Texas Tech University

Engineering Professor to Study High-quality Micromachining of Brittle Materials

Amanda Bowman

December 14, 2021

Weilong Cong

Associate professor Weilong Cong received a $342,861 National Science Foundation grant.

Texas Tech University's Weilong Cong, an associate professor of industrial, manufacturing and systems engineering (IMSE) in the Edward E. Whitacre Jr. College of Engineering, received a $342,861 National Science Foundation (NSF) grant to find a method to fabricate microfeatures on brittle materials without creating large chipping damage and heat-related oxidation.

The goal of the project is to generate a fundamental understanding of tool and workpiece behavior in rotary ultrasonic micromachining to enable an effective, efficient and high-quality microfeature mechanical grinding process for brittle materials.

“This project is using an ultrasonic, mechanical way to do the micromachining for brittle materials,” Cong said. “The idea originally comes from solar wafers. There are different types of solar wafers. High-efficiency metal wrap through silicon solar panels are required to drill a large number of holes/vias, which can connect electrical contacts on the front side to those on the backside.

“But, traditional, thermal-based drilling methods – like laser machining, for example – cause the materials to oxidize. That is not desired for the solar wafer. So, we are developing a new mechanical method to drill microholes on the brittle material without causing oxidation.”

The objective is to discover the mechanisms of material removal, cutting force generation and surface formation and quality through the contacting interactions between tool and workpiece with the assistance of ultrasonic vibration.

Cong is the sole principal investigator on the project, though he plans to hire a graduate student to help in the lab.

“The College of Engineering and the IMSE department provides a lot of support for my research,” Cong said. “I have some pretty good lab space, and the department also is providing support for students conducting research in the lab.”