" Substrate " PCB manufacturing process of a glass epoxy resin (Glass Epoxy) or similar material is made to start .
Image ( forming / wire production)
The first step is to establish a production line wiring between components . We use negative transfer (Subtractive transfer) method on the working performance of the metal conductor film . This technique is the entire surface covered with a thin layer of copper , and to eliminate some of the excess . Supplemental type transfer (Additive Pattern transfer) is another way people use less , which is just where it is needed before putting the copper wire method, but we are not here to talk about it.
If making a double-sided , so both sides of the PCB substrate are covered with foil , if making a multilayer , the next step will be to these boards stuck together.
The following flow chart describes how the wire is welded to the substrate .
Positive photoresist (positive photoresist) is made of a photosensitive agent , it will dissolve in the light ( if it is a negative photoresist through the illumination will not decompose ) . There are many ways to deal with the copper surface resist , but the most common way is to heat it , and rolling on the surface containing the photoresist (called dry film photoresist ) . It can also be used in the top spray mode liquid , but the dry film to provide a relatively high resolution , can produce a relatively thin wire.
Hood is only a template layer PCB manufacturing . In the PCB after the photoresist before exposure to UV light , a hood covering the upper portion of the photoresist can be prevented from being exposed area ( assuming positive photoresist is used ) . The place is covered with photoresist , will become wiring .
After developing the photoresist to etch the other bare copper parts. Etching process can etch the board dipped in solvent or solvent sprayed on the board . Solvents are generally used as an etching , ferric chloride (Ferric Chloride), basic amino (Alkaline Ammonia), sulfuric acid is added hydrogen peroxide (Sulfuric Acid + Hydrogen Peroxide), and copper (Cupric Chloride) chloride and the like. After the end of the etching to remove the remaining photoresist . This is known as stripping (Stripping) program .
Drilling and plating
If you are creating a multi-layer PCB, and the inside contains a buried hole or blind hole , then each layer before bonding the board must first drilling and plating. If you do not go through this step , then there is no way connected to each other .
After drilling according to the needs of drilling machinery and equipment , must be inside Kongbi plating ( plated through hole technology , Plated-Through-Hole technology, PTH). After Kongbi inside for metal processing , allowing the internal layers of the line can be connected to each other . Before starting the plating must be cleared away debris hole . This is because the epoxy resin composition after heating will produce some chemical change , and it will cover the internal PCB layers , so first cleared away . Clear and plating action will be completed in the chemical manufacturing process .
