Thermal characteristics of integrated circuit packages have been and increasingly will be a major consideration to both producers and users of electronics products. This is because an increase in junction temperature (TJ) can adversely effect the long term operating life of an IC. The advantages realized by miniaturization often have trade–offs in terms of increased junction temperatures. Some of the variables affecting TJ are controlled by the IC manufacturer and others are controlled by the system designer. Depending on the environment in which the IC is placed, the user could control well over 75% of the current that flows through the device.