一种芯片三维外观视觉检测光路设计

半导体芯片的三维外观检测是芯片生产过程中的一个重要环节,而其中的光路设计是三维外观检测技术中的一个难点和重点。针对QFP芯片的三维外观检测,提出了一种新的光路。新的光路通过采用数字相机和平面反射镜,在一个视场内同时实现了芯片的底面和四个侧面的成像。新的光路降低了标定的难度和后续软件计算芯片三维指标的难度,同时也减少了硬件成本。新的光路采用平行光路设计,可对外形尺寸为5mm×5mm～40mm×40mm范围内的QFP芯片进行清晰成像,从而使得一套外观检测装置可以检测各种型号的QFP芯片。此外,该光路减少了芯片输送时间,提高了检测效率。该光路已成功应用在外观检测设备中,实验结果表明,它较好的克服了目前外观检测装置的不足,并且能够满足工业实际生产要求。

Optical path design for three-dimensional exterior inspection based on machine vision of semiconductor chip

The three-dimensional exterior inspection is an critical step in the manufacturing process of semiconductor chips,and the optical path design is an unsolved problem in this step.In order to solve this problem,a novel optical path is proposed for the three-dimensional exterior inspection of QFP(plastic quad flat package).The new optical path can obtain the images of the chip’s bottom and four sides simultaneously by using the digital camera and planar specula.The new optical path reduces the difficulties of calibration and the subsequent software for calculating the chip three-dimensional index,and the hardware cost.It is suitable for the QFP chip whose size is from 5mm×5mm to 40mm×40mm by using parallel optical path design.Therefore,it can detect various types of QFP chips.In addition,the optical path can shorten the conveying time of the chips,and the efficiency of inspection is greatly improved.The optical path has been successfully applied in exterior inspection device,and the experimental results reveal that it is able to overcome some drawbacks of current exterior inspection device,and satisfy the industrial production requirements.