Wafer Direct Technology for Mini LED Flip Attachment

Abstract

We would like to introduce the mechanism structure of our wafer direct die attachment technology for mini LED. Wafer direct technology is structured from two parts of that one is adhesive one shot dipping and other is pinhole free chip shooting. 1st, we developed “One shot wafer dipping” which can transfer the adhesive to around 30,000 chips of mini LED on a wafer at once. Second section is to take about die mounting. Common die bonder use an ejector pin to pick up mini LED chip. Ejector pin makes a pinhole on wafer and lead air into between wafer and mini LED chip. This air is effective to remove mini LED chip from wafer by the pick up nozzle. Ejector pin of die bonder leaves a broken piece of wafer on chip. We developed wafer direct chip shooting technology. Wafer direct chip shooter also use an ejector pin for shooting down mini LED chip. But wafer direct does not make any pinhole on wafer that means no broken piece of wafer exists. Our wafer direct technology maximize productivity of mini LED die bonding and minimize faulty ratio of mini LED die bonding.