Homebrew PCBs

On Thu, 15 Mar 2012 17:21:12 -0000, you wrote:

>I had wondered about the photo etch method and if it had this problem.

if a laser produces the pattern, yes.  If an inkjet, no.

>
>The mesh method is mentioned - do you mean use a very fine mesh pattern for the solid ground plane?  I'm not sure how to do this in Eagle or ExpressPCB programs.  Sounds like a good idea - mesh fine enough it "looks" solid on transfer?

Nope, charge tends to congregate at the edges of any pattern.  A large
black area will be darker at the edges with a laser printer.  Inkjet,
nope.


>
>With the normal transfer, the ground plane "looks" like it has good toner transfer - very black.  BUT, on etching it doesn't look so good with many tiny holes showing.

if that's toner transfer, welcome to the club.

If you can do a mesh, then you're using a lot of fine lines, so the
holes are deliberate.  That'll work.

You can control the size of the holes, but too small, and you don't
equalize the charge enough.

>
>Thanks for the suggestions and info - I might have to try photo - etching.  That does seem to have better results.

Depends on how the master pattern is laid down.

Harvey

>
>Ken H>
>
>
>--- In Homebrew_PCBs@yahoogroups.com, Malcolm Parker-Lisberg <mparkerlisberg@...> wrote:
>>
>> Use a mesh pattern, rather than solid. It happens because the electrostatic charge migrates from large areas.
>> 
>> Malcolm
>>  
>> I don't suffer from insanity I enjoy it!
>> Mene, mene, tekel, upharsin
>> The writing is on the wall.
>> 
>> 
>> ________________________________
>>  From: sailingto <sailingtoo@...>
>> To: Homebrew_PCBs@yahoogroups.com 
>> Sent: Thursday, March 15, 2012 3:15 PM
>> Subject: [Homebrew_PCBs] ground planes
>>  
>> 
>>   
>> Does anyone have problems getting large ground plane areas to stay good 'n solid with copper?  I've been having a bit of problem with large ground plane areas using toner transfer method.  If I do a board without a large ground plane, the traces look good - trace size ranges from .015" to .050" or so.
>> 
>> I clean copper good, wash with alcohol.  Toner transfer at 360ºF with a laminator using Pulsar toner transfer paper, then etch in HCl and H2O2.  I used the green film last board and it seems a bit better, but not sure about large areas yet.
>> 
>> Just checking to see if anyone else has this problem, or maybe found a solution...... or maybe it's just me?
>> 
>> Thanks for any guidance and suggestions.
>> 
>> Ken H> 
>> 
>> 
>>  
>> 
>> [Non-text portions of this message have been removed]
>>
>