JPH0541592A - Circuit module - Google Patents

Abstract

PURPOSE:To provide a circuit module in which a soldering fixture is eliminated, an assembling operability is improved and which can be effectively grounded in the module having a printed circuit board formed with a circuit, and a shielding case for connecting a ground circuit, shielding and containing it. CONSTITUTION:Wedge-shaped sectional protrusions 4 are arranged at a predetermined interval on an inner periphery of a shielding case 2, an elastic member 6 is so arranged as to press a printed circuit board 1 on the protrusions 4 from a rear surface of the board 1 provided with a ground pattern 5 at an edge oppositely to the protrusions 4, and settling preventing stoppers 7 of elastic members 6 are arranged. Further, the members 6 are arranged at opposite positions of the protrusions 4, or the members 6 each having conductivity are arranged, and the pattern 5 is provided at opposite position of the member 6 on a rear edge of the board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit module comprising a printed wiring board which constitutes a circuit, and a shield case which is connected to the ground circuit to shield and house it.

Recently, the development of semiconductor integrated circuits has greatly contributed to recent electronic devices, and high-density mounting, miniaturization, and high performance have been remarkably promoted, and the electronic devices have been further developed. This allows
Circuit modules, in which components are collectively mounted on a small printed wiring board and combined into a small circuit, have come into wide use.

Further, various circuit modules and parts are collectively mounted on a parent printed wiring board to form a circuit package having a plug-in structure for each maintenance and handling unit. The configuration scale of the circuit module is gradually increasing in size, so that high density packaging, high shielding, component productivity and economic efficiency are required.

Furthermore, as a measure for reducing the noise that enters or is induced in the wiring of the signal circuit, it is necessary to strengthen the circuit ground.

[0005]

2. Description of the Related Art FIG. 3 shows an example of a conventional circuit module. A circuit module 39 is configured by housing a printed wiring board 19 on which the component 9 is mounted in a shielding case 29 formed by molding a thin metal plate into a box shape with one surface open.
Is mounted on a parent printed wiring board (not shown), and the connection terminals 91 provided on the printed wiring board 19 and the protruding terminals 28 protruding from the opening edge of the shielding case 29 are connected and fixed.

Printed wiring board in this circuit module 39
The fixing of 19 is performed by abutting the peripheral edge of the printed wiring board 19 against a stopper 79 provided by punching on each side surface of the shielding case 29 at a predetermined interval and at a predetermined level from the opening, and at the peripheral edge of the opposite surface to the contact surface. The predetermined ground pattern 5 and the side surface of the adjacent shielding case 29 are fixed by soldering, and at the same time, the earth of the signal circuit is connected to the shielding case 29.

[0007]

However, in this method of fixing the printed wiring board 19, the heat capacity of the shielding case 29 is large, it takes a long time for soldering, and the assembling workability is poor. Further, the printed wiring board 19 is also exposed to high temperature for a long time, which is not preferable for the printed wiring and may cause peeling of the wiring or a solder bridge. There are problems such as.

In view of the above problems, it is an object of the present invention to provide a circuit module in which soldering and fixing are eliminated, assembly workability is improved, and grounding can be reliably performed.

[0009]

As shown in the principle explanatory view of FIG. 1, [1] the printed wiring board 1 on which the component 9 is mounted to form a circuit is provided.
And a shield case 2 which is connected to the ground circuit of the printed wiring board 1 to be shielded and accommodated therein.
In the above, from the back surface of the printed wiring board 1 in which the convex portions 4 having a wedge-shaped cross section are arranged at a predetermined interval around the inside of the shielding case 2 and the ground pattern 5 is provided on the edge surface facing the convex portions 4, Elastic member 6 for pressing the printed wiring board 1 against the convex portion 4
This is achieved by the circuit module 3 of the present invention in which the stopper 7 for preventing the elastic member 6 from being set is disposed. [2] Here, the circuit module 3 in which the elastic member 6 is arranged at a position facing the convex portion 4 may be used. [3] Also, the elastic member 6 having conductivity and the ground pattern 5 provided on the back edge surface of the printed wiring board 1 and at a position facing the elastic member 6 serve as the circuit module 3, which is sufficient.

[0010]

1 is a side sectional view for explaining the principle of the present invention.
(a) is before assembly, (b) is after assembly.

That is, a ground pattern 5 is provided on the edge of the printed wiring board 1, a wedge-shaped convex portion 4 is formed inside the side wall of the shield case 2, and an elastic member 6 is compressed vertically in the drawing.
And a stopper 7 are provided, and the width dimension A of the printed wiring board 1, the inner dimension B of the shielding case 2 and the head-to-face dimension C of the convex portion 4 are set, and the relation of B> A ≧ (B + C) / 2 If it is, the printed wiring board 1 can be fixed.

In FIG. 1 (a), when the printed wiring board 1 is housed in the shielding case 2 from the top to the bottom in the figure, it is supported at the position of the convex portion 4 first. The flexure convex portion 4 moves backward to pass the printed wiring board 1. Then, next, it hits the stopper 7 and the elastic member 6
While applying a pushing force to the lower surface of the printed wiring board 1, the bending of the side surface is self-recovered and the convex portion 4 is located above the upper surface of the printed wiring board 1. If the pushing force from above is eliminated in this state, the printed wiring board 1 is pushed up by the action of the elastic member 6 and is elastically pressed and fixed to the convex portion 4. At this time, the ground pattern 5 of the printed wiring board 1 is pressed against the convex portion 4 and the elastic member 6, and a conductive connection state is obtained.

