Bubble Method Detection
PVD coating bubble method detection is preferred for PVD coating containers or devices that are being processed. PVD coating bubble method detection means filling the tested part with a certain pressure leak indication gas, and then put the tested part into the liquid. The gas will enters to the surrounding liquid through the leak hole to form bubbles. And the place where are bubbles is the position of leak hole. Furthermore, the leakage rate of the hole can be estimated according to the formation rate and the size of the bubbles, as well as the physical properties of the leak indication gas.
Cover Method Detection
Cover Method Detection refers to a method that covering the whole PVD coating device with an ethylene plastic bag (cover), and then filling the bag with helium, that is, the entire vacuum container is immersed in the helium for leak detection. After fully evacuating the gas, make the main valve, rough valve, and leak valve turn off. And then use a B-A ionization vacuum gauge to measure the change in pressure rise to determine whether there is leakage.
The PVD coating is the sum of the pressure rise due to the gas leakage and the pressure rise caused by the material degassing, and finally it is a linear increase that is proportional to time. When the PVD coating curve exhibits such a state as described above, that means the device leaks. When there is no leakage and only the material degassing, the curve should be saturated. If there is only leakage without material degassing, it is a straight line that is proportional to time at the beginning.