1. PCB circuit board manufacturing
After receiving the order of PCBA, analyze the Gerber file, pay attention to the relationship between the hole spacing of PCB and the bearing capacity of the board, do not cause bending or fracture, and whether the wiring takes into account the key factors such as high-frequency signal interference and impedance.
2. Component procurement and inspection
Purchasers of components need to strictly control channels, and must pick up goods from large traders and original factories, and avoid 100% second-hand and fake materials. In addition, set up a special incoming inspection post, strict inspection of the following items, to ensure that the components without failure.
PCB: test the temperature of reflow soldering furnace, prohibit flying line, whether the hole is blocked or leakage of ink, whether the plate is bent, etc
IC: Check whether the screen printing is completely consistent with the BOM, and keep it at constant temperature and humidity
Other common materials: check screen printing, appearance, power-on measurement value, etc., the inspection items are carried out in accordance with sampling inspection, the proportion is generally 1-3%
3, SMT Assembly processing
The solder paste printing and reflow furnace temperature control are the key points. It is very important to use laser steel mesh with good quality and in line with the process requirements. According to the requirements of PCB, part of the steel mesh need to be increased or reduced, or use U-shaped hole, according to the process requirements of steel mesh. Control of furnace temperature and speed in reflow soldering is critical for solder paste infiltration and soldering reliability, which can be controlled in accordance with normal SOP operation guidelines. In addition, AOI testing needs to be strictly enforced to minimize the adverse effects caused by human factors.
4. Plug-in processing
The die design for wave soldering is the key point in the plug-in process. How to use molds to maximize the probability of good products after passing the furnace is a process that PE engineers must constantly practice and summarize experience.
5. Program firing
In the early DFM report, it is suggested to the customer to set some Test Points on the PCB, in order to Test the PCB and the conductivity of PCBA circuit after welding all components. If the condition, you can ask the customer to provide procedures, through the burning device (such as ST-Link, J-Link, etc.) will be burned to the main control IC, you can more intuitively test a variety of touch action brought by the functional changes, in order to test the integrity of the whole PCBA function
6. PCBA board test
For the orders with PCBA Test requirements, the main Test contents include ICT (In Circuit Test), FCT (Function Test), Burn In Test, temperature and humidity Test, drop Test, etc., which can be operated according to the customer's Test scheme and the report data can be summarized.
