Company Profile

Gas Mass Flow Controllers and Mass Flow Control for Vacuum Coating

Quick Answer: Vacuum coating lines need gas mass flow controllers that hold repeatable argon, nitrogen, oxygen and reactive gas flow into PVD or CVD chambers. Silver Instruments supplies thermal mass flow controllers and meters for coating systems with ranges from 0 to 5 sccm up to 0 to 1000 slm. Send your gas type, flow range, pressure and valve type for a specific quote.

What Makes Gas Delivery Smart in Vacuum Coating

Vacuum coaters use mass flow controllers to feed process gas into chambers at pressures from 0.1 Pa to 10 Pa. A thermal mass flow controller measures gas mass flow directly, not volume flow. It keeps gas delivery stable even when line pressure or temperature changes. This matters because coating thickness and film quality depend on repeatable gas flow.

Most engineers skip this part. They focus on target power or substrate bias and forget that gas flow drift causes poor color or adhesion. We have seen this on customer sites many times. A hard coating line in Malaysia had nitrogen flow drift of 3 percent. The result was visible color variation on decorative titanium nitride coatings.

Common Gases and Flow Ranges for PVD and CVD

Different coating processes need different gases. Magnetron sputtering uses argon for plasma and oxygen or nitrogen as reactive gas. Plasma enhanced CVD uses silane, methane, hydrogen and ammonia. Typical flow ranges start at 0 to 5 sccm for research coaters and go up to 0 to 500 slm for large architectural glass lines.

We recommend these typical ranges for thermal mass flow controllers in vacuum coating.

Argon: 0 to 100 sccm for small coaters, 0 to 50 slm for industrial sputtering. Nitrogen: 0 to 50 sccm for reactive TiN or CrN, 0 to 20 slm for large batch coaters. Oxygen: 0 to 20 sccm for oxide films like TiO2 or SiO2. Silane: 0 to 100 sccm for PECVD, with metal seals and high purity cleaning.

These are starting points. Send us your chamber volume, pump speed and target size for a more exact range.

Thermal Mass Flow Controllers vs Other MFC Types

Thermal mass flow controllers are common for vacuum coating because they respond fast and measure low flow rates well. A capillary sensor heats a small gas stream. Two PT100 elements detect temperature difference. That signal gives mass flow directly. The built in control valve adjusts flow to setpoint. Silver Instruments uses this working principle in our gas mass flow controllers.

Coriolis mass flow meters can measure gas mass flow accurately but they cost more for small sccm ranges. Electromagnetic flow meters do not work for gas. Ultrasonic and vortex flow meters suit larger pipe flow, not low flow coating gas delivery. In practice, thermal MFC is the workhorse for sputter and evaporation tools.

Key Specifications to Send Us for a Quote

We ask for four details when you request a gas mass flow controller price. First, list the gas type or gas mixture. Second, define the full scale flow range in sccm or slm. Third, tell us the process pressure and upstream pressure in bar. Fourth, specify the signal output you need such as 4-20 mA, RS485 Modbus or 0-5 V.

Also include valve type. Normally closed valves are standard for vacuum safety. Metal seals are better for reactive gases like silane or hydrogen. Elastomer seals suit clean dry air and inert gases. Specify fitting size such as 1/4 inch VCR, 1/8 inch NPT or DN15. We can supply 316L stainless steel wetted parts, PTFE or PFA coatings on request.

Send us your gas type, flow range, pressure in bar, and pipe size or fitting type. Our engineers will reply within 24 hours.

Case Example: Reactive Sputtering in Thailand

A hard coating job shop in Thailand runs titanium nitride coating on cutting tools. They needed nitrogen mass flow control from 0 to 20 sccm with repeatabi