When the pvd coating machime is repaired, what are the requirements for welding? It is a question that everyone is more concerned about. Whether the welding is done well or not will directly affect the quality of the film layer of the later product. Although welding is only a small part of many coating processes, coating engineers must pay attention to this process in order to ensure the quality of coatings in the later stage. The following is a brief introduction to the vacuum coating equipment in detail. I will introduce the requirements for welding of pvd coating machine during maintenance. I hope it can help you:

One: When designing the weld structure, the joint must be fully welded, and the harmful space for gathering dirt should be avoided. The correct welding is to place the weld on the vacuum side and perform deep fusion welding. Most of the wrong welding will form a dead space, that is, some space is blocked between the two welds, and there is gas stored in it.
      Two: The weld should be welded at one time to avoid dead space caused by two welding and unable to detect leaks.
      Three: When the welding seam needs to be welded on both sides because of its strength, the internal welding seam should be airtight. For the purpose of leak detection, a drilling plug should be set during the external welding.
      Four: If structural welding is required in the vessel, the internal weld should not be continuous to allow gas from any grooves to escape easily, and the structural weld should not intersect the sealing weld.
      Five: Welded assemblies should be designed so that the maximum number of welds can be individually tested at the manufacturing stage and corrected prior to final assembly.
      Six: The maximum allowable leak rate (to air) of the welded seal is about 10-7Pa·m3(s·m) on the length of the weld. If the leak rate is relatively high, the weld should be ground off until the base metal is exposed, and then re-welded. Remember not to weld twice in the place where the air leak occurred, because repair welding is not easy to block the leak, but it is easy to generate stress. Create new cracks in the weld.
       The coating process of pvd coating machine is cumbersome and complicated, but every link is crucial. Whether it is welding, cleaning, or coating process, every link must be strictly controlled, so as to minimize the rate of defective products.