The Benefits of Polyalkylene Carbonate Binders (QPAC) for LowTemperature Glass Frit or Powdered Glass in Low Temperature ProcessedThick Film ApplicationsP. Ferraro Empower Materials, New Castle DE, S. Hanggodo- Empower Materials, New Castle DEAbstractQPAC 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 binders low decomposition temperature allows fo r 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 ultralow firing (420 oC) 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.IntroductionMany different electronic and optical products utilize thick film technology in their respective manufacture, including but not limited to, plasma displays, ceramic packaging, hermetic packaging, ceramic circuits, electronic chip components, and solar cells and microelectromechanical systems (MEMS).In general, all thick film processes use liquid thick film materials to enable manufacture of the device. Typically, these liquids are dispersions of inorganic particles dispersed within a liquid solution of multiple components and are comprised of at least the following materials: One or more inorganic powders A solution containing:o A solvent liquid in which to disperse the powderso A dispersant to enable suspension of the inorganic powder within in the liquid solutiono An organic binder to modify the rheological properties of the liquid to enable precise deposition of the thick film, as well as to impart mechanical robustness to the dried, deposited thick filmo One or more modifiers to improve either the properties of the dried film or the stability of the liquid or to provide additional properties required by the applicationIn practice, the liquid thick film is precisely deposited using screen printing, doctor blading, or the like, then is dried to a solid, then heat treated to remove the organic materials as well as to sinter the inorganic powders into the functioning material and configuration/device desired. As such, it is typically desired that the only materials that remain in the final device are the inorganic materials and not the organic materials. The organic materials are almost always “a means to an end” in that they enable precise deposition of the inorganics, as well as impart sufficient mechanical robustness to the “green”, unfired film so that it can be handled during manufacture. Since the organic materials are intended to be completely removed during thick film processing, they are typically called sacrificial materials in the thick film formulation.In many cases, carbon-based organic materials which are not completely removed from the final device will leave carbon impurities that will adversely affect the materials properties of the finished inorganic thick film material. These impurities can become gaseous during processing, leading to additional porosity in the fired material thereby reducing mechanical strength and resistivity of the fired thick film. The carbon-based impurities that remain can reduce conductivity in fired metal thick films and can limit current carrying capacity in thick film resistors. Carbon based impurities can dramatically reduce dielectric breakdown strength and insulati