- 學位論文
黏晶封裝銀膠厚度與晶片傾斜度自動化光學檢測
Bond-line Thickness and Die Tilt Automated Optical Inspection in Die Bonding Process
摘要
由於半導體製程與封裝技術的進步，相對的線上檢測技術需求也日與俱增，其中黏晶製程與覆晶封裝檢測技術係相當重要的一環，有別於以往透過打線的互連模式，透過焊料或銀膠對半導體晶片與基板表面進行接合，其膠厚通常為數十至數百微米。接合劑注入之厚度與均勻度對於晶片模組之可靠度、導電性和導熱性影響甚大，故銀膠厚度與晶片傾斜度的自動化線上檢測系統，能解決現有以人工檢測為主流的品質不穩定及效率受限等困擾。 本研究重點在建立一套用於半導體封裝的銀膠厚度與晶片傾斜度自動化檢測系統，具體作法係透過兩台線性CMOS感測器掃描擷取待測物影像，使用立體視覺技術搭配一種新的演算法來決定待測物上特定點的三維座標，並據以進一步檢測黏晶品質。實驗樣本為表面黏著一片已知高度800mm、面積15x15mm^2之晶片的基板，實驗結果顯示其銀膠厚度和晶片傾斜度的平均值分別為76.398μm和〖0.0569〗^°，量測可於1.6秒內完成，因此以本技術執行黏晶品質線上檢測的目標是可以達成的。
並列摘要
Due to the progress of the semiconductor industry, the demand for high resolution in-line inspection at the packaging process is expanding. The mainstream technology focuses around die attach and flip-chip packaging. The bond-line thickness (BLT), which is the adhesive thickness between the bottom surface of a semiconductor die and the top surface of a substrate, is generally from tens of micrometers to hundreds of micrometers. The performance of the adhesive depends on its properties, the substrate being bonded, surface preparation on the substrates, and the adhesive thickness. The most important aspects of adhesive thickness or BLT are its magnitude and its uniformity. Since BLT has significant influence on reliability, electrical performance, and thermal resistance of package, it is a critical that must be measured with high accuracy. This study focuses upon building an automated inspection system for the in-line measurement of BLT and die tilt in die attach for semiconductor packaging process. A prototype of visual utilizing the line scan stereo vision technique via two linear CMOS cameras has been developed for the die bonding quality inspection. A novel algorithm is proposed for the determination of the 3D coordinate of certain points on an object. The BLT and die tilt of a die attached chip of substrate height 800 mm and cross section 15x15 mm^2 were measured to be approximately 76.398 μm and 〖0.0569〗^°, respectively. The measurement can be completed within 1.6 seconds. Thus the in-line inspection of die bonding quality can be expected with the propose technique.