Frequently Asked Questions

Vacuum Metalizing

What's the difference between thermal evaporation and sputtering?

Thermal evaporation is a process where you heat the metal to be deposited (usually aluminum) in a vacuum chamber until it melts and then boils-off as a vapor. There are different ways to heat the aluminum, but a tungsten filament is the most common. The vapor condenses onto all surfaces in the vacuum chamber forming a thin film. Thermal evaporation is the process most traditional vacuum metalizing suppliers use.

Sputtering, on the other hand, is a plasma-based process whereby the metal to be deposited is bombarded by high energy ions, which causes atoms of the metal to be knocked off, or sputtered, from the surface. These atoms condense on the part surfaces inside the vacuum chamber, forming a thin film. The advantages of sputtering include 1) precise control of deposition rates and thickness; 2) compatibility with nearly all metals, including metal alloys.

How thin are the layers applied during the vacuum metalizing process?

Shielding films are typically 1-2 microns thick.

Reflective films are typically .05 - .1 microns thick.

Decorative films can be from .02 - .1 microns thick.

Do you use topcoats?

VTI has two automatic conveyor-based UV-cure robotic spray paint lines. We can topcoat after metalizing if the required abrasion resistance for the metalized parts are severe.

What size items do you accept for vacuum metallization?

The maximum part size that will fit the vacuum chamber is 28” wide by 48” tall.

The maximum part size that can be painted is 16 “ wide by 20” tall.

Are there any materials you can’t coat?

There are certain plastics which are very difficult to coat and get good adhesion. Polypropylene is the most problematic.

How long is the turnaround time for a project?

A typical job takes about 2-3 weeks to get into our production schedule. The time for production depends on the number of pieces that need to be coated.

What are your minimum and maximum order sizes?

We are structured primarily for higher-volume jobs. We do not accept “one-off” jobs, nor very low-volume work. Annual production value should be in the $10,000 range and above. We have no maximum order size.

PVD Coating

What temperatures do my parts see during processing?

The CatArc coatings can be deposited as low as 400°F, but the higher the temperature the better the adhesion and performance. Sputtered coatings are done at 950°F.

What are your most frequently run coatings?

CrN, AlTiN, and TiN are all run daily.

What is your typical turnaround time?

Three to five business days are standard. Expedited delivery is available on request.

EMI & RFI Shielding

What Is the Difference Between EMI and RFI?

The terms EMI and RFI are often used interchangeably. EMI is any frequency of electrical noise, whereas RFI is a specific subset of electrical noise on the radio frequency spectrum spanning from 30 Hz to 300 GHz. Shielding coatings produced via PVD are rather thin when compared to the wavelength of lower frequency radio waves. This means that although PVD can be used throughout the electromagnetic spectrum, it is most effective when blocking frequencies above the Ultra High Frequency (UHF) threshold of 300 MHz.

What is the difference between an EMI/RFI Shielding Coating and an ESD Coating?

An ESD (electrostatic discharge) coating is simply a continuous metal film with resistivity less than 10 ohms/square. The film spreads an electric charge across the surface of the part preventing an arc discharge from occurring and damaging sensitive items.

An RF shielding coating actually blocks radio waves from passing through the coating.

What Products Benefit from EMI Shielding?

Automotive radar for ADAS (Advanced Driver Assistance Systems)
Medical devices such as infusion pumps and monitoring devices
Marine electronics
Mobile phones
Process control components and sensors
EMI Shielding Wrap for Wires

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We are a high-volume manufacturer of OE parts. Personal & individual runs and specials are not available. 
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