JPH07183683A - Shield structure - Google Patents

Abstract

PURPOSE:To reduce working man-hours and improve quality by performing an entire heating method by means of a reflow furnace at the time of soldering a shield to be used for a high frequency electric appliance. CONSTITUTION:A shield with a soldered part bent into an L-shape is mounted on a printed board 5 with cream solder printed in advance, and they are made to pass through a reflow furnace to have them soldered together. The shield is brought into contact with a shield case or cover 8 via a spring contact piece 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield structure used for high frequency electric equipment such as microwave communication equipment, and more particularly to a shield structure for a printed circuit board to which surface mounting technology is applied.

[0002]

2. Description of the Related Art In a high frequency electric device such as a microwave communication device, a plurality of circuit blocks are mixed on one printed circuit board in order to reduce the size and weight. To prevent radio wave leaks,
For soldering the metal shield wall to each circuit block to electrically shield it, the public utility model publication, Hei 5
The shield case structure disclosed in No. 13038 is disclosed. In this structure, as shown in the perspective view (a) of the shield plate of FIG. 4 and the sectional view (b), the soldering portion 1 and the positioning portion 4 are combined, and this portion is soldered.

However, this shield structure has a structure as a lead component, and the self-supporting property of the shield itself is poor. It cannot be applied to the soldering work process. Therefore, when the shield is attached to the surface-mounted printed circuit board, a method has been adopted in which the surface-mounted component is soldered in a reflow furnace and then manually attached.

[0004]

However, in this conventional method, since it is not possible to use an automated line for surface mounting, the number of man-hours required for soldering by hand of the shield is large, or the soldering is difficult. Because of the large heat capacity for the cost such as defective soldering,
There was a quality problem.

The object of the present invention was proposed in order to solve the problems of each of the above-mentioned conventional techniques. In a printed circuit board to which the surface mounting technique is applied, the cost is low and the quality is high. Is to provide a shield structure for carrying out.

[0006]

In order to achieve this object, in the present invention, a shield is mounted on a printed circuit board on which cream solder is printed in advance, and a reflow oven is used to separate the surface mount component from other surface mount components. At the same time, the shield is soldered. Therefore, the shield
The shield is bent into an L shape to allow surface connection with the ground pattern of the printed circuit board, and the shield itself can stand on its own. On the other hand, the contact with the shield cover surface side uses the elasticity of the spring material provided above the shield. The contact piece has a structure.

According to the above-mentioned shield structure, it is possible to mount and solder on a printed circuit board in the same step as the surface mounting component, so that the cost can be reduced and the quality can be improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In the embodiment described here, in a state in which the space surrounded by the outer frame is divided by various shield walls,
It is designed to have substantially the same conventional electrical shield characteristics.

First, FIG. 1 is a perspective view showing a shield structure of the present invention. As shown in this figure, the shield includes an L-shaped soldering portion 1, a shield wall portion 2, and
It is composed of a contact piece 3 with the shield cover and a positioning projection 4. This shield is on the printed circuit board 5,
The protrusions 4 are aligned with the substrate and placed. At this time, the soldering portion 1 is placed on the ground pattern portion of the printed circuit board 5, and this ground pattern is connected to the ground pattern on the back surface of the printed circuit board 5 by through holes. At this time, the hole into which the positioning protrusion 4 is inserted may be the through hole. In addition, 6 is a surface mount component.

FIG. 2 is a sectional view taken along the line AA of FIG. 1 in a state in which the shield / case is closed by the shield case / cover, and the shield of the present invention contacts the case / cover 8 by the contact piece 3 having a spring property.

FIG. 3 shows a state diagram when the shield of the present invention is temporarily fixed by the cream solder 7 applied in advance to the upper surface of the printed circuit board 5. At this time, other surface mount components are already mounted on the above-mentioned printed circuit board.

[0012]

As described above, the shield structure of the present invention has an L-shaped soldered portion, which improves the self-supporting property of the shield itself and the bending strength of the shield itself. Since the thickness of itself can be reduced and the overheated state during the soldering process has become stable, the shield structure of the present invention can be surface-mounted and can be reflowed simultaneously with other surface-mounted components. It has the result that it can be applied to the working process of soldering by the whole heating method using a furnace.

[Brief description of drawings]

FIG. 1 is a perspective view showing a shield structure of the present invention.

FIG. 2 is a sectional view when the embodiment of the present invention is closed by a shield case and a cover.

FIG. 3 is a state diagram when the shield of the present invention is temporarily fixed by cream solder.

FIG. 4 is a perspective view (a) and a sectional view (b) showing a conventional shield structure.

[Explanation of symbols]

 1: Soldered part 2: Shield wall 3: Contact piece 4: Positioning protrusion 5: Printed circuit board 6: Surface mount component 7: Cream solder 8: Shield case and shield cover 9: Solder

Claims (3)

[Claims] 1. A shield structure for shielding a plurality of circuit blocks on a printed circuit board by a metal shield wall,
The printed circuit board is provided with a ground pattern connected to the ground pattern on the rear surface through through holes existing on the front surface, and the printed circuit board connecting portion of the metal shield wall is L-shaped.
A shield structure, which is bent into a letter shape, and the bent portion and the ground pattern are connected by soldering. 2. The shield structure according to claim 1, wherein the bent portion of the metal shield wall and the ground pattern are soldered by cream solder. 3. The shield structure according to claim 1, further comprising a spring-like contact piece around the metal shield wall, the contact piece being in contact with the shield case.