| 초록 |
In the present work, the thermal properties and morphological behaviors of liquid crystalline polymers (LCP) for a high brightness light emitting diode (LED) reflector applications were studied. The LCP were prepared from para p-hadroxy benzoic acid (HBA), biphenol (BP), terephthalic acid (TPA), isophthalic acid (IPA) and hydroxy naphtoic acid (HNA) by polycondenstaion reactions. The prepared resins were com-pounded with different wt% of fillers which were various types of titanium dioxide (TiO2), wollastonite, chopped glass fiber (CGF) and milled glass fiber (MGF). The thermal and optical properties of LCPs were evaluated to monitoring the realibilty of the color maintaince and mechanical performance of LCP under the high temperature of LED light radiation circumstance. Additionally, the morphological behaviors were also investigated to see the adhesive properties between the resin and lead frame, and between the resin and encapsulant. As a result, the conventional LCP composites are showed extremely comparabile thermal stability and optical adavantges in reliability test with the high flowability and mechanical strength compared to conventional polyamide (PA) reflector materials. However, due to the poor adhension to other package materials with lower reflectivity and whithness of inherent LCPs properties, newly developed LCPs are introduced for LED reflector applications. The new LCPs highly improve the the adhesive properties with better whithness caused by removing the monomer materials could lead to reflection drops and anisotropic properties. For achieving these goals, surface-treated MGFs are also in-ventted in particular. |
