JPH0355899A - Printed wiring board - Google Patents

Abstract

PURPOSE:To improve solder disconnection, and to provide a printed wiring board which eliminates a solder bridge by forming a conductor pattern part for soldering an electronic component or the like in a sharpened shape. CONSTITUTION:A land shape is formed at an acute angle. In case of soldering, solder tends to retain at the land 2 due to surface tension of melted solder, but an action of an opportunity of breaking the surface tension is operated at the acute part, and a solder disconnection is improved. Since the solder amount of the land is reduced, it can prevent a solder bridge.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention is directed to the improvement of printed wiring boards. [Conventional technology] Conventionally, even when the pitch between legs of D I P I C is small (for example, 1.778 mm, 1.78 mm), the land provided on the printed board is a general land as shown in Fig. 7. I am using it. In Figure 7. (1) is a hole provided in the printed board, (2> is a land. Various shapes of lands are used, and in Fig. 7 (a), the shape of land (2) is circular, and in Fig. 7 (a), the shape of land (2) is circular; b) shows the case where the land (2) has an elliptical shape, FIG. 7(c) shows the case where the land (2) has the shape of an ellipse, and FIG. 7(d) shows the case where the land (2) has the shape of a cut land. [Problems to be Solved by the Invention] In the conventional printed wiring board as described above, when soldering the legs of electronic components, surface tension makes it difficult to cut the solder and the solder accumulates on the lands, causing As shown in Figure 8, there is a problem in that solder bridges that bridge adjacent lands tend to occur.This invention was made to solve this problem. [Means for Solving the Problem] A printed wiring board according to the present invention is a printed wiring board on which electronic components, etc. are mounted, in which the electronic components, etc. are soldered. In this invention, the conductor pattern part has a pointed shape. [Function] In this invention, the shape of the conductor pattern part is made into an acute angle to improve solder cutting. [Example] Fig. 1 shows this example. FIG. 2 is a diagram showing the land-shaped structure of a printed wiring board according to an embodiment of the invention. In the diagram, (1) is a hole provided in the printed wiring board. (2) is a variety of lands with acute-angled shapes. By making the land shape acute as shown in Figure 1, when soldering, the solder tends to remain on the land (2>) due to the surface tension of the melting solder, but the acute angle creates an opportunity to break the surface tension. As a result, the amount of solder on the land portion is reduced, and solder bridging is prevented as shown in Figure 6.Also, if the land has an oval or other shape, In this case, the above-mentioned effect can be achieved by making the solder resist (3) punched out at an acute angle as shown in Figure 2. Figure 3 is another example of making the land shape acute.
Figure 4 shows another example where the solder resist shape has an acute angle. In this case as well, the effects described above are achieved. Figure 5 (a) shows another example in which only the land (2) has an acute angle, and Figure 5 (b) shows another example in which only the solder resist (3) has an acute angle.
) is shown in FIG. 5(c) as an example in which the land (2) and the solder resist (3) have acute-angled shapes. These cases also produce the same effects as described above. [Effects of the Invention] As explained above, this invention has the effect of improving solder breakage and preventing solder bridging by making the land shape or the solder resist shape, and the land shape and the solder resist shape at an acute angle.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a land shape of a printed wiring board according to an embodiment of the present invention, FIG. 2 is a diagram showing a solder resist shape of a printed wiring board according to an embodiment of the present invention, and FIGS. 3 to 5 6 is a diagram showing the land shape and solder resist shape of a printed wiring board according to another embodiment of the present invention.
The figure is a cross-sectional view of the printed wiring board of this invention. Figure 7 shows the land shape of a conventional printed wiring board. Figure 8 is a cross-sectional view of a conventional printed wiring board. In the figure, (1)...hole, (2)...land, (
3)...Solder resist. Note that the same reference numerals in each figure indicate the same or equivalent parts. Figure 2 Figure 3 Figure 4 Figure 5 (0) (b) (C)

Claims (1)

[Claims] 1. A printed wiring board on which electronic parts and the like are mounted, characterized in that a conductor pattern portion to which the electronic parts and the like are soldered has a sharp shape.