IMAGE: Primoceler was selected to build robust and hermetic laser-welded optical sensor packages for future European Space Agency orbital missions. (Image credit: Primoceler)
Laser welding technology company Primoceler (Tampere, Finland) was selected by the European Space Agency (ESA) to develop and fabricate new optical sensor packages for use in future orbital missions. The benefits of the technology include a permanent, transparent seam and a hermetic seal to protect package contents--namely, delicate optical sensor equipment.
"Working with aerospace applications and space is every engineer's dream," said Primoceler laboratory engineer Antti Maattanen. "The unforgiving conditions of the orbital environment push components to their absolute limit. When creating packages for electronics, it's not enough that the instruments survive, they must also function within expected parameters. We have developed and tested forward-thinking industrial techniques that achieve this goal."
Laser welding technology from Primoceler, which creates an impermeable seam using only glass, meets every technical requirement of ESA scientists. This technology is also currently undergoing testing to determine whether it is robust enough to survive the zero-pressure environment of space indefinitely. CMOS optical sensors and onboard electronics are incredibly sensitive; all associated fabrication processes must take this into account. Using only one material to manufacture this package helps to avoid any problems due to thermal changes while ensuring long-term stability.
Primoceler says that welding with glass presents numerous advantages over standard welding or adhesive techniques. For instance, the heat-affected zone (HAZ) is significantly smaller; at only micrometers across, the HAZ of the welding process does not affect nearby sensitive components. The weld also creates a perfectly hermetic seal, an important feature when the package must endure destructive conditions.
The packages created by Primoceler for ESA will contain high-precision optoelectronics components. These instruments require flawless transparency to function as intended. Glass welding allows for this degree of clarity by leaving no bubbles within the seam or vapors within the package.
Primoceler's adhesive-free glass welding technology is a simple one-step process requiring no adhesives. In aerospace applications, adhesives are a non-starter because they lose hermeticity bonding capacity over time, especially when subjected to high heat and cold and rapid pressure changes.
Yet another advantage of glass welding is its transparency to radio and infrared signals. This particular quality is not applicable to ESA's optoelectronics package, but generally speaking, electromagnetic transparency is a highly desirable feature. Medical devices, for instance, must be able to send and receive data without undue interference.
Maattanen added, "ESA is a true pioneer and has developed a robust set of best practices for reliability testing. Being able to take part in agency's stringent testing protocol, we expect that our latest innovation in welding technology will quickly be adapted to other industries. Pushing the limits of welding technology is our ultimate goal."
Primoceler's business plan is to continually explore new applications for its precision laser welding technology. The selection of the company's glass welding methods by ESA stands as a proof of concept; future directions for the technology include consumer electronics and medical devices, among others.