JPH0350456B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a shield case device used in a high frequency circuit device such as a television tuner device, and particularly to a shield case device provided with a shield plate for shielding a plurality of high frequency circuits. This invention relates to a shield case device.

[Summary of the invention]

The present invention provides a shield case device used for high frequency circuit devices such as television tuner devices, for example, by providing a groove-shaped recess on the inner surface of the shield case to support the shield plate substantially upright. The shield plate is reliably guided and supported by the recess, and when soldering is performed, molten solder is sucked up into the recess due to capillary action, allowing reliable connection and conduction between the shield case and the shield plate.

In addition, the soldering of the shield case and the shield plate can be performed simultaneously during the solder dip for connecting the circuit components arranged on the printed circuit board, making it possible to significantly improve the efficiency of assembly work. become.

[Conventional technology]

Electronic devices such as television receivers and radio receivers are equipped with printed circuit boards on which high-frequency circuits such as tuner circuits are formed. If it receives electrostatic or electromagnetic interference, it will cause oscillation and become unstable, so it should be stored in a shielded case made of conductive metal to prevent it from receiving electrostatic induction from the outside. It is used by shielding it so that it does not have any effect.

By the way, in the case of such a printed circuit board, it may be necessary to form a plurality of high frequency circuits on the printed circuit board, and in this case, in order to prevent interference between these circuits, conductive metal is used. A shield plate is provided within the shield case to electrostatically divide the printed circuit board. Conventionally, this shield plate is attached to the shield case as described below.

Hereinafter, a conventional shield case device will be explained with reference to the drawings. In the conventional shield case device, as shown in FIGS. 7 and 8, a printed circuit board 102 is disposed inside a shield case 101, and A shield plate 103 is provided to stand upright on the substrate 102. The shield plate 103 is provided with a plurality of leg pieces 104, and each leg piece 104 is attached to the printed circuit board 10.
It is inserted into a mounting hole 105 provided in the shape of a slit in 2. Furthermore, the printed circuit board 102
A wiring pattern forming surface 102a on which a circuit wiring pattern is formed using copper foil or the like of the printed circuit board 102 in order to connect and fix circuit components disposed on the printed circuit board 102.
When a solder dip is applied to the shield plate 103 and the shield case 101 or the printed circuit board 102, the solder 106 is used to fix the shield plate 103 and the shield case 101 or the printed circuit board 102 at the same time. This shield case device is opened with an upper lid 107 and a bottom lid 108 to provide electrostatic shielding from the outside.

However, in the conventional example, since the contact area between the shield plate 103 and the shield case 101 is small, variations in the soldering state tend to occur, making it difficult to achieve reliable electrical connection. Therefore, it is not possible to obtain a sufficient shielding effect by the shield plate 103, and mutual interference occurs between the circuits, significantly deteriorating the performance of the high frequency device.

Therefore, conventionally, a shield plate 103 facing above the printed circuit board 102 as shown in FIG.
It is known that solder 109 is applied to one end of the shield case 101 by hand soldering or the like to ensure a reliable connection and conduction.

[Problem to be solved by the invention]

However, in the case where the shield plate 103 and the shield case 101 are connected by manual soldering, etc., the soldering work such as the manual soldering is complicated, and the efficiency of the assembly work of this shield case device is reduced. has decreased significantly.

Therefore, the present invention has been proposed in order to eliminate the drawbacks of the above-mentioned conventional products, and it is possible to easily and reliably install a shield plate inside a shield case, thereby obtaining a sufficient shielding effect. The purpose of the present invention is to provide a shield case device that can

[Means to solve the problem]

In order to achieve the above object, the present invention includes a shield case, the shield case is arranged substantially parallel to the bottom surface of the shield case, the edge is in contact with the inner surface of the shield case, and the bottom surface side has wiring. a printed circuit board on which a pattern is formed; a shield plate provided upright on the printed circuit board so that its edge contacts the inner surface of the shield case; A leg portion of the shield plate that penetrates the substrate and reaches the back surface, two protrusions formed on the inner surface of the shield case along the edge, and between the protrusions, the above-mentioned and a groove-shaped recess configured to hold at least the edge of the leg that has reached the back side of the printed circuit board, and when soldering the back side of the printed circuit board, at least the bottom surface of the shield case is open. and the molten solder rises through a gap formed between the concave portion and the end edge of the leg portion, whereby the shield case and the shield plate are soldered together. The above-mentioned problem is solved by using the shield case device.

[Effect]

The shield case device according to the present invention can reliably support the shield plate with the groove-shaped recess provided in the shield case, and also sucks up the molten solder by the action of capillary action during solder dipping, thereby ensuring a reliable connection. Conductivity can be achieved.

