PREMIER 6" x 6" Film Mask
Emulsion Film Photomask
200k DPI - 4um CD
5" x 5" x 0.007"
All of our standard resolution photoplotted films are imaged and processed using the latest high-tech technology, which is a fully automated process allowing us to queue and image films whatever part of the day - or night. This automation helps to improve quality by reducing handling - and of course means that we have a high capacity in production..
BASE MATERIAL
All of our photomask films are imaged onto Agfa Idealine film 0.18mm thick polyester film which has a photographic emulsion coated onto one side. These are specially manufactured for consistent high quality results. They are both imaged, and inspected, in controlled environments which is crucial to their dimensional stability. For the most accurate films possible, please use this films in an environment of 21 deg C and 50% humidity.
RESOLUTIONS
GRADE 5 (PREMIER): 200k dpi with features down to 4um in clearfield and 6um in darkfield . Note that although this film can resolve smaller features, the edge definition of the lines appear more soft and distorted under high magnification.
CAD FORMAT
Data formats listed above are only a small section of what is available. If your chosen format is not listed, please contact us for further information and clarification. We are also able to provide a full drafting service whereby we can create your designs from drawings and descriptions.
PRODUCTION TURNAROUND
Our standard production turnaround is 3-4 days from receipt of the artwork, purchase order and related documents. We generally send checkplots with every order, and it is vital that these are replied to within a short delay in order that we can meet the schedule required. The production schedule assumes the original data package is correct and does not need to undergo revisions or changes. For large volume orders, or large photomasks on high resolutions, please enquire before ordering premium services.
Standard (4 days) : This is our standard service, and whilst we get 99% of orders shipped within this period, these are guidelines only and may change in periods of high demand. Where data packages are good, and all paperwork is completed promptly, we can often ship early. Expected return of checkplot by customer is within 4 hours. Any orders received after 1pm will assume day 1 to be the following day.
2 Days : A premium service. A complete manufacturing package (data/instructions/order) must be with us by no later than 11.00am. Expected return of checkplot by customer is within 1 hour.
Sameday: A premium service. A complete manufacturing package (data/instructions/order) must be with us by no later than 9.30am. Does not include photomasks bigger than 7". Expected return of checkplot by customer is within 30 mins.
8 Days: This is a discounted service for orders that are not urgent.
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POLARITY Masks are normally referred to as Clearfield (positive) & Darkfield (negative) Positive means that the data you have drawn in CAD will be Emulsion on the mask, with the background (the field) being clear polyester. Negative is the opposite of this, where the items drawn on CAD will be clear and the background will be emulsion. We also need to know which way round the mask has been designed on your screen. The easiest way to select this is to add some reference text (anything you like) to the design somewhere - maybe in the corner - and then specify if the text needs to be right reading or wrong reading. |
INSPECTION
Standard : We firstly inspect the piece by eye for flaws, design inaccuracies and contaminations. We also inspect a test coupon (placed in the bottom corner of the mask) for line width accuracy and edge definition. Next we measure the overall dimension of the mask, and record both of these measurements on our internal inspection records. Finally, we find the CD of the mask, measure that, record it, and also take a digital photo that is saved with the inspection log. We use Nikon MM40 at 900x magnification and an OGP ZIP 300 at 400 x magnifications for this.
Certificate of Conformance: In addition to the standard inspection process described above, we will also supply a printed Certificate of Conformance.
Certificate of Measurement : By selecting this option during the ordering process, we will inspect upto 10 customer defined measurements, with customer supplied tolerances. You will need to send us a document, or a separate layer of the design, showing us where you want us to take the measurements from. There can be upto 10 positions defined by the customer. These dimensions are then programmed on the co-ordinate measuring system and the mask is compared to this unique program. A certificate of measurement /conformity is given if the mask passes the inspection process. Additional positions can be requested if required.
CHECKPLOT
A method of sending an email copy of the design for verification before the mask is written. The ‘PDF Checkplot” is a low resolution (4000 dpi) graphic representation of the final photomask - the quality of the PDF does not represent the quality of the final photomask, it is a "gross overview". You must approve this by email before we can proceed.
