DocumentCode :
2507872
Title :
Effect of chip die bonding on thermal resistance of high power LEDs
Author :
Ayodh, Tri ; Han, Hun Sik ; Kim, Joongnyon ; Kim, Seo Young
fYear :
2012
fDate :
May 30 2012-June 1 2012
Firstpage :
957
Lastpage :
961
Abstract :
Thermal resistance of high power blue Light Emitting Diode (LED) package is experimentally examined. The LED package consists of eight CREE EZ900 chips. The dimension of each chip is 880 μm×880 μm and the metal board area is 30 mm×32 mm with 3 mm thickness. The LED package is operated at the current of 11 A with 10 % duty cycle. To measure junction temperature, the forward voltage method is used. The metal board temperature is measured by attaching K-type thermocouple. Then, the thermal resistance from junction to metal board is calculated. For comparison, six identical LED packages are examined. Each LED package shows different thermal resistance from 0.4 K/W to 10.3 K/W. To investigate how the chips are well attached on the metal board, X-ray computed tomography (CT) images of the LEDs are taken and air gap areas are evaluated. The result shows that the thermal resistance increases with the increase of air gap area.
Keywords :
X-ray microscopy; air gaps; computerised tomography; light emitting diodes; microassembling; thermal resistance; thermocouples; CREE EZ900 chips; CT images; X-ray computed tomography; air gap areas; chip die bonding effect; current 11 A; forward voltage method; high power LED; high power blue light emitting diode package; junction temperature; k-type thermocouple; metal board temperature; size 3 mm; thermal resistance; Junctions; Light emitting diodes; Metals; Temperature measurement; Thermal resistance; Voltage measurement; X-ray computed tomography; forward voltage method; junction temperature; light emitting diode; thermal resistance;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm), 2012 13th IEEE Intersociety Conference on
Conference_Location :
San Diego, CA
ISSN :
1087-9870
Print_ISBN :
978-1-4244-9533-7
Electronic_ISBN :
1087-9870
Type :
conf
DOI :
10.1109/ITHERM.2012.6231529
Filename :
6231529
Link To Document :
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