Based on many years of actual production experience and service experience, the author now makes a brief analysis of the causes of bubbling on the copper plating surface of the circuit board.
Many factors affect the quality of PCBA quality, including human, machine, material factors, technological factors, environmental factors, etc. The quality of pcba process is mainly affected by the following conditions.
In the actual study, it is found that PCB design mainly has four aspects of interference: power supply noise, transmission line interference, coupling and electromagnetic interference (EMI).
In the design of PCB electromagnetic compatibility, the main problem that needs attention is the interference problem of power supply and ground.
In the process of PCBA production, the selection of PCBA transtin is also very important. In the process of through hole plug-in, tin penetration is not good, which is easy to cause problems such as virtual welding, tin cracking and even falling parts.
The content of PCB incoming material inspection includes PCB size and appearance inspection, PCB warping and distortion detection, PCB weldability test, PCB solder resistance film integrity test, PCB internal defect detection.
Although PCB can be called a high-tech product in the electronics industry, but now the development of PCB is not only challenged by its own cost-effectiveness problems, more is from the challenge of energy conservation and environmental protection.
SMT manufacturing units are fully automatic, high precision and high speed. As the degree of automation increases, PCB design must meet the SMT equipment requirements.
The PCB processing process from the inner line pattern transfer of PCB substrate to the outer line pattern transfer by pressing several times will cause different growth and contraction of the warp and weft of the jointed board.
Common ways to prevent PCB copying board: 1, grinding, 2, sealing glue, 3, use special encryption chip, 4, the use of uncracking chip, 5, use MASK IC, 6, the use of nude, 7, in the current of the signal line series more than 60 ohms of resistance, 8, use
Protection measures of multilayer PCB edge radiation: The three elements of EMC problems are: electromagnetic interference source, coupling path, sensitive equipment
When designing the PCB, please note the following points: The shape of a and Mark point is symmetrical up and down or symmetrical left and right, and the size of b and A is 2.0mm. c, from the outer edge of Mark point 2.0mm, there should be no shape and co
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