Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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Effect of the Residual Impurity on the Prepreg Surface on the Wettability of Encapsulant for Chip on Board Package

칩 온 보드 패키지 적용을 위한 프리프레그 표면 잔류 불순물이 봉지재의 젖음성에 미치는 영향

  • Gahui Kim (School of Materials Science and Engineering, Andong National University) ;
  • Doheon Kim (Amkor Technology Korea Inc.) ;
  • Kirak Son (STATS ChipPAC Korea Ltd) ;
  • Young-Bae Park (School of Materials Science and Engineering, Andong National University)
  • 김가희 (국립안동대학교 반도체.신소재공학과) ;
  • 김도헌 ((주)앰코테크놀로지 코리아 기술연구소) ;
  • 손기락 ((유) 스태츠칩팩코리아) ;
  • 박영배 (국립안동대학교 반도체.신소재공학과)
  • Received : 2024.05.17
  • Accepted : 2024.06.20
  • Published : 2024.06.30
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Abstract

The effect of the residual impurity on the prepreg surface on the wettability of encapsulant for chip on board package was analyzed with microstructure, compositions and chemical bonds using a scanning electron microscope and X-ray photoelectron spectroscopy. As a result, the contact angle of w/ residual impurity sample was measured to be 28° higher than that of w/o residual impurity sample, and the C-O bond was decreased to be 4% lower than that of w/o residual impurity sample. The surface energy of the prepreg decreased because the impurity ions, Na and F, generated by the manufacturing process and wet etching, reacted chemically with the C on the prepreg surface, forming C-F bonds and breaking the C-O bonds on the prepreg surface. Therefore, the wettability of the encapsulant was degraded because the contact angle between the encapsulant and the prepreg was increased.

칩 온 보드(chip on board) 패키지 적용을 위해 프리프레그(prepreg) 표면에 잔류하는 불순물이 봉지재(encapsulant)의 젖음성에 미치는 영향을 규명하기 위해 전자현미경(scanning electron microscope)과 X-선 광전자 분광기(X-ray photoelectron spectroscopy)를 이용하여 미세구조, 조성 및 화학 결합을 분석하였다. 프리프레그 표면에 잔류 불순물이 존재하는 시편의 경우 잔류 불순물이 존재하지 않는 시편보다 접촉각이 28° 높게 측정되었으며, C-O 결합은 4% 낮게 도출되었다. 이는 공정 중 잔류 불순물인 Na, F이 프리프레그 표면에 존재하는 C와 화학 반응을 하여 C-F 결합 생성으로 인해 프리프레그 표면의 C-O 결합이 끊어지면서 프리프레그 표면에너지가 낮아지게 되고 이로 인해 접촉각이 증가하게 되면서 봉지재의 젖음성이 저하되는 것으로 판단된다.

Keywords

Acknowledgement

이 논문은 안동대학교 기본연구지원사업에 의하여 연구되었음.

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