〔Example〕

A specific embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 1, the shield case device according to the present invention includes a shield case 1 formed as a rectangular casing made of conductive metal, and a printed circuit board 2 disposed inside the shield case 1. A conductive metal shield plate 3 is provided upright on the printed circuit board 2 in order to shield a plurality of high frequency circuits.
On one side 3a of the shield plate 3, a fourth
As shown in the figure, leg pieces 4, 4 are integrally formed so as to extend along both end sides 3b, 3c in contact with side surfaces 1a, 1b of this shield case 1 when installed in the shield case 1, and these legs. piece 4,4
One side 3 of the shield plate 3 has the same protrusion amount as
A plurality of leg pieces 5 formed at predetermined intervals in the middle of a
is provided. The printed circuit board 2 also has a slit 6 corresponding to the leg piece 4 provided on the shield plate 3 and a slit 7 corresponding to the leg piece 5.
The legs 4 and 5 of the shield plate 3 are inserted into these slits 6 and 7, respectively, so as to face the back surface 2b of the printed circuit board 2 on which the circuit wiring pattern is formed. Board 2
The shield plate 3 is arranged so as to stand upright. The slit 6 of the printed circuit board 2 is cut out in a substantially T-shape in correspondence with shield plate support portions provided on side surfaces 1a and 1b of the shield case 1, which will be described later.

On the other hand, side surfaces 1a and 1b of the shield case 1
, both end sides 3b, 3c of the shield plate 3
As shown in FIGS. 1 and 4, shield plate support portions 8, 8 each formed into a pair of protrusions are provided by stamping the side surfaces 1a, 1b, for example, at positions facing the shield plate. , both sides 1a, by these pair of shield plate supporting parts 8,8.
As shown in FIG. 2, both end sides 3b and 3c of the shield plate 3 are inserted and supported in the groove-shaped recesses 9 and 9 formed in the shield plate 1b.

In the shield case device having the above configuration, the shield plate 3 is connected to the back surface 2 of the printed circuit board 2.
(b) That is, when a solder dip is applied to connect the circuit components arranged on the printed circuit board 2 to the wiring pattern forming surface of the circuit, the solder is fixed at the same time. That is, as shown in FIG. 3, the printed circuit board 2 and the shield plate 3 are fixed by the solder 10 during the solder dip, and the groove-shaped recesses 9 provided on the side surfaces 1a and 1b of the shield case 1 are The molten solder is sucked up by capillary action into the gap formed by the leg piece 4 and both end sides 3b and 3c of the shield plate 3, and reaches the extent far above the recess 9, for example, at least to the surface 2a side of the printed circuit board 2. Handa 11 enters the
The shield case 1 and the shield plate 3 are coupled and fixed over a wide range.

The shield case 1 has an upper lid body 12.
It is opened by a bottom lid 13, and electrostatic shielding from the outside is achieved.

As described above, in the above embodiment, the solder is soldered by the capillary phenomenon that occurs in the gap between the groove-shaped recess 9 formed by the shield plate support part 8 provided in the shield case 1 and the both end sides 3b and 3c of the shield plate 3. 11 is deposited over a wide range, the reliability of the connection and conduction between the shield case 1 and the shield plate 3 is significantly improved, and the shield plate 3 can obtain a sufficient shielding effect. Furthermore, the soldering of the shield case 1 and the shield plate 3 can be performed simultaneously during the solder dip for connecting the circuit components arranged on the printed circuit board 2, which significantly improves the efficiency of the assembly work. Is possible.

Next, an application of the present invention to a television tuner device will be described with reference to the drawings.

As shown in FIGS. 5 and 6, the television tuner device has a circuit component mounting surface 22a on which various circuit components 23 constituting the tuner circuit are arranged, and a wiring pattern formed of copper foil or the like. It is constructed by attaching a printed circuit board 22 having a wiring pattern forming surface 22b to a shield case 21 made of conductive metal. The printed circuit board 22 has a plurality of tuner circuits, for example, two tuner circuits.
Various types of high frequency circuits are formed, and a shield plate 24 is provided to prevent electrostatic interference between these high frequency circuits. This shield plate 24 includes a side surface 21 of the shield case 21.
Leg pieces 25, 25 integrally formed to extend along both end sides 24a, 24b in contact with a, 21b
A plurality of leg pieces 26 are provided which are arranged at intermediate positions between these leg pieces 25 and 25, and these leg pieces 25 and 26 are inserted into slits 27 and 28 provided in the printed circuit board 22. The shield plate 24 is arranged to stand upright with respect to the printed circuit board 22.

