Large Format Film Resolutions

The following information refers to emulsion coated polyester patterns, upto a maximum of 2400mm in size.

large-film-resolutions

CHOOSING RESOLUTIONS

We can write masks at 4 different resolutions, called "dpi" (dots per inch which refers to addressability, not optical resolutions. The higher the resolution, the better the quality. For each increase in DPI, there will be a 2x improvement in the following parameters: Addressability, Minimum Line, Edge Roughness, CD Uniformity.

4k DPI : LOW Resolution. Although this resolution may resolve smaller features, we recommend keeping feature sizes above 75um as corner rounding is considerable. Edge sharpness and definition is acceptable for non critical design types, although designs with arcs/circles and lines running off 90 degree grid may show pixilation. NO features such as lines / circles / spots / squares below 60 um unless on a 'best effort' basis previously agreed with our technicians.

10k DPI : MEDIUM Resolution. This resolution will usually resolve down to 48 micron lines with decent line edge qualities with only a slight pixilation along edges. Corner rounding is still noticeable under magnification. NO features such as lines / circles / spots / squares below 40um unless on a 'best effort' basis previously agreed with our technicians.

16k DPI : HIGH Resolution.It offers an excellent price/quality balance. This resolution will resolve down to 24-micron lines and has very good line edge qualities with little pixelation along edges, although some circles/squares and spots may have some distortion to them. Corner rounding is usually acceptable at this level.

20k DPI : PREMIER Resolution.It is excellent for demanding, high-precision photomasks, and is the best quality that we can offer. This resolution will resolve down to16 micron lines (depending on the geometry type ) and has good line edge qualities with little pixelation along edges, and corner rounding is only noticeable under high magnification. Note that where feature sizes are required below 16um, it may be possible given increased setup costs.


FEATURE TOLERANCES

There are two different values that we specify for tolerances. The first is a ‘feature tolerance’, which equates to one specific feature (also known as CD or Critical Dimension). So, if part of your mask design has a 75um channel and this is a critical feature, you can use the table below to work out possible deviations to the channel width, depending upon which resolution you choose. As a rule, the higher the resolution, then the more accurate the individual feature size will be.

Resolution
Material
CD & Tolerance
4k dpi
polyester film
75um +/- 25um
10k dpi
polyester film
48um +/- 16um
20k dpi
polyester film
20um +/- 5um

All figures above in Microns....


DIMENSIONAL TOLERANCES

Our photo-mask films are produced in conditions of 21deg C / 50% humidity, and if dimensional accuracy is a concern when using the polyester mask, then you must replicate these conditions in your own clean rooms and acclimatize the mask in these conditions for upto 8 hours before you intend to use it – only then can it be considered to be dimensionally accurate and stable. We strongly recommend using glass-based substrates where dimensional stability is a concern.

NOTE:
When using films in your own production environment, be aware that ...
1 Deg C temperature change = 18 ppm (1.8um per metre length)
1% Humidity change = 9ppm (0.9um per metre)


Capabilities

Resolutions
4k dpi
10k Dpi
16k Dpi
20k Dpi
Smallest Feature
0.016mm @ 20k dpi
Smaller features on special request
Materials
Photo Emulsion gel on 0.18mm Polyester
Largest Image
2397mm x 1587mm
Customisation
Punched Holes
Bespoke Sizes