JPS5856495A - Printed circuit board and method of producing same - 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 The present invention relates to a printed wiring board and a method for manufacturing the same.

Printed wiring boards commonly used in consumer electronic devices are
A close-up of the completed product shows that the entire surface, except for the soldering areas (land areas), has been coated with sturder resist. This printed wiring board is usually manufactured through the steps shown in FIG. First, in step I, a circuit pattern is drawn on the copper-clad laminate by screen printing or photography.

Next, in step 2, unnecessary copper foil portions are removed using an etching solution such as ferric chloride or cupric chloride. Next, in step 3, a soldering resist is applied to the entire surface except for the soldering area (land area). A screen printing method using a squeegee is used for this. Next, in step 4, write letters 1! on the front and back sides. FJN! Part No. 1, Cape Value, is printed and displayed. Next, in Step 5, the component lead wire insertion hole and the external cape are punched out using a press, and the soldering parts are treated with copper foil to prevent rust.

The conventional printed wiring board has the above structure and manufacturing method. By the way, recently, high-density components have been mounted on printed wiring boards. For this reason, very fine chip parts are used as electronic parts, and the chip part mounting work is also carried out by automatic mounting equipment. As a result, the printed wiring board itself is required to have high precision with respect to the position of the second end.

In particular, in order to improve the positional accuracy of the land portion, it is necessary to accurately determine the position at which the solder resist is to be applied. However, since solder resist is applied over almost the entire surface of the printed wiring board (the rest is the land area), there is a large amount of misalignment due to printing, and the circuit pattern KJE* has a small area ratio.
Difficult to match the rest of the coating.

This invention was made to deal with the above circumstances,
It is an object of the present invention to provide a printed power distribution board that allows land portions to be positioned with high precision and has excellent corrosion resistance, weather resistance, and abrasion resistance, and a method for manufacturing the same.

The Meiyu side of this invention will be explained below with reference to the drawings.

First, in this invention, nickel plating is used in place of the conventional solder resist. Also, as a method of leaving a land portion, a mesh resist ink is applied to this portion in advance.

Next, to explain the steps one by one, as shown in FIG. 2, in step 11, a circuit pattern is drawn on the copper-clad laminate by screen printing or photography. Next, in step 12, unnecessary copper foil parts are removed from ferric chloride or ferric chloride.
It is removed with @Hina's etching solution. Next, in step 813, K-metsukiresist ink is applied to the soldering portion (second soldering portion). Next, in step 14, the circuit pattern except the soldering portion is plated with nickel. This nickel plating may be electroless nickel plating or electrolytic nickel plating.

Next, in step 15, the previous mesh resist ink is peeled off. This exposes the land and then the work 81
At step 6, characters and symbols are printed on the front surface and &Ii. Next, in step 17, the component lead wire insertion hole, external shape, etc. are punched out using a press. A is done.

Next, when the parts are installed and soldered, the wire, machining $ 1
As shown at 8419, after the glyph 2x coating, a rosin-based 72x is applied, and soldering is performed in step 20.

As described above, according to the present invention, in the step IS, the land forming portion Km is coated with the non-stick resist ink. The area of the 2nd forming part is 10~b of the area of the printed wiring board.When applying the resist ink by screen printing,
The smaller the printing area, the lower the squeegee pressure.As a result, the friction between the squeegee and the screen is also smaller], and the screen is less likely to be distorted or stretched. It is possible to match the resist coating position with high precision.

Next, in the work@74, nickel plating is applied. This has the following effects.

In particular, electroless nickel plating is easy to handle and rarely self-decomposes, and the resulting plating film has excellent corrosion resistance, abrasion resistance, and weather resistance. It has properties that exceed those of solder resist inks. Furthermore, in the case of solder resist ink, it is difficult to completely remove the copper foil edges of the circuit pattern, and the copper foil edges may meet very thinly or be exposed, resulting in poor corrosion resistance and weather resistance. However, when plating is performed as in this method, the nickel plating film is completely covered up to the edges, so it is possible to obtain a product with excellent corrosion resistance, weather resistance, and abrasion resistance. When soldering, use rosin type 72.
By using a nickel plate, solder does not stick to the nickel, and the nickel plating can act as a solder resist.

As mentioned above, this printed wiring board and land part can be positioned at a high altitude, contributing to the packaging and miniaturization of high-density electronic components, and has excellent corrosion resistance, weather resistance, and abrasion resistance. A manufacturing method thereof can be provided.

[Brief explanation of the drawing]

1st - Butterfly Explanatory diagram showing the conventional printed wiring board manufacturing process, 2nd
The figure shows a printed wiring board manufacturing process 8 according to the present invention! FIG. IS...Process of applying Metsukiresist ink to the t-land portion, 14...Process of applying nickel plating, 15...
・Step of removing Metsuki Regis F ink. Applicant's agent Patent attorney Takehiko Suzue Figure 1
Figure 2 41

Claims (2)

[Claims] (1) A printed wiring board characterized in that the part to be soldered t#<other parts are nickel plated. (2) On the printed wiring board body on which the circuit pattern has been formed, a step of applying metskiresist ink to the land forming portion of the circuit pattern, a step of applying nickel plating to the circuit pattern after this step, and a step of applying nickel plating to the circuit pattern after this step. A method for manufacturing a printed wiring board, comprising: a step of peeling off the metskire resist ink.