When printed circuit boards are inspected and tested, whether bare pcb boards or full-load assembly boards, once defects are detected. Cost-effective maintenance methods need to be assessed. While it provides products that they are reliable as the original product. For a few simple circuit boards with defects, that is usually uneconomical to reprocess it. However, many circuit boards have high complexity, and the full load assembly board may be very expensive, so it will be more economical to reprocess the unqualified products to pass the test.
The double sided PCB board is not usually repaired because it poses a reliability risk for future assembly use. The price of the bare board is relatively low compared to the assembly board. Combined with the above factors, in high reliability and military applications, it is not allowed to repair and reprocess the bare board, and the reprocessing of the bare board can only be used for commercial use. But the maintenance of the board must conform to the original design requirements.
In addition, some used double sided PCB boards need to be repaired and reprocessed. In most cases, it is necessary to remove the existing components and replace a new component, which is usually done manually. For boards with through holes, repairs can be done by simple tools such as soldering iron and capillary knitting. For SMD, on the other hand, a special reprocessing table is required, which relies on hot air reflow soldering equipment. A large number of chemicals need to be used in the repair process, especially in cleaning, moisture removal, flux removal, lubricant wiping, and freezing spray to locate heat-sensitive components, and so on.
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