JPS61241995A - 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 [Field of Industrial Application] The present invention relates to a printed wiring board in which through-hole plating holes for connection of the printed wiring board are filled with solder resist ink. - [Prior Art] Conventionally, through-hole plating holes for connection in printed wiring boards were filled by soldering. FIG. 2 is a sectional view showing a part of a conventional printed wiring board disclosed, for example, in Japanese Patent Application Laid-Open No. 56-91496. In the figure, 1 is a printed wiring board, 2 is a solder resist ink on the side with the number of components υ, 3 is a solder resist ink on the soldering side, 4 is a through-hole plating hole for connection, and 5 is a solder.

Now, when the printed wiring board 1 is subjected to an in-circuit tester, the printed wiring board 1 performs vacuum suction to establish continuity with the contact probes of the in-circuit tester. At this time, the vacuum suction power is improved by blocking the holes in the printed wiring board 1.

Ensures continuity with the contact probe.

Among the holes in the printed wiring board 1, the connection through-hole plating holes 4 are usually filled by the following method.

As shown in FIG. 2 above, the solder resist ink 3 on the soldering surface of the printed wiring board 1 is applied avoiding the connection through-hole plating holes 4, and the solder resist ink 2 on the component mounting surface is applied. The coating is also applied to the connection through-hole plated holes 4. For this reason, it is necessary to attach the parts of the connection through-hole plated hole 4 [at the end of the fitl].
The component mounting surface side solder resist ink 2 drips a little into the connection through-hole plating hole 4. To avoid such dripping of the solder resist ink 2 on the component mounting surface, prevent the solder 5 soldered from the soldering surface side into the connection through-hole plated hole 4 from rising, and solder onto the component mounting surface side. The connection through-hole plating hole 4 is filled in such a way that the connection through-hole plating hole 4 does not reach the hole 5.

[Problem that the invention seeks to solve]

In the conventional printed wiring board as described above, the connection through-hole plating holes 4 are filled with solder 5 as described above.
By reducing the diameter of the through-hole plated hole 4 for connection.

There was a problem in that the connection through-hole plating holes 4 were not reliably filled with the solder 5, and as a result, the vacuum suction force against the printed wiring board IK was reduced.

This invention was made to solve these problems, and eliminates solder bridges.

To obtain a printed wiring board which can improve suction force when vacuum suctioning a printed wiring board when the printed wiring board is subjected to an in-circuit tester by filling through-hole plating holes for connection.

[Means for solving problems]

In the printed wiring board according to the present invention, solder resist ink is also applied onto the connection through-hole plating holes in order to fill the connection through-hole plating holes, and after drying,
Solder resist ink is again applied to the connection through-hole plating holes on the soldering surface side to fill the holes.

[Effect]

In the printed wiring board of the present invention, to fill holes as large as the connection through-hole plating, solder resist ink is dripped into the connection through-hole plating using a mask that allows the solder resist ink to enter the connection through-hole plating, and Apply ink using a mask that covers the connection through-hole plating holes on the soldering surface side, and fill in the connection through-hole plating holes.

〔Example〕

FIG. 1 is a sectional view showing a part of a printed wiring board according to an embodiment of the present invention. In the figure, 1 is a printed wiring board, 2 is solder resist ink on the mounting surface of the component mounting 9, 3 is solder resist ink on the soldering surface, 4 is a through hole for connection to be filled, and 6 is a through hole for connection. Solder resist ink for reapplication used for filling plating holes 4.

7 is a through-hole plated hole for attaching parts.

Next, a method of filling the connection through-hole plating holes 40 of the printed wiring board 1, which is an embodiment of the present invention shown in FIG. 1, will be described. The solder resist ink 2 on the component mounting side of the printed wiring board 1 is as follows.

Using a commonly used roughness solder resist mask (not shown), apply it on the through-hole plating holes 4 for connection, and apply the solder resist to the through-hole plating holes 7 for attaching one component. The solder resist used is coated with a lot of heat.

Solder resist ink 3 on the soldering side is applied onto the connection through-hole plating hole 4 using a mask with a slightly larger roughness, and soldering is carried out into the connection through-hole plating hole 4. The surface-side solder resist ink 3 is allowed to sag.

At this time, the escape of the solder resist from the through-hole plating holes 7 for component mounting is completely prevented, and the adhesion of solder resist ink to the lands of the through-hole plating holes 70 for component mounting due to bleeding is completely prevented. The re-applying solder resist ink 6 is applied to the through-hole plating holes 4 for connection on the soldering surface side using a normally used solder resist mask with roughness, and is applied to the through-hole plating for attaching 1g products. The hole 7 is also coated with two coats of solder resist ink, rather than the solder resist ink that is normally used.

〔Effect of the invention〕

As explained above, in the printed wiring board, this invention
Since the through-hole plating holes for connection are filled with solder resist ink, the through-hole plating holes for connection can be reliably filled, and the vacuum suction force against the printed wiring board when using an in-circuit tester is improved. In addition, since the connection through-hole plating holes are filled with solder resist ink instead of solder, excellent effects such as the elimination of solder bridges caused by the connection through-hole plating holes are achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of a printed wiring board according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a part of a conventional printed wiring board. In the diagram, 1... Printed wiring board, 2... Solder resist ink on the side to which parts are attached, 3... Solder resist ink on the side to be soldered, 4... Through-hole plating hole for connection. , 6... Solder resist ink for reapplication. 7...Through-hole plating hole for parts plating. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (3)

[Claims] (1) A printed wiring board characterized in that the through-hole plating holes for connection are filled with solder resist ink. (2) The solder resist ink is printed so as to fill the plating holes of the connection through-holes, so that the solder resist ink drips into the connection through-hole plating holes. The printed wiring board according to claim 1, characterized in that the printed wiring board is filled with hole plating. (3) The printed wiring board according to claim 1, wherein the solder resist ink is printed twice on the soldering surface side of the printed wiring board.