JPH07131139A - Wiring board for electronic parts - Google Patents

Abstract

(57) [Abstract] [Purpose] To efficiently collect the molten solder in the land pattern on the wiring board and realize stable terminal soldering of electronic components. [Structure] When connecting a wiring board 1 and a terminal 2 of an electronic component 3 with a solder 5, a land pattern 4 for soldering the terminal on the wiring board 1 and a protrusion continuously provided on the land pattern 4 are formed. And one or more auxiliary land patterns 6 in the shape of a circle. When the solder paste is applied to the land pattern 4 and the auxiliary land pattern 6 and the electronic component 3 is set and reflowed, the molten solder on the auxiliary land pattern 6 moves to the land pattern 4 side.
The amount of solder on the top can be increased and soldering can be ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board for soldering electronic parts.

[0002]

2. Description of the Related Art A conventional wiring board for electronic parts is shown in FIG. In FIG. 3, (a) is a top view, (b) is a side view, 1 is a wiring board manufactured by a general method, 2 is a terminal provided on the electronic component 3, and tin is used as necessary. Plated and solder plated. A land pattern 4 is provided on the wiring board 1 for soldering the terminals 2, and the terminals 2 are connected to the land patterns 4 by the solder 5.

In order to realize the solder connection of the above-mentioned conventional example, first, a wiring board 1 is prepared, and a solder paste is applied to a predetermined land turn 4 on the wiring board 1 by screen printing or the like. The solder paste applied at this time is generally the same size as or slightly smaller than the land pattern 4. Next, the electronic component 3 is placed at a position where the terminal 2 is on the land pattern 4, and the whole is heated by a hot air oven or the like, or is locally heated by a light beam, a hot air jet, or the like to remove the solder paste. Reflow, then solidify to complete the connection.

FIG. 4 shows another conventional example. Figure 4
2A is a top view and FIG. 2B is a side view. The wiring board 11 is provided with through holes 15 in the land pattern 14 for inserting the terminals 12 of the electronic component 13. Solder paste is applied to the land pattern 14, the terminals 12 of the electronic component 13 are passed through the through holes 15 from the back side of the wiring board 11, and the electronic component 13 is fixed to the wiring board 11 with an adhesive 16. Is bent on the land pattern 14. Next, by heating the whole in a hot air oven or the like, the solder paste reflows and solidifies to become the solder 17, and the terminal 12 is connected to the land pattern 14.

As described above, even if the above-mentioned conventional method is used,
The wiring board and the terminals of the electronic component can be connected by soldering.

[0006]

However, the above-mentioned conventional solder connection has the following problems. That is, when the solder paste is applied to the land pattern on the wiring board by screen printing or the like, the application amount of the solder paste varies, and when the amount of the solder decreases, the terminals of the electronic component are deformed and the terminal floating occurs. If, for example,
Soldering becomes uncertain, connection strength becomes insufficient, connection reliability deteriorates, and in the worst case, solder connection becomes impossible.

As a countermeasure, a method of increasing the thickness of the screen at the time of printing the solder paste to secure the coating amount can be considered. In that case, however, the solder paste is less likely to escape from the opening of the screen and the coating amount is The problem that the variation becomes large occurs.

Further, the amount of solder can be increased by printing by making the aperture size of the screen larger than the land pattern. However, when the solder paste is applied to a size larger than the land pattern, the solder melted during the reflow heating cannot be collected in the land pattern and is left as a solder ball on the wiring board. As a result, it becomes a conductive foreign substance, which causes a defect such as a circuit short circuit.

Further, the amount of solder can be increased by additionally supplying solder paste with a dispenser or placing a solder preform, but in this case, equipment cost and man-hours increase, and There is a problem of increasing costs.

The present invention solves the above-mentioned conventional problems, and provides a wiring board for an electronic component, which can improve the soldering quality of the wiring substrate and the terminals of the electronic component without increasing the processing cost. The purpose is to do.

[0011]

In order to achieve the above-mentioned object, the present invention provides a land pattern for soldering terminals of an electronic component, and one protrusion-like pattern continuously provided on the land pattern. The auxiliary land pattern described above is provided. The land pattern may be provided with a through hole for passing a terminal of the electronic component.

[0012]

Therefore, according to the present invention, the solder paste is applied to both the land pattern and the auxiliary land pattern,
When the terminals of the electronic component are mounted and heated, the solder paste applied to the auxiliary land pattern of the molten solder paste moves to the land pattern side of a wider area due to its own weight and wetting and spreading force, The amount of solder supplied to the pattern increases, and the solder connection of the terminals can be ensured.

[0013]

(Embodiment 1) FIG. 1 shows the configuration of a first embodiment of the present invention. For convenience of explanation, the same elements as those used in the conventional example of FIG. The symbol is attached.
In FIG. 1, (a) is a top view and (b) is a side view. Reference numeral 1 is a wiring board, 2 is a terminal provided on the electronic component 3, and tin plating, solder plating, or the like is applied as necessary. A land pattern 4 is provided on the wiring board 1 for soldering the terminals 2, and is connected to the terminals 2 by the solder 5. Reference numeral 6 denotes one or more protrusion-shaped auxiliary land patterns for collecting the solder, and in this embodiment,
Four auxiliary land patterns formed in a wedge shape are provided so that their respective bases are continuous with both corners and both sides of the land pattern 4.

