AVR-Chat

On Mar 27, 2006, at 3:12 PM, Thomas Keller wrote:

> Henry Carl Ott wrote:
>> Artwork for a simple bootice PCB on my projects page.
>> http://users.rcn.com/carlott/projects.html
>>
>
>    Great page!   Thanks!   A tip for those interested in the toner
> transfer PCB technique:
>
> Apparently, it is not necessary to pay for expensive made to purpose
> "toner transfer papers."  This is alluded to in Henry's article,  
> wherein
> he notes that Epson Photo Paper also works. I am told, and have seen
> truly impressive results from people using this technique, that simply
> using glossy magazine paper works very well.  It is, of course,  
> somewhat
> more difficult to inspect your printed pattern for pinholes and  
> voids as
> a result of the existing print, but it is free. (use of a magnifying
> glass for inspection has been advised by several practitioners)  I  
> have
> seen any number of PCBs using fine pitched SMD devices fabricated  
> using
> this techniquem and the boards look VERY good.  Clean, crisp pattern
> edges, no blurring, no patteern tearing.
>

I've used various glossy papers before, and found that I get much  
better results from the TTS paper and green film (over the toner to  
seal).

http://www.pulsar.gs/

I can do a consistent 8mil layout with no problems; I should be able  
to do somewhat better than that.

Here's a page on my Wiki about my process:
http://ned.bike-nomad.com:8080/Ned/56

> I have not, as yet, used this technique, though I am planning to next
> week.  I have used Eagle (www.cadsoft.com) Schematic Capture and PCB
> Layout [check out their free demo versoin, for up to 3" X 4" (79.2mm X
> 101.6mm) single sided PCB work] software to lay out several TQFP to  
> DIL
> adapter boards,so I can mount SMD AVRs to my solderless breadboarding
> station.,  I'll let you know how it goes, and perhaps post some  
> pictures.

Some more tips:
- use a sponge for quick (no heating, no bubbling) etching
- consider using a laminator instead of an iron for tranferring the  
toner.
- use Contact paper to do double-sided work (to mask one side while  
etching the other)

Look at:

http://www.pulsar.gs/PCB/a_Pages/5_Support/5b_Tips_Tricks/ 
Tips_Tricks.html

I've found that using Toner Transfer and sticking exclusively to  
surface mount components (and maybe some top-side jumpers) means that  
I can have very fast turn around from idea to finished board (no  
drilling, for one thing!) with just a single-sided etch. Using double- 
sided board then gives you a back-side ground plane for free.

-- 
Ned Konz
ned@bike-nomad.com