The MiniContac RS unit is made for galvanic through-plating of circuit boards using the black hole process and for galvanic reinforcement of copper surfaces.  The unit can be used for double-sided and multi-layer circuit boards.

The unit consists of a durable plastic and metal case containing the tanks for the chemical baths, the motion mechanism, the circuit board holders, and the control panel with status display.  The control panel is located on the right of the unit top and the main switch is located on the right side panel of the unit.

Maximum PCB Overall Size: 230 X 330 mm

Maximum PCB Plating Size: 200 X 260 mm (Due to mounting constraints, one end of board cannot be plated)

Minimum diameter via hole: 0.4 mm common (0.2 mm possible)

Standard Circuit Board Processing Time Estimate: 3 hours

Copper deposition rate: approximately 0.1 - 0.2 um per minute (6-12 um per hour)  This value is only an estimate and depends on tank temperature, current, circuit board size, and condition of chemical baths.

Phase 1: Degreasing the circuit board

Estimated processing time: 65 min

Phase 2: Cleaning the circuit board

Estimated processing time: 5 min

Phase 3: Activating the circuit board

Estimated processing time: 15 min

Phase 4: Copper plating the circuit board

Estimated processing time: 90 min

Reverse Pulse Plating Capability:  The “Reverse Pulse Plating“ mode is activated in profiles 2, 4, and 6 preedited by LPKF. Reverse Pulse Plating is implemented in the special LPKF control circuit that monitors the the whole through-plating process. Conventional electroplating results in increased deposition of material on the rims of the via holes due to the distribution of flux lines. This so-called "dog-bone effect" of edge buildup during metal deposition occurs especially at a large depth-to-diameter ratio of the via holes.  Reverse pulse plating uses short inverted pulses during which the circuit board acts as an anode. This causes parts of the bulging material to be removed so that the overall copper deposition is more uniform.

Common Tasks and Processing Tips

Changing the plating profile (See Available Process Profiles)

Note: You can abort by pressing the left arrow key, several times if necessary.

Starting the process or specific phase of the process

Note: You can abort by pressing the left arrow key, several times if necessary.

Setting calculated current for custom size circuit boards

Once required current setting has been determined from the Custom Size Circuit Board Current Calculator, you must enter this value into the appropriate profile to be applied during processing.

Note: Make sure you have the proper profile selected in the controller before proceeding with change.

Note: You can abort by pressing the left arrow key, several times if necessary.

Inserting the circuit board into a chemical bath

Phase 1: Degreasing the circuit board (complete sample requirements and preparation step above before proceeding)

1. Insert the circuit board with several knocking movements into tank 1.

2. Select and start PHASE 1 on the controller.

When the time counter is down to 0, a beep sounds and the status display prompts you to rinse the board.

3. Acknowledge the end of PHASE 1 by selecting and confirming END on the controller.

4. Take the circuit board out of the tank and rinse it thoroughly water in an external basin or sink.

Note: It is necessary to rinse the circuit board immediately after taking it out of bath 1 to prevent the degreasing agent from hardening. To rinse the circuit board move it up and down in a jet of water for about 15 times or at least 30 seconds. Ensure that the circuit board fastenings are also rinsed in order to minimize carry-over.

Phase 2: Cleaning the circuit board

1. Insert the circuit board with several knocking movements into tank 2.

2. Select and start PHASE 2 on the controller.

When the time counter is down to 0, a beep sounds and the status display prompts you to rinse and subsequently dry the board.

3. Acknowledge the end of PHASE 2 by selecting and confirming END on the controller.

4. Take out the circuit board and rinse thoroughly with tap water in an external basin or sink.

5. Rinse the circuit board with distilled, de-ionised, or ultra pure water. Make sure that the via holes are also rinsed thoroughly in this step.

Note: Take special care rinsing the circuit board otherwise the ACTIVATOR chemical is ruined by trace elements of the tap water (chlorine, calcium carbonate etc.) and has to be replaced completely.

6. Blow off the circuit board with oil-free compressed air or nitrogen until the water is removed from the holes.

7. Dry both sides of the circuit board with a heat gun.  Make sure that the holes are completely cleared for the next phase.

Note: The circuit board has to be completely dry, water will dilute the ACTIVATOR chemical!  

8. Cover tanks 1 and 2 to minimize evaporation losses.

Phase 3: Activating the circuit board

1. Insert the circuit board with several knocking movements into tank 3.

2. Select and start PHASE 3 on the controller.

When the time counter is down to 0, a beep sounds and the status display prompts you to dry the board.

3. Acknowledge the end of PHASE 3 by selecting and confirming END on the controller.

4. Take the circuit board out of the tank and wipe off the ACTIVATOR on both sides letting the liquid drip back into tank 3 using a squeegee.

5. Tap the almost dry circuit board on a soft surface so that surplus ACTIVATOR is removed even from small via holes.

6. Unfasten the board from the circuit board holder.

7. Let the circuit board dry thoroughly (e.g. using a heat gun, max. temperature 95 °C, +/- 5 °C for 4 minutes +/- 1 minute) and remove surplus ACTIVATOR by tapping the board in turns on a soft surface.

Note: Drying the ACTIVATOR can also be achieved using a drying cabinet at 100 °C max. (95 °C, +/- 5 °C for 4 minutes +/- 1 minute).  

Note: Ensure that the holes are not blocked by residues.

8. If you are using FR4 base material with copper film remove the film after drying.

Phase 4: Copper plating

1. Remove any oxide layers on the circuit board holder with electrical connector using sandpaper (copper gleam must be visible at the bolt and the flat surfaces).

2. Fasten the circuit board to the circuit board holder with electrical connector.

3. Ensure that the cathode connector is plugged in properly on the right side of the enclosure.

4. Insert the circuit board with several knocking movements into tank 4.

5. Select and start PHASE 4 on the controller.

Checking whether all via holes are plated with copper.

6. After approx. 15 to 20 minutes select and confirm PAUSE in order to interrupt the through-plating process.

The countdown is halted.

7. Take the circuit board out of the tank.
8. Rinse the circuit board thoroughly in an external basin or sink.
9. Check the circuit board:

Check whether the circuit board edge is copper-plated already.

For multi-layer circuit boards the edges of which you have sealed with adhesive tape, use a magnifying glass to inspect the largest via hole whether it is copper-plated already.  

If the circuit board edges (or holes) are already copper-plated the process works fine. Otherwise: Check the parameter settings (current, RPP).

10. Reinsert the circuit board with several knocking movements into tank 4.

11. Select and confirm START on the controller.

The countdown is resumed.

When half the time is over a beep is sounded and you are prompted to turn around the circuit board.

12. Take the circuit board holder with the circuit board out of the tank, turn it 180 °, and re-insert it with several knocking movements into the tank.

13. Select and confirm START on the controller.

When the time counter is down to 0, a beep sounds and the status display prompts you to rinse and subsequently dry the board.

14. Acknowledge the end of PHASE 4 by selecting and confirming END on the controller.

PHASE 4 can be repeated as often as needed by pressing the u key.

15. Take the circuit board out of bath 4 and let the chemical drip back into the bath.

16. Rinse the circuit board in an external basin or sink with running water for at least 30 seconds.

17. Blow off the circuit board with oil-free compressed air or nitrogen.

18. Dry the circuit board quickly, using warm air if possible (e.g. with a hair dryer or heat gun).

Note: This should be done as quickly as possible to prevent the copper from oxidizing.