With the rapid development of mobile phone, electronics and communication industries, the PCB circuit board industry continues to grow and grow rapidly, at the same time, people have higher requirements on layer number, weight, precision, material, color and reliability of PCB. So how do you tell if a PCB is good or bad?
However, due to the fierce price competition in the market, PCB material costs are also on the rise. In order to enhance the core competitiveness, more and more manufacturers monopolize the market with low prices. but these ultra-low prices are achieved by reducing the cost of materials and process, which makes PCB prone to cracks, scratches, and its precision, performance and other comprehensive factors are not up to the standard, which will seriously affect the solderability and reliability of the product, etc. In the face of various PCB boards on the market, the quality of PCB boards can be identified from two ways: the first way is to distinguish and identify from the appearance; the other is to identify from the quality specification requirements of the PCB board itself.
Methods to identify the quality of PCB:
A: Distinguish the quality of the circuit board from the appearance
Generally, the appearance of PCB board can be analyzed and identified from three ways:
- a) Standard rules for size and thickness
The thickness of the PCB board to the standard circuit board is different size, customers can measure and check according to their own product thickness and specifications.
- b) Gloss and color
The external PCB board is covered with ink, the circuit board can play the role of insulation, if the color of the board is not bright, less ink, insulation board itself is not good.
- c) weld appearance
PCB board due to many parts, if the soldering is not good, components easy to fall off the PCB board, seriously affect the soldering quality of the PCB board, good appearance, careful identification is very important
B: High quality PCB circuit board should meet the following requirements:
- a)After the components are installed, the board should be good working, that is, the electrical connection should meet the requirements;
- b) The line width, line thickness and line spacing shall meet the requirements to avoid line heating, circuit opening and short circuit.
- c) High temperature coppers is not easy to fall off;
- d)The surface of copper is not easy to oxidize, which affects the assembly speed. it soon goes bad after oxidation
- e) No additional electromagnetic radiation
- f) The shape is not deformed, so as to avoid deformation of shell and dislocation of screw hole after installation. Now it is all mechanized assembly, the hole position of PCB board and the distortion error of lines and design should be within the allowed tolerance range.
- g) High temperature, high humidity and special environment should also be considered.
- h) The mechanical properties of the surface shall conform to the assembly requirements.