Making a photomask
Creating a photomask
This is a simple guide on the steps required to make a photomask.
If you are intending to use the mask aligner in SIOS then the mask size that you require is 4x4inch and your design must take into account the aperture of the aligner which is approximately 3.5 Inches in diameter.
The design of the mask can be layed out using any cad type package but we usually use dwf/dwg formats, and this can be made with qcad in linux or autocad in windows. Autocad 2005 is available through Microsoft Application Virtualization (access may require an email to IS asking to be added to the permitted user list). There are some important rules to obey when doing your design.
- Do not go too close to the edge of the mask, eg. Leave a 5-10mm gap from the edge.
- Try to align features on a grid, this makes it easier for the machine that writes the mask.
- The most detailed features (requiring the highest resolution) should go into the centre of the mask.
- Work radially outwards with increasing feature size from the centre
The company we use for producing photomasks is www.jdphoto.co.uk. They have a good website covering what services they offer and a price calculator. A local copy of the most recent design guide for photomasks is available here. (link to local copy pdf date it)
How to order
Get a price from the calculation page and submit and order for to jo mee who knows how this is done. Email them to say you are submitting and order and that it will be coming from UoN etc. Then when you get the order confirmation email, email the drawing data file using the reference from the order confirmation. They wll then check your drawing and produce proofs before making he mask. The proofs must be checked and approved.
They can be contacted by
- Phone 0161 627 2949
- Email firstname.lastname@example.org
- online live web chat http://www.jdphoto.co.uk/ on contact page,
they are generally very helpful.