Laser Registration of Resist

Author: Tom Eddleman

Posted:

Revised: August 03, 2005

I don’t know how many of you have lost substrate through incorrect positioning of resist, but I have and decided to make the process a little more “Idiot Proof”. This method works as I’ve been using it for about a year with no losses so far. Depending on how many pieces in the job will determine how much time you save. If it’s the same substrate there’s not much to adjust, but if you are using a different substrate the jig has to be modified.

The heart of the device is a laser with an X and Y axis. See fig.1. The one made by CST Berger called the model LC650 LaserMark Laser Cross does a good job. It doesn’t have a self leveling feature which is something that you don’t want. Most of the ones that are self leveling shut down when they’re tilted and this one is tilted 90 degrees. My Tool Store has them for $67 + frt. at this writing. You can talk to David Pearce at 1 800 347-5096. http://www.mytoolstore.com/berger/lasrcros.html

fig.1

This is the basic unit prior to mounting.

fig.2

This is after it’s bolted to a plate and attached to the ceiling. I used sheet metal that sways and has to steady before you can use it. I would suggest either using wood or stiffer metal to fix that problem. When you turn on the two rocker switches it will project a vertical and a horizontal line on a desk or table. Take a plumb on the vertical laser beam and make sure it is pointing straight down. If it needs adjusting just twist the outer ring of the LaserMark. It’s graduated in degrees. Make a note of the setting.

fig.3

This is a simple wooden jig for the placement of a mug. The handle is positioned parallel with the table and the strips are placed so that when you insert the mug it’s held firmly. All that needs to be done then is to find the exact vertical and horizontal and put index marks on the jig.

fig.4

This is the jig with a mug in it. Notice that there are no marks on the mug to act as resist. You line up the laser with the index marks that you have on your resist and set it down. It will be straight without a doubt. Just check each time before you set the resist down and make sure that the laser cross is on the index marks on the jig.

I would appreciate it if you would let me know how it works for you.