The temperature of the cathode target of the pvd coating machine has a great influence on the arc. Whether the temperature control is timely and reasonable directly affects the coating effect of the substrate and the high-quality product rate. Professional coating engineers can not only control costs but also improve efficiency. So what impact does the cathode target temperature of the pvd coating machine have on the arc?

  The stability of the cathode arc discharge combustion of the target source depends on the evaporation temperature of the cathode surface, and reducing the cathode surface temperature will bring high arc combustion stability. At the same time, lowering the temperature of the cathode evaporation surface will also lead to a reduction in the number of large particles and large sputters in the metal vapor.
       Observe the burning condition of the cathode arc of the pvd coating machine target. Whenever the arc is extinguished, it is always found that the arc spot is extremely rough. Sometimes even clusters of arc spots appear. After extinguishing, observe that the target surface is red and the target surface temperature is very high. The appearance of the rough arc spot makes the arc current more concentrated on the target surface, which leads to the over-concentration of the spot current on the target surface under the arc spot, which makes the target surface temperature under the arc spot higher and produces a large amount of thermionic emission. As a result of a large amount of local thermal electron emission on the target surface, on the one hand, it neutralizes a large number of space charges, making the electric field on the cathode surface a deceleration field, and even causing the electric field on the cathode surface to be equal to zero. On the other hand, the large amount of hot electron emission produces a considerable cooling effect on the cathode surface. As a result, there is neither a strong electric field generated by space charges to maintain surface emission, nor an extremely high surface temperature to generate thermionic emission, leading to the extinction of the arc.
       Therefore, in the design of the multi-arc target source of the pvd coating machine, attention should be paid to adequate cooling of the cathode target. It is best to use direct water cooling. When indirect water cooling is used, the adjacent components such as the cathode seat should use materials with good thermal conductivity (such as copper, copper, etc.) Aluminum, etc.)