Multi-jet atmospheric glow plasma cleaning of ablation debris from micro-via drilling process

We devised a multi-jet atmospheric glow plasma system and successfully verified a possibility to ignite and maintain an atmospheric pressure discharge using helium, argon or a mixture of helium and oxygen gas. In this study, as an alternative method to the conventional wet cleaning process, the multi-jet atmospheric glow plasma system was applied to clean the ablation debris inside the blind via holes from micro-via drilling process of printed circuit boards (PCBs) prior to electroplating process. Scanning electron microscope images, after the multi-jet atmospheric glow plasma treatment of the PCBs, showed effective removal of residual organic impurities and massive fibrous debris when compared with low-pressure vacuum plasma treatment. Consequently, we demonstrated that multi-jet atmospheric glow plasma system could not only effectively remove organic impurities and massive fibrous debris generated during micro-via drilling process, but also enhance the electroplating process and the wire bondability.