Mass transfer of micro structures using adhesives

US10325893B2 · kind B2 · utility

Assignee

• HONG KONG BEIDA JADE BIRD DISPLAY LIMITED · CN

Inventors

• Wing Cheung Chong · Tseung Kwan O, CN
• Lei Zhang · Shanghai, CN
• Fang Ou · Monterey Park, US
• Qiming Li · Beijing, CN

Key dates

• Filing date: Dec 8, 2017
• Grant date: Jun 18, 2019
• Expiry date: Dec 8, 2037

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/825
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Mass transfer of micro structures are effected from one substrate to another using adhesives. In the context of an integrated micro LED display, a micro LED array is fabricated on a native substrate and corresponding CMOS pixel drivers are fabricated on a separate substrate. The micro LED substrate (e.g., sapphire) and the CMOS substrate (e.g., silicon) may be incompatible. For example, they may have different thermal coefficients of expansion which make it difficult to bond the micro LEDs to the pixel driver circuitry. The micro LED array is transferred to an intermediate substrate (e.g., silicon) by use of an adhesive. This intermediate substrate may be used in a process of bonding the micro LED array to the array of pixel drivers. The intermediate substrate is separated from the micro LED array by releasing the adhesive.