Silicon-based wafer level packaging has as a main advantage to reduce the packaging cost, being in the range of 50% for conventional technologies right now.
Silicon has a high heat dissipation capability with a heat conductance of around 160 W/(mK) (dependent on the doping density). Through Silicon Vias (TSVs) may add another efficient heat dissipation channel. Furthermore, TSVs facilitate to put the contacts to the package backside, providing a full-area metal contact for improved heat conductance and the possibility to shrink the package size. This lowering of the form-factor on the same time enables a larger amount of LEDs to be packaged on one silicon wafer. Furthermore silicon packaging allows the direct integration of an IC circuitry such as protecting diodes. Another advantage of silicon is its low thermal expansion that together with mature MEMS manufacturing technology provides a toolset for high reliability LED packages.
Are you aware of any LED manufacturers that use the packaging scheme described above (multilple LED chips, TSVs, integrated ICs) or is this a technology in te development phase?
Right now silicon submounts with an embedded Zener-diode are already used for packaging of HB-LEDs, especially for automotive headlight applications. The main advantage of such a concept is the protection of the LEDs against electrostatic discharge in an early stage of the packaging process.
The production of wafer level packaging (WLP) including TSVs is just ramping up right now, being mainly driven by Taiwanese players such as TSMC, Xintec, Visera or tMt. Also other silicon based packaging manufacturers have this technology on their scope.
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