The four special plating methods in PCB production, are the reel linked to choose plating, through-hole plating, refers to the row of plating equipment, brush plating, this article for everyone to introduce these four special methods.
 
1. Roller linkage selection plating
The pins and pins of electronic components, such as connectors, integrated circuits, transistors, and flexible printed circuits, all use selective plating to achieve good contact resistance and corrosion resistance.
This plating method can be used manual plating production line, you can also use automatic plating equipment, a separate choice for each pin is very expensive to choose, it must use batch welding, in the plating production is usually rolled into the required thickness of the metal foil The nickel, the gold, the silver, the rhodium, the button or the tin-nickel alloy, the copper-nickel alloy, the nickel-lead alloy, and the like, are electroplated by a chemical or mechanical method.
 
2. Through-hole plating
There are a number of ways in the through-hole plating to create a layer of desired plating on the walls of the substrate, which is known as pore-wall activation in industrial applications. Its printed circuit commercial production process requires multiple intermediate storage tanks, each tank has its own control and maintenance requirements.
Through hole plating is a necessary process for the subsequent production of the drilling process. When the drill bit is drilled through the copper foil and the underlying substrate, the heat generated causes the insulating synthetic resin constituting the majority of the substrate substrate to melt, melt the resin and other drilling debris Accumulate around the hole and apply to the newly exposed hole in the copper foil.
In fact, this is detrimental to the subsequent electroplated surface, and the melted resin will remain on the wall of the substrate with a layer of thermal axis that exhibits poor adhesion to most activators, which requires the development of another Kind of techniques like stains and back etching chemistry: ink!
The ink is used to form a highly tacky, highly conductive film on the inner wall of each through-hole, so that it is not necessary to use a plurality of chemical processes, requiring only one application step, followed by heat curing, The inside of the formation of a continuous film, it does not require further processing can be directly plated. This ink is a resin-based material, it has a very strong adhesion, can be effortlessly bonded to most of the hot-polished hole wall, thus eliminating the erosion of this step.
 
3. Refers to the type of plating equipment
In the electroplating often need to be rare metal plated in the edge of the board connector, the board side of the protruding contacts or gold finger to provide a lower contact resistance and high wear resistance, the technology is called the type of plating or protruding part of the plating The
In the plating also often gold plated in the inner layer of nickel-plated board edge of the connector on the protruding contact, gold finger or board side of the protruding part of the manual or automatic plating technology, the current contact with the plug or gold on the gold finger has been plated Lead, plated button instead.
 
4. Brush plating
The last method is called "brush plating": it is an electrodeposition technique in which not all parts are immersed in the electrolyte. In this electroplating technique, only a limited area is electroplated and has no effect on the rest.
Typically, the rare metal is plated on the selected portion of the PCB, for example, such as a board edge connector. Brush plating in the electronic assembly workshop to repair the use of waste boards more. A special anode (chemical reaction inactive anode, such as graphite) is wrapped in an absorbent material (cotton swab), which is used to bring the plating solution to the place where plating is required.