Date of Award

August 2020

Document Type

Thesis

Degree Name

Master of Engineering (MEngr)

Department

Mechanical Engineering

Committee Member

Joshua B Bostwick

Committee Member

John R Saylor

Committee Member

Oliver J Myers

Abstract

Soldering is a commonly used method to join two non-ferrous metals together, such as bonding copper wires or electrical components to circuit boards. Flux is typically used to remove the oxide layer on the metallic substrate but can release harmful chemicals and degrade the solder joint quality. Ultrasonic Assisted Soldering (UAS) was developed as an alternative to traditional soldering which eliminates the need for flux by using ultrasonic vibrations to nucleate microbubbles which remove the oxide layer during cavitation. The interaction between the applied acoustic field and solder melt affects the wetting properties of the solder joint by increasing the wetted area. A model is developed to predict the solder bead geometry, as it depends upon capillarity, gravitational effects, and the acoustic radiation pressure due to ultrasonic vibrations. Numerical results are compared with careful experiments using the automated UAS system to generate solder lines that are imaged with optical profilometry to quantify the degree of wetting. The agreement between theory and experiment is good and we show the wetted width can be predicted as a function of the input ultrasonic power. This capability is greatly needed to automate the UAS process for precision soldering and is a major advance for the manufacturing industry.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.