For more accurate checkplot representation , it is best to send you a detailed CAD checkplot which will represent the design perfectly – in high resolution – and gives you the ability to also measure. You do not need to install any special software, we will give you the link to our online CAD viewer at the time of the checkplot.
YOUR DRAWING NUMBER
Please let us know the CAD file name / number so that we can tie together the uploaded data and the order.
NOTES
Here you can inform us of any other requirements or specifications regarding the order.
Please see the TECHNICAL sections, DOWNLOAD sections and FAQ for further information. If you still require clarification, please either email or click for LIVE SUPPORT.
SPECIFICATION
Polyester Film is a typical substrate used in the photographic process, and forms the most common substrate in applications that involve general multiple exposures (such as PCBs, etching, printing etc.). Polyester is excellent due to its low-cost nature, but must be handled carefully and used in controlled environments if dimensional accuracy is required.
Films used for photo-masks have the following component layers: a plastic base, a photosensitive emulsion layer (silver halide) and a backing layer.
This plastic base is polyester material, and has a thickness of 0.18 mm. The emulsion layer is composed of gelatine and silver halide and other chemicals, which adds another 0.005mm in total.
When we expose the film in the imager, the light energy from the laser interacts with the silver halide crystals suspended in the coated gelatine layers. Development, a chemical process, converts exposed silver halide grains into metallic silver. The next step in the chemical process is fixation. The fixer stops development and removes the unexposed silver halide grains in non-image areas. Finally, the film is washed/dried/cleaned and inspected.
The final result is a ‘black’ image coated on one side of the polyester base. The density of the film is very high, typically Dlog of 4.5 – 5, giving it an excellent opacity to all common light sources.
Two concerns with emulsion film over glass are stability and robustness. Both the polyester and the gelatine absorb moisture and heat from their surroundings, and as such they undergo dimensional changes – quite considerably for some large area films. The other problem with the Gelatine/Emulsion is that it is relatively soft and must be handled carefully to avoid damage and scratches.
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 acclimatise 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.
FAQ's
Q: What is the smallest feature that you can do ?
A: This depends upon the resolution that we image at, the tone of the photomask, and most importantly the feature type (Spot, square, line etc). This all makes it very hard to give a figure, but as a very rough guide we can make 8 -10 um using class 128 and down to 3 - 4um with our PREMIER range.
Q: How accurate are the features, what tolerances do you work to ?
A: This is dependant upon the resolution that we image the photomask at. The QUICK REFERENCE brochure in the DOWNLOADS section will give you a chart, specifying both feature and dimensional tolerances.
Q: What resolution should i pick ?
A: The higher the resolution, then the sharper the edges of the features, the smaller the features possible, the more accurate the features will be, the sharper the corners in of the features, and also the smoother the circles. Some customers will notice this difference straight away, some will hardly notice any difference. Every customer has different requirements and different priorities. If in doubt, chose a higher resolution to ensure your requirements are met, but we are happy to advise if you send us your design.
Q: What does the term POLARITY and FIELD mean ?
A: Polarity is the tone of the photomask, and in layman terms this can be thought of as Positive or Negative of the photomask. When you draw your photomask design, polarity determines whether the features on the mask are CLEAR or DARK on the final plate. The field refers to the background tone of the mask. So, a DARKFIELD mask would have the items you have drawn as CLEAR, with the background of the mask as DARK. Obviously this is the opposite for CLEARFIELD, where the field behind is clear and the design features are DARK. Remember, this is polarity or tone of the mask that we manufacture, and NOT the polarity of the wafer you are using. If used in contact lithography, the tone of the photoresist that you use will also affect which polarity to order.
Q: I've designed my mask with the wrong polarity - what do i do ?
A: We can use the original design file and simply reverse the tone of the photomask. This is much easier than supplying new data.
Q: What is Right Reading, Wrong Reading and Mirrored.
A: Right Reading Emulsion side Down is a common way to describe a photomask that will be used for contact lithography. When you hold the mask in your hands with the emulsion side facing down closest to the wafer, the image on the mask will be correct (right reading) or how it should appear on the wafer. This is equivalent to Wrong Reading Emulsion side Up. For us to make this happen we have to Mirror the image of your photomask before we write it.
