Factors affecting the thickness of vacuum evaporation coating

Vacuum evaporation coating is a method of heating the raw materials of the film to be formed in the evaporation vessel in the vacuum chamber, making the atoms or molecules escape from the surface, forming a steam flow, incident on the surface of the solid (called substrate or substrate) and condensing to form a solid film. As the main physical process of vacuum evaporation or vacuum evaporation is produced by heating evaporation materials, it is also called thermal evaporation. Using this method to make thin films has a history of several decades and is widely used. But in the vacuum evaporation coating, there are many factors that affect the coating quality, and the film thickness is one of the main reasons. It is of great significance to analyze the influence of the thickness of vacuum evaporation coating on the coating quality.

Effect of coating raw material density:

Under the condition that the quality of coating raw materials and the distance from the substrate center to the evaporation source remain unchanged, the coating raw materials with different densities are used. On this basis, the films with different thicknesses are prepared by vacuum coating. The thickness of the films is measured by equipment. It can be found that with the increase of the density of the coating raw materials, the film thickness shows a downward trend.

The influence of substrate to evaporation source distance:

Under the condition that the quality of the coating raw material and the angle of the substrate surface relative to the evaporation source remain unchanged, the distance from the substrate to the evaporation source is set to different values. The thickness of the vacuum evaporation coating decreases with the increase of the distance from the substrate center to the evaporation source, that is, the greater the distance, the thinner the film thickness.

Influence of coating raw material quality:

Under the condition that the distance from the center of substrate to the source of evaporation remains unchanged, the quality of coating materials is changed. With the increase of the quality of coating materials, the film thickness increases in a straight line. The greater the quality of raw materials, the thicker the film thickness.