JPH0147911B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wiring board soldering method for soldering plate-shaped electrical components having no leads.

The prior art will be explained with reference to FIGS. 1, 2, 3, and 4. Fig. 1 is a perspective view of a plate-shaped electrical component without leads, Figs. 2 and 4 are plan views showing part of a wiring board according to the prior art, and Fig. 3 is a sectional view taken along line A-A in Fig. 2. It is. In Figures 1, 2, 3, and 4, 1 is a plate-shaped electrical component, 2 is an electrode portion of the plate-shaped electrical component, 3 is a substrate electrode, 4 is a paste-like solder, and 5 is a substrate.

A wiring board for soldering connection of a plate-shaped electrical component without leads according to the prior art has first, second,
As shown in Figures 3 and 4, first, the electrode 3 on the substrate 5 is
A paste-like solder 4 is formed by printing to cover the plate-like electrical component 1, and then the plate-like electrical component 1 is mounted, and the paste-like solder 4 is heated and melted to connect the electrode portion 2 of the plate-like electrical component and the board electrode 3 to the solder 4. Obtained by soldering connection via.

Here, as shown in FIG. 2, the length of the plate-shaped electric component 1 is L, the width is W, and the substrate electrodes 3 on two opposing sides
When the interval is a, the length is b, the width is c, and the width of the pattern of the paste solder 4 is d, in the conventional technology, the width c of the board electrode 3 and the paste solder are smaller than the width W of the plate-shaped electrical component 1. Because the width d of the pattern of the solder 4 is wide, it seems that there is a degree of freedom in the mounting position of the plate-shaped electrical component 1, but in reality, the mounting position may shift or be mounted tilted, resulting in two parts facing each other. If the degree of adhesion between the paste-like solder 4 on the surface and the electrode portions 2 of the plate-shaped electric component 1 is different, the plate-shaped electric component 1 will be pulled to one of the substrate electrodes 3 by the melting of the solder, as shown in FIG. connected to the other substrate electrode 3
The drawback was that it caused poor solder connections on the side.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, improve the yield of the solder connection process, and further facilitate the mounting work of plate-shaped electrical components. The present invention provides a method for soldering a board.

The main point of the present invention is that by providing an electrode pattern that is narrower than the width of the chip component and a solder pattern that is wider than the width of the chip component on the electrode pattern, mounting of the plate-shaped electrical component is facilitated. The purpose is to ensure that the solder is connected to the substrate electrode even if the solder is pulled and moved by the substrate electrode due to melting of the solder.

The present invention will be explained below with reference to FIGS. 5 and 6. FIG. 5 is a plan view of a portion of a wiring board showing an embodiment of the present invention, and FIG. 6 is a sectional view taken along line BB in FIG. In FIGS. 5 and 6, 1 is a plate-shaped electric component, 2 is an electrode part of the plate-shaped electric component, 3 is a substrate electrode,
4 is paste solder, and 5 is a substrate.

As shown in FIGS. 5 and 6, the wiring board according to the present invention for soldering plate-shaped electrical components without leads is first formed by printing a paste-like solder 4 to cover the electrodes 3 on the board 5. Then, the plate-shaped electric component 1 is mounted, and the paste-like solder 4 is mounted.
It is obtained by heating and melting and connecting the electrode part 2 of the plate-shaped electric component and the substrate electrode 3 via solder 4'. The specific pattern dimensions of the wiring board according to the present invention are as shown in FIG.
When the interval is a′, the length is b′, the width is c′, and the width of the paste solder 4 pattern is d′, d′>W>c′ and a′+
It is in the range of 2b'>L≧a'+b'. From this pattern dimension, even if the pattern width c' of the board electrode 3 is narrower than the width W of the plate-shaped electrical component 1, the pattern width d' of the paste solder 4 is wider than the width W of the plate-shaped electrical component 1, so the mounting position It allows for greater flexibility in accuracy and makes mounting work easier. Moreover, since the relationship between the pattern of the plate-shaped electric component 1 and the substrate electrode 3 is W>c', a'+2b'>L≧a'+b', the plate-shaped electric component 1 is attached to one of the substrate electrodes 3 by melting the solder. Even if it is pulled and connected, it will not come off from the other substrate electrode 3 and will not cause a solder connection failure.

As described in detail above, the present invention provides a degree of freedom in the mounting position accuracy of the plate-shaped electrical component, and does not cause a solder connection failure even if the plate-shaped electrical component moves due to being pulled by the board electrode due to solder melting. This has the effect of improving the yield in the process, making it easier to mount the plate-shaped electrical components, and making the width of the substrate electrode smaller than before, making high-density packaging possible.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a plate-shaped electrical component without leads, Figs. 2 and 4 are plan views showing part of a wiring board according to the prior art, and Fig. 3 is a sectional view taken along line A-A in Fig. 2. , FIG. 5 is a plan view of a portion of a wiring board showing an embodiment of the present invention, and FIG. 6 is a sectional view taken along line BB in FIG. 1: Plate electric component, 3: Board electrode, 4: Paste solder, 5: Board.

Claims (1)

[Claims] 1. In the solder connection of a plate-shaped electrical component without leads, an electrode pattern narrower than the width of the plate-shaped electrical component and a solder pattern wider than the width of the plate-shaped electrical component are provided on the electrode pattern. After mounting the plate-shaped electrical component on the solder pattern, the solder is heated and melted to make the solder connection of the plate-shaped electrical component. However, the pattern dimensions are as follows: L is the length of the above plate-shaped electrical component, W is the width of the above-mentioned plate-shaped electrical component, and When the distance between the two opposing electrode patterns is a', the length is b', the width is c', and the width of the solder pattern is d', d'>W>c' and a'+2b'>
A method for soldering a wiring board, characterized in that L≧a′+b′.