Vacuum coating (includingPVDPhysical vapor depositionCVDChemical vapor depositionALDAtomic layer deposition and other related fields are the core combination of vacuum technology and materials science,Vacuum valve as a component of vacuum system “Flow and isolation control core”It directly affects the vacuum stability, film purity, production efficiency, and equipment lifespan of the coating process. Starting from the entire process of coating technology, the following provides a detailed breakdown of the application scenarios, selection requirements, and typical configurations of vacuum valves, accurately matching the actual needs of the industry:

1、 Core technical requirements for vacuum valves in the vacuum coating industry

Vacuum coating requires 高真空（10⁻³~10⁻⁵ Pa）/超高真空（10⁻⁶~10⁻⁹ Pa） In the environment, and with strict requirements for gas purity, particle pollution, and temperature compatibility, valves must meet:

1.Excellent sealing performance: Leakage rate≤10⁻ ¹² Pa・m³/s(Need for ultra-high vacuum scenarios)≤10⁻¹⁵ Pa・m³/s）To avoid the invasion of air and water vapor that may cause oxidation and inclusion of the film layer;

2.Low deflation and high cleanlinessThe valve body material needs to have low vapor pressure (such as316LStainless steel polishing, titanium alloy), with fluororubber selected as the sealing element（Viton）Perfluororubber（Kalrez）Or metal sealing, reducing its own gas release（H₂OTheCO₂Etc.), particle production amount≤1piece/m³(Particle size)≥0.1μm）；

3.Accuracy of flow regulationPartial scenarios require linear flow control (such as reaction gas introduction, vacuum gradient adjustment), and flow conductivity coefficient（C）Need to adapt to the extraction system (usuallyC=100~1000 L/s）；

4.Temperature resistance and corrosion resistanceSuitable heating environment for coating process（≤400℃, partiallyALDCraftsmanship800℃）And it can withstand sputtered ions and reactive gases (such as...)CF₄TheO₂TheNH₃）Corrosion;

5.High reliability and long lifespanMeet the continuous operation requirements of the production line and ensure the lifespan of the switch≥10⁶Secondary (vacuum isolation valve), regulating lifespan≥10⁴Secondary (flow control valve).

2、 Application scenarios and selection of valves for the entire vacuum coating process

1. Vacuum system pumping and chamber isolation link

⑴core functionRealize the switching of the coating chamber from atmospheric pressure to the target vacuum, as well as the isolation and protection between the chamber and the pumping system.

⑵Typical valve types:

lVacuum plug valve (gate valve)Used for coating chambers and molecular pumps/The main isolation between diffusion pumps is characterized by high flow conductivity（C≥500 L/s）Reliable sealing, recommended model:Pfeiffer DUO 65 M(Ultra high vacuum type, metal seal, leakage rate)≤10⁻ ¹³ Pa・m³/s）TheCKD KVSeries (pneumatic drive, suitable for fast isolation);

lbutterfly valve: Suitable for coarse drawing/Pre extraction stage (from atmospheric pressure to10⁻³ Pa）Compact structure and fast switching speed（≤1Seconds), it is recommended to use oil-free lubrication design (such asBusch DVMSeries), to avoid oil contamination of the chamber;

lUltra high vacuum baffle valve: Used forALDHigh precisionPVDIn ultra-high vacuum scenarios, magnetic fluid seals or metal bellows seals are used to ensure no leakage. Typical applications include connecting pipelines between chambers and ion pumps.

2. Process gas control link

⑴core functionAccurate control of reaction gases（CVD）Sputtering gas（PVD）The amount and proportion of carrier gas directly affect the composition and thickness uniformity of the film layer.

⑵Typical valve types:

lMass flow controller（MFC）Supporting valves：MFCThe built-in needle valve or ball valve needs to have high-precision flow regulation capability (repeatability)≤±0.5% F.S.）Strong corrosion resistance, suitable for gases:ArTheN₂TheO₂TheCF₄TheSiH4Wait, recommended brand:MKS 1179ASeriesHoriba STEC SEC-Z500Series;

lPneumatic diaphragm valveUsed for gas main circuit switch, adopting corrosion-resistant sealing (such as Hastelloy valve seat) to avoid gas corrosion and seal failure, suitable forCVDCorrosive gas circuit of the process;

lAngle seat valveAdapt to fast on/off of sputtering gas, response time≤50msEnsure stable gas pressure during the coating process.

3. Connection link between coating chamber and transmission system

⑴core function: Realize wafer fabrication/Workpiece in vacuum transfer chamber（Load Lock）The isolation and transmission channel switching between the coating chamber requires zero particle pollution.

⑵Typical valve types:

lVacuum isolation valve (slide valve)Adopting a translational sealing structure, no friction particles are generated, recommended model:SMC XLGSeries (Cleanroom)Class 1Grade, suitable for semiconductor coating equipment)Nor-Cal AVSeries (metal sealed, ultra-high vacuum compatible);

lQuick vacuum baffle valve: Used forLoad LockAtmosphere of the chamber/Vacuum switching, pumping time≤30Seconds (from atmospheric pressure to10⁻³ Pa）Equipped with pressure sensors to achieve automatic control and improve production efficiency.

4. Tail gas treatment and auxiliary system link

⑴core functionToxic and harmful exhaust gases generated during the coating process (such asCl₂TheHFSafely export metal vapor to processing equipment to avoid leakage and contamination.

⑵Typical valve types:

lCorrosion resistant vacuum valveThe valve body is made of Hastelloy and Monel alloy, and the sealing element is made of perfluororubber. Recommended model:Swagelok SS-6P4Series (needle valve, compatible with corrosive gases)Celerity CVSeries (ball valve, temperature resistant)≤200℃）；

lsafety valve/pressure relief valveUsed for chamber pressure overload protection and setting pressure accuracy ±5%To avoid damage to the chamber due to sudden pressure changes, it is recommended to use a spring type structure (such asPfeiffer PR 400）.

3、 Differences in valve configuration for different coating processes

4、 Industry application trends and selection suggestions

1.Ultra high true cavitation trend: WithALDHigh precisionPVDWaiting for the popularization of technology, ultra-high vacuum valves (leakage rate)≤10⁻¹⁵ Pa・m³/s）The proportion of applications has increased, and metal seals (such as copper pads and nickel pads) are preferred to replace rubber seals;

2.Intelligent integrationValves need to integrate position sensors and pressure feedback modules, supportingPLCLinkage control to achieve vacuum degree-traffic-Closed loop regulation of valve status, suitable for automated production lines;

3.customized requirementsFor high-temperature coating (such as>400℃）High temperature resistant valves (such asInconelValve body, metal bellows seal) to avoid aging of seals;

4.cost controlCivilian coating equipment can choose cost-effective rubber sealed valves (such as fluororubber), while semiconductor grade coating equipment should prioritize cleanliness and corrosion resistance, and choose metal sealed or perfluororubber sealed valves.

If specific coating processes are required (such as a certain model)PVDEquipmentALDRecommended valve model and brand configuration for chambers or media (such as specific corrosive gases), with additional explanation of requirements, will provide more accurate technical solutions!

Hangzhou Yushi Technology Co., LtdFocusing on providing technical services and solutions related to flow, pressure, vacuum detection and control for industrial and scientific research customers, the company acts as an agent and distributor in the United StatesALICAT、 Swiss Vogtlin, American MKS, Japanese EBARA and other brands, combined with their agent products, provide customers with high-quality flow and pressure monitoring solutions, aiming to improve customers' research and production efficiency, improve their manufacturing processes, and promote their scientific research and innovation progress.