Homebrew PCBs

>I showed these pictures to a friend
who had tried hacking an R220 and 
>his reply is that it's
great, but he doubts that it is possible to get 
>the
registration close enough to do double sided boards. I'm curious if

>you have any reply to that.


In the past, I used below method but it requires accurate X/Y positioning and I'll use it for this printer also, it has a starting point accuracy of
~+/-10micron meter. 

You need to have reference holes on
printer bed on  center of X-axis, which requires fixed board size or
multiple reference holes. Your board also needs to have pre-drilled
reference holes. Something like below,
              X-axis
|--------------------------------|
|                                 *                                 
  |
|                                      
                                 |
|                                                                     
   |
|                                                                     
   |
|                                                                     
   |
|                                 *                                 
  |
|--------------------------------|
*Reference holes
Prepare your image centered at
	reference holes, after printing 1st side flip on X-axis
	and print 2nd side. You can also eliminate requirement of
	centered image by adding offset but centering is easier.
>He uses unmodified inkjets to
	print transparencies, aligns them as a 
>set, then uses a
	vacuum table to hold them on a pre-sensatized board 
>while
	exposing under an UV lamp. He says he regularly gets 5 and 5 and
	
>is happy to be able to do double sided. 

Yes he can get
	it, everybody uses this method . Personally I want to avoid stock of
	photosentized boards or photo resist, developer and for me it is double work and it can be as good as your master film but this method is
	proven no doubt about it. 

>I think a possible solution is
	to purchase thinner than normal single 
>sided stock, etch
	seperatly, and then bond the two with the backing 
>together
	and the copper sides out. No registration problems because the
	
>registration is done after the etch. Someone else had
	described this 
>here in more detail.

It is possible, but how to avoid
	air bubbles between layers without vacuum? If you use oven during
	soldering  bubbles can separate glued layers.

Cheers,
Volkan  


	



      

[Non-text portions of this message have been removed]