Four Special Electroplating Methods for Circuit Board Production (Part 1)

1.Finger Row Electroplating    Circuit board production often requires rare metals to be plated on edge connectors, edge protruding contacts, or gold fingers to provide lower contact resistance and higher wear resistance. This technique is called finger row plating or protruding part plating. . Gold is often plated on the protruding contacts of the board edge connector with the inner plating layer of nickel. The gold fingers or the protruding parts of the board edge are manually or automatically plated. At present, the gold plating on the contact plug or gold finger has been plated or led , Instead of plated buttons. The process is as follows: 1) Strip the coating to remove the tin or tin-lead coating on the protruding contacts 2) Rinse with washing water 3) Scrubbing with abrasives 4) The activation is diffused in 10% sulfuric acid 5) The thickness of nickel plating on the protruding contacts is 4 -5μm 6) Clean and demineralize water 7) Gold penetration solution treatment 8) Gold plated 9) Cleaning 10) Drying

2. Through-Hole Plating There are many ways to build a layer of electroplating layer on the whole wall of the substrate drilled hole. This is called hole wall activation in industrial applications. The commercial production process of its printed circuit requires multiple intermediate storage tanks. The tank has its own control and maintenance requirements. Through-hole plating is a necessary follow-up process of the drilling process. When the drill bit drills through the copper foil and the substrate underneath, the heat generated to melt the insulating synthetic resin that constitutes most of the substrate matrix, the molten resin, and other drilling debris It accumulates around the hole and is coated on the newly exposed hole wall in the copper foil. In fact, this is harmful to the subsequent electroplating surface. The molten resin will also leave a layer of the hot shaft on the whole wall of the substrate, which exhibits poor adhesion to most activators. This requires the development of a class of similar de-staining and etch-back chemical technologies.   

A more suitable method for prototyping printed circuit boards is to use a specially designed low-viscosity ink to form a high-adhesion, high-conductivity film on the inner wall of each through-hole. In this way, there is no need to use multiple chemical treatment processes, only one application step, followed by thermal curing, can form a continuous film on the inner side of all the hole walls, which can be directly electroplated without further treatment. This ink is a resin-based substance that has strong adhesion and can be easily adhered to the walls of most thermally polished holes, thus eliminating the step of etch-back.