Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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Effects of Dielectric Curing Temperature and T/H Treatment on the Interfacial Adhesion Energies of Ti/PBO for Cu RDL Applications of FOWLP

FOWLP Cu 재배선 적용을 위한 절연층 경화 온도 및 고온/고습 처리가 Ti/PBO 계면접착에너지에 미치는 영향

  • Kirak Son (STATS ChipPAC Korea Ltd) ;
  • Gahui Kim (School of Materials Science and Engineering, Andong National University) ;
  • Young-Bae Park (School of Materials Science and Engineering, Andong National University)
  • 손기락 ((유) 스태츠칩팩코리아) ;
  • 김가희 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • 박영배 (안동대학교 신소재공학부 청정에너지소재기술연구센터)
  • Received : 2023.05.09
  • Accepted : 2023.06.01
  • Published : 2023.06.30
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Abstract

The effects of dielectric curing temperature and temperature/humidity treatment conditions on the interfacial adhesion energies between Ti diffusion barrier/polybenzoxazole (PBO) dielectric layers were systematically investigated for Cu redistribution layer applications of fan-out wafer level package. The initial interfacial adhesion energies were 16.63, 25.95, 16.58 J/m2 for PBO curing temperatures at 175, 200, and 225 ℃, respectively. X-ray photoelectron spectroscopy analysis showed that there exists a good correlation between the interfacial adhesion energy and the C-O peak area fractions at PBO delaminated surfaces. And the interfacial adhesion energies of samples cured at 200 ℃ decreased to 3.99 J/m2 after 500 h at 85 ℃/85 % relative humidity, possibly due to the weak boundary layer formation inside PBO near Ti/PBO interface.

팬 아웃 웨이퍼 레벨 패키지의 Cu 재배선층 적용을 위해 Ti 확산방지층과 폴리벤즈옥사졸(polybenzoxazole, PBO) 절연층 사이의 계면 신뢰성을 평가하였다. PBO 경화 온도 및 고온/고습 시간에 따라 4점 굽힘 시험으로 정량적인 계면접착에너지를 평가하였고, 박리계면을 분석하였다. 175, 200, 및 225℃의 세 가지 PBO 경화 온도에 따른 계면접착에너지는 각각 16.63, 25.95, 16.58 J/m2 로 200℃의 경화 온도에서 가장 높은 값을 보였다. 박리표면에 대한 X-선 광전자 분광분석 결과, 200℃에서 PBO 표면의 C-O 결합의 분율이 가장 높으므로, M-O-C 결합이 Ti/PBO 계면접착 기구와 연관성이 높은 것으로 판단된다. 200℃에서 경화된 시편을 85℃/85% 상대 습도에서 500시간 동안 고온/고습 처리 하는 동안 계면접착에너지는 3 .99 J/m2까지 크게 감소하였다. 이는 고온/고습 처리동안 Ti/PBO 계면으로의 지속적인 수분 침투로 인해 계면 근처 PBO의 화학결합이 약해져서 weak boundary layer를 형성하기 때문으로 판단된다.

Keywords

Acknowledgement

이 논문은 2022년도 산업통상자원부 및 산업기술평가관리원(KEIT) 연구비 지원에 의한 연구(20016465)와 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구(No.2022R1A2C1092453)결과로 수행되었으며, 샘플 제작에 도움을 주신 한국재료연구원 김도근 박사님께 감사드립니다.

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