Enhanced Polyvinylbutyral Binder Burn-Off Via Supercritical Fluid Extraction
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-27
This development improves binder burn-off (BBO) of polyvinylbutyral binder in a ceramic system used for semiconductor applications. The development describes a pretreatment of the binder polymer which will enchance BBO and not alter its processing into green sheets. The polyvinyl butyral binder is extracted with a supercritical fluid (SCF), and then the extracted binder is formulated into ceramic green sheets. Burnout may then take place in oxidizing atmospheres at low temperatures. The excellent solvent properties of SCF lend themselves to the purification of a binder such as polyvinylbutyral. The new porcessing method is to extract the polyvinyl butyral with either CO2 or propane, which removes impurities and antioxidants which inhibit BBO.