There are various ways of production of assembly payments in house conditions. The main distinction consists in method of transfer of the image from template on textolite. The best quality is reached at application of the photo mask permeable for ultraviolet rays.
It is required to you
- - the foiled glass fiber laminate
- - POSITIV 20 photoresist
- - educator of TRANSPARENT 21
- - photoresist developer
- - solution for copper etching
- - acetone
1. Create the image which will be postponed for photo mask. For this purpose it is possible to use PCAD or the suitable graphic editor. Try to move apart paths on the maximum distance from each other. Consider that various electronic components can have the different thickness of legs.
2. Create photo mask. For this purpose print out the prepared image on normal paper for the printer. Check whether the printer distorts the actual sizes of template, if necessary introduce amendments in the initial image. The press of photo mask needs to be made with the maximum filling, without toner regime of economy.
3. Carefully clean the surface of glass fiber laminate. Apply photoresist on payment, dry it. Lay the printed-out image on payment. Fix it by adhesive tape. Apply on template the educator. He will make paper transparent for ultraviolet. Establish the turned-out "sandwich" under the ultra-violet lamp. Hold time depends on many factors, including on lamp power, and is selected in the experimental way.
4. Make photoresist solution. For this purpose dissolve in water caustic soda, in the ratio 7 grams of NaOH on one liter of water. Time of manifestation is 30-60 seconds. If the drawing is not shown within two minutes, it is necessary to increase hold time under the ultra-violet lamp.
5. Etch excess copper from the printed circuit board. Prepare solution of chloric iron. Consider that it etches any metal, including stainless steels. Use only plastic tanks. Do not allow hit of solution on integuments. Use gloves and goggles. Etching time about 20 minutes. It is desirable to provide continuous hashing of solution in capacity.
6. Wash away residues of reagents acetone. Drill in opening payment if it is necessary. Now the payment is ready to tinning and unsoldering of electronic components.