Finer and More Precise – 12-layer PCB in Prototyping Lab

Until recently, the production of multilayer PCBs in the electronics laboratory was initially limited to four, then to eight layers. The LPKF application center has now produced a 12-layer PCB with LPKF systems.


Complex circuits require additional connection and shielding layers or integrated antennas. The attempt proves that precise laboratory technology can also solve such challenges. In the experiment, the European map format was processed at 100mm x 160mm.


The LPKF ProtoLaser U4 with the latest software version has demonstrated its capabilities at several stations. However, the first step took place on the PC with the CircuitPro system software: LPKF's standard 8-layer PCB process was expanded to include additional layers, essentially copying the already existing procedures. LPKF standard profiles were used for pressing and through-plating.


Single-sided FR4 with a thickness of 0.2 mm was used for the outer layers, while double-sided FR4 with a thickness of 0.125 mm forms the inner layers. The prepregs are 0.105 mm thick.

The work steps in detail:  

  1. Structuring inner layers with the ProtoLaser U4: Structuring layouts on both sides of the substrate. Create reference and holding holes for the pressing process.
  2. Make reference and holding holes on the outer layers.
  3. Assemble a press package from outer layers, inner layers and prepregs.
  4. Press the press package into a multilayer PCB in a pressure and temperature-optimized process with the LPKF MultiPress S4.
  5. Cut continuous contact holes with the ProtoLaser U4.
  6. Galvanic contacting with the LPKF Contac S4.
  7. Structuring outer layers and cutting uncontacted holes with the ProtoLaser U4.
  8. Apply a full-surface solder mask with the LPKF ProMask paint. Selective removal/opening of the solder mask with the ProtoLaser U4.

    The result: a 12-layer PCB with a thickness of less than 2mm - prepared for assembly and soldering.

    The following running times for the individual steps were determined for the entire processing. Processing takes place automatically after the start, and the applicators are informed by the systems about necessary interventions.



    Processing [min]

    LPKF ProtoLaser U4

    Structuring layers 2-11


    LPKF MultiPress S4

    Pressing and cooling


    LPKF ProtoLaser U4

    Drill contact holes


    LPKF Contac S4

    Galvanic coating
    (+25 µm Cu)


    LPKF ProtoLaser U4

    Structuring above and below

    Drill “uncoated” through holes (bottom)

    Cut out


    LPKF ProMask

    Application, drying, selective laser removal


    In total


    ~ 7 p.m

    (plus handling and cleaning times)


    layer structure (png - 37 KB)


    LPKF Laser & Electronics SE
    Osteriede 7
    D-30827 Garbsen
    Fon: +49 (0) 5131 7095-0
    Fax: +49 (0) 5131 7095-90