JPS62296597A - Printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a printed wiring board used in electrical equipment.

BACKGROUND OF THE INVENTION In recent years, high-density packaging of printed wiring boards has progressed, and the shape of solder lands due to no solder resist formation is becoming important because it causes solder bridges when the solder resist is printed misaligned.

An example of a conventional printed wiring board will be described below with reference to the drawings.

4 and 6 show conventional printed wiring boards. In FIGS. 4 and 6, reference numeral 11.14 denotes a wiring foil, which has a solder land 12 at one end of the wiring foil 14 close to the wiring foil 11. The wiring foils 11 and 14 are covered with a solder resist 13, and a solder land 12 is formed in the non-printed area of the solder resist 13. 16 is an insertion hole for an electric component. In the case of FIG. 4, it is a circular solder land, and in the case of FIG. 6, it is a D-shaped solder land.

In the printed wiring board configured as described above, the insertion hole 16
The lead of the electrical component is inserted into the lead and the surrounding solder land is soldered to ensure continuity and mechanical fixation of the electrical component.

Problems to be Solved by the Invention However, in the above configuration, the solder land 12
When the adjacent wiring foil 11 is close to each other, when a misalignment occurs in the printing process of the solder resist 13, the wiring foil 11 is exposed as shown in FIG. 5, and the soldering with the solder land 12 is sometimes difficult. There is a high possibility that a short circuit will occur. On the other hand, the shape of the solder land shown in FIG. 6 is effective when printing misalignment occurs in the direction of the wiring foil 11 as shown in FIG. 7, but as shown in FIG. If printing misalignment occurs in the direction, the solder land 12 becomes smaller and the amount of solder for fixing the leads of the electrical component decreases, resulting in poor mechanical fixing strength of the electrical component and reliability of conduction by soldering. Moreover, the soldering work becomes worse. Therefore, in the conventional printed wiring board, the wiring foil 11 and the solder land 12 shown in FIG.
The distance between them has to be large, which poses a problem in that it hinders high-density mounting of electrical components.

In view of the problem described in item 1, the present invention improves the reliability of soldering of electrical parts even if the printing misalignment of the resist occurs.
Furthermore, the present invention provides a printed wiring board that enables high-density packaging.

Means for Solving the Problems In order to solve the above problems, the printed wiring board of the present invention has the following features:
The shape of the solder land with no solder resist formed is fan-shaped on the side adjacent to the wiring foil side.

Effects of the present invention With the configuration described in the above, it is possible to secure the size of the solder land even if the solder resist is printed misaligned, and it is also possible to reduce the unformed portion of the adjacent wiring foil by half a meter and seven strokes. Bonding is less likely to cause short circuits with adjacent wiring foils, reduces deterioration in soldering strength, and enables high-density mounting of electrical components.

EXAMPLE Hereinafter, a printed wiring board according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a printed wiring board according to a first embodiment of the present invention. In Figure 1, 1°4 is wiring foil, 2
3 is a solder land, 3 is a solder resist, and the non-resist solder land 2 has a fan-shaped notch 6 in the adjacent wiring foil 1, and is characterized by having a ring slit shape as a whole. .

In the above configuration, first, as shown in FIG. 2, if a printing misalignment of the solder resist 3 occurs on the adjacent wiring foil 1 side, the portion of the wiring foil 1 where the solder resist 3 is not covered is minute, and this Therefore, short circuits due to soldering are less likely to occur. Next, as shown in Figure 3, solder resist 3 is applied in the opposite direction to Figure 2.
When a printing misalignment occurs, the solder land becomes a substantially circular solder land although it is deformed, so that the soldering strength of the component lead can be ensured.

As described above, according to this embodiment, by providing the circular solder land fan-shaped notch, it is possible to ensure a short circuit with the adjacent wiring foil and an appropriate soldering area when the solder resist prints out of alignment. Density packaging can be achieved.

Effects of the Invention As described above, in the printed wiring board of the present invention, the shape of the solder land is a circular slit shape with a fan-shaped notch on the side of the adjacent wiring foil, so that even if the printing misalignment of the solder resist occurs, the printed wiring board of the present invention can be easily fixed. It is possible to obtain a printed wiring board that is less likely to be short-circuited with a wiring foil and to have less reduction in soldering strength, thereby realizing high-density packaging.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the printed wiring board of the present invention, FIGS. 2 and 3 are explanatory diagrams of the printed wiring board when misalignment of the solder resist occurs, and FIGS. FIG. 6 is a plan view of a conventional printed wiring board, and FIGS. 5, 7, and 8 are explanatory views of the same printed wiring board when misalignment of solder resist occurs. 1.4...Wiring foil, 2...Solder land, 3...Resist, 6...Component insertion hole, 6...Fan Shape cutout. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 4
Figure 7 Figure 8

Claims (1)

[Claims] A printed wiring board that has a wiring foil on the surface and a solder resist formed to include the wiring foil, and the shape of the solder land that should be exposed due to the non-formation of the solder resist is set adjacent to the solder land portion. A printed wiring board characterized in that the wiring foil side has a circular slit shape with a fan-shaped cutout.