Processing method for wrapping side surface of printed-circuit connector product with nickel gold

Abstract

The invention discloses a processing method for wrapping a side surface of a printed-circuit connector product with nickel gold. The processing method comprises the following steps of A, addition of gold-plated leads: adding leads on the corner of a square bonding pad and at a welding ring position of a solder resist covering via hole in a mode of adding the leads on the two sides; B, prevention of gold-plating permeation: adopting processes of using a photosensitive wet film as the base, and performing one-time exposure pattern transferring after photosensitive dry film protection is carried out so as to realize the prevention of gold-plating permeation; and C, performing protection while etching the leads: choosing a Dupont GMP220 thick dry film with the thickness of 2mil, and adopting an alkali etching process so as to prevent circuit corrosion and oxidization caused by attack of liquid medicine on the inlet surface.

Description

Technical field [0001] The invention relates to the technical field of printed circuit board processing, in particular to a method for processing gold on the side of a printed plug product. Background technique [0002] With the development of the communication field, the use environment of the product is becoming more and more complex. The traditional flash gold + printed plug hard gold processing PCB is used, because the side of the printed plug is the copper surface remaining after etching, and the sidewall of the pad cannot pass The customer's stricter salt spray test requirements, so the customer put forward the processing requirements of the printed plug product side wrapped nickel gold (referred to as gold). [0003] The limitations of traditional production technology to produce products with printed plugs. Taking the common flash gold + printed plug hard gold-plated optical module products as an example, the traditional process flow mainly includes the following process f...

AI Technical Summary

Problems solved by technology

[0005] First, after the surface treatment is completed, carry out alkaline etching operation, and rely on nickel gold for protection during etching. After etching, there will be copper exposure on the side wall of the printed plug and the side wall of the pad. Due to the existence of side etching factors, nickel will be produced at the same time. Gold protruding edge metal, printed plugs and pad sidewalls cannot pass the salt spray test because of exposed copper, and do not meet the requirements of the product state that the printed plugs and pad sidewalls are covered with nickel gold;

[0006] Second, after the surface treatment is completed, a solder mask is made on the finished nickel-gold layer. The gold surface cannot be roughened. The solder mask is directly combined with the gold surface, and the bonding force is poor. The surface treatment is before the solder mask, and the copper after development Insufficient cleanliness of the surface will cause solderability problems;

[0007] Third, the product IPC processed by flash gold + printed plug hard gold plating process accepts the convex edge metal formed by side etching, but when there is nickel thinning or side etching during PCB processing, the gold finger is plugged in and out of contact with the card slot There is still a hidden danger of short circuit caused by side erosion