Author Topic: PCB Etching test pattern?  (Read 4518 times)

0 Members and 1 Guest are viewing this topic.

Offline Jebnor

  • Regular Contributor
  • *
  • Posts: 155
  • Country: ca
  • Absolutely! Yes, kind of, sort of, not really, no.
PCB Etching test pattern?
« on: July 13, 2013, 03:43:33 am »
Does anyone have a PCB Etching test pattern for a 4x6, or smaller, board?   I have had to buy a new UV Lamp and I'd like to test it before I etch 'real' boards. 

Ideally, I'll have 4-6 of the same pattern on a 4x6" board. I'll then bracket the expected exposure time to see which turns out best. If I can't find one, I'll make one.  It will probably just have positive and negative trace widths and a couple of drill pad diameters.  When building my own boards I just leave a 16mil center for the pads and vary the outer diameter to the required size.  This allows me to use whatever drill size is appropriate and if I miss a little, I don't have non-copper next to the hole.  If I end up making one, I'll post it.
Before this, there was a typo.
 

Offline Paul Price

  • Super Contributor
  • ***
  • Posts: 1411
Re: PCB Etching test pattern?
« Reply #1 on: July 13, 2013, 04:53:58 am »
Why not use some free download PCB generating software and make your own in a few minutes?
 

Offline hlavac

  • Frequent Contributor
  • **
  • Posts: 520
  • Country: cz
Re: PCB Etching test pattern?
« Reply #2 on: July 15, 2013, 06:44:53 am »
I have made one in the past for exactly this purpose (calibrating exposure time for my UV source).
I'll try to find whether I still have it when I get back to my computer in a bit...
« Last Edit: July 15, 2013, 06:46:32 am by hlavac »
Good enough is the enemy of the best.
 

Offline 4to20Milliamps

  • Regular Contributor
  • *
  • Posts: 248
  • Country: us
Re: PCB Etching test pattern?
« Reply #3 on: July 15, 2013, 10:02:33 am »
This seemed like a good reason to fire up eagle and see if I could still use it, I'm not sure if this is what you had in mind or not:

« Last Edit: July 15, 2013, 11:02:12 am by 4to20Milliamps »
 

Offline hlavac

  • Frequent Contributor
  • **
  • Posts: 520
  • Country: cz
Re: PCB Etching test pattern?
« Reply #4 on: July 15, 2013, 10:52:10 am »
Found it, here it is. Eagle format (5.x I think, it's been a while). Don't forget to run Ratsnest before printing it.
Its very simple. Cover it all, leave just the section 10 exposed. Turn on the UV light, and every time interval (I used 1 minute at the time, my UV source was not very strong) uncover another section.

When you develop the board, low numbers will be underexposed, high will be overexposed, and somewhere in between there will be your sweet spot ;) Turned out to be about 4 minutes for me at the time (UV lightbulb for dark light, not very ideal, too short wavelength). With my new UV LED based source it would be more like 10 second intervals.
Good enough is the enemy of the best.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf