Advanced Materials for Electronics

PC Electroless Copper

Adherent copper deposition system for thru-hole plating, printed circuit boards, plastics and other materials.

MATERIALS FOR PLATING NON-METAL, THRU-HOLE PLATED PCB:

Solutions should be used in the following order:

  1. Solution C;
  2. Solution D;
  3. Solutions A & B.

SURFACE SENSITIZING (SOLUTION C)
Immerse pre-cleaned copper-clad epoxy/glass laminates in Solution C for 2 minutes. Do not stir or agitate the solution. Avoid contamination from metal objects. Use glassware and plastic-coated tweezers or transfer racks for handling. Remove surface sensitized pieces; after water rinse, transfer to next solution.

ACTIVATOR (SOLUTION D)
PC boards should be allowed to stand in Solution D for 2 minutes. Again, do not agitate or stir. Finally, remove work and thoroughly rinse in distilled water.

PC ELECTROLESS COPPER BATH (SOLUTIONS A & B)
Bath Make Up: Mix A & B in equal volumes.

Operation of Bath: Use at 30-45 °C (not over 50 °C). Bath should be held at optimum operation temperature of 40 °C for uniform plating thickness. Continuous mild agitation of work. Nominal plating rate 0.2 mil/hour. PC Electroless Copper is used for depositing thin layers of copper, up to 0.5 microns. For thicker films, Transene Copper Plating Acid Type should be used after initial electroless copper deposition. The copper content is 16 grams/gallon.

Thru-Hole Plating Instructions

CLEANING PROCEDURE

  1. Solvent Decrease – Removes oil and grease; followed by vigorous water rinse.
  2. Pumice Powder – Wet or dry, removes oxides, heavy soils (and/or vapor-blasting); followed by thorough water rinse.
  3. Alkali Soak (5 Min) – Hot 150° to 180°F to further clean copper surface; condition laminate; improve surface wetting. Followed by warm water rinse.
  4. Persulfate Etch (2 min) – Produces matte pink copper surface: ammonium persulfate – 200 gm/L; sulfuric acid – 10 ml/L. Followed by water rinse.
  5. 10% Sulfuric Immersion (2 min) – Removes insoluble salts (Step #4). Followed by water rinse.
  6. 33% HCL Immersion (2 min) – To protect from harmful drag-in.

PROCEED DIRECTLY TO SENSITIZER
COPPER DEPOSITION

  1. Sensitizer Solution C (2 min. immersion) – Seeds epoxy/glass laminate. Followed by water rinse.
  2. Activator Solution D (2 min. immersion) – Activates an autocatalytic layer for copper deposition. Followed by thorough water rinse.
  3. 5% Sulfuric Dip (3-5 min. immersion) – Speeds electroless copper deposition, protects from drag-in contamination. Followed by water rinse.
  4. Electroless Copper Parts A & B (5-10 min. typical) – Immerse in plating bath and agitate slowly. Operate @ 30-45 °C. Followed by water rinse.
  5. 5% Sulfuric Dip – Neutralizes surface. Follow by water rinse.
  6. 20% HCl Acid Dip (10-60 sec.) – Followed by water rinse.
  7. Electroplate Copper – To build up desired copper thickness.