The Benefits of Polyalkylene Carbonate Binders (QPAC~®) for Low Temperature Glass Frit or Powdered Glass in Low Temperature Processed Thick Film Applications

摘要

QPAC® 40 Poly(Propylene Carbonate), or PPC is an exceptional binder for use in low temperature firing thick film pastes because it decomposes at low temperatures leaving minimal residue after debind. The binder's low decomposition temperature allows for binder thermolysis at temperatures well below the sintering temperature of glass and metal powders that are used in ultra-low firing thick film applications. The potential for dramatically reduced levels of remnant carbon after thermal processing enables improvement in the mechanical, optical and electronic properties of a fired thick film device. Additionally, it is proposed that the use of clean burnout QPAC® binders will enable increased utilization of thermal processing equipment and will result in a reduction in periodic maintenance for removal of binder tars and the like from manufacturing thermal processing equipment, both which will reduce manufacturing costs and associated per device costs. In this paper glass pastes using QPAC® PPC carbonate binders were studied. Thermal analyses of the rate of debinding of thick film glass pastes made with ultra-low firing (420 °C) glass were performed and compared with analogous thick film pastes made with other common thick film binders as well as a commercially available ultra-low fire thick film paste. Rheological properties of the constituent binder vehicles as well as the respective thick film pastes were also evaluated and compared. The resulting fired thick film samples were also visually inspected and the QPAC® fired thick films most closely resembled the color of the fired neat glass powder, while the fired thick films made from other common thick film binders were much darker, indicating high levels of remnant carbon and possibly chemical reduction of the ultra-low firing glass. These obvious advantages can be applied to numerous low fire thick film applications including glass packaging, solder glass, sealing glasses, phosphors, dopants, and other solar cell device and display sealing applications.