i'm kind off struggling with making a double sided boards .
so , thats what i do:
-coat one side with positiv 20 spray
-expose this side to light ...
-put the board into caustic soda +water...
-drill some holes to allign the other side more easily
-coat the second side of the board with positiv 20
-expose to light
-put the board into caustic soda again ...
-etch
now , the problem is, the second time i put the board into caustic soda it can damage the first side ....that was made earlier...
is there a solution?
one more question:
when using boards that come coated with photoresist (without using positiv 20) .the double sided boards got 2 stickers , one at each side ...
so , how am i supposed to use those?
i cant put it in water while the other side is still covered with the sticker....🙄
so , thats what i do:
-coat one side with positiv 20 spray
-expose this side to light ...
-put the board into caustic soda +water...
-drill some holes to allign the other side more easily
-coat the second side of the board with positiv 20
-expose to light
-put the board into caustic soda again ...
-etch
now , the problem is, the second time i put the board into caustic soda it can damage the first side ....that was made earlier...
is there a solution?
one more question:
when using boards that come coated with photoresist (without using positiv 20) .the double sided boards got 2 stickers , one at each side ...
so , how am i supposed to use those?
i cant put it in water while the other side is still covered with the sticker....🙄
I once did diy-doublesided boards with the following:
Print out both sides and glue the 2 films together like a bag (glued on 2 opposite sides). As the films are transparent it is easy to fit them. Put the doublesided coated pcb in this bag and light from both sides with a glass pressing on each side (or one side after the other, without taking off the glasses or the pcb might move inside the bag). Develop and etch both sides at the same time.
Mike
Print out both sides and glue the 2 films together like a bag (glued on 2 opposite sides). As the films are transparent it is easy to fit them. Put the doublesided coated pcb in this bag and light from both sides with a glass pressing on each side (or one side after the other, without taking off the glasses or the pcb might move inside the bag). Develop and etch both sides at the same time.
Mike
Still better
Just glueing 2 films together will work but you risk to scratch the films when you slide in the pcb, and you still need to position the pcb proberly.
A better solution is to cut an L shaped piece of plastic or metal of the same thickness as your pcb, say 1,5 mm. You can then tape the first film to side A so that the film is optimally positioned when the pcb touches both legs of this "ruler". No you can tape the other film to side B - you need to fiddle a bit but it should be quite strightforward to exactly match both sides.
Once the films are taped you can put the pcb in repeatedly and get it back to it's optimal position. Now you expose side 1 then side 2.
You can further improve this "ruler" if you cut it such that you have two small "bumps" on each leg - say 1 mm high - so that the two sides of the pcb will only touch those bumps and as a result will fit more precisely, especially when your pcb has uneven sides. It's a bit hard to describe but I hope you can understand what I mean?
Just glueing 2 films together will work but you risk to scratch the films when you slide in the pcb, and you still need to position the pcb proberly.
A better solution is to cut an L shaped piece of plastic or metal of the same thickness as your pcb, say 1,5 mm. You can then tape the first film to side A so that the film is optimally positioned when the pcb touches both legs of this "ruler". No you can tape the other film to side B - you need to fiddle a bit but it should be quite strightforward to exactly match both sides.
Once the films are taped you can put the pcb in repeatedly and get it back to it's optimal position. Now you expose side 1 then side 2.
You can further improve this "ruler" if you cut it such that you have two small "bumps" on each leg - say 1 mm high - so that the two sides of the pcb will only touch those bumps and as a result will fit more precisely, especially when your pcb has uneven sides. It's a bit hard to describe but I hope you can understand what I mean?
- Status
- Not open for further replies.