An automated workcell for meniscus coating on 24-in packaging substrates

Improved coating procedures are essential to the success of low-cost large substrate multichip module (MCM) fabrication, as existing coaters are slow and waste too much material. New coaters are needed that are able to coat large area substrates and have sufficient throughput and material savings to substantially reduce the manufacturing costs. The requirements for a large substrate coater include sufficient flexibility to coat a wide range of materials at various film thicknesses. This paper describes a meniscus coating workcell that meets these requirements. The complete coating workcell includes robotic material handling, automated sample transport, and convection drying of coated films. In-situ viscosity monitoring and in-line thickness measurements can be retrofitted into this workcell. Feasibility of a thin and uniform polymer coating with thickness on the order of a micrometer is demonstrated on a 24×24 in glass substrate using the automated coating operation. Preliminary study indicates that a throughput of ~20 substrates/h is achievable by optimizing the turnaround time of the coater heads, substrate holder, and substrate loading/unloading by the robot