Vacuum Etching 

The vacuum etching forms the key component of the New Etching Options. To minimize the puddle effect, suction lances are installed between the nozzle pipes which take up the used etching medium and lead it into the module tank. Powerful vacuum blowers generate constant vacuum. Unlike with water jet pumps the vacuum never collapses – no matter whether the height-adjustable suction lances take in used etching medium or leak air. The result is an absolutely uniform etching rate and less chemistry consumption.

Nozzle Configuration

With the optimized nozzle configuration the SCHMID system offers maximum flexibility because it is able to adapt to any design to be etched and to refine the etching processes. A uniform distribution of pressure at the nozzles (up to 4 bar spraying pressure) not only improves the etching result, but also increases the etching rate. As a consequence the process time of the subsequent intermittent etching is reduced.

Optimized transport system

The optimized placement of transport disc rollers within the standardized etching module represents another New Etching Option. In addition to the vacuum etching, the improved design and placement of the transport disc rollers lead to an improved drain behavior of the process chemistry, thus decreasing the puddle effect detectably.

• CuCl2 etching of particularly fine structures with L/S < 50 μm
• Thick copper etching applications: obtainment of high-angled flanks e.g. copper layer 23 μm, etching factor > 6
• Uniform differential etching: copper removal 40 μm, StDev < 0.9
• Fulfillment of process capability CpK > 1.6
• Increase of the etching speed up to 20 %

Cu Reduction (StDev) with NEO < 0.9

Etching Capability (CpK) with NEO > 1.6

Etching Factor with NEO > 5.0