Effects of Surface Morphology and Molecular Structure on the Wettability of Photosensitive Acrylic Film

• Main Authors: Yen-Rung Jhu, 朱彥蓉
• Other Authors: Wen-Tung Cheng
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/49855257410404265637

碩士 === 國立中興大學 === 化學工程學系所 === 105 === The rapid development of opto-electrical industry promotes the photosensitive polymer films becoming the most common application of photoresist to be used for printed circuit board, semiconductor device and micro-electrical mechanics. However, the wettability between developer and the photosensitive polymer film is one of the critical factors in lithography process for the resolution of the pattern. Therefore, the contribution of the morphology and molecular