1. Field of the Invention
This invention relates in general to instruments for measuring formation characteristics in wells, and in particular to a means for transferring heat from electronic components within the instrument.
2. Description of the Prior Art
A wireline logging instrument is an instrument that is lowered into a borehole or well for measuring earth formation characteristics. The instrument has a sealed tubular housing within which electrical and electronic components are located. Present day logging instruments are complex, having thousands of components in the downhole tool, and often extending to lengths of 30 feet or greater. Some of these components include circuitry such as microprocessors, power supplies and telemetry components.
The environment of the well is hostile to such sensitive electronic components. In some cases, the temperature is 300.degree. F. or greater which is deleterious to the electric components in the instrument. Also, some of the components give off considerable heat themselves. For example, power transistors are normally mounted simply on a circuit board along with other components. These elements produce heat into the atmosphere within the tool, and the heat is not readily dissipated.