Defect Inspection of Flip Chip Solder Bumps Using an Ultrasonic Transducer

Sensors

Lei Su¹  Tielin Shi¹  Zhensong Xu¹  Xiangning Lu² 

[1] State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; E-Mails:;Jiangsu Normal University, Xuzhou 221116, China; E-Mail:

关键词: flip chip;    ultrasonic inspection;    support vector machine;    defect inspection;   

DOI  :  10.3390/s131216281

来源: mdpi

【 摘 要 】

Surface mount technology has spurred a rapid decrease in the size of electronic packages, where solder bump inspection of surface mount packages is crucial in the electronics manufacturing industry. In this study we demonstrate the feasibility of using a 230 MHz ultrasonic transducer for nondestructive flip chip testing. The reflected time domain signal was captured when the transducer scanning the flip chip, and the image of the flip chip was generated by scanning acoustic microscopy. Normalized cross-correlation was used to locate the center of solder bumps for segmenting the flip chip image. Then five features were extracted from the signals and images. The support vector machine was adopted to process the five features for classification and recognition. The results show the feasibility of this approach with high recognition rate, proving that defect inspection of flip chip solder bumps using the ultrasonic transducer has high potential in microelectronics packaging.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.