- Aug 07, 2017 -
What is the PCB production process?
The first step in the production is to create wiring between parts. We use the negative transfer (Subtractive transfer) way to work negatives in the metal conductor. This technique is to spread the entire surface of a thin layer of copper foil, and the excess part to eliminate. Additive Pattern transfer is another way in which fewer people use it, which is the only way to apply copper on the need, but we are not talking about here. If the production of double-sided panel, then the PCB board> PCB board on both sides of the substrate will be covered with copper foil, if the production of multi-layer board, the next step will be the board stick together.
Drilling and plating
If you are making a multi-layer PCB board> PCB board, and inside the hole or blind hole, then each layer of the board must be in the first hole before drilling and plating. If you do not go through this step, then no way After the drilling of the machine according to the drilling requirements, the hole must be electroplated (Plated-Through-Hole technology, PTH). In the hole after the metal processing, you can let the internal Of the layers of the lines can be connected to each other. Before starting the plating, you must first clear the hole in the debris. This is because the resin epoxy after heating will produce some chemical changes, and it will cover the internal PCB "PCB Board, so first clear away. Both the removal and plating actions are done in the chemical process.
PCB board pressure
Each monolithic layer must be pressed to create a multilayer board. The clamping action involves adding an insulating layer between the layers, and sticking to each other. If there are several layers of guide holes, then each layer must be repeated. The wiring on the outer sides of the multilayer board is usually handled after laminating the multilayer board. Processing the solder mask layer, the screen printing surface and the gold finger part of the plating next to the solder paste will be covered in the outermost layer of wiring, so that the wiring will not come into contact with the plating part of the outside. The screen printing surface is printed on it to indicate the position of the parts, it can not cover any wiring or gold finger, or may reduce the solderability or current connection stability. Gold finger parts are usually plated with gold, so that when inserting the expansion slot, to ensure high-quality current connection.
PCB board is short-circuit or open circuit conditions, you can use optical or electronic test. Optical scanning is used to identify defects in each layer. Electronic tests are usually performed with a flying probe (Flying-Probe) to check all connections. Electronic tests are looking for short circuits or broken circuits are more accurate, but optical tests can more easily detect incorrect gaps between conductors.