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The production process of PCB circuit board patch processing is very complicated, including many important process processes such as PCB board manufacturing process, component procurement and inspection, SMT patch assembly, DIP plug-in, and PCB circuit board testing. Among them, PCB circuit board testing is the most critical quality control link in the entire PCB circuit board processing process, which affects the final use performance of the product. So what are the test forms of PCB circuit boards?
PCB circuit board testing mainly includes five forms: ICT test, FCT test, aging test, fatigue test, and harsh environment test.
1. ICT test mainly includes circuit on-off, voltage and current value, fluctuation curve, amplitude, noise, etc.
2. FCT testing needs to carry out IC program firing, carry out simulation tests on the basic functions of a whole PCB circuit board, find out the problems in the hardware and software, and equip with necessary chip processing production jigs and test racks.
3. Fatigue test is mainly to sample PCB circuit boards and carry out high-frequency and long-term operation of basic functions, observe whether there is failure, and judge the probability of failure in the test, so as to feedback the working performance of PCB circuit boards in electronic products. .
4. The test in harsh environment is mainly to expose the PCB circuit board to the extreme temperature, humidity, drop, splashing, and vibration, and obtain the test results of random samples, thereby judging the reliability of a whole batch of PCB circuit board products. sex.
5. The aging test is mainly to energize the PCB circuit board and electronic products for a long time, maintain their work and observe whether there are any failures. After the aging test, the electronic products can be sold in batches.
The production process of PCB circuit boards is complicated. During the production and processing, various problems may occur due to improper equipment or operation, and there is no guarantee that the products produced are qualified. For this reason, PCB testing is required to ensure that each product is not There will be product quality problems.
Precautions for SMT chip processing of PCB circuit boards
The main purpose of SMT chip processing is to accurately install surface mount electronic components on a fixed position on the PCB circuit board. What should we pay attention to when performing SMT chip processing? Next, I will introduce the following aspects in detail.
1. There should not be any food or drink in the working area of the PCB circuit board, smoking is strictly prohibited, no items not related to work should be placed, and the workbench should be kept clean and tidy.
2. Regularly inspect EOS/ESD workbenches to ensure that they can work normally (anti-static). The various risks of EOS/ESD components may be caused by incorrect grounding methods or oxides in the ground connection parts. For this reason, special protection should be given to the "third line" grounding terminal joints.
3. It is forbidden to stack the PCB circuit boards, which will cause physical damage. There should be various special brackets on the assembly work surface, and they should be placed according to the type.
4. Do not pick up the soldered surface during the SMT patch processing of PCB circuit boards with bare hands or fingers, because the grease secreted by human hands will reduce solderability, and soldering defects are very likely to occur.
5. The operation steps for PCB circuit boards and electronic components are reduced to a minimum to prevent risks. In the assembly area where gloves must be used, soiled gloves will cause contamination. For this reason, gloves must be replaced frequently when necessary.
6. Do not use skin-protecting oils to coat hands or various silicone-containing detergents, as they can cause problems in solderability and adhesion of conformal coatings. A specially formulated detergent for the soldering surface of PCB circuit boards is available.
7. In the PCB circuit board SMT patch processing, these operating rules should be strictly followed, and the correct operation can ensure the final use quality of the product, and reduce the damage of electronic components and reduce the cost.
8. Electronic components and PCB circuit boards that are sensitive to EOS/ESD must be marked with appropriate EOS/ESD marks to prevent confusion with other electronic components. In addition, in order to prevent ESD and EOS from endangering sensitive electronic components, all operations, assembly and testing must be completed on a workbench that can control static electricity.
