&lt;title&gt;One-point-of-view high-precision and versatile optical measurement of different sides of objects&lt;/title&gt;

To improve the measurement accuracy and speed of online coplanarity measurement of integrated circuit (IC) leads, a new single camera vision system for small outline packaging IC leads was developed. Firstly, a novel imaging optical structure with multiple reflection mirrors and a total reflection rectangular prism was devised. With this structure, the two side views of IC leads are captured at the same time in a small field of view. To guarantee a good assembly quality, the relationship between the assembling deviation of optical components and measurement error is investigated. Secondly, a fast algorithm for the coplanarity measurement of the IC leads is proposed. This algorithm mainly consists of three parts: the IC lead tips searching, the local sub-pixel positioning and the local image correction. Finally, a high precision measurement instrument is used to verify the accuracy of the proposed approach. The experimental results show that the proposed approach is effective in measuring the coplanarity of IC leads in real-time and the measuring error of the standoff is less than 4 mm. Furthermore, the proposed method can gain higher measuring speed and accuracy than existing methods.

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“…Stanke et al (1999) proposed a projection method to search the IC lead tips. Before projection, the whole image should be segmented.…”

Section: Measurement Algorithmsmentioning

confidence: 99%

“…Special layout based method . Stanke et al (1999) designed a special layout with four mirrors and a back light source to capture four side views of a QFP IC in one point view. The four mirrors were installed on the four different sides.…”

Section: Introductionmentioning

confidence: 99%