Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Mold Technology for Precision Injection Lens

초정밀 사출렌즈 금형 기술

  • Ha, Tae Ho (Department of Ultra Precision Machines & Systems, Korea Institute of Machinery & Materials) ;
  • Jo, Hyoung Han (N2A. Ltd.) ;
  • Song, Jun Yeob (Department of Ultra Precision Machines & Systems, Korea Institute of Machinery & Materials) ;
  • Jeon, Jong (N2A. Ltd.)
  • Received : 2014.05.22
  • Accepted : 2014.06.12
  • Published : 2014.07.01
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Abstract

Precision injection mold is an essential element in order to manufacture small and precision plastic lenses used for phone camera. There are many critical factors to meet the requested specifications of high quality plastic lenses. One of the main issues to realize high quality is minimizing decenter value, which becomes more critical as pixel numbers increases. This study suggests the method to minimize decenter value by modifying ejecting structure of the mold. Decenter value of injection-molded lens decreased to 1 ${\mu}m$ level from 5 ${\mu}m$ by applying suggested ejecting method. Also, we also developed BIS (Built-in Sensor) based smart mold system, which has pressure and temperature sensors inside of the mold. Pressure and temperature profiles from cavities are obtained and can be used for deduction of optimal injection molding condition, filling imbalance evaluation, status monitoring of injection molding and prediction of lens quality.

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References

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  1. Development of Injection Mold for Subminiature Lenses Using Shell Runners Containing Multiple Holes vol.32, pp.11, 2015, https://doi.org/10.7736/KSPE.2015.32.11.961
  2. Design and Analysis of Shell Runners to Improve Cooling Efficiency in Injection Molding of Subminiature Lens vol.39, pp.10, 2015, https://doi.org/10.3795/KSME-A.2015.39.10.1021