通孔填充中電鍍銅的生長行為及微結構之研究

A study on the growth behavior and microstructure of the electroplating Cu in the through hole structure

陳宏杰(Hung-Chieh Chen)

指導教授 ： 何政恩

元智大學/工程學院/化學工程與材料科學學系/碩士(2013年)

https://doi.org/10.6838/YZU.2013.00295

摘要

摘要 通孔填充技術(through hole filling)是製造高密度互連(high density interconnection technology，HDI)印刷電路板的關鍵製程。本研究使用場發射掃描式電子顯微鏡(field-emission scanning electron microscope，FE-SEM)、電子背向散射繞射(electron backscatter diffraction，EBSD)分析隨電沉積時間延長通孔填充中銅的微結構演變過程。SEM觀察結果顯示，填孔銅厚度係與沉積時間成正比。在爆衝前銅厚度的增加較緩慢，但在爆衝時因銅沉積速度增快，造成銅厚度短時間內顯著增大。EBSD分析結果顯示，在電沉積銅中主要以大角度晶界(>15)為主，且具有高比例的特殊晶界，例如Σ3，Σ9等。從方向觀察發現，<111>與<101>方向是電沉積銅主要的擇優取向。同時本研究也針對爆衝前後電沉積銅的平均晶粒尺寸與晶體結構進行討論。另一方面，研究發現噴流流量是影響通孔填充結果的因子之一。適當的噴流可以提升銅離子於通孔內的置換性，進而減少包孔發生的機率。此系列之研究係可提供電子工業所需之金屬化填孔的相關知識，以作為填孔製程再精進的重要依據。 ii 關鍵詞:通孔、電沉積銅、電子背向散射繞射、微結構、擇優取向、噴流流量。

關鍵字

通孔 ； 電沉積銅 ； 電子背向散射繞射 ； 微結構 ； 擇優取向 ； 噴流流量

並列摘要

Abstract
Department of Chemical Engineering and Materials Science
College of Engineering
Yuan Ze University
Through hole (TH) filling technology has become a critical process for fabricating high density interconnection (HDI) circuit boards. In this study, the microstructural evolution in the Cu pillar with plating time (t) was analyzed by using optical microscopy (OM), field-emission scanning electron microscope (FE-SEM), and electron backscattered diffraction (EBSD). The OM observation showed that the thickness of the electroplating Cu increased as a function of t: it deposited in a moderate rate (approximately 0.3 μm/min) before the 〝fast deposition period〞, but dramatically increased to a large thickness with the extremely fast deposition rate (approximately 4 μm/min) in the 〝fast deposition period〞. EBSD analysis indicated that the high
iv
angle grain boundaries (HAGBs) were the dominating boundaries in the electrodeposited Cu, including high percent of special GBs, such as Σ3 and Σ9. And, <111> and <101> were the main preferred orientations in the electroplating Cu seen from the transverse direction . Besides, the average grain size and crystallographic texture before and in the 〝fast deposition period〞were also discussed.
Futhermore, a well designed jet impingement system simultaneously reduced the incidence of voided through holes. Based on this result, solution flow should be carefully chosen to achieve the balance between levels of fill and plating quality for the through hole filling process.
Keywords: though hole ; Cu; electroplating; EBSD; microstructure; preferred orientation ; jet impingement

並列關鍵字

though hole ； Cu electroplating ； EBSD ； microstructure ； preferred orientation ； jet impingement

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