Light emitting device with reduced epi stress
AssigneeKoninklijke Philips N.V.
InventorsFREDERIC STEPHANE DIANA, YAJUN WEI, STEFANO SCHIAFFINO, BRENDAN JUDE MORAN
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Abstract
Elements are added to a light emitting device to reduce the stress within the light emitting device caused by thermal cycling. Alternatively, or additionally, materials are selected for forming contacts within a light emitting device based on their coefficient of thermal expansion and their relative cost, copper alloys being less expensive than gold, and providing a lower coefficient of thermal expansion than copper. Elements of the light emitting device may also be structured to distribute the stress during thermal cycling.
Claims14
A light emitting device comprising:
- a submount having first contacts separated by at least one first channel,
- a light emitting structure having a metal layer with second contacts separated by at least one second channel, and
- one or more elements added to the light emitting structure to reduce a thermally induced stress in the light emitting structure in a vicinity of the second channel.
A light emitting device comprising:
- a submount having first contacts separated by at least one first channel, and
- a light emitting structure having a metal layer with second contacts separated by at least one second channel,
- wherein the metal layer includes an alloy having a CTE that is less than a CTE of copper within a temperature range of 20-250 C.
Dependencies are inferred from the claim text.