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In the manual soldering process of SMT patch, short circuit is a relatively common processing defect. To achieve the same effect as manual SMT patch and machine pasting, short circuit is a problem that must be solved. Short-circuit PCBA cannot be used. There are many ways to solve short-circuit in SMT patch processing. The following is a brief introduction about SMT patch processing.
1. To develop a good habit of manual welding operation, use a multimeter to check whether the key circuit is short-circuited. Every time you manually SMT an IC, you need to use a multimeter to measure whether the power supply and the ground are short-circuited.
2. Light up the short-circuited network on the PCB diagram, look for the place on the circuit board that is most likely to be short-circuited, and pay attention to the internal short-circuit of the IC.
3. If there is a short circuit in the same batch in SMT patch processing, you can take a board to cut the line, and then power on each part to check the short circuit.
4. Use a short-circuit location analyzer to check.
5. If there is a BGA chip, since all the solder joints are covered by the chip and cannot be seen, and it is a multi-layer board (above 4 layers), the power supply of each chip is separated during the design and connected with magnetic beads or 0 ohm resistors., In this way, when there is a short circuit between the power supply and the ground, the magnetic bead detection is disconnected, and it is easy to locate a certain chip.
6. Be careful when welding small-size SMT patch processing surface-mount capacitors, especially the power supply filter capacitors (103 or 104), which are large in number, which can easily cause a short circuit between the power supply and the ground.
How to improve the quality of smt patch processing products?
The smt patch processing technology has been widely used in the electronics industry. The product quality of smt patch processing is related to the actual effect of product forming, and it is also a test of corporate strength. Improving the quality of smt patch processing products is the overall goal of every smt factory.
1. Select enterprise technical personnel. Establish an internal product quality organization network within the enterprise, provide timely and accurate product quality feedback, select product quality personnel to serve as product quality inspectors on the production line, and the management is still managed by the product quality department; to avoid other factors interfering with the determination of product quality.
2. Ensure the accuracy of testing and maintenance of equipment and equipment. Check and maintain the product through the necessary equipment and equipment such as multimeter, anti-static wrist, soldering iron, ict and so on. Therefore, the product quality of the equipment itself will directly affect the quality of the produced products. In order to ensure the reliability of the equipment, inspections and measurements should be carried out in a timely manner in accordance with regulations. Jingbang Technology has high-precision testing equipment such as Yali offline aoi detector, x-ray detector, lcr bridge detector, 60 times digital electron microscope, etc., to ensure the quality standard of each product.
3. Formulate product quality regulations. The Quality Department shall formulate necessary product quality related rules and regulations and a departmental responsibility system, restrict avoidable quality accidents through laws and regulations, and give clear rewards and punishments, and participate in product quality assessment by economic means; and establish a monthly quality within the enterprise prize.
4. The implementation of management measures. Quality management, in addition to strictly controlling the quality of the production process, it also takes the measures of inspectors to sample and inspect (or comprehensively inspect) the outsourced parts before entering the warehouse, determine that the pass rate does not meet the requirements of the national standard, and return the goods. And record the inspection results in writing.
5. Set product quality process control points. In order to ensure the normal progress of smt patch processing, it is necessary to strengthen the quality inspection of each process to monitor its operating status. Therefore, it is particularly important to establish product quality control points after some key processes in order to discover and correct quality problems in the subsequent processes in time to prevent unqualified products from entering the next process.
