Paper
2 February 1998 Automated optical inspection technology for HDD head suspension
Satoru Sakai, Hiroshi Oka, Moritoshi Ando
Author Affiliations +
Proceedings Volume 3306, Machine Vision Applications in Industrial Inspection VI; (1998) https://doi.org/10.1117/12.301241
Event: Photonics West '98 Electronic Imaging, 1998, San Jose, CA, United States
Abstract
We have developed an automated visual inspection technology for hard disk drive head suspensions. It consists of foreign materials detection technique and a precise, high-speed pattern width measurement. High S/N-ratio sensing is necessary for foreign materials detection. We developed a spectral sensing method that senses the reflection of two colors, blue and red, and calculates the reflection coefficients of the colors for every pixel. With this method, the S/N-ratio is enhanced by seven times. A high accuracy is required for measuring pattern widths. The problem is that this must be achieved within an inspection time of 0.4 s/suspension, which conventionally takes several seconds. To obtain a pattern signal at high speeds, suspensions are illuminated with transmitted light and their images are captured with a CCD line sensor. A sub-pixel method that calculates interstitial signal level enables both a high accuracy and high-speed measurement. An automated optical inspection system utilizing these technologies is currently operating in one of Fujitsu's factories. This paper describes this optical system, its measuring procedures, and the measured results of the system.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Satoru Sakai, Hiroshi Oka, and Moritoshi Ando "Automated optical inspection technology for HDD head suspension", Proc. SPIE 3306, Machine Vision Applications in Industrial Inspection VI, (2 February 1998); https://doi.org/10.1117/12.301241
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KEYWORDS
Gold

Inspection

Head

Sensors

Optical inspection

Reflectivity

Light sources

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