新式LED封裝塑料之評估與產品應用

An Evaluation of Novel Packaging Material on LED Applications

李政翰(Cheng-Huan Lee)

指導教授 ： 莊賦祥

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2013年)

摘要

目前LED的射出導線架大多以熱塑型材料為主，而使用最大量的即是PPA (Polyphthalamide)及PCT (Poly1,4-cyclohexylene dimethylene terephthalate)，PPA主要使用為低功率應用，而一些中低功率使用主要為PCT，兩種材料在市場上都相當成熟，但是隨著降低成本下使用功率的提升及全新照明應用，支架本身對於環境，如硬度及吸水性…等，另外抗熱效果的提升就很重要，如耐黃化…等,因此市場上多了一些熱固型材料的選擇，如 EMC (Epoxy Molding compound ) 及SMC (Silicone Molding compound ) ....等。

本論文主要要探討熱固型材料EMC在高功率產品上的應用，預計會使用2W以上，一開始針對製程上差異作比較分析，如噴砂及下料....等，實際封裝實驗結果發現經過噴砂除膠製程並不會造成光學損失,且透過滲透實驗可以知道熱固型材料與支架結合程度與熱塑型材料無差異,與接著主要會比較光學上性質透過光量測儀器了解比較熱固材料反射率及封裝後初始亮度與熱塑材料無差異,而透過烘烤 150 oC 長時間烘烤及250 oC 反覆過爐的實驗看耐熱程度及抗黃化的表現熱固型皆比熱塑型為優，最後使用熱固型材料(EMC)透過長時間在常溫25 oC、60 oC 及 85 oC 上的點亮測試(@400mA)比較光衰減及壽命推估表現。

關鍵詞：LED發光源、LED塑料(PPA、PCT、EMC、SMC)

關鍵字

LED發光源 ； LED塑料(PPA ； PCT ； EMC ； SMC)

並列摘要

In present, the thermoplastic polymer has been commonly utilized as one of LED packaging materials, in which thermoplastic-based PPA(Polyphthalamide) and PCT(Poly1,4-cyclohexylene dimethylene terephthalate)-based material are abundantly used. The PPA and PCT are mainly used for low- and medium-power applications, and both are the most commercial available materials in the LED packaging market. However, with reducing cost and increasing input power in LED solid-state lighting applications, the new packaging materials with better resistance to impact, humidity, heat, and encapsulant yellowing, have been developing for passing different environmental loads. Hence, there are some thermosetting polymer-based materials developed to meet the requirement, such as EMC (Epoxy Molding Compound) and SMC (Silicone Molding Compound), etc.

The study is mainly focused on the applications of EMC package (with thermosetting polymer-based material) in high-power LED products, which is driven by greater than input power of 2W. First, it is to make a detailed analysis on each LED packaging process, such as sandblasting and punching, etc, and to further measure the initial light intensity of the package, relating to EMC's reflectivity after packaged. Next, the material heat resistance and optical characterization for the package were examined before and after the long-term high-temperature aging and several reflow cycling tests. Finally, the adhesive bond at an interface between EMC material and silver leadframe was observed with a red ink experiments. In the mean time, the light decay and lifetime for the package were also determined by experimentally recording the LED light intensity when continually operated at a certain driven I=400mA under different ambient temperature conditions of 25 oC, 60 oC, 80 oC for a long time.

Keywords: LED, Package, EMC thermosetting-based packaging material, PPA thermoplastic-based packaging material

並列關鍵字

LED ； Package ； EMC thermosetting-based packaging material ； PPA thermoplastic-based packaging material

參考文獻

[1] S. Nakamura and S. F. Chichibu, 2000, “Introduction to nitride semiconductor blue laser diodes and light emitting diodes”, London, UK: Taylor and Francis.

[2] 許招墉譯，2004，最新圖解半導體製程槪論，東芝Йтヵ⑦ФヱУ-社普林斯頓國際有限公司。

[3] 蔡國猷，1992，發光二極體基礎技術，建興出版社。.

[4] 小山稔，奧野保男，柏原鳳一郎執筆，柏瑞芳譯，1991，發光二極體及其應用，工業技術硏究院工業材料硏究所。

[5] A. H. Mueller, M. A. Petruska, M. Achermann, D. J. Werder, E. A. Akhadov, D. D. Koleske, M. A. Hoffbauer and V. I. Klimov, 2005, “Multicolor Light-Emitting Diodes based on semiconductor nanocrystals encapsulated in GaN charge injection layers”, Nano Letters, vol. 5, pp. 1039-1044.