Base Materials

The precision patterns are typically made on Soda Lime glass, Quartz (fused silica), or Polyester Film. Choosing the correct substrate will depend very much on your applications, the type of features and accuracy that you need, the type of light source that you will use, and of course, the budget that you have for the project.

Typical Material Configurations

CHROME ON SODA LIME

One of our most common mask types is a hard chrome surface on soda lime glass. These are very high resolution, easy to clean with most chemicals and the chrome surface is fairly hard-wearing. The glass gives the mask improved dimensional accuracy over polyester film, and the normal density of 3.0+ is acceptable for normal UV applications. Most material stocked is Low Reflective coating which gives a brownish tint (an oxide) to the chrome surface.

CHROME ON QUARTZ

This configuration is not as common due to the expense of the material, but quartz brings the very best stabilized material thermally, along with a very clear base that allows wavelengths of many sizes to transmit with very little absorption/reflection. Stocked sizes and quantities are lower due to it not being a common product

BLACK CHROME ON WHITE GLASS

Some customers require a high contrast target to be used in optical applications with reflected light. These are mostly used for testing lens and video quality and diffusions. After many years of trials and testing, we have perfected a process where we use a low reflective black chrome that is coated onto a white translucent glass. The only thickness available is 1.25mm, and size is limited to 200mm maximum.

POLYESTER FILM

A film (polyester) mask is a mask that is made in fairly large sheets. The polyester film is coated with a sensitive photographic emulsion by the manufacturer (Agfa) and we buy the mask blanks in various sheet sizes. When exposed and developed, the emulsion turns black and the remainder of the unexposed area is washed out clear. The remaining black part has a very high optical density of 5+. This film is very flexible, but the emulsion layer is soft and can damage if not handled correctly. Typically, these masks are used by PCB manufacturers, chemical etchers, printers, etc. and are lower resolution than glass masks.

ALUMINIUM ON QUARTZ

This configuration is generally used for laser ablation purposes. The high energy and heat generated by laser ablation is dissipated quicker and easier by the aluminum metal coating, and the quartz substrate can cope with much higher temperatures than standard SL glass. Very few sizes are stocked for this product.