author
9CommentsJoined January 1st, 2013

Tell us about yourself!

Complete Your Profile
  • splud commented on jmsaavedra's instructable Custom PCB Prototyping Using a Laser Cutter2 months ago
    Custom PCB Prototyping Using a Laser Cutter

    I can get a really nice looking PCB by doing the vector outlines only, and it is WAY faster to prep too. However, if you don't have suitable clearance between pads for SMD components, you're going to have a greatly increased chance of bridging (ESPECIALLY when there are heatsink pads underneath some devices). This wouldn't be as much of a problem if you were using solder mask, but this method of prototyping doesn't involve solder mask.Printing a raster image on the laser can end up resulting in jagged edges on the verticals. That can be mitigated by following up the raster etch with an outline cut, which then ensures everything has a crisp transition.Avoid jacking up the power too much - it will delaminate the copper (won't etch the copper itself, just cause the adhesive bond underne...

    see more »

    I can get a really nice looking PCB by doing the vector outlines only, and it is WAY faster to prep too. However, if you don't have suitable clearance between pads for SMD components, you're going to have a greatly increased chance of bridging (ESPECIALLY when there are heatsink pads underneath some devices). This wouldn't be as much of a problem if you were using solder mask, but this method of prototyping doesn't involve solder mask.Printing a raster image on the laser can end up resulting in jagged edges on the verticals. That can be mitigated by following up the raster etch with an outline cut, which then ensures everything has a crisp transition.Avoid jacking up the power too much - it will delaminate the copper (won't etch the copper itself, just cause the adhesive bond underneath it to gas out and separate the copper). Might not seem like a big issue if the spots being heated are areas you want to remove anyway, but this delaminating impacts adjacent material - so that thin trace you DO want may lift away from the PCB (and in fact, may etch away because the etchant gets underneath it).Experiment with different paints. Primer versus top coat enamel, versus lacquer, etc. You can have different results between Ferric Chloride (the brown stuff) versus Cupric Chloride (the bright green stuff made from priming Muriatic Acid and Hydrogen Peroxide with Copper). I have some Nalgene bottles with good seals that I use for "shaking it up" with small prototype PCBs - complete etch in < 5 minutes.If you botch a laser etch (say because the PCB design wasn't registered proper to your copper and ran off the edge), you can clean the PCB and repaint it to use again later. If you just spray over the botched area, you'll have an uneven thickness of paint and an area which may be more prone to partial etch.Note carburetor cleaner also works great for removing paint from the PCB.For the best results, make sure your cutting deck is level and the top of the PCB material is at the focal point of the laser.

    View Instructable »