process_2s-plate

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This is for PCBs with traces and/or components on both sides of the board, and a need to electroplate the board (most commonly, for vias).

Be sure you actually NEED to electroplate before starting this! The plating process can take in excess of three hours (depending on how closely you're watching it), and it is liable to not always work, especially due to things that are mostly out of your control. There is an alternative! Plating is typically avoidable by designing your vias as a standard hole with a diameter of 40 mil (1 mm). A standard 0.1” header pin can then be pushed through and soldered on both the top and bottom.

Before starting, make sure:

Step 1: Process setup and first drilling on the ProtoMat

  • The ProtoMat will pause at a step called “Dismount Material”.
  • Once it reaches that point, remove the substrate from the ProtoMat and click “Abort” in the Wizard.
  • Continue with Step 2.

Step 2: Electroplating with the Contac S4
Quick Plating Tips:

  • If you would like to adjust the plating time, ask a PI to put you in touch with an MPI.
  • Do not let your substrate sit in the bath (any bath) for very long after the timer runs out.
  • If the machine throws an error on startup, it’s likely a bath needs to be topped off. Get a PI to help.
  • After bath 3 (activator):
    • Swipe a “reasonable” amount off with squeegee (mostly just don’t want it dripping)
    • Dry for 20+ mins at 150F. (Higher than this can cause the ink to bake into the copper.)
    • When rinsing after drying (after “bath 4”), scrub the copper surface with a sponge to remove as much of the dried activator off the copper as possible.

Step 3: Etching with the ProtoLaser

Step 4: Routing with the ProtoMat


For issues with the ProtoMat, see the ProtoMat Knowledge Base.
For issues with the ProtoLaser, see the ProtoLaser Knowledge Base.


Common Electroplating Issues

  • “Device in failed state” on tool boot up.
    • Potential issue: Baths 1 and/or 2 are low.
      • Lift the lids to baths 1 and 2. If they are low, get a PI/MPI/Staff to refill from the chemical cabinet in the storage closet in the Semi-clean room.
  • Zero plating current error during plating step (Bath 5)
    • Potential issue: Too much copper buildup on the PCB holder.
      • Put on the chemical safety gear (apron, goggles, gloves, in that order) and remove the board from bath 5. Using the drip tray, go to the sink and rinse the drip tray, board, holder, and gloves well. Remove the board from the holder with the allen key. Using a fine-grit sandpaper, file, or sanding block, sand off any copper build-up on the posts and on the metal on the underside. Big flakes of copper may come off; this is expected. Once it looks cleaner, seat the empty holder into an empty bath (Bath 4 works well) and screw it down. Get a multimeter. The resistance between either of the posts on the holder and the metal strips with the pegs that run down the line of baths should be less than 1 ohm. If the multimeter confirms the resistance as below 1 ohm, re-attach the substrate to the holder, don the chemical gear again, place it back into Bath 5 and screw it down, and press the play button to continue.
      • If the error continues to be triggered, the resistance remains high, or you are not comfortable doing this, please get a PI.
    • Potential issue: Insufficient contact between the metal pegs in the tool and the metal underside of the tool holder.
      • While wearing the chemical safety gear, make sure that the tool holder is completely screwed down onto the pegs.
      • If the toolholder screws will not tighten further but is not in contact with the rail (i.e. there is a gap between the tool holder and the metal side railings), attempt to re-seat the holder onto the pegs While wearing the chemical safety gear.
      • If that is unsuccessful in solving the issue, while wearing the chemical safety gear, remove the board+holder from Bath 5 and, using the drip tray, move to the sink to rinse the board, holder, gloves, and drip tray. Remove the board from the holder with the allen key. Using a wire brush, sandpaper, or other means, clean out the peg holes in the tool holder. This may require disassembly of the holder entirely. To test the connection, make sure to don the chemical safety gear again before slotting the holder (without the substrate) into Bath 5. Using a multimeter, measure the resistance between the posts on the holder to the metal rails; this should be below 1 ohm. Rinse the holder when you remove it from the Bath while wearing the chemical safety gear.
  • process_2s-plate.1610679667.txt.gz
  • Last modified: 2021/01/14 22:01
  • by benh