Oerlikon Adds B-Stage Epoxy To Its Cover Glass Portfolio

Balzers, Liechtenstein — Oerlikon Optics is a leading supplier of cover glasses to the semiconductor packaging industry and is well known for the outstanding cleanliness of its coatings. By adding b-stage epoxy to the portfolio these cover glasses are made suitable to a broader variety of applications.

The packaging of light sensitive semiconductor devices consists of a cover glass mounted to a ceramic backplane. One of the technologies applied for the assembly of these two pieces is a so called b-stage epoxy. This epoxy is supplied on the glass lid in a dry and particle-free state and the curing of the epoxy at the eventual packaging it is done by tempering – depending on the epoxy at 120°C to 150°C.

Oerlikon has added b-stage epoxy printing and processing to its cover glass lids portfolio. Together with clean glass and low defect coatings this allows for a comprehensive supply to semiconductor packaging and prevents customers from chemical handling. As this type of epoxy is available in black color — better absorbing than any black Chrome — it may additionally be applied as an aperture protecting underlying electronics against light.

Oerlikon has carefully selected the latest developed epoxies that improve and ease the assembly processing. The focus of the selection has been on lowering the curing temperature and providing an excellent hermetic seal. The epoxy is applied and processed in a way that allows for highest cleanliness on the clear aperture of the cover glass.

Besides adhesive bonding technologies Oerlikon supports soldering of cover glass to backplanes made of ceramics or metal alloys. Gelot coated glass surfaces — providing a Gold surface — can be perfectly soldered with Pd or Au pre-frames to backplanes. Soldered assemblies provide a perfect hermetical seal and are stable at high temperatures. Whereas b-stage epoxy is mainly applied for CMOS packaging, soldering suits best for packaging of MEMS devices.

Eventually, with the addition of b-stage epoxy to its services Oerlikon intends to make its outstanding low defect coatings applicable to a broader range of semiconductor packaging solutions.

SOURCE: Oerlikon Optics