HB LED packaging materials pros and cons

By Debra Vogler, senior technical editor

April 1, 2011 — Daniel Duffy, research scientist in Henkel’s Advanced Technology Group, was a presenter at MEPTEC’s The Heat is On event (3/21/11, Santa Clara, CA). Summarizing the encapsulant materials used for high-brightness LEDs (HB-LEDs), he noted the pros and cons of epoxy and silicone. The material challenges for epoxies are temperature stability and color (aging); and for silicone, contamination and adhesion, as well as barrier properties. In the future, epoxies will have to be stable with respect to blue light (T>150ºC); and silicone material will have to fulfill the condition T<Tg CTE <60ppm/K. "Silicone encapsulants are very stable," said Duffy. "But it is not enough — future power demands require higher levels of photo-thermal stability."

Die attach material challenges include transparency, CTE, interfacial TC, and adhesion properties. Such materials will need to have stable thermal resistance, high TC, matched TCE, and good adhesion properties. Duffy specifically mentioned adhesion as a critical property for LED packaging. "Delamination leads to increased interfacial thermal resistance," said Duffy. "Localized temperature increases can shorten device life." Furthermore, cracking can lead to weakening of wire bonds and cracks; also, delamination weakens barrier protection.

In this podcast interview, Duffy discusses the outlook for new materials and/or enhanced materials for HB-LED applications, including quantum dots. "Quantum dots are very interesting materials…when we learn how to tune the interactions between then and the rest of the materials involved in LED packaging, they will play a continuous role in the future," said Duffy. "They offer a wide variety of colors, tunability of color, and lots of options for tuning their performance with temperature, with time and, maybe even other optical effects we’re not even considering now…they’re here to stay."  The challenge, he noted, will be getting them into materials for higher-power applications.

Listen to Duffy’s podcast interview:  Download (iPhone/iPod users) or Play Now

 


 

Subscribe to Solid State Technology/Advanced Packaging.

Follow Advanced Packaging on Twitter.com by clicking www.twitter.com/advpackaging. Or join our Facebook group

POST A COMMENT

Easily post a comment below using your Linkedin, Twitter, Google or Facebook account. Comments won't automatically be posted to your social media accounts unless you select to share.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

NEW PRODUCTS

Spectral reflectometer for film thickness measurement
04/08/2014Verity Instruments, Inc. is pleased to announce the availability of its new SP2100 Spectral Reflectometer designed for film thickness measurement f...
New Kimtech Pure G3 EvT nitrile gloves
04/03/2014Kimberly-Clark Professional has introduced a new glove that is designed to provide process protection for the semiconductor and electronics industries....
UVOTECH releases UV-Ozone Cleaning System
04/03/2014Using a UV-Ozone Cleaner, near atomically clean surfaces can be achieved in minutes without any damage to your devices. ...