# Experimental Study on Laser-Controlled Explosive Welding of Microscale Metallic Foils Driven by Energetic Materials

## TL;DR

This paper explores using laser-controlled explosive welding to bond microscale metallic foils, showing promise for microelectronics and MEMS.

## Contribution

The study introduces laser-controlled explosive welding for microscale metallic foils using energetic materials.

## Key findings

- Laser energy successfully controlled energetic materials to bond Al/Cu interfaces.
- Elemental diffusion at the Al/Cu interface confirms the method's viability.
- Unloading rebound at the interface suggests a need for better impact control.

## Abstract

In response to the challenge of achieving highly reliable interface fabrication in the fields of microelectronics and micro-electromechanical system (MEMS) packaging, this study harnesses the superior characteristics of solid-state bonding inherent in explosive welding (EXW) technology. This study investigates the precise EXW of milligram-scale metallic foils by employing focused laser energy to control the explosion behavior of liquid energetic materials, thereby generating shockwaves that induce high-velocity oblique collisions between metallic foils and base plates. Laser-focused energy was utilized to regulate energetic materials for conducting precision EXW experiments on Al/Cu couples. The technical feasibility and interfacial quality of this method for fabricating Al/Cu bonding interfaces were systematically evaluated through in situ observation of the dynamic welding process, comprehensive analysis of interfacial microstructures, and numerical simulations. The results reveal distinct Al/Cu elemental diffusion at the bonding interface, confirming the technical viability of the approach. However, an unloading rebound phenomenon is observed at the interface, which is inherently associated with the dynamic impact process, indicating the need for further optimization in the precise control of impact loading.