Circuit board PCBA processing process can be roughly divided into: empty plate loading - printed solder paste - mounting devices - reflow welding -AOI testing - receiving plate - finished product inspection - parts after welding - circuit board open/short
Pay attention to the wiring of signal lines under the magnetic beads, between the pads and those that may come into contact with the magnetic beads. Some magnetic beads conduct electricity quite well and may produce unexpected conductive paths.
Common bad reasons for PCBA welding resistance film processing :1. Welding pad and through hole connection. 2. Solder resistance design between pad and pad, solder resistance graphic specifications should conform to the design of welding end distribution
Common heat dissipation mode of circuit board: 1, high heating device plus radiator, heat conduction plate, 2, through the circuit board itself heat dissipation, 3, the use of reasonable design to achieve heat dissipation function, 4, for the use of free
In PCB processing and production, static electricity is not the hazard, the real danger lies in the accumulation of static electricity, and the resulting electrostatic discharge.
In the process of production, packaging and transportation, and the processing, debugging and testing of the integrated machine, it is inevitable to suffer from external or own friction and form a high surface potential.
SMT patch processing emphasizes fast and efficient production. General SMT patch workshops will carry out non-stop production. The shutdown and line change of machines will increase production costs and reduce profits.
The cleaning process needs to consume energy, manpower and cleaning materials, especially the waste gas, waste water discharge and environmental pollution caused by cleaning materials, which has become a problem that must be paid attention to.
Mixing process is in the PCB board A side has a number of IC components, and inserted with through hole components, on the other side of the PCB (B side) and there are many patch resistance capacitance electrical parts, sometimes IC, often called "mi...
Due to the different heat capacity and heating conditions of pad and pin, the temperature to which pad and pin are heated during reflow welding is also different. If the temperature difference is relatively large, it may cause poor welding.
There are two important concepts in IPC-SM-782, "Producibility Levels" and "Component Mounting Complexity Levels", which are different but have corresponding three levels.
The reasons for the need for post-welding processing are as follows: 1, the components are not resistant to high temperature, 2, the components are too high, 3, there are a small number of plug-ins in the side of the wave crest, 4, the components plug-in
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