Mechatronics toward development of a fully automated meniscus coating system

The electronics industry is driven toward product miniaturization with higher functionality at reduced costs. Material deposition techniques can be a significant contributor to the overall manufacturing costs. We have investigated meniscus coating as a low-cost tool for large area polymer deposition. Meniscus coating has the following advantages over the conventional spin coating: (i) minimal material waste; (ii) higher throughput; (iii) higher planarity; (iv) minimal defect density; and (v) thickness uniformity over a large area. All these factors help reduce the overall manufacturing costs. This paper reports materials and process optimization for 12 inch x 12 inch substrates that is scalable to 24 inch x 24 inch substrates. A variety of polymer photoresists and polymer dielectrics are used for thick film coating on 12 inch PWB and glass substrates. For each material, the deposition process is optimized to the desired film thickness. For higher throughput and lower manufacturing costs, an automated coating workcell is designed for the 24 inch coating substrates. The proposed coating workcell includes a robotic material handling and convection drying of coated films with automated loading/unloading capability. Design and fabrication of the integrated workcell, coating throughput and uniformity of coating are addressed. Preliminary study indicates that a throughput of similar to20 substrates per hour is achievable by optimizing the turnaround time of the coater heads, substrate holder, and substrate loading/unloading by the robot. Thickness on the order of a micrometer has been obtained on 24 inch glass substrates using liquid polymers.