Heat sinks for minimizing noise in precision electronic components

摘要

A hermetic package (12) mounted on a substrate 30 (eg a printed circuit board) is provided with a heat sink 54 which has a skirt 64 depending from its lower end to enclose the space between the base of the package and the surface of the substrate and form a substantially isothermal enclosure to maintain the temperature of the leads of the package substantially constant. The depending skirt also blocks, or absorbs, radiation from the ambient environment of the package which prevents such radiation from being transmitted through the glass lead-seals of the package to minimize the production of photoelectric induced error voltages induced in photosensitive circuits of the component. The package contains a precision analog component such as an operational amplifier and a spacer 28 separates the base of the package from the substrate. The heat sink is provided with longitudinally extending fins and has a slit to enable it to be fitted onto the hermetic package.