SES InfinityLine

Alkaline Etching with Vacuum Etching System (Option)

In a typical outer layer line, the photo resist is used to structure an additionally deposited metal resist layer. This plating resist is removed in the resist stripper using an alkaline solution. In the etching section the copper which is not protected by the metal resist is etched off using an ammoniacal etching solution. In last step, the metal resist layer (Sn or SnPb) is removed in the tin stripper. At the end of a SES line, a high effective dryer system with dry jets ensure a perfect drying of the printed circuit boards.


  • Innovative filter technology for stripping of the plating resist
  • Reduced chemistry and water drag-out helps
    especially after the plating resist stripper to reduce the production costs and to avoid high costs for the water treament
  • Magnetic-driven conveyor system in dryer and output sections for particle-free production
  • ESD transport to avoid any electrostatic shocks to the outer layer with fine structures and panels with embedded components


Vacuum etching system for alkaline etching modules

Thanks to the vacuum etching system with suction bars and the powerful suction blower the well-known puddle effect on the top side of the panel during the etching process could be extremely minimized.

In addition, by the faster exchange of the etchant on the panel surface the standard distribution will in- crease and the etching factor will rise.

Alkaline etching results with vacuum system:

  • For alkaline etching with a high etching rate and a good etching factor > 5
  • For thick copper etching applications to obtain steep conduct edges
  • For Cu reduction to reduce the standard
    distribution <1μm
  • Significant reduction of the etching undercut with a high process capability

    Alkaline etching results with vacuum system:


  • Advanced vacuum etching system for higher
    etching performance
  • Spray manifold with an excellent spray pressure distribution in the etching modules for a perfect etching of structurized printed circuit boards
  • Large sliding door with an inflatable sealing for an advanced sealing of the etching module and for a better accessibility to the module during cleaning and maintenance

Why is the SCHMID vacuum system better than others based on a vacuum injector?

The key benefit of the SCHMID vacuum system compared to competitors is the powerful vacuum blower system that works consistently if too much air is sucked in by the suction lances instead of etchant because of small plate formats or holes in the panels. Competitors are working with a vacuum injector system, whose vacuum becomes instable and can collapse if too much air is sucked in.


Intermittent Etching with selective spray pipe control

The intermittent etching is based on a spraying system which prevents for the „puddle effect“ on the top side of the board. This application is particularly interesting for etching systems that work without the vacuum system. The spray pipes of the spray manifold are equipped with a varying number of spray nozzles (see picture). Each single nozzle of the triangularly arranged nozzles can be controlled directly via the PC. The spraying of the board works individually with an optimum adjustment to the board size. The result: An absolutely uniform etching pattern.

Advanced filter system for resist stripping

Innovative Filter Technology for Stripping Processes The entire stripping solution is cleaned via the filter system before being returned to the pump sump. 

Depending on the different type of resist, a cyclone
filter system or a cyclone and drum filter  ombination can be used.

Transport system for all PCB formats and applications

Various transport systems for nearly all types of PCB are available. To protect the PCBs against uncontrolled electrical discharges an ESD transport system is spendable. Another option is the particle free magnetic-driven transport system especially for dryer output modules.


Etching in a closed loop system in advanced design:

Through the consequent optimization of the regeneration processes, the space requirement for the regeneration system could be reduced to a minimum while the system does have same effectivity as before. This effects a cost reduction for the equipment and saving of the production plant.

Process Description

First, the etching agent with 80gCu/l is buffered in an intermediate tank 1 (80gCu/l). In the subsequent low working tank, on which the easily accesible electrolysis cells stand for the copper harvest, the copper content of the etching agent is reduced from 80 gCu/l to 30gCu/l. In the buffer tank, the etching agent is stored in the etching module until further use. 3 kg Cu/h can be gained for electrolysis cell.

Advantages of Elofast

  • Reduction of process costs
  • More stable etching chemistry and thus more
    consistent etching results
  • Better etching results at an etching rate of
    40-45 μm/min

Reduction of process costs:

With alkaline etching in a closed loop, the accelerator additive EloFast 60 is used instead of a convention- al replenisher solution. Process costs per kg/Cu for EloFast 60 are approx. 95% lower compared with standard replenisher costs. Due to the additional repurchase value of copper, the investment pays off within a short period of time.

With the etching in a closed-loop system using the accelerator additive, the consumption cost can be reduced to a minimum by regeneration of the chemistry.