On the other hand, the side surface 21a of the shield case 21,
21b, both end sides 24 of the shield plate 24
A pair of shield plate holding parts 29, which are divided into two in the vertical direction in FIG.
29, 30, 30 are formed by punching,
These shield plate holding parts 29, 29 and 30, 3
Both end sides 24a, 24b of the shield plate 24 are inserted and supported in the groove-shaped recesses 31, 32 formed by the shield plate 24. Then, the recess 32 between the shield plate support portion 30 facing the wiring pattern forming surface 22b side of the printed circuit board 22 and the both end sides 2 of the shield plate 24
4a and 24b, molten solder is absorbed by capillary action when a solder dip is applied to the wiring pattern forming surface 22b in order to connect and fix the circuit components 23 arranged on the printed circuit board 22. The solder 33 extends to the extent that the solder 33 faces the circuit component mounting surface 22a of the printed circuit board 22, thereby ensuring the soldered connection between the shield case 21 and the shield plate 24.

Furthermore, one side 21 of the shield case 21
C is provided with an antenna terminal 41 for supplying a signal received by the antenna to the printed circuit board 22 on which the high frequency circuit is formed, and a pin jack 51 for connection to other electronic circuit devices.

This antenna terminal 41 consists of a terminal body 42 and a terminal pin 43, and this terminal body 42 is connected to an opening 44 provided in one side 21c of the shield case 21.
It is fixed to the shield case 21 by caulking a caulking piece 46 formed by a slit 45 provided adjacent to the opening 44 . At this time, the antenna terminal 41 is prevented from wobbling in the vertical direction by the locking edge 47 of the shield case 21, which is formed by punching out along a part of the upper edge of the opening 44.

On the other hand, the pin jack 51 is composed of a cylindrical jack body 52 and a base end portion 53 formed with a slightly smaller diameter than the jack body. It is inserted into an opening 54 provided with approximately the same diameter as the portion 53 and fixed by soldering. At this time, the pin jack is temporarily fixed by a pair of locking pieces 55, 55 which are punched out and formed on the shield case 21 so as to face the periphery of the opening 54, and in this state, a solder dip is applied. It is fixed by soldering.

In addition, the other side 2 of the shield case 21
1a, an insulator 62 is provided so that a plurality of, for example, five through terminals 61 for applying a control voltage etc. from the outside to the high frequency circuit formed on the printed circuit board 22 face the circuit component mounting surface 22a. has been inserted through. One end 63 of this through terminal 61 is bent and inserted into a terminal mounting hole 64 provided on the printed circuit board 22.
Connection and conduction are achieved by soldering to a connection land provided on the wiring pattern forming surface 22b.

The shield case 21 has an upper lid body 3.
4 and a bottom lid 35 to provide shielding from the outside.

As described above, in the above embodiment, even if the shield plate supporting parts 29 and 30 are provided in the shield case 21 by dividing them into two in the vertical direction in FIG. It is possible to ensure reliable connection and conduction and obtain a sufficient shielding effect.

〔Effect of the invention〕

As is clear from the description of the embodiments above,
In the present invention, it is possible to securely connect the shield case and the shield plate by soldering to achieve a reliable conductive connection, and it is possible to obtain a sufficient shielding effect.

Furthermore, in the present invention, the shield case and the shield plate can be soldered together at the same time as these components are connected by using a solder dip used for connecting circuit components arranged on a printed circuit board, for example, and the assembly work can be simplified. It has become possible to significantly improve efficiency.

[Brief explanation of drawings]

Figures 1 to 4 show one embodiment of a shield case device to which the present invention is applied.
The figure is an exploded perspective view of the main part, Fig. 2 is a partially cutaway external perspective view of the main part, Fig. 3 is a longitudinal cross-sectional view of the main part taken along line B-B in Fig. 2, and Fig. 4 is Fig. 3 C-C. FIG. 5 and 6 show other embodiments of the present invention, FIG. 5 is a partially cutaway external perspective view of the television tuner device, and FIG.
The figure is a longitudinal cross-sectional view taken along the line DD in FIG. 5. FIG. 7 is a partially cutaway external perspective view of a conventional example;
FIG. 8 is a vertical cross-sectional view of the main part taken along line A-A in FIG.
FIG. 9 is a partially cutaway external perspective view of another conventional example. DESCRIPTION OF SYMBOLS 1, 21... Shield case, 2, 22... Printed circuit board, 3, 24... Shield plate, 4, 25... Leg piece, 9, 32... Recessed part.

Claims (1)

[Claims] 1. A shield case, disposed substantially parallel to the bottom surface of the shield case,
a printed circuit board whose edge is in contact with the inner surface of the shield case, and on which a wiring pattern is formed on the bottom side; a shield plate formed along the edge and extending through the printed circuit board to reach the back surface of the shield case; It has two protrusions formed on the inner surface, and a groove-shaped recess formed between the protrusions and configured to hold at least the edge of the leg that has reached the back side of the printed circuit board. When solder-dipping the back surface of the printed circuit board, at least the bottom surface of the shield case is opened so that the molten solder rises through the gap formed by the recess and the edge of the leg. A shield case device characterized in that the shield case and the shield plate are soldered together.