An evaluation of solvents in order to increase cavitational effects for the surface treatment of a range of electronic materials

Abstract

Polymers and ceramic materials are used as substrates in the fabrication of electroless copper plated components for electronic devices. These substrates must be pretreated prior to electroplating to facilitate good adhesion between the substrate and the metal coating. There are a variety of established pre-treatment methods. Most of the industrial methods utilize hazardous chemistry (toxic acids), require long process times, use large amounts of waste water to remove chemicals, and require high temperatures. The aim of this project was to investigate the ability of power ultrasound to pre-treat these materials by utilizing non-hazardous chemistry, lower temperatures and short process times. In this project four different substrates were investigated; Epoxy resin, ABS, Noryl and Ceramic. The materials were treated with ultrasound under four different conditions (40 °C, 0 °C, freezing before pre-treatment, and the addition of solvent to the bath). The changes on the surfaces were monitored with several analysis techniques including: Weight loss, Contact angle measurement, Roughness measurement, Gloss meter determination, SEM surface analysis and adhesion testing. The optimum power setting for the epoxy material was found to be between 50 W and 80 W. In addition the most effective surface modification conditions for the Epoxy material was found to be achieved by lowering the temperature to 0 °C during the sonication processes and utilizing a power setting of 50 W. The most effective parameter to employ to surface-modify ABS material was found to be utilizing 5 % gamma-caprolactone solution with a power setting of 50 W at 0 °C. The most effective parameters to employ to surface modify Noryl material was found to be by utilizing 5 % ethylene glycol solution with a power setting of 50 W at 0 °C. Of the four tested materials, the ceramic material was least effected by sonication. The best results for this material were obtained with the frozen samples which were then treated with 50 W power at 0 °C. Solvents results did not shown significant results as those obtained with frozen samples. The project determined that each material required very specific pre-treatment parameters and demonstrated that surface modification could be achieved at lower temperatures, with far fewer chemicals, and a possibly safer, more economical process than the conventional industrial techniques.

Date of Award	2010
Original language	English
Awarding Institution	Coventry University
Supervisor	Larysa Paniwnyk (Supervisor) & Andrew Cobley (Supervisor)