Heat Sink Profile Design Using Finite Element Analysis Simulation for Laser Heat Dissipation in a CD-DVD Optical Pick-up Unit

For Optical Pickup Units (OPU), the dissipation of laser heat is a primary requirement for performance reliability & life expectancy of the device when operated continuously at extreme service temperatures. Heat sinks are components that enhance heat dissipation from a hot source to a relatively cooler ambient in order to maintain the laser device within the specified service temperature for continuous operation. Typically the heat dissipated by the laser diode anchored inside a plastic housing is fed to a copper sheet heat sink for air convection cooling through a conductive path comprising thermal interface silicon elastomer pad & thermal compounds. In this paper, descriptions pertain to steady-state heat transfer FEA simulation utility in evaluating and optimising heat sink profiles for a multi-component (8 materials) configuration. Temperature distribution has been evaluated for varying heat sink profiles & convection area in order to limit the laser stem (case) temperature below 70°C while dissipating heat.