The stopper 7 is a stopper for preventing the printed wiring board 1 from being pushed down and hitting the elastic member 6 and pushing down the elastic member 6 more than a limit to make it loose.

Thus, according to the present invention, it is possible to provide a circuit module which eliminates soldering and fixing, improves assembly workability, and can be surely connected to the ground.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the drawings. Throughout the drawings, the same reference numerals denote the same objects. FIG. 2 shows a block diagram of an embodiment of the present invention.

This embodiment is applied to a circuit module for optical-electrical conversion, and is a rectangular parallelepiped having an outer shape of 42 × 82 × height 12 mm, and a plurality of connecting / fixing terminals are mounted on one surface so as to be mounted on a parent printed wiring board. Connection terminals are provided and an optical connector is provided on one side surface.

As shown in FIG. 2, the circuit module 3 is composed of a printed wiring board 1 having a component 9 and a connection terminal 91 mounted at a predetermined position to form a circuit, and a shielding case 2 for accommodating the printed wiring board 1. ..

The shielding case 2 is a 0.3 mm thick iron thin plate, which is a box-shaped case 21 having an open top and one side, and an optical connector 99.
It is composed of a side plate 22 to which is attached one by one, and is fixed by fastening with a fixing screw.

In this case 21, the printed wiring board 1 is housed and fixed, and wedge-shaped convex portions 4 are punched out at predetermined intervals so that the ground connection is automatically performed, and a stopper 7 is provided therebetween. By cutting and raising, an elastic member 6 of an L-shaped cantilever spring, which is provided at a predetermined level position on three side surfaces and faces the convex portion 4 and has a bottom surface as a fixed end, is integrally formed by cutting and raising. In addition, a plurality of protruding terminals 28 for grounding are integrally provided on the edge of the opening.

The printed wiring board 1 is provided with ground patterns 5 connected to the signal circuit on both sides in the area facing the open ends of the convex portions 4 and the elastic member 6. Thus, the printed wiring board 1 on which the components are mounted is pressed and inserted from the opening of the shielding case 2, and is pushed down until it passes through the convex portion 4 and hits the stopper 7, and if left unattended, the elastic member 6 that hits the lower surface.
Is pushed up by the elastic force of and is pressed against the convex portion 4 and fixed. At this time, the protrusions 4 and the ends of the elastic member 6 are pressed into contact with the earth pattern 5 to make a reliable earth connection, and the projecting terminals 28 of the case 21 provide a low impedance to the parent printed wiring board (not shown). Be connected securely.

The above embodiment is an example, and the shape, size, and material of each part are not limited to these. The convex portion 4 is independently projected and integrally projected to the case 21, but if another bent elastic member is fixed to have a wedge-shaped cross-section and is pressed by the edge of the printed wiring board 1. It may be deformed and passed, and immediately after passing, it may be restored by spring force to withstand pressing, and in this case, a band-shaped elastic member along the peripheral edge may be used.

Although the elastic member 6 is provided integrally with the case 21, a separate member may be fixed to the case 21. Alternatively, the elastic member 6 may be provided not at a position facing the convex portion 4 but at a shifted position. Similarly, the stopper 7 may be a member to which another member is fixed, and the position thereof is not limited, but in the case of the integrally formed convex portion 4, a position apart from the stopper 7 surely provides a stop action and is safe. is there.

[0023]

As described above, according to the present invention, the soldering fixing of the printed wiring board and the shielding case is eliminated, the assembly workability is remarkably improved, and the circuit module which can be surely connected to the ground is obtained, and the cost is low. Greatly contributes to higher quality.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention (a) before assembly (b) after assembly

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a circuit module of a conventional example.

[Explanation of symbols]

1,19 Printed wiring board 2,29 Shielding case 3,
39 Circuit module 4 Convex part 5 Ground pattern 6
Elastic member 7,79 Stopper 9 Parts 21
Case 22 Side plate 28 Projection terminal 91
Connection terminal 99 Optical connector

Claims (3)

[Claims] 1. A printed wiring board (1) on which a component (9) is mounted to form a circuit, and a shield case (2) which is connected to the ground circuit of the printed wiring board (1) and is housed in a shielded manner. Circuit module consisting of
In (3), convex portions (4) having a wedge-shaped cross section are arranged at a predetermined interval around the inside of the shielding case (2), and the ground pattern (5) is provided on the edge surface facing the convex portions (4). From the back surface of the printed wiring board (1) provided with the elastic member (6) for pressing the printed wiring board (1) to the convex portion (4), and the stopper (7) for preventing the elastic member (6) from being settled. ) And a circuit module characterized by being provided. 2. The circuit module according to claim 1, wherein an elastic member (6) is arranged at a position facing the convex portion (4). 3. An elastic member (6) having conductivity, wherein a ground pattern (5) is provided on the back edge surface of the printed wiring board (1) and at a position facing the elastic member (6). The circuit module according to claim 1.