The adhesive bonding of components has become more important in recent years and presents various advantages and challenges when it comes to semiconductor assembly. Almost all materials can be bonded either to materials of the same type or to others. By choosing the right adhesive, curing temperature and time, you can achieve very gentle, electrically or thermally conductive and insulating adhesive bonds.
Generally, epoxy or acrylate adhesive is used to either fix different components together, encapsulate them or to improve the general mechanical stability of components. Regardless of the type of adhesive used and the application, the adhesive only reaches its full strength once it has it has been cured. With most products this is done by means of a heat treatment.
We choose the optimal adhesive method depending on the quantity of adhesive, the requirements in terms of the precision of application, the viscosity and other material properties of the adhesive. We use modern, software-controlled curing ovens which enable us to precisely and reproducibly adhere to the conditions, e.g. temperature ramps or waiting time, specified by the adhesive manufacturer. In addition to the temperature profile, the level of air circulation can also be freely programmed. This is particularly important if a lack of air exchange could result in an intrinsic contamination of the components that are to be cured. This can happen if, for example, components must be left to rest for several hours at moderate temperatures before the adhesive is cured in the next step.
To ensure a high level of quality and in order to ensure that the reproducibility of the curing processes is not compromised, we have developed an oven control system that is specially tailored to our processes. It considers the load of the the oven is and ensures that all specified curing phases are processed correctly. The curing profile is recorded electronically and printed out for documentation purposes. If desired, the temperature profile can also be made available to our customer for quality assurance.
Depending on the substrate size and applications, the following adhesive methods may be used.
- Automatic time/pressure dispenser
- Automatic spindle dispenser
- Automatic stamping
- Manual and automatic scraping
- Automatic jet dispenser
- Freely programmable dispensing pattern
- Protection of wire bonds by means of glob-top encapsulation
- Dispensing of silver conductive adhesive for chip assembly
- Adhesive bonding of glasses and optical components
- Dispensing of flux for soldering BGA chips
- Protection of chip contact surface by means of underfill
- Filling of cavities
- Covering of LED chips with silicone, acrylate or transparent epoxy adhesives