Preparation of Soft Etchant to Improve Adhesion Strength between Photoresist and Copper Layer in Copper Clad Laminates

CCL 표면과 포토리지스트와의 접착력 향상 위한 Soft 에칭액의 제조

  • Lee, Soo (Department of Chemical Engineering, Changwon National University) ;
  • Moon, Sung-Jin (Department of Chemical Engineering, Changwon National University)
  • 이수 (창원대학교 화공시스템공학과) ;
  • 문성진 (창원대학교 화공시스템공학과)
  • Received : 2015.08.10
  • Accepted : 2015.09.30
  • Published : 2015.09.30


In this research, environmental friendly organic acid containing microetching system to improve adhesion strength between photoresist resin and Copper Clad Laminate(CCL) was developed without using strong oxidant $H_2O_2$. Etching rate and surface contamination on CCL were examined with various etching conditions with different etchants, organic acids and additives. to develope an optimum microetching condition. Etching solution with 0.04 M acetic acid showed the highest etching rate $0.4{\mu}m/min$. Etching solution with the higher concentration of APS showed the higher etching rate but surface contamination on CCL is very serious. In addition, stabilizer solution also played an important role to control the surface contamination. As a result of research, the etching solution containing 0.04 M of acetic acid, 0.1 M of APS with 4 g/L of stabilizer solution(ST-1) was best to improve adhesion between CCL and photoresist resin as well as showed the most clean and rough surface with the etching rate of $0.37{\mu}m/min$.


  1. T. Sutter, Inkjet-Based Micromanufacturing; Inkjet Fabrication of Printed Circuit Boards, eds J. G. Korvink, P. J. Smith, and D.-Y. Shin, Wiley-VCH Verlag GmbH & Co. Weinheim, Germany. Chap. 16, (2012).
  2. Y. J. Park, and G. B. Lee, "Analysis of Energy Efficiency and Productivity in Dry Process in PCB Manufacturing, Inter. J. Precision Eng. Manuf., 14(7), 1213-1221 (2013).
  3. D. Tews, F. Michalik, R. Haidar, M. Thoms, M. Goh, and S. Li, Non-Etching Adhesion Promoter for Dry Film for Semi-additive Manufacturing-Advanced Dry Film Pre-treatment, 2013 8th International IMPACT Conference, IEEE Catalog Number: CFP1359B-ART (2013).
  4. Z. Sheng, M. H. Azarian, and M. G. Pecht, Surface Insulation Resistance of Conformally Coated Printed Circuit Boards Processed With No-Clean Flux, IEEE Transactions on Electronics Packaging Manufacturing, 29(3), 217-223 (2006).
  5. Mitsubishi Gas Chemical Co., Kor. Pat. Pub. No. 10-2014-0044908 (2014).
  6. Atotech Deutschland Gmbh, Method for providing organic resist adhesion to a copper or copper alloy surface, U. S. Pat. 20140141169 A1 (2014).
  7. Atotech Deutschland Gmbh, Acidic treatment liquid and method of treating copper surfaces, U. S. Pat. 7,153,449 B2 (2006).
  8. Y. -J. Kang, M. -E. Hong, and D.-H. Kim, Study on Soft Etching Material Development to Improve Peel Strength between Surface of Copper and Solder Resist Ink, J. Korean Ind. Eng. Chem., 20(2), 172-176 (2009).
  9. J. Ou, W. Hu, S. Liu, M. Xue, F. Wang, and W. Li, Superoleophobic Textured Copper Surfaces Fabricated by Chemical Etching/Oxidation and Surface Fluorination, ACS Appl. Mater. Interfaces, 5, 10035-10041 (2013).
  10. J. Hernandez, P. Wrschk and G. S. Oehrlein, Surface Chemistry Studies of Copper Chemical Mechanical Planarization, J. Electrochem. Soc., 148(7), G389-G397 (2001).
  11. Toyama Nippon Denki KK, Surface Treating Agent for Copper and Copper Alloy, Japan Patent 02-236289,A (1990).
  12. Pennwalt Cor., Etching of copper and copper bearing alloys, US 4,859,281 A (1987).
  13. IBM Corporation, Copper cleaning compositions, processes and products derived therefrom, U. S. Pat. 6830627 B1 (2004).
  14. MacDermid Inc., Microetchant for copper surfaces and processes for using same, U. S. Patent 5,328,561 (1994).
  15. W. Zhou, R. Song, L-L. Jiang, W-P. Xu, G-K. Liang, D-C. Cheng, and L-J. Liu, Chemical etching process of copper electrode for bioelectrical impedance technology, Trans. Nonferrous Met. Soc. China, 22, 1501-1506 (2012).
  16. Atotech Deutschland Gmbh. Solution for etching copper surfaces and method of depositing metal on copper surfaces, WO 2004085706 A1 (2004).
  17. T. Horiuchi, H. Ishii, Fabrication of precise copper micro-coils using electrolytic etching, Microelectronic Engineering, 97, 212-215 (2012).