When we use a vacuum coating machine, we will inevitably encounter some failures that cannot be found and cannot be detected. This is a pseudo fault.
During the coating process, there will be dark black nickel coating, sometimes even white stripes. In this case, we only need to add a little bit of black salt to restore color. But when we started using it for a period of time, it took about 1 hour. This happened again. After inspection, the vacuum coating equipment was found to be caused by too much impurity in the bath. The blackening agent can only temporarily alleviate this situation. With the increase of coating time and the consumption of blackening agent, this happens again. This is generally an external appearance. In most cases, it occurs in one process, but his reason exists in another process. This is the so-called pseudo fault.
In fact, if you want to extend the service life of vacuum coating equipment, then we must use the correct operation. The correct operation can not only extend the service life of the coating machine, but also ensure the quality of the coating and reduce the rework time.
The argon purity should be controlled above 99.99%, and the vacuum degree should be maintained at 0.67pa or more, and the pumping system should be checked regularly to avoid the vacuum cannot reach the required degree of vacuum. Some parts need to be coated with primer. For vacuum coating, the primer needs to be fully baked and cured, otherwise moisture and other substances will evaporate as the temperature in the vacuum furnace rises, affecting the degree of vacuum. For the same reason, for some workpieces with a lot of volatile impurities inside themselves, it is necessary to perform drying before coating, and the above operation can be performed to prevent the film from appearing dark or black.