JP2003309333A - Structure of printed board grounded on frame ground - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely ground a frame ground pattern on a frame via a clamping screw, without complicating a manufacturing step in a printed board, and to provide a method for grounding the board. <P>SOLUTION: At the contact part of a copper foil pattern (3) with a printed board mounting screw (6) on a printed board, the exposed part (2) of the pattern (3) with a base material is formed in a fringe state, and a resist is extracted (4). Thus, the excess rise of a solder rise (5) formed by flow soldering the foil pattern is prevented, and the proper contact, with a screw head or the frame at the clamping time to the frame by the screw clamping, is guaranteed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground connection structure via a screw of a printed circuit board mounted by soldering.

[0002]

2. Description of the Related Art In order to surely ground a printed circuit board through a screw, the screw and the printed board must be in contact with each other. In order to improve this contact, a structure was considered in which the rattling of screws was suppressed by placing solder on the copper foil in the contact area of the printed board and making use of the cushioning properties of the solder. However, when the amount of solder was large, there was a risk that the screws would loosen due to the creep of the solder. Therefore, a structure was proposed in which the copper foil was covered with a resist in a striped pattern or a concentric pattern to prevent the solder from being excessively deposited and to stabilize the shape and height of the solder (FIG. 5) (FIG. 6). .

[0003]

However, in recent years, a solder bath having a structure in which solder is thinly applied to avoid a solder bridge has been generalized, and in the conventional structure in which a copper foil is covered with a resist, the solder is lower than the resist surface. There is a possibility that it will not be able to come into contact with the screw because it will only be filled up to the position (Fig. 7).

An object of the present invention is to secure a reliable bis-earth by making it possible to deposit solder evenly even if it is thin without complicating the manufacturing process of a printed circuit board.

[0005]

In view of the above-mentioned problems, the present invention forms a striped frame earth contact portion of a printed circuit board by a screw with a copper foil pattern, and the gap portion of the striped pattern is a resist. It is possible to prevent excessive build-up of the solder build-up part formed by flow soldering etc. on the copper foil pattern by adopting a structure that does not apply etc., and it is good with the screw head or frame when fixed to the frame by screw tightening. It provides a structure that guarantees secure contact. In this structure, the area where the resist is not applied is larger than the screw head, and it is desirable that there is a sufficient margin. Further, the striped copper foil patterns are connected to each other by copper foil patterns around the peripheries of the striped copper foil patterns to reduce the impedance when grounding to the frame.

[0006]

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

FIG. 1 is a plan view showing a structure according to an embodiment of the present invention.

The base material of the substrate and the copper foil pattern are alternately exposed in an arbitrary range around the screw hole, and the periphery covers the resist.

FIG. 2 shows a state after the board is soldered.

Solder rides on the exposed portion of the copper foil pattern, and the base material portion is exposed.

FIG. 3 is a sectional view taken along line A in FIG.

Further, FIG. 4 shows a state in which screws are tightened.

A screw head rides on the thinly laid solder and makes stable contact with the cushioning property of the solder. This ensures a reliable ground connection.

[0014]

As described above, since the structure of the printed board to be grounded to the frame ground of the present invention allows the solder to be evenly spread, the good contact with the screw can be maintained and the earth connection can be surely performed. The effect of appearing.

[Brief description of drawings]

FIG. 1 is an example of a printed circuit board showing an embodiment of the present invention, an enlarged partial plan view of a ground connection portion, and a resist for making the ground connection portion independent.

2 is a plan view after solder is filled in the embodiment. FIG.

FIG. 3 is an enlarged cross-sectional view of a printed circuit board according to an embodiment.

FIG. 4 is an enlarged cross-sectional view of the printed circuit board of the embodiment fixed to a frame with screws.

FIG. 5 is an enlarged cross-sectional view of a conventional printed circuit board.

FIG. 6 is an enlarged cross-sectional view of a conventional printed circuit board fixed to a frame with screws.

FIG. 7 is an enlarged cross-sectional view of a conventional printed circuit board on which solder is thinly deposited.

[Explanation of symbols]

1 screw hole 2 base materials 3 copper foil pattern 4 resist 5 Solder filling part 6 screws

Claims (3)

[Claims] 1. A structure of a frame ground contact portion of a printed circuit board, wherein a copper foil pattern is arranged in a striped pattern on the surface of the printed circuit board to ground the ground via a screw for fixing the printed circuit board. 2. The structure of a frame earth contact portion of a printed circuit board according to claim 1, wherein a contact between the solder buildup portion and the screw or the frame is ensured without applying a resist between the conductors at a portion contacting with the screw. 3. The structure of a frame ground contact portion of a printed circuit board according to claim 1, wherein the outer periphery of the striped pattern is connected to the copper foil pattern.