JPH03234108A - electronic parts equipment - Google Patents

Abstract

PURPOSE:To decrease ripple and to increase an attenuation characteristic by connecting a metallic frame and a metallic plate connecting electrically to part of a case of a surface acoustic wave(SAW) filter and arranged to separate input and output leads electrically. CONSTITUTION:A metallic plate 12 connecting electrically to part of a case 5 of a SAW filter separates input and output leads 6 and the metallic plate 12 and a metallic frame 10 are connected electrically. That is, the case 5 of the SAW filter is connected to the metallic frame 10 directly through the metallic plate 12 to make a ground level of the case 5 of the SAW filter close to a reference ground level of the metallic frame 10 and the coupling is suppressed by separating the input and output leads 6. Thus, the ripple is reduced and the attenuation characteristic as the SAW filter is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electronic component device having a SAW filter used in a demodulation section of an indoor receiver for satellite broadcasting.

BACKGROUND OF THE INVENTION First, a brief explanation of the SAW filter will be given. 6th
As shown in the figure, a SAW filter chip 1 includes a blind-shaped input side metal electrode 3 and an output side metal electrode 4, which are arranged facing each other for input and output on the surface of a crystal plate 2 made of a piezoelectric material.
It is formed by depositing. The input signal is supplied to the input side metal electrode 3 and converted into a SAW, propagates on the surface of the crystal plate 2, reaches the output side metal electrode 4, and is converted into an electric signal and becomes an output signal. A chip of such a SAW filter is housed in a metal housing 6 as shown in FIG. 6, and the SAW filter is used as an electronic component. Since this SAW filter can be made smaller in circuit size and requires no adjustment, it is expected to be applied and developed in various electronic devices such as TV receivers.

Note that 6 is an input and output lead, and 7 is a ground lead.

Next, an explanation of an electronic component device using this SAW filter will be given with reference to FIGS. 7 and 8.

FIGS. 7 and 8 show assembled perspective views of the conventional example. Enter,
Output IJ-1-'6, ground I)-Y7 to Lee 1 of board 8.
' After inserting the SAW filter 6 into the hole 9 and mounting it on the board 8, it is mounted inside the metal frame 10 and DIP soldered in the direction of the arrow in FIG.
Attach 1. FIG. 8 shows the DIP soldering surface before the shield cover 11 is attached. The input and output IJ-1-'6 are connected to the front and rear circuits by the conductive pattern 12 of the board 8, the ground IJ-1-'7 is connected to the conductive pattern 13, and the soldering part 14
It is grounded to the metal frame 10 via.

Problems to be Solved by the Invention In the UHF band such as the demodulation section of an indoor receiver for satellite broadcasting, as shown in FIG.
When using the SAW filter shown in FIG. As shown in the figure, since the connection is through a conductive pattern with a length β, the ground lead is connected to the metal frame 10.
The potential will be different from the reference ground potential of

(A bond occurs between Kalidro who enters the audience and leaves the audience.

Due to the reasons (1) and (2) above, the ripples are large and the attenuation characteristics as a SAW filter are reduced.

The present invention solves the above problems. (1) The ground potential of the SAW filter casing is brought as close as possible to the reference ground potential of the metal frame.

G2) Minimize coupling between input and output leads.

According to (1) and (2) above, the purpose is to reduce the IJ pull and increase the attenuation characteristics as a SAW filter.

Means for solving the problem and to achieve this object, the present invention provides the above-mentioned SAW
A metal plate electrically connected to a part of the filter housing partitions the input and output leads, and the metal plate and the metal frame are electrically connected.

Effects The present invention has the above-described configuration. (1) Since the SAW filter casing is directly connected to the metal frame via the metal plate, the ground potential of the SAW filter casing can be brought close to the reference ground potential of the metal frame. can.

(2) By separating the input and output leads with a metal plate that is electrically connected to the metal frame and has a potential close to the reference ground potential, coupling between them can be suppressed.

