THERMAL INDICATING PACKAGE
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
Thermal analysis and fault detection for low-end packages is accomplished using inexpensive liquid crystal temperature indicators. Low-end packages are required to withstand large temperature excursions and many more temperature cycles than high-end systems. Despite this, the packages must still be reliable and low cost. This article describes an inexpensive system for temperature monitoring for production packages. This system may also be used to provide high spatial resolution and fine temperature definition for research and development on thermal characteristics of new packaging methods, such as Tape Automated Bonding (TAB) and Surface Mounted Technology (SMT). This system utilizes the selective color scattering of chiral nematic liquid crystals (LC) resulting from the temperature variations of the chiral pitch.