The poor film strength (film weakness) of vacuum electroplating equipment is mainly manifested as follows:

The poor film strength (film weakness) of vacuum electroplating equipment is mainly manifested as follows:

① Wipe or tear with special tape, resulting in pieces falling off;

② Wipe or tear with special tape, resulting in point-like shedding;

③ After boiling for 15 minutes, use special tape to pull and tear to produce dots or flakes;

④ Rubbing with a special rubber head and 1Kg force for 40 times, there will be a path;

⑤ When the film is wiped or not wiped, cracks and mesh-like fine lines appear.

Film strength of vacuum plating equipment

Film strength is an important indicator of lens coating, and it is also the most common defect in the coating process.

Filling Density of Vacuum Electroplating Equipment

Packing density is defined as the ratio of the volume of the solid portion of the film to the total volume of the film, including voids and pores. For optical films, the packing density is usually 0.75 to 1.0, mostly 0.85 to 0.95, and rarely reaches 1.0. Packing densities less than 1 cause the refractive index of the evaporated material to be lower than that of its bulk. During deposition, the thickness of each layer is monitored by an optical or quartz crystal. Both techniques have their own advantages and disadvantages, which are not discussed here. What they have in common is that they are all used in a vacuum when the material is evaporated, so the refractive index is the refractive index of the evaporated material in vacuum, not the refractive index of the material exposed to moist air. The moisture absorbed by the film replaces the pores and voids, causing the refractive index of the film to increase. Since the physical thickness of the film remains constant, this increase in refractive index is accompanied by a corresponding increase in optical thickness, which in turn causes a shift in the spectral properties of the film toward longer wavelengths. To reduce this spectral shift caused by the volume and number of micropores within the film layer, energetic ions are employed to transfer their momentum to the evaporating material atoms, thereby greatly increasing the mobility of the material atoms during condensation at the substrate surface .

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