DOI QR코드

DOI QR Code

점탄성 테이프를 적용한 고댐핑 적층형 전자기판의 기본 특성 검증

Characteristic Validation of High-damping Printed Circuit Board Using Viscoelastic Adhesive Tape

  • 투고 : 2020.02.05
  • 심사 : 2020.04.10
  • 발행 : 2020.05.01

초록

다양한 산업분야에서 전자기판과 전장품의 기계적 체결을 위해 적용되는 웨지락(Wedge Lock)은 우주용 전장품에서도 장·탈착 용이성, 발사진동저감 효과 때문에 폭넓게 적용되고 있다. 그러나 기판의 가장자리에만 제한적으로 구속 가능한 장착 조건 때문에 기판의 크기가 증가할수록 극심한 발사환경에서의 굽힘거동에 의한 전자소자 솔더부의 피로수명 보장에 한계가 존재한다. 종래에는 상기 굽힘거동 최소화를 위해 기판에 별도의 보강재를 적용하였으나, 이는 전장품의 무게 및 부피증가가 불가피하다. 본 연구에서는 상기 한계점을 극복하고자, FR-4 재질의 박판을 기판의 배면부에 다층으로 적층하고, 각 층간에 점탄성 테이프를 적용하여 발사환경에서 소자의 피로수명 확보에 유리한 고댐핑 적층형 전자기판을 제안하였다. 본 적층형 기판의 설계 유효성 검증을 위해 상이한 온도조건에 따른 자유감쇠시험 및 인증 수준의 발사진동시험을 수행하였으며, 시험 결과에 기반한 고집적화 소자의 피로수명을 예측하였다.

Wedge locks have been widely used for spaceborne electronics for mounting or removal of a printed circuit board (PCB) during integration, test and maintenance process. However, it can basically provide a mechanical constraint on the edge of the board. Thus, securing a fatigue life of solder joint for electronic package by limiting board deflection becomes difficult as the board size increases. Previously, additional stiffeners have been applied to reduce the board deflection, but the mass and volume increases of electronics are unavoidable. To overcome the aforementioned limitation, we proposed an application of multi-layered PCB sheet with viscoelastic adhesive tapes to implement high-damping capability on the board. Thus, it is more advantageous in securing the fatigue life of package under launch environment compared with the previous approach. The basic characteristics of the PCB with the multi-layered sheet was investigated through free-vibration tests at various temperatures. The effectiveness of the proposed design was validated through launch vibration test at qualification level and fatigue life prediction of electronic package based on the test results.

키워드

참고문헌

  1. Seong, J. K., Lee, W. H., Kim, C., Jeong, S. Y., Yi, D. W., and Kim, S. Y., "Simulation and Design of Electrical Equipments Based on Airborne System," Proceedings of the KSME Thermal Engineering Division Spring Conference, 2011, pp. 501-504.
  2. Hosseinloo, A. H., Tan, S. P., Yap, F. F., and Toh, K. C., "Shock and Vibration Protection of Submerged Jet Impingement Cooling Systems: Theory and Experiment," Applied Thermal Engineering, Vol. 73, 2014, pp. 1074-1084.
  3. Jang, H. J., Lee, J. G., Lee, J. C., and Park, S. J., "Design of Digital Controller for Divert Control Actuator System Based on BLDC Motor," Proceedings of KSPE Fall Conference, 2012, pp. 833-837.
  4. Jang, T. S., Rhee, J., and Seo, J. K., "A Study on Fabrication of Monolithic Lightweight Composite Electronic Housing for Space Application," Acta Astronautica, Vol. 117, 2015, pp. 497-509. https://doi.org/10.1016/j.actaastro.2015.09.014
  5. Focardi, M., et al., "The Instrument Control Unit of the ESA-PLATO 2.0 Mission," Proceedings of Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave, Vol. 9904, 2016, 99042Y:1-15.
  6. Go, J. S., Kim, H. B., and Oh, H. U., "Structural Safety Verification of PCB-based CubeSat Solar Panels in Launch Vibration Environment," Proceedings of the KSNVE Annual Autumn Conference, 2019, p. 189.
  7. Kwon, S. C., Jo, M. S., Ko, D. H., and Oh, H. U., "Viscoelastic Multilayered Blade-type Passive Vibration Isolation System for a Spaceborne Cryogenic Cooler," Cryogenics, Vol. 105, 2020, pp. 1-16.
  8. Chen, B. M., "Free Vibration Analysis of Printed Circuit Boards with Different Types of Edge Support," Texas Tech University, 1992.
  9. http://www.wakefield-vette.com/
  10. https://www.tsd-space.it/
  11. https://www.3m.com/
  12. http://esmat.esa.int/a11_6.htm
  13. European Cooperation for Space Standardization (ECSS-E-HB-32-21A), 2011.
  14. Yu, D., Al-Yafawi, A., Nguyen, T. T., Park, S. B., and Chung, S. W., "High-cycle Fatigue Life Prediction for Pb-free BGA under Random Vibration Loading," Microelectronics Reliability, Vol. 51, 2011, pp. 649-656. https://doi.org/10.1016/j.microrel.2010.10.003
  15. Cinar, Y., Jang, J. W., Jang, G. H., Kim, S. S., and Jang, J. S., "Effect of Solder Pads on the Fatigue Life of FBGA Memory Modules under Harmonic Excitation by Using a Global-local Modeling Technique," Microelectronics Reliability, Vol. 53, 2013, pp. 2043-2051. https://doi.org/10.1016/j.microrel.2013.06.018