JPH09331186A - Printed circuit board shield ground structure - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To realize a shield structure for a printed circuit board which has an inexpensive and reliable die-cast chassis for shield by eliminating the earth spring and the inner plating of the long hole. The grounding of the printed circuit board and the die-cast chassis is provided on the wall of the die-casting shield, and a step for receiving the circuit board is provided, and the printed circuit board is grounded at the stepped portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grounding structure for a shield of a wireless device or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a shield board 2 protruding from a die-cast chassis 1 is fitted with an earth spring 3 for grounding the board, and a printed board 4 having an elongated hole 5 for allowing the shield wall to pass therethrough. Fit into the earth spring 3,
The contact between the ground plate 3 and the printed circuit board 4 is
The end surface plating 10 applied to the inner wall of the elongated hole 5 is performed.

[0003]

In the conventional method of forming a shield room by the board and the die-cast wall through the shield wall protruding from the die-cast chassis through the long hole provided in the printed board, the grounding of the printed board and the die-cast wall is performed by the die-cast wall. In order to make contact between the earth spring and the board, which is attached to the ground spring and the inner wall of the printed circuit board elongated hole through which the die casting wall passes, the ground spring and the inside of the printed circuit board elongated hole must be plated. There is also a possibility that the earth may become unstable due to the spring pressing due to external vibration.

It is an object of the present invention to provide an inexpensive and reliable earth structure by eliminating these earth springs and inner plating of long holes.

[0005]

In order to achieve the above object, the present invention provides a step portion on which a printed circuit board is mounted on a printed circuit board contact portion of a die cast shield wall protruding from a chassis through a printed circuit board elongated hole. The contact is made by an earth pattern provided on the upper surface of the portion and the creeping surface of the lower surface of the printed circuit board elongated hole. Further, in order to fix the contact between the printed circuit board and the die cast, the screw is arranged near the shield wall, or the printed circuit board holding metal fitting attached to the die cast shield wall is used.

As a result, it is necessary to plate the end face of the long hole portion for making contact between the die cast and the substrate, which is weak against external vibration, and for making contact between the spring earth and the printed circuit board, which is inexpensive and highly reliable. Enables a ground structure.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

Reference numeral 1 is a die-cast chassis, 2 is a die-cast wall for shield protruding from the chassis, 7 is a step portion for receiving a printed circuit board provided on the shield wall, 4 is a printed circuit board, 5
Is an elongated hole made in the printed circuit board through which the die-casting wall for shielding is passed. 6 is an earth pattern for making contact between the printed circuit board and the die-cast chassis (the entire circumference of the lower surface of the elongated hole).
It is. Further, as shown in FIG. 2, the die casting of the printed board is fixed by a screw 8 in the vicinity of the elongated hole of the printed board. As shown in FIG. 3, a holding metal fitting 9 attached to the die casting shield wall is used.
There is a method of fixing the printed circuit board.

This operation will be described below.

A printed circuit board 4 having an elongated hole 5 through which the die casting wall 2 passes is inserted into a shield die casting wall 2 provided with a printed circuit board receiving step 7 protruding from the die casting chassis 1 of FIG. The printed circuit board 4 is placed on the stepped portion 7 provided on the wall, and screws are tightened as shown in FIGS.

FIG. 4 shows an overall view of the die casting chassis.

[0012]

As a result, the earth pattern provided on the lower surface of the slot for earthing the printed circuit board, the die casting chassis, and the shield wall step can be easily and accurately grounded.
It is possible to improve the reliability of grounding in vibration-applied devices such as in-vehicle equipment.

[Brief description of drawings]

FIG. 1 is a structural diagram of the present invention without using a ground spring.

FIG. 2 is a diagram showing a printed circuit board fixed with a screw according to the present invention.

FIG. 3 is a diagram showing a printed circuit board fixed by a holding metal fitting of the present invention.

[Figure 4] Overall view of die casting structure

[Fig. 5] Conventional ground structure

[Explanation of symbols]

 1: Die-cast chassis 2: Die-cast shield wall 3: Earth spring 4: Printed circuit board 7: Printed circuit board receiving step

Claims (2)

[Claims] 1. In a shield structure of a printed circuit board, wherein a shield room protruding from the die cast chassis is provided in a slot provided in the printed circuit board to form a shield room with the substrate and the die cast wall, the earth of the printed circuit board and the die cast is connected to the die cast shield wall. A shielded ground structure for the printed circuit board, in which a step for receiving the circuit board is provided and the printed circuit board is grounded at that step. 2. A grounding pattern is provided on the lower surface of the elongated hole through which the die-casting shield wall of the printed circuit board passes, and the pattern and the die-casting board receiving step are grounded. Item 2. The shield ground structure for a printed circuit board according to Item 1.