ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
As Recently, wafer level packaging (WLP) received lots of attention in system because itshows the potential to reduce packaging cost, while the yield of devices after dicing and packagingcan be increased. In this study, we newly proposed WLP for light emitted diodes (LED) using MEMStechnology. Our silicon package structure is composed of base and reflector cup. The role of base isthat settle LED chip at desired position and supply electrical interconnection for LED operation.Reflector cup was formed by an-isotropic wet etching. Package platform could be fabricated byeutectic bonding between base and reflector cup using AuSn. We carried out process using six sigmamethodology. We first decided 2 factors and 3 levels by design of experiment (DOE). One factor isthe kind of metal model. The other is the shape of pattern. It was used that three-kind metal models areAu (cup), AuSn (cup), and AuSn (base). The bonding strength is measured using a die shear strengthtester. It carried out in the repetition experiment by a unit of 3 times. As a result of this test, theAuSn(base) metal model and the No.3 pattern were applied by the optimal condition. We set the valueof the low limit at shear strength 950g/mm2 for applying sigma level. This value is a generally used foreutectic bonding packages. The experiment results have 3.13 sigma level (95% yield). In this paper,We show the final LED package which is finished up to LED attach, wire bonding, encapsulation, etc.This wafer level bonding process demonstrates its promising potential at the wafer level packaging inLED packaging
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/23/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.124-126.519.pdf
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