering portions 30A and 30B, and the function of the grounding lead of the conventional SAW filter is replaced with the stem portion 22 by the soldering portions 30A and 30B, so that the grounding lead becomes unnecessary. The board 27A and the input / output leads 26A, and the board 27B and the input / output leads 26B
Connected by 1A (not shown) and 31B, and the partition of stem 22
The butted portions of 25A and 25B are connected by the soldered portion 32.

The electronic component device of this embodiment is an alternative to the ground lead.
By connecting the stem portion 22 of the SAW filter housing directly to the frames 29A and 29B, a grounding effect can be obtained for high-frequency signals.
The partitioning portion 25, which can be brought close to the reference ground potential of A and 29B and is integrally formed from the housing, that is, has a potential close to the reference ground potential, can suppress the capacitive coupling between the input / output leads 26A and 26B. In the UHF band, the effect of easily achieving the target state of the ripple and damping characteristics shown in FIG. 8 is obtained. As a unique effect of the present embodiment, the partitioning portion is formed by sheet metal press working.
Since 25 is formed, it is cheaper and more mass-producible than processing methods such as die casting.

Effect of the Invention As described above, according to the electronic component device of the present invention, the ground potential of the SAW filter housing can be made closer to the reference ground potential of the frame, and the capacitive coupling between the input and output leads can be suppressed. In addition, a SAW filter can be mounted, and the effect of achieving the target for the ripple and attenuation characteristics shown in FIG. 8 in the UHF band is obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of an electronic component device according to one embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of FIG.
FIG. 4 is a block diagram of a satellite broadcast receiver, FIG. 4 is a perspective view of a SAW filter chip, FIG. 5 is a perspective view of a conventional SAW filter, and FIG. 6 is an electronic component device using the conventional SAW filter. FIG. 7 is an exploded perspective view of a main part, FIG. 7 is a back side perspective view of the electronic component device, and FIG. 8 is an explanatory diagram of electrical characteristics of the electronic component device using a SAW filter. 21 ... SAW filter, 22 ... Stem, 25 ...
Partition part, 25A, 25B ... Partition piece, 26A, 26B ... I / O lead, 27
A, 27B ... board, 29A, 29B ... frame.

Claims (2)

(57) [Claims] 1. A surface acoustic wave filter, a substrate on which the surface acoustic wave filter is mounted, and a metal frame on which the substrate is mounted, wherein a stem of the surface acoustic wave filter is substantially opposed to the frame. An electronic component device, comprising: an opposing portion that is electrically connected and grounded by soldering the opposing portion and the frame. 2. The electronic component device according to claim 1, wherein a partition portion is formed between the two input / output leads of the surface acoustic wave filter by a partition portion provided on the stem portion and mounted on a substrate. .