Facing the growth of the film has a very important impact. If the surface roughness of the substrate is large, and more and more combined with surface defects, it will affect the attachment and growth rate of the film. Therefore, before the vacuum coating starts, the substrate will be pre -processing, which plays the role of the surface roughness of the substrate on the surface of the substrate. After the ultrasonic intervention, the surface of the substrate will form a small scratch, which increases the contact area of the thin film particles and the surface of the substrate, which can significantly increase the formality of the rotor and the combination of membrane base.
For most of the substrate materials, as the roughness of the substrate decreases, the film adhesion increases, that is, the membrane base binding force becomes stronger; there are also some substrate materials that are special cases, such as the film attachment of the ceramic base. Decreased degrees, that is, the membrane base binding force becomes weakened.
In the influencing factors that match the film and film, the thermal bulk coefficient plays a decisive role. When the thermal expansion coefficient of the film is greater than the thermal expansion coefficient of the matrix, the torque is negative, and the maximum tension is at the free boundary. It is close to the center of the center to become compressed, and the film may appear layered. Take the sedimentary Skinus thin film as an example. Because the thermal expansion coefficient of diamond is small, when the gas phase deposition is over, the substrate temperature is reduced from a higher sedimentary temperature to room temperature, and the contraction of diamond is reduced compared to the substrate. A large thermal stress will produce inside. When the thermal expansion coefficient of the film is less than the heating ledger coefficient of the substrate, the torque is positive, and the film is not easy to layer.
–This article is released by vacuum coating machine manufacturer Guangdong Zhenhua
Post time: Feb-29-2024