Here is the abstract you requested from the IMAPS_2016 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Innovative Uses for Plasma in the Assembly of Electronic Devices|
|Keywords: plasma, assembly, polymeric materials|
|Electronics manufacturing involves processes and chemicals that present special challenges to the use of polymeric materials. Some examples include removing smear from drilling through multi-layer boards, eliminating carbon deposits and flux residues, improving adhesion of inert materials such as Teflon, and applying potting compounds and conformal coatings evenly and consistently without affecting PCB functionality. This presentation describes recent advances in vacuum and atmospheric plasma surface treatment that offer electronics assemblers a safe, environmentally sound, and technically proficient means of overcoming such challenges. In particular, we address three important and emerging applications for plasma. First we examine the use of plasma for conformal coatings. Electronic terminals, such as Ni-Pd-Au materials, are susceptible to corrosion in humid environments. While corrosion can be reduced by applying conformal coatings, applying these to some materials can be difficult. Plasma treatment can improve adhesion of conformal coatings on PCBs without adversely affecting functionality of the assembled board. Plasma enhances the surface wettability, and improves adhesion of conformal coatings to difficult to adhere to substrates such as solder-mask materials. Plasma can enhance the quality of the conformal coating by providing a bubble-free, hermetic closed-surface, and increase the thickness and uniformity of conformal coatings on electrical terminals. Second, we describe the use of plasma for improving the underfill of mounted devices. The underfill process plays an important role in determining the yield and reliability in chip assembly. Underfill problems such as delamination, uneven or shallow fillet height can plague electronic assembly, and result in failures due to premature shear failure. Plasma can improve performance and reliability by increasing the height and uniformity of fillet; improving the pull strength of wire bonds and increasing adhesion of flip chip devices to reduce delamination. Finally, we discuss the application of plasma for LED potting compounds and encapsulants. LED potting compounds are engineered to prevent fragile wire bonds from breaking, preventing damage to LED components. Plasma treatment prior to potting ensures a good hermetic seal, reduces current leakage and provides stronger physical bonding to the device. While the demand for LED encapsulants is expected to double over the next few years, proper encapsulation requires that epoxy, urethane and silicone potting materials be evenly applied, and adhere to a range of substrates. We show that plasma is an effective means for enhancing the performance of LED potting compounds.|
|Andy Stecher, President/CEO North America