Short answer
Clean the worn fingers, degrease at 10 to 12V DC, plate nickel at 5 to 6V over any exposed copper, then plate 24K gold at 6 to 8V. Because metal only deposits where the pen tip touches, you can restore one finger at a time without a plating tank. The Contact Repair Kit ($400) has everything needed.
Signs the fingers need re-plating
- Copper showing through the gold on the contact area
- Dull, discolored or corroded fingers
- Intermittent contact when the board is seated
- Visible wear tracks from repeated insertion
Why a pen instead of a tank
Tank plating a populated board is not practical, and stripping components to plate the edge connector costs more than the repair is worth. With a plating pen, the solution stays in the tip. You plate the finger you are touching and nothing else, which is why rework technicians use it on boards that are otherwise good.
Hunter pens are self-contained cartridges, so there is no bath to mix, maintain or dispose of.
Step by step
- 01
Remove oxide and discoloration
If the surface is discolored or oxidized, polish it with a fine metal polish until the oxide is gone, then wipe it clean with a lint-free cloth.
- 02
Degrease at 10 to 12V
Set the supply to 10 to 12V and use the Absorbent / Degreaser pen (PL-1002). Connect the part to the negative (−) lead of the power supply and the pen to the positive (+) lead. Hold the pen so the whole tip touches the surface, and move it lightly back and forth in a slow stroke. Small bubbles form as oil and grease come off. Rinse with water when done. Stainless steel takes the Stainless Steel Degreaser pen (PL-1014) instead.
- 03
Check what is exposed
If copper shows through, it needs nickel before gold. If the gold is only thin and the nickel underneath is intact, go straight to gold.
- 04
Nickel over exposed copper at 5 to 6V
Plate with the Nickel pen (PL-1006), working one finger at a time. About 0.4 µm in 2 minutes on a 1 in² area. Rinse.
- 05
24K gold at 6 to 8V
Plate each finger with the Gold 24K pen (PL-1003). About 0.5 µm in 2 minutes and 0.8 µm in 3 minutes on a 1 in² area. Standard pens reach 1.5 to 1.8 µm maximum.
- 06
Rinse and wipe
Rinse and wipe the fingers with a soft cloth before reseating the board.
Cleaning badly contaminated fingers
For fingers with heavy corrosion or residue, the Micro-Jet 200 micro-abrasive blaster handles PCB-level cleaning and surface prep with controlled particle delivery, so it cleans the contact without damaging fine traces or nearby component bodies.
What it costs
The Contact Repair Kit (PL-1000C, $400) includes the power supply, connector cables and the Absorbent, Nickel and Gold 24K pens. Replacement Gold 24K pens are $145 and Nickel pens are $70. Each pen holds 10 ml of solution and covers roughly 300 square inches, which is a lot of gold fingers.
Frequently asked questions
Can you repair PCB gold fingers without replacing the board?
Yes. Worn fingers can be re-plated on the board with a brush plating pen: degrease, nickel over any exposed copper, then 24K gold.
Will plating one finger bridge to the next?
Metal only deposits where the pen tip touches, so careful work plates one finger without plating its neighbors.
Do I need nickel under the gold on PCB fingers?
If copper is exposed, yes. The gold pens plate over gold, nickel or silver, not bare copper. If the original nickel is intact, plate gold directly after cleaning.
What kit do I need for gold finger repair?
The Contact Repair Kit (PL-1000C) has the power supply, cables, and Absorbent, Nickel and Gold 24K pens. The heavy-duty version (PL-1000CHD) is for higher-volume work.
Not sure which pens your part needs?
Tell us the substrate and the finish you need. The people who build the system will tell you the sequence.