New laser welding process holds potential for medical uses

Tampere, Finland - Primoceler, a microfabrication developer, has created what it calls the world's first sapphire-to-sapphire laser welding process that can be used in the manufacture of sensors, lenses and many other devices.

The cost-effectiveness, durability, high melting point, chemical inertness, transparency and capacity for optical transmission make sapphire highly suitable for many industrial applications. "At Primoceler, we constantly expand technological boundaries," said Ville Hevonkorpi, Primoceler's managing director, who says his company was the first to laser weld glass to glass, glass to silicon, and now sapphire to sapphire. "Sapphire-to-sapphire welding is even more difficult than glass-to-glass welding."

With its resistance to heat and chemical erosion, sapphire substrates currently are being used in the manufacture of LEDs for mobile handsets, television, auto headlights, and general lighting. "Now that we have developed this totally new technology, we're anticipating that it will open new possibilities for industries, just as our glass-glass welding technology did," said Hevonkorpi.

Medical applications for the use of sapphire abound. As an optical material, its durability is second only to diamond; sapphire also is chemically inert and non-thrombogenic, so it won't cause blood clots, making it an excellent material for use in surgical tools, medical implants, and braces, as well as endoscopes and laser windows, according to the company.

Primoceler's prior developments include a laser welding process that produces very little heat-affected zone (HAZ) and expands the market for packaging of fragile components, including under or inside glass, said Hevonkorpi. To date, Primoceler has successfully applied its technology in laser welding glass to glass for medical applications, he added, and sapphire also holds potential for use in medical devices.

"Sapphire is widely used in sensors, different types of lenses and other devices, so there is a range of potential for this new technology," said Hevonkorpi. "Companies that use sapphire for their products will come to us with ideas of how sapphire-to-sapphire welding technology can benefit them. We always welcome customers to challenge us and test their products."

A new laser welding machine developed by Primoceler for the new sapphire process is similar to its laser-based welding system that produces a small HAZ. The new machine contains a fiber laser optimized for the welding process by Corelase (Tampere, Finland). The system includes in-house developed software and components, and it can weld a wide range of materials including glass, silicon, and sapphire.

Primoceler will expand on its laser welding of glass materials in a feature article to appear in the July/August 2014 issue of Industrial Laser Solutions.