全場光學三維量測技術於表面黏著電子封裝元件之檢測

Full-field optical 3D measurement for the quality inspection of SMT electronics packaging

顏旭男(Hsu-Nan Yen)

指導教授 ： 蔡篤銘

元智大學/工程學院/工業工程與管理學系/博士(2004年)

摘要

摘 要
全場光學三維量測技術於表面黏著電子封裝元件之檢測
在表面黏著電子封裝製程中，三維量測對元件品質檢測相當重要。基於X射線（X-ray）或雷射掃瞄（Laser scanning）方法的精密三維量測系統，不僅建置成本高，且系統校正耗時費力。本研究針對表面黏著電子封裝元件之品質檢測，發展一建置成本低、量測效益高之全場光學三維量測系統。
本系統是依據相位量測技術（Phase measuring technique）進行微小物體之三維量測。檢測步驟為由可程式控制光柵，如液晶顯示（LCD）穿透式面板或數位光學處理（DLP）反射式投射單元，產生正弦條紋圖案，並由共面白光照射，得到一具有正弦相位分佈的光柵；將此正弦光柵投射於待測物上，原本平行之正弦光柵將因物體表面形貌而變形；最後，經由計算在不同相位移時的變形正弦光柵影像，以得到待測物之表面高度值。由於運用可程式控制光柵為基礎的相位量測架構，使得本系統不僅可以精準地讓正弦光柵進行相位移，更可以迅速、彈性地因應所需量測精度及待測物大小，變換正弦條紋圖案的大小及條紋週期寬度。
經由標準一毫米塊規的量測驗證，本研究所發展之光學三維量測系統，其量測精度可達十微米。此外，由於採用全場量測方式，量測速度快，可在兩秒內完成一張640×480像素影像的量測。從錫膏（Solder paste）、球格陣列錫球（BGA solder ball）及覆晶凸塊（Flip-chip solder bump）的初步實驗，證明本系統在表面黏著電子封裝元件的品質檢測上有其功效。

關鍵字

三維量測 ； 錫膏體積 ； 球格陣列 ； 覆晶 ； 共平面檢測 ； 條紋投射 ； 相位移 ； 機器視覺

並列摘要

Abstract
Full-field optical 3D measurement for the
quality inspection of SMT electronics packaging
Three-dimensional (3D) measurement is important for the quality inspection of SMT electronics packaging. In this study, a cost-effective machine vision system for precise and full-field 3D measurement is proposed. This system especially aims at the 3D measurement applications in SMT soldering inspection such as volume measurement of the solder paste, and coplanarity inspection of BGA solder balls and flip-chip solder bumps.
The proposed system is based on a phase measuring technique, in which the phase is efficiently and effectively shifted by a software-controlled grating using a liquid crystal display (LCD) panel or a digital light processing (DLP) projection unit. A sinusoidal fringe pattern is generated on the software-controlled grating, projected onto the object, and deformed in accordance with the object surface. The surface profile is then obtained from the evaluation of intensity images of the deformed fringe patterns in different phase shifts. The LCD- and DLP-based phase measuring schemes not only can shift the fringe pattern with accurate phase increments, but can also adaptively generate the fringe pattern with varying periods to accommodate the required resolution and size of an inspection object.
The measurement accuracy of the proposed system is in the micrometer range, which is demonstrated by a standard 1 mm gauge block of grade 0. The processing time of the proposed 3D measurement system for an image of 640×480 pixels is less than 2 seconds on a typical personal computer. Experimental results from solder pastes, BGA solder balls and Flip-chip solder bumps have shown the efficacy of the proposed system in the quality inspection of SMT electronics packaging.

並列關鍵字

3D measurement ； Solder paste ； Ball-Grid-Array ； Flip chip ； Coplanarity inspection ； Fringe projection ； Phase shift ； Machine vision

參考文獻

1.S. C. Richard, “The complete solder paste printing processes,” Surface Mount Technology, 13, pp. 6-8, 1999.

2.K. Ho and A. Teng, “Survey on delamination of IC packages in electronic products,” 2000 International Symposium on Electronic Materials and Packaging, pp. 269 —273, 2000.

4.Danielsson, H., “Surface mount technology with fine pitch components,” Chapman & Hall, New York, 1995.

6.A. Kashitani, N. Takanashi, and N. Tagawa, “A solder joint inspection system for surface mounted pin grid arrays,” International Conference on Industrial Electronics, Control, and Instrumentation, 3, pp. 1865-1870, 1993.

7.K. W. Ko and H. S. Cho, “Solder Joints Inspection Using a Neural Network and Fuzzy Rule-Based Classification Method,” IEEE Transactions on Electronics Packaging Manufacturing, 10, pp. 93-103, 2000.