應用相位展開技術於SMT之錫膏高度量測

Three-dimensional measurement of reflow solder pastes using phase unwrapping techniques in a phase shift system

楊宗訓(Tsung-Hsun Yang)

指導教授 ： 蔡篤銘

元智大學/工程學院/工業工程與管理學系/碩士(2004年)

摘要

迴焊（reflow）製程為表面黏著技術（Surface Mounting Technology, SMT）之後段處理程序，隨著電子產品朝向輕、薄、短、小的設計，迴焊之電子元件檢測也更為精密。一般三維量測常使用雷射量測系統，但雷射量測需要逐點掃描，檢測時間較長，且設備昂貴，因此本研究使用Yen與Tsai【2004】所發展之相位移三維量測系統，同時配合不同之相位展開技術針對迴焊錫膏進行量測。

本研究所使用之相位移三維量測系統之建構成本低，並且可快速量測物體之三維資訊。研究中探討Yen與Tsai所發展之區域相位展開法（方法一）、相位變異量（phase derivative variance）品質導引法（方法二）與條紋對比度（fringe contrast）品質導引法（方法三）三種相位展開技術於處理不連續之封包相位（wrapped phase）的影響以及量測效果，並應用於迴焊製程中迴焊錫膏之量測。實驗結果顯示方法二之量測表現不佳，方法一與方法三有相同之量測精度，而方法三比方法一有較佳之量測重現性，但所需之計算時間也遠高於方法一。

由於迴焊製程取得之影像中，包含電子元件、基板與錫膏等多種材質，在檢測時須將錫膏影像由多種材質中分離出來，以量測迴焊錫膏之高度。研究中利用量測之高度資訊與型態學（morphology）技術將迴焊錫膏部分有效分割，此分割結果將使得往後之迴焊錫膏體積之量測更為便利。

關鍵字

三維量測 ； 迴焊錫膏 ； 相位移 ； 相位展開

並列摘要

Reflow process is the back-end procedure in surface-mounting-technology (SMT) manufacturing. As the design of electronic products has been trending light, thin, and multi-function, precise 3D inspection has become more and more important for increasingly small reflow components. Currently, 3D measurements for reflow components are mainly performed by laser-based systems. However, they not only suffer from low inspection speed due to the physical line-scanning process, but also require expensive implementation cost.

In this research, a fast and cost-effective 3D measurement system improved from Yen and Tsai [2004] is used for the inspection of reflow components. The full-field 3D measurement system uses a DLP（Digital Light Processing）-based phase shifting technique, in which the continuous phase is originally obtained from a local region phase unwrapping technique. Two additional phase unwrapping techniques based on phase-derivative-variance and fringe-contrast quality guides are evaluated and compared with the local region phase unwrapping technique.

Generally, a reflow printed circuit board contains three different materials, i.e., electronic components, substrate and solder pastes. In this study, reflow solder pastes are successfully segmented by using thresholding of measured heights and morphological operations. Quality inspection of SMT reflow components can be efficiently and effectively realized using the proposed phase-shift 3D measurement system.

並列關鍵字

Three-dimensional measurement ； Reflow solder paste ； Phase shifting ； Phase unwrapping