JPH0529176U - Printed board - Google Patents

Abstract

(57) [Abstract] [Purpose] In soldering the ground connection that is performed when fixing the printed circuit board to the chassis or housing,
(EN) Provided is a printed circuit board capable of preventing the solder from rising at an end of a soldering pattern, eliminating a solder correction step, and reducing costs. In a printed circuit board having a conductor pattern to be soldered, the shape of the end portion of the pattern is made to be an acute angle so as to prevent the solder from rising at the end portion of the pattern during soldering, and a solder correction step is performed. The printed circuit board is not needed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a printed circuit board for mounting electronic components, and more particularly to a printed circuit board to which solder used for connection can be applied with a uniform film thickness.

[0002]

[Prior Art]

 Conventionally, when fixing a printed circuit board on which electronic components are mounted to a chassis or housing, a grounding pattern built into the printed circuit board is soldered and then connected to the chassis or housing to perform grounding. was there.

As shown in the schematic plan view of FIG. 3, with respect to the printed circuit board 1 having an earth pattern (pattern to be soldered) formed on the back surface, a resist is provided at the end where the earth pattern is formed. 4 is not applied, and the other portions are masked with resist 4. When the back surface of the substrate 1 was put in a solder bath and moved (solder flow), the solder was attached only to the portion without the resist 4.

Then, after that, when the printed circuit board 1 is fixed to the chassis or the housing, the ground pattern and the chassis or the housing are connected by solder, and the ground is connected.

In the soldering process as described above, for example, when the printed circuit board 1 coated with the resist 4 is moved in the direction of the arrow with respect to the solder bath as shown in FIG. 3, the left end of the base plate 1 is moved. It entered into the solder bath (tip) and the right end came out of the solder bath (end) at the end.

Specifically, as shown in the plan view of FIG. 4A, the conventional printed circuit board 1 has a rectangular shape or a strip shape on the board 1, and the front end portion and the end portion are opposed to each other in the solder flow direction. Then, the soldering pattern 2'made of a conductive material is formed by patterning in a vertical shape, and the solder is coded on the soldering pattern 2 '.

[0007]

[Problems to be solved by the device]

 However, in the above-mentioned conventional printed circuit board, when soldering is performed by the solder flow, as shown in the cross-sectional explanatory view of FIG. 4B, the solder rises at the end portion of the soldering pattern 2 ', and the chassis or Since it cannot be mounted on the housing, there is a problem in that solder correction must be performed to flatten the raised solder.

The present invention has been made in view of the above circumstances, and prevents the solder from rising at the terminal end of the board during soldering, so that the solder has a uniform film thickness. It is an object of the present invention to provide a printed circuit board that does not require a solder correction process.

[0009]

[Means for Solving the Problems]

 The present invention for solving the above-mentioned problems of the prior art is characterized in that, in a printed circuit board on which a pattern of soldered conductors is formed, the end portions of the pattern have an acute angle.

[0010]

[Action]

 According to the present invention, since the printed circuit board has the soldering pattern having an acute end, the solder adhesion area becomes smaller toward the end of the soldering pattern, and the adhesive force of the solder becomes smaller. It is possible to prevent excess solder from adhering to the ends of the soldering pattern during the flow, and the solder liquid is well drained when it comes out of the solder bath to prevent the solder from rising at the end. This can be prevented, and solder correction is not required, and the cost can be reduced.

[0011]

Embodiment An embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a plan view of the back surface of a printed circuit board according to an embodiment of the present invention. In the printed circuit board of this embodiment, a pattern (soldering pattern) 2 for soldering for grounding is provided on the back surface of the substrate 1 on which electronic components are mounted.

The soldering pattern 2 of this embodiment is formed by patterning a conductive material such as copper (Cu), gold (Au) plating, silver (Ag) plating, etc. Both of them are formed in a dogleg shape, and specifically, as shown in FIG. 1A, the angle of the dogleg end is about 45 degrees.

Next, the soldering state of the printed circuit board of this embodiment will be described. FIG. 1 (b) is a cross-sectional explanatory view showing a solder adhesion state when soldering is performed using the printed circuit board of this embodiment.

Soldering is performed by putting the printed board 1 in a solder bath and flowing it in the direction of the arrow. As shown in FIG. 1B, in the printed circuit board 1 of the present embodiment, the solder 3 does not rise at the terminal end of the soldering pattern 2, and the solder 3 can be adhered flat with a uniform film thickness.

That is, since both the tip end portion and the end portion of the soldering pattern 2 are formed in a dogleg shape, the solder adhesion area becomes smaller toward the end of the soldering pattern 2. As a result, the adhesive force of the solder becomes small, the solder liquid runs out easily during the solder flow, and it is possible to prevent the solder from rising at the end of the soldering pattern 2.

According to the printed circuit board of the present embodiment, since solder can be evenly deposited with a uniform film thickness, the step of solder correction can be omitted, and the cost can be reduced, and at the same time, due to a correction error or the like. There is an effect that it is possible to prevent a decrease in yield.

Further, according to the present embodiment, there is an effect that the process of solder correction can be easily omitted by slightly changing the shape of the soldering pattern without adding new equipment or construction method. ..

In the present embodiment, the angle of the dog-legged portion of the tip portion and the terminal portion of the soldering pattern 2 is set to 45 degrees. However, as a result of performing experiments by changing the shape and the angle of both end portions, both end portions are shown. If the angle is in the range of 30 degrees to 60 degrees, the solder does not rise at the end and a good solder shape can be obtained, and the solder correction step is unnecessary, and the same effect as this embodiment can be obtained. It is what is done.

As another embodiment, as shown in the plan view of FIG. 2, the shape of the end portion of the soldering pattern 2 is changed to a shape obtained by cutting diagonally instead of the dogleg shape. Even in this case, the same effect as that of the present embodiment can be obtained.

[0020]

[Effect of the device]

 According to the present invention, since the printed circuit board has the soldering pattern having an acute end, the solder adhesion area becomes smaller toward the end of the soldering pattern, and the adhesive force of the solder becomes smaller. It is possible to prevent excess solder from adhering to the end of the soldering pattern during the flow, and to prevent the solder liquid from running out of the solder bath and prevent the solder from rising at the end. Therefore, there is an effect that solder correction is unnecessary and cost can be reduced.

[Brief description of drawings]

FIG. 1A is a plan view of a printed circuit board according to an embodiment of the present invention, and FIG. 1B is a sectional view of a printed circuit board according to the present embodiment when soldered.

FIG. 2 is a plan view of a printed circuit board according to another embodiment.

FIG. 3 is a schematic plan view of a printed circuit board showing how to apply a resist when soldering an earth pattern.

FIG. 4A is a plan view of a conventional printed circuit board, and FIG. 4B is a cross-sectional view of a conventional printed circuit board soldered.

[Explanation of symbols]

1 ... Printed circuit board, 2 ... Soldering pattern, 3 ...
Solder, 4 ... Resist

Claims (1)

[Scope of utility model registration request] 1. A printed circuit board on which a conductor pattern to be soldered is formed, wherein the shape of an end of the pattern is an acute angle.