Newsgroups: comp.robotics
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From: dpi@lofty.com (Doug Ingraham)
Subject: Re: datak..photoresist & pc board
Message-ID: <1995Feb28.042825.23350@lofty.com>
Organization: Lofty Pursuits Public Access Unix for Rapid City, SD USA
References: <3itikq$902@hpuerci.atl.hp.com>
Date: Tue, 28 Feb 95 04:28:25 GMT
Lines: 46

In article <3itikq$902@hpuerci.atl.hp.com>, mdd@hpuerca.atl.hp.com (Mark Doble) writes:
> Has anyone had any experience with the datak pc board kit?
> 
> I am able to make my good quality negatives from my original artwork.
> 
> The problem is when i expose my photoresist doped copper clad board
> through the negative.  The exposed photoresist does not develop a nice
> pattern on the board after developing.
> 
> I have tried several exposure times ranging from 5min to 15min. and have
> tried doping the board with two layers of spray on photoresist. (The
> photoresist comes in a spray bottle that you spray on the clean copper
> board, then dry and expose.)
> 
> I am using a 3200K color temp, 500watt bulb at a distance of 12".   
> 
> Does anyone have any pointers when using this system or some general
> tips on using photoresist and exposure times.

I used to use it but gave it up a couple of years ago.  I found it to be
difficult to get to work reliably.

The board must be really clean and dry.  I found that heating the board
with a heat gun right before spraying helped to get a more even coating.
I always gave it a second coat.  I had just as good of luck if I dried it
in an oven or let it air dry overnight.

My lamp was a 300 watt halogen at about 15 inches for 25 minutes.

Follow the directions for development and only use the developer once.

I remember having to rinse the pattern in fresh developer to clean it up.

Etch it at an elevated temperature.  For some reason a slow etch allows
undercutting.

Once you get frustrated enough switch to the Kepro Dry film and you will
never turn back.  It is so easy and the chemicals are all water based.

Good luck!

-- 
Doug Ingraham (Owner/Design Engineer/SysAdmin)
Lofty Pursuits (Makers of fine Electric RC Gadgets since 1992)
2274 Aster Ct. Rapid City, SD 57702  (605) 343-8760
Internet: dpi@lofty.com or 75116.473@compuserve.com
