PMID- 23978189
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20140422
LR  - 20130925
IS  - 1944-8252 (Electronic)
IS  - 1944-8244 (Linking)
VI  - 5
IP  - 18
DP  - 2013 Sep 25
TI  - High-performance light-emitting diodes encapsulated with silica-filled epoxy 
      materials.
PG  - 8968-81
LID - 10.1021/am402035r [doi]
AB  - Packaging materials have a great impact on the performance and reliability of 
      light-emitting diodes (LEDs). In this study, we have prepared high performance 
      LED devices through encapsulating LEDs by epoxy materials incorporated with 
      filler powders. A set of evaluation methods have also been established to 
      characterize the reliability of LED devices. No delamination or internal cracking 
      between packaging materials and lead frames has been found for the encapsulated 
      high performance LED devices after the package saturation with moisture and 
      subsequent exposure to high-temperature solder reflow and thermal cycling. Four 
      kinds of inorganic silica fillers, namely, quartz, fused silica, cristobalite, 
      and spherical silica, and one kind of organic filler, that is, spherical silicone 
      powder, were incorporated into the epoxy packaging materials to compare their 
      effects on performance of LED devices. The properties of epoxy packaging 
      materials and LED devices were studied by differential scanning calorimetry 
      (DSC), thermogravimetric analyses (TGA), dynamic mechanical analysis (DMA), 
      thermomechanical analyzer (TMA), ultravioletvisible spectrophotometer (UV-vis), 
      scanning acoustic microscopy (SAM), and scanning electron microscopy (SEM). 
      Except the spherical silicone powder filled epoxy materials, all the other filled 
      systems showed lower equilibrium water sorption content and smaller water 
      diffusion coefficient in both water sorption and moisture sorption tests. The 
      coefficient of thermal expansion (CTE) values were also decreased with the 
      addition of fillers, and the systems filled with quartz, fused, and filled with 
      spherical silica gave the best performance, which exhibited the reduced CTE 
      values both below and above Tg. The results of TGA essentially showed no 
      difference between filled and unfilled systems. The glass transition temperature 
      changed little for all the filled systems, except the one incorporated with 
      spherical silicone. The modulus at room temperature increased with the addition 
      of fillers. The light transmittance of filled epoxy materials varied with fillers 
      after UV and thermal aging.
FAU - Li, Tian
AU  - Li T
AD  - State Key Laboratory of Molecular Engineering of Polymers, Department of 
      Macromolecular Science, Fudan University , Shanghai 200433, China.
FAU - Zhang, Jie
AU  - Zhang J
FAU - Wang, Huiping
AU  - Wang H
FAU - Hu, Zhongnan
AU  - Hu Z
FAU - Yu, Yingfeng
AU  - Yu Y
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130906
PL  - United States
TA  - ACS Appl Mater Interfaces
JT  - ACS applied materials & interfaces
JID - 101504991
EDAT- 2013/08/28 06:00
MHDA- 2013/08/28 06:01
CRDT- 2013/08/28 06:00
PHST- 2013/08/28 06:00 [entrez]
PHST- 2013/08/28 06:00 [pubmed]
PHST- 2013/08/28 06:01 [medline]
AID - 10.1021/am402035r [doi]
PST - ppublish
SO  - ACS Appl Mater Interfaces. 2013 Sep 25;5(18):8968-81. doi: 10.1021/am402035r. 
      Epub 2013 Sep 6.