Bonding optical components mainly requires adhesives with suitable optical properties. Due to small dimensions and high accuracy requirements of the bonding process, the dispensing process also must be very accurate. There are different technologies for performing the dispensing of the adhesive. The most common is the needle dispensing as well as the jet dispensing.
While needle dispensing is a well-known process, the jet dispensing is a more and more evolving technology. Especially when optimizing productivity, the jet dispensing has many advantages but requires a higher technological effort as well. Another technology might be the direct dispensing. This is based on a process like stamping and can provide high productivity at complicated dispense patterns.
However, the correct dispensing of the well-chosen adhesive is particularly important for conducting the high precision alignment of the optical components which ensure the high-quality operation of the photonic products. A common bonding process is to use a UV-curing adhesive and to do a pre-curing before the alignment process. After the iteration algorithm found the best position of the optical component within the still wet adhesive the alignment system holds the component, and the UV-curing system performs the curing of the adhesive. This guarantees the best results because the components cannot move due to shrinkage or similar effects.
