Medical Device Laser Welding

Project Summary

Medtronic uses laser welding to seal custom batteries used in their neurostimulator devices. The case and cover of the batteries are held together through a fixture which rotates the battery 360 degrees so that a laser is able to seal the case to the cover around the whole battery. Medtronic currently has a system where the laser beam is delivered vertically. They would like a new system which allows the laser to weld the battery from the side.

Design Goal

The goal of this project was to create a welding fixture that can hold the battery case and cover together to complete a weld 360 degrees around the battery without having to modify the position of the fixture or part during the process.

Design Constraints

• The fixture must apply a constant 1lb force on the battery
• The fixture must rotate around the centroid of the battery
• The fixture must allow 0.5” clearance for the laser welding nozzle
• The operator must be able to load a part outside the safety shield