1.PCB circuit board manufacturing
Afterreceiving the order of PCBA, analyze the Gerber file, pay attention to therelationship between the hole spacing of PCB and the bearing capacity of theboard, do not cause bending or fracture, and whether the wiring takes intoaccount the key factors such as high-frequency signal interference andimpedance.
2.Component procurement and inspection
Purchasersof components need to strictly control channels, and must pick up goods fromlarge traders and original factories, and avoid 100% second-hand and fakematerials. In addition, set up a special incoming inspection post, strictinspection of the following items, to ensure that the components withoutfailure.
PCB:test the temperature of reflow soldering furnace, prohibit flying line, whetherthe 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, andkeep it at constant temperature and humidity
Othercommon materials: check screen printing, appearance, power-on measurementvalue, etc., the inspection items are carried out in accordance with samplinginspection, the proportion is generally 1-3%
3,SMT Assembly processing
Thesolder paste printing and reflow furnace temperature control are the keypoints. It is very important to use laser steel mesh with good quality and inline with the process requirements. According to the requirements of PCB, partof the steel mesh need to be increased or reduced, or use U-shaped hole,according to the process requirements of steel mesh. Control of furnacetemperature and speed in reflow soldering is critical for solder pasteinfiltration and soldering reliability, which can be controlled in accordancewith normal SOP operation guidelines. In addition, AOI testing needs to bestrictly enforced to minimize the adverse effects caused by human factors.
4.Plug-in processing
Thedie design for wave soldering is the key point in the plug-in process. How touse molds to maximize the probability of good products after passing thefurnace is a process that PE engineers must constantly practice and summarizeexperience.
5.Program firing
Inthe early DFM report, it is suggested to the customer to set some Test Pointson the PCB, in order to Test the PCB and the conductivity of PCBA circuit afterwelding all components. If the condition, you can ask the customer to provideprocedures, through the burning device (such as ST-Link, J-Link, etc.) will beburned to the main control IC, you can more intuitively test a variety of touchaction brought by the functional changes, in order to test the integrity of thewhole PCBA function
6.PCBA board test
Forthe orders with PCBA Test requirements, the main Test contents include ICT (InCircuit Test), FCT (Function Test), Burn In Test, temperature and humidityTest, drop Test, etc., which can be operated according to the customer's Testscheme and the report data can be summarized.