高功率發光二極體之高熱導鑽石複合固晶材料

Abstract

本研究主要提出利用錫膏與鑽石混合做為複合式固晶材料與晶片端接觸，提供一個導熱的通道以改善高亮度發光二極體焦耳熱效應的問題。研究一共分為兩個主題：第一個主題為鑽石表面的鍍層材料選擇，選擇合適的鍍層材料做為與錫膏接合共晶面，選擇鎳或鈦鍍層至鑽石表面，避免間隙產生形成介面熱阻。另一個主題為改善固晶層材料，一般常見的固晶材料銀膠，從微觀的結構來看，是一水平式的結構，熱傳遞的途徑會有很多的介面熱阻產生，而在封裝領域提供一個新的想法藉由鑽石的高導熱性質，來提升固晶材料的散熱能力，因此我們研究二種垂直式的固晶層結構，一種是使用鑽石混合錫膏，定量於基板表面於晶片做接合，形成一個單層結構的鑽石固晶層材料，提供一個導熱的通道，另一種結構是使用BCB(Bzocyclobutene)材料固定鑽石，形成一個單層結構的鑽石固晶層材料，再與錫膏晶片做接合，提供一個導熱的通道。

In this thesis , the main idea use of as a solder (SAC305 Sn3wt% , Ag0.5wt% , Cu) mixed with diamond composite die attach material in contact with the LED chip, providing a thermally conductive channel in order to improve the high-brightness light-emitting diodes Joule heating effect. The thesis includes two themes: first part , the diamond surface coating material selection, choose the right coating material as bonding and eutectic solder surface, nickel or titanium plating to choose the diamond surface, avoiding the formation of interface heat generation gap resistance. The second part , to improve the die attach material, the general common die attach material is silver plastic, from microscopic structure, is a horizontal structure, there are many ways to heat transfer interface thermal resistance, and in the packaging field provide a new idea by high thermal properties of diamond, to improve the cooling capacity of die attach material. Therefore , we examined two vertical structure , the first structure is solder SAC305 mixed diamond, quantitative do on the substrate surface to the LED chip bonding , to form a solder mix diamond of a single layer die attach structure. Another structure is the use of BCB (Bzocyclobutene) material fixed diamonds, to form diamond single layer structure, and then do the LED chip bonding and paste to provide a thermally conductive channel.