Cold plate Thermal management (electronics)

1 cold plate

1.1 principle
1.2 construction , materials
1.3 performance

cold plate

placing conductive thick metal plate, referred cold plate, heat transfer interface between heat source , cold flowing fluid (or other heat sink) may improve cooling performance. in such arrangement, heat source cooled under thick plate instead of being cooled in direct contact cooling fluid. shown thick plate can improve heat transfer between heat source , cooling fluid way of conducting heat current in optimal manner. 2 attractive advantages of method no additional pumping power , no heat transfer surface area, quite different fins (extended surfaces).

principle

heat sinks function efficiently transferring thermal energy ( heat ) object @ high temperature second object @ lower temperature greater heat capacity. rapid transfer of thermal energy brings first object thermal equilibrium second, lowering temperature of first object, fulfilling heat sink s role cooling device. efficient function of heat sink relies on rapid transfer of thermal energy first object heat sink, , heat sink second object.

the common design of heat sink metal device many fins. high thermal conductivity of metal combined large surface area result in rapid transfer of thermal energy surrounding, cooler, air. cools heat sink , whatever in direct thermal contact with. use of fluids (for example coolants in refrigeration) , thermal interface material (in cooling electronic devices) ensures transfer of thermal energy heat sink. similarly, fan may improve transfer of thermal energy heat sink air.

construction , materials

a heat sink consists of base 1 or more flat surfaces , array of comb or fin-like protrusions increase heat sink s surface area contacting air, , increasing heat dissipation rate. while heat sink static object, fan aids heat sink providing increased airflow on heat sink—thus maintaining larger temperature gradient replacing warmed air more passive convection achieves alone—this known forced-air system.

ideally, heat sinks made thermal conductor such silver, gold, copper, or aluminum alloy. copper , aluminum among most-frequently used materials purpose within electronic devices. copper (401 w/(m·k) @ 300 k) more expensive aluminum (237 w/(m·k) @ 300 k) twice efficient thermal conductor. aluminum has significant advantage can formed extrusion, making complex cross-sections possible. aluminum lighter copper, offering less mechanical stress on delicate electronic components. heat sinks made aluminum have copper core trade off. heat sink s contact surface (the base) must flat , smooth ensure best thermal contact object needing cooling. thermally conductive grease used ensure optimal thermal contact; such compounds contain colloidal silver. further, clamping mechanism, screws, or thermal adhesive hold heat sink tightly onto component, without pressure crush component.

performance

heat sink performance (including free convection, forced convection, liquid cooled, , combination thereof) function of material, geometry, , overall surface heat transfer coefficient. generally, forced convection heat sink thermal performance improved increasing thermal conductivity of heat sink materials, increasing surface area (usually adding extended surfaces, such fins or foam metal) , increasing overall area heat transfer coefficient (usually increase fluid velocity, such adding fans, pumps, etc.).

online heat sink calculators companies such novel concepts, inc. , @ www.heatsinkcalculator.com can accurately estimate forced , natural convection heat sink performance. more complex heat sink geometries, or heat sinks multiple materials or multiple fluids, computation fluid dynamics (cfd) analysis recommended (see graphics on page).