Can you recommend a high resolution printer to fabricate plastic photo masks for lithography (esp. for SU8).
Please recommend a specific printer that's suitable for printing minimum feature size of 5 um.
Hi,
With 2 micron minimum feature size acheivable:
http://www.cen.iitb.ac.in/slotbooking/GLIMPSE/1_Glimpse.pdf
Interesting article but not optimized to get to 1 micron... change the head, etc
Article SU-8 inkjet patterning for microfabrication
Hope this gives you some ideas
Dear Navid Kashaninejad , most (all?) printers (home and office printers) are designed for our eyes resolution and therefore the number of pixels per inch is relatively low, what makes difficult to reach resolutions below 25 um, even in top range models. To circunvent this issue you can print your mask in a common printer and then use photoreduction optics. Quartz-Cr masks are often fabricated in a 4x size and then photoreduced. You also can try in a professional printer company. We did that with good results (5um resolution), cheap and fast. I don´t know the name or model of the printer, sorry. If you choose this option, ask the company staff do not curl or roll the masks to avoid scratches that can cut a contac.
Hope it helps!
Manuel Gómez Thank you so much for your answer. Could you please explain more about "using photoreduction optics "?
Dear Navid, photoreduction consists on making a projection of your mask through an optical system. It is a set up that works like an inverted telescope. I mean, you place the large mask in the high aperture side and a light behind, and your lithographic substrate on the other side, an image of your mask will be formed over the resist and after focusing it properly you can get your structures reduced.
You could even try with a single lens, but I think it is better to use a collimated illumination beam, your large mask and the projection optics, focusing on the surface of your resist material. If you cannot change your optics, you always can print the large mask in the appropiate size to obtain the right size upon the resist.
Hope it helps.
Regards!
Dear Navid, you could try to directl inkjet print a patterned SU-8 layer (e.g. Kayaku Advanced Materials PriElex SU-8 C1). Although the minimum feature size will be more in the range of 50um; for openings the minimum featues size can be down to 10um.
Kind regards, Joost
https://www.elveflow.com/microfluidic-reviews/soft-lithography-microfabrication/fabrication-of-glass-and-film-photomasks/
this might be helpful..
copied content: Step 4 – Transparent film photomask fabrication Process
The film is fed into the processor after imaging via a series of rollers, and undergoes some chemical changes through the development of the image. Development changes the exposed silver halide crystals into ‘black’ particles in the emulsion layer of the photomask.
The development times and temperatures are critical for maintaining the correct CD of the photomask, and the transportation of the film from one step to another needs to be finely tuned. Fresh chemicals are added to the tanks in pre-defined rates according to the mask size, and the chemistry is pumped and re-circulated through the tank to ensure correct dilution.
Fixation is the next chemical process of the photomask fabrication and is necessary to stop the development reactions and obtain a stable image. At this stage, the unexposed silver halide is washed out of the film photomask and the base dyes are cleared. Just like during development, the fixer is consumed during the process, and materials washed out of the film build up in the fixer tank. Fixer replenishment helps to counteract these processes.
Following adequate fixation, it is important to wash the film to remove residual processing chemicals and byproducts. Again, careful replenishment rates are set to ensure that the wash stage is clean and free of contaminates (which are washed to drain). The chemical and wash phases are complete and all that remains is to dry the film.
At this stage the most important factors are adequate drying of the film while maintaining good dimensional stability.
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