Micro dispensing of adhesives and other polymers

Abstract

Due to the progress in miniaturization of electronic and optoelectronic devices, new processing methods are needed for micro dispensing of adhesives and other polymers. Applications are found in fields like joining, marking and coating. Here, micro dispensing is defined in volume ranges of 30-500 pl (/spl sim/30-500 ng). Not only small volumes but also precision and flexibility are in high demand. For a certain range of adhesives and other polymers used especially in optoelectronic devices, microdrop provides equipment for microdispensing. The basic technique is a spin-off from inkjet-technology and profits from the flexibility and precision of this technology due to the contactless drop ejection. Also, extremely aggressive organic solvents do not cause problems for the valve-free dispensers. This makes the microdrop technology very attractive for solved polymers as used for LEP (light emitting polymer) applications. Here, the actual applications and possibilities are illustrated and the current developments for improved processing strategies are described. There are some demands on the properties of such polymers usable for micro dispensing. These are explained and the limitations are discussed.