Dispensing Improvements with Drop on Demand Technology

Building on existing technologies in microelectronics dedicated to packaging and encapsulation, liquid polymer dispensing is a leading technology that is widely deployed In this field, developments correlate with the application requirements and improvements are segmented in specific applications, such as conformal coating and capillary underfilling. In the context of the developments, heterogeneity is a constant driver. On the one hand, dot diameter or line width reduction is a constant requirement for advanced microelectronic applications. On the other hand, equipment has to be compatible with existing or increasing dispensing areas. The consequence is a need for more accuracy on a larger area and smaller dispensing pattern units for higher panel volume. Drop on Demand DoD) dispensing is a common answer to these challenging requirements. The first building blocks of DoD for coatings were laid with inkjet printing more than 40 years ago, with optimal physical parameters corresponding to low-viscosity coating materials. Today's coatings are quite similar to inks and can be introduced in DoD dispensing equipment. Starting from the results acquired with optimized coatings dispensed only with a dedicated pneumatic actuator, the experiments are extended to new materials and equipment technologies. The results are supported by high-speed camera measurements. The data acquired in these experiments lead to multiple process windows considering the predicted strong interaction between equipment and materials.