Meiao Kitchen & Bath PVD Process Revealed

PVD (Physical Vapor Deposition) technology is an advanced surface treatment technology carried out under vacuum conditions, whereby the surface of a solid or liquid material source is physically vaporised into gaseous atoms, molecules or partially ionised into ions, which are deposited on the surface of the substrate to form a thin film with a special function. The technology is divided into three main categories: vacuum evaporation coating, vacuum sputtering coating and vacuum ion coating, which incorporate a variety of process methods such as evaporation, sputtering and electric arc.

In the PVD process, the first step is the gasification of the plating material, where gaseous atoms, molecules or ions are produced by heating the material source to the evaporation temperature, causing it to gasify, sublimate or sputter. These gases then migrate and deposit on the substrate surface in a vacuum environment to form a thin film. The whole process is simple, non-polluting and environmentally friendly, and the film formation is uniform and dense, with strong bonding to the substrate.

PVD technology is widely used in aerospace, electronics, optics, machinery, construction and other fields, can be prepared to wear-resistant, corrosion-resistant, decorative, electrically conductive, insulating, photoconductive, piezoelectric, magnetic, lubrication, superconductivity and other characteristics of the film. With the development of high technology and emerging industries, PVD technology is constantly innovating, and many new advanced technologies, such as multi-arc ion plating and magnetron sputtering compatible technology, large rectangular long arc target and sputtering target, etc., have emerged to promote the development of the technology.

Our factory uses the first type of vacuum evaporation coating, and the whole process of this coating will be described in detail below.

Vacuum evaporation coating is one of the oldest and most commonly used methods in PVD technology. In this process, the plating target is first heated to the evaporation temperature, causing it to vaporise and leave the liquid or solid surface. Subsequently, these gaseous substances will migrate to the substrate surface in a vacuum and eventually deposit to form a thin film.

To achieve this process, an evaporation source is used to heat the plating material to evaporation temperature. There are various options for evaporation sources, including resistance heating, electron beams, laser beams, and others. Of these, resistance evaporation sources and electron beam evaporation sources are the most common. In addition to conventional evaporation sources, there are also some special-purpose evaporation sources, such as high-frequency induction heating, arc heating, radiant heating and so on.

The basic process flow of vacuum evaporation plating is as follows:

1. Pre-plating treatment: including cleaning and pretreatment. Cleaning steps include detergent cleaning, chemical solvent cleaning, ultrasonic cleaning and ion bombardment cleaning, etc., while the pretreatment includes de-static and primer coating.

2. Furnace loading: this step includes cleaning the vacuum chamber, cleaning the plated parts hangers, as well as installing and debugging the evaporation source and setting the plated parts lab coat card.

3. Vacuum pumping: Firstly, carry out rough pumping to above 6.6Pa, then start the front stage of diffusion pump to maintain the vacuum pump, and then heat up the diffusion pump. After sufficient preheating, open the high valve and use the diffusion pump to pump the vacuum to a background vacuum of 0.006Pa.

4. Baking: The plated parts are heated to the desired temperature.

5. Ion bombardment: Ion bombardment is carried out in a vacuum of about 10 Pa to 0.1 Pa, using negative high voltage up to 200 V to 1 kV, and ion bombardment is carried out for 5 minutes to 30 minutes.

6. Pre-melting: Adjust the current to pre-melt the plating material and degas for 1 minute to 2 minutes.

7. Evaporation Deposition: Adjust the evaporation current as required until the desired end of deposition time is reached.

8. Cooling: Cool the plated parts to a certain temperature in the vacuum chamber.

9. Removal: After removing the plated parts, close the vacuum chamber, pump the vacuum to 0.1Pa, then cool the diffusion pump to the permissible temperature, and finally close the maintenance pump and cooling water.

10. Post-treatment: Carry out post-treatment work such as applying top coat.