According to (1) and (2) above, the ripple can be reduced and the attenuation characteristics as a SAW filter can be increased.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

An embodiment of the present invention is shown in FIGS. 1 to 4. Note that parts with the same names as those in the conventional example are given the same numbers. Further, for the sake of simplification of the drawing, the conventional ground IJ-t'7 is omitted from the drawing. Partition part 15 formed integrally and then folded
After applying the cream solder 18 to the base part 17 of the grounding plate 13 having the following characteristics, SA! The filter is mounted on the ground plate 16. Then, the completed SAW filter and the ground plate 16 are oven-soldered and attached to the board 8 while inserting the input and output IJ-I''e into the lead holes 9. Then, in this state, they are mounted inside the metal frame 10. The shield cover 20 having the protrusion 19 is then attached to the metal frame 10. A cross-section of the moom in FIG. 2 is shown in FIG. At the same time that the frame 1o is connected to the soldering section 21, the board 8 and the input/output card are connected to the soldering section 22.In addition, the SAW filter casing 6 and the ground plate are connected by the opening process before that. 16 is connected to the metal frame 10 by soldering at the part 18. Furthermore, since the protrusion 19 is pressed against the partition part 15, the partition part 15 is electrically connected to the metal frame 10 via the shield cover 20.

Here, a method of connecting the back surface of the pace part 1 in the soldering part 22 and the partition part 12 in FIG. 1 will be explained. FIG. 3 shows an enlarged view of the assembly of the SAW filter and the ground plate 16. Although not shown in FIG. 2 to simplify the drawing, by providing a small hole 23 near the center of the abutting part of the partition part 16 in the pace part 17, a third As shown in FIG. 4, which is a cross section taken along line B-B in the figure, when the SAW filter housing 5 and the ground plate 16 are connected as the soldering part 18 in the oven process, molten cream solder is applied through the small hole 23. The parts 1 and 1 are guided to the abutting part between the back surface of the partition part 12 and the parts 19 are soldered and connected at the same time.

With the above structure, (1) By connecting the SAW filter housing 5, which is the root of the grounding lead 7, directly to the metal frame 1o via the grounding plate 16, a grounding effect can be obtained for high frequency signals, and the SAW The ground potential of the filter housing 5 is connected to the metal frame 1.
It can be brought close to the reference ground potential of 0.

(2) Since the input and output ports are partitioned by the partition portion 16 that is integrally formed with the ground plate 16 and electrically connected to the metal frame 10 via the shield cover 20, coupling between them can be suppressed. I can do it.

Furthermore, as a unique effect of this embodiment, since the cream solder 18 that melts at a low temperature is used, there is no risk of thermal damage to the SAW filter, which often occurs when manual soldering is performed using a high-temperature soldering iron. can give.

In this embodiment, a case has been described in which the partition portion 16 and the SAW filter casing 5 are separate pieces, but the partition portion 15 may be integrally formed with the SAW filter casing 5.

Further, the protrusion 19 may be formed integrally with the metal frame 1o.

Effects of the Invention As described above, according to the present invention, (1') the ground potential of the SAW filter housing can be brought close to the reference ground potential of the metal frame.

(2) Coupling between input and output leads can be suppressed.

Therefore, it is possible to reduce the ripple and increase the attenuation characteristics as a SAW filter.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of an embodiment of the present invention. Fig. 3 is an exploded perspective view of the same, Fig. 4 is a sectional view taken along line B-B in Fig. 3, Fig. 6 is a perspective view of the SAW filter chip, Fig. 6 is a perspective view of the SAW filter, and Fig. 7 is a perspective view of the SAW filter. FIG. 8 is an exploded perspective view of a conventional example. 5...8 AW filter housing, 6...
Input, output lead, 7...-ground lead, 8...
...Substrate, 10...Metal frame, 12...
...9 partitions (metal plate).

Claims (2)

[Claims] (1) A metal frame, a surface acoustic wave (SAW) filter provided in this metal frame, and this SAW filter.
A metal plate is electrically connected to a part of the casing of the AW filter and is arranged to partition between the input and output leads of the SAW filter, and the metal plate and the metal frame are electrically connected. Electronic parts equipment. (2) A ground plate is provided within the metal frame, a SAW filter is provided on the ground plate, and a board is provided below the ground plate, and the input and output leads of the SAW filter are passed through the ground plate to conduct electricity on the board. 2. The electronic component device according to claim 1, wherein a metal plate electrically connected to the pattern and partitioning the input and output leads is formed integrally with the ground plate, and is formed by bending and bending the metal plate.