In order to realize the solder connection in the first embodiment, first, the wiring board 1 is prepared, and the predetermined land turns 4 and auxiliary land turns 6 on the wiring board 1 are prepared.
Solder paste is applied to by screen printing or the like. The solder paste applied at this time is the same as or slightly smaller than the land pattern 4 and the auxiliary land turn 6. Next, in the electronic component 3, the terminal 2 has the land pattern 4
The solder paste is reflowed by placing it on the upper position and heating the whole with a hot air oven or the like or locally heating with a light beam, hot air jet, etc. Hold and connect to the connection part of. At this time, of the melted solder, the melted solder on the auxiliary land pattern 8 moves to the side of the land turn 4 having a larger area due to its own weight and the wetting and spreading force between the melted solder and the auxiliary land pattern 8. Because
The amount of solder supplied to the land pattern 4 for soldering the terminals 2 can be increased.

As described above, according to the first embodiment,
Since the amount of solder supplied to the land pattern 4 increases, it is possible to prevent a defective solder connection due to variations in the amount of coating and floating of the terminals 2. Further, since it is not necessary to increase the thickness of the printing screen, the solder paste does not easily come off from the screen, and the variation in the applied amount does not increase. Further, since the aperture size of the screen can be made the same as that of the land pattern, there is no fear of generating solder balls, and problems such as short circuit will not occur. Furthermore, since a sufficient amount of solder paste can be applied by printing once, there is no increase in equipment cost and man-hours.

(Embodiment 2) FIG. 2 shows a second embodiment of the present invention. For convenience of explanation, the same reference numerals are given to the same elements as those used in the conventional example of FIG. It is attached. Figure 2
2A is a top view and FIG. 2B is a side view. 1
Reference numeral 1 is a wiring board, and 12 is a terminal provided on the electronic component 13, and tin plating, solder plating, or the like is applied as necessary. Reference numeral 14 is a land pattern provided on the wiring board 11 for soldering the terminals 12, and reference numeral 15 is a through hole provided in the land pattern 14 for passing the terminal 12. Reference numeral 16 is an adhesive for holding the electronic component 13 on the back surface of the wiring board 11, and 17 is solder for connecting the terminal 12 to the land pattern 14. 18
Is one or more protrusion-shaped auxiliary land patterns for collecting the solder, and in the present embodiment, 4 is formed in a wedge shape.
One auxiliary land pattern is provided so that its base is continuous with each corner of the land pattern 14.

For the solder connection in the second embodiment, the wiring board 11 in which the land pattern 14 and the auxiliary land pattern 18 are coated with the solder paste is prepared, and the through hole 15 is formed.
The terminal 12 is inserted into the wiring board 11, the electronic component 13 is fixed to the wiring board 11 with the adhesive 16, and the terminal 12 is bent and placed on the land pattern 14. Then, the whole is heated by a hot air oven or the like to reflow the solder paste. At this time, similar to the above-described embodiment, the molten solder on the auxiliary land pattern 18 moves to the land pattern 14 side, increasing the amount of solder on the land pattern 14.

As a result, also in this embodiment, the same operation and effect as those obtained in the first embodiment can be obtained.

In the above first and second embodiments,
Although the land pattern for connecting the terminals by soldering is rectangular, the same effect can be obtained with a round shape or another shape.

[0020]

As is apparent from the above embodiment, the present invention provides a land pattern for soldering terminals of an electronic component, and one or more auxiliary protrusions provided continuously to the land pattern. Since the molten solder on the auxiliary land pattern moves to the land pattern side during reflow, it is possible to increase the amount of solder supplied to the land pattern. Even if the terminal of the electronic component rises, the solder connection can be ensured.

[Brief description of drawings]

FIG. 1A is a top view of a wiring board on which an electronic component according to a first embodiment of the present invention is mounted, and FIG. 1B is a side view of FIG.

FIG. 2A is a top view of a wiring board on which an electronic component is mounted according to a second embodiment of the present invention. FIG. 2B is a side view of FIG.

3A is a top view of a wiring board on which a conventional electronic component is mounted, and FIG. 3B is a side view of FIG.

4A is a top view of a wiring board on which a conventional electronic component is mounted, and FIG. 4B is a side view of FIG.

[Explanation of symbols]

 1 Wiring Board 2 Terminal 3 Electronic Component 4 Land Pattern 5 Solder 6 Auxiliary Land Pattern 11 Wiring Board 12 Terminal 13 Electronic Component 14 Land Pattern 15 Through Hole 16 Adhesive 17 Solder 18 Auxiliary Land Pattern

Claims (2)

[Claims] 1. A wiring board for electronic parts, comprising a land pattern for soldering terminals of an electronic part, and one or more projecting auxiliary land patterns continuously provided on the land pattern. 2. A land pattern for soldering a terminal of an electronic component is provided with a through hole for inserting the terminal.
A wiring board for an electronic component as described above.