Henkel Corporation, FlexTech Alliance, and the Flexible Display Center at Arizona State University completed a multi-phase project developing debondable laminating adhesives to enable active matrix backplane fabrication on flexible substrates.
December 2, 2011 — Henkel Corporation, FlexTech Alliance, and the Flexible Display Center (FDC) at Arizona State University completed a multi-phase project developing debondable laminating adhesives to enable active matrix backplane fabrication on flexible substrates.
The process uses the existing LCD display manufacturing infrastructure to fabricate flexible large-area displays or novel form factor applications with minimum process modification or capital investment, the team reports.
A flexible PEN substrate is temporarily bonded on a rigid carrier and amorphous silicon thin film transistors (a-Si TFT) backplane devices are fabricated. The rigid carrier enables proper planarity, dimension stability, and lithographic registration. The flexible substrate is then peeled off the carrier, without residues or component damage.
Benefits include absence of particulate contamination, good film thickness uniformity, superior thermal stability to 200°C, and ease of debonding. The adhesive preferentially adheres to the carrier when separated and can be removed by high-temperature heating, enabling the carrier to be re-used.
Reliable temporary bonding mechanisms were the key to the project?s success, said Lirong Bao, technical manager at Henkel. The bonds had to tolerate multiple high temperature/high vacuum steps and remain debondable. ?During the project we also discovered that, with fine tuning of the adhesives for different performance requirements, we [can commercialize] the product for other applications, specifically photovoltaics.?
The lead candidate formulation has demonstrated sufficient performance for 6? wafers and Gen II panels at the FDC. Henkel supplies the adhesives to FDC, and will now work to commercialize the material.
Lirong Bao will present the project results at the 2012 Flexible Electronics & Displays Conference & Exhibition. Visit www.flexconference.org for more details.
The FlexTech Alliance fosters the growth, profitability, and success of the electronic display and the flexible, printed electronics supply chain. More information about the FlexTech Alliance can be found at the industry portal: www.flextech.org.