Earlier this year Massimo Fiorani, Managing Director of WISE s.r.l. from Italy and Christian Buske, Managing Director of Plasmatreat GmbH, signed an international cooperation agreement for the use of Openair-Plasma in PCB-FPC and chemical milling market; Plasmatreat's technology was applied on the new Wonderwise 220 machine from Wise. Wise is an international leader in wet processing equipment with a Worldwide sales distribution and has presented Wonderwise, a new compact machine for horizontal inner layer copper surface preparation.
The machine can prepare copper surfaces on a single side as well as both sides fully automatically in the PCB-FPC manufacturing. A plasma process was developed in cooperation with Plasmatreat to achieve a high degree of activation on the copper surface for the adhesion of photoresist films. This concept of surface preparation is fundamentally different from conventional processing methods because plasma does not generate roughness but energy surface tension. This activates the copper surface, thereby optimizing the adhesion of the photosensitive material. Due to the high surface energy, the process enables good wettability for excellent adhesion, without any alteration of the original surface roughness. "The plasma process is an alternative to chemical or mechanical processes. It uses normal compressed air or gases, which are far more environmentally friendly, yet produce better results," explains Fiorani.
By implementing Openair-Plasma, Wise has been able to avoid the costly use of chemicals or the mechanical cleaning step to prepare the copper surface of the board for its next process. The footprint is reduced to around 3 square metres for the new Wise system. Furthermore, it is possible to integrate the Wonderwise 220 into production lines, as the board can be laminated directly after the surface preparation process. The process can be done in a yellow room. "This solution reduces the cost of use of the entire plant, for energy, water and waste disposal", Fiorani continues.
The use of plasma reduces the deformation of the copper board during the process to a minimum. In addition, less thicker boards are required, as the copper surface is not worn or roughened. There is no reduction in material, only an activation of the surface.