The first piece test of SMT patch proofing is very important. As long as the component specification, model, and polarity direction of the first piece are correct, the machine will not place the wrong components during mass production. If the offset is correct, the machine is generally able to ensure the repeatability of the mass production.
Some common methods of first piece testing are introduced. Generally, different testing methods are selected according to the different production requirements of patch processing.
- ICT testing is usually used on models that have been mass-produced, and the amount of SMT patch processing is usually relatively large, the testing efficiency is high, but the manufacturing cost is relatively high.
- X-RAY examination is used for some circuit boards with BGA packaged components, SMT small-batch processing sometimes need to do X-ray examination when the first piece is produced. X-ray examination can show the thickness, shape and Soldering quality and density.
- The AOI test is mainly to determine the soldering problems of the components through the appearance characteristics of the components processed by the SMT patch. It can also determine whether the components on the circuit board are wrong by checking the color of the components and the silk screen on the IC.
- the first production testing system can directly input the produced product BOM into the system, and the system’s own test unit will automatically test the first sample, and check with the input BOM data to confirm whether the produced first sample meets Quality requirements.
- Flying probe test is usually used in some small batch production. It is a kind of convenient testing with strong program variability and good versatility. Basically, it can test all types of circuit boards. But the test efficiency is relatively low, and the test time for each board will be very long.
- Function testing is usually used on some more complicated circuit boards. The circuit boards that need to be tested must be soldered and passed through some specific fixtures to simulate the formal use of the circuit board. Place the circuit board in this simulation. In the scenario, turn on the power and observe whether the circuit board can be used normally.
7. LCR measurement . This test method is suitable for some simple circuit boards. The components on the circuit board are not so much. There is no need to reheat after the completion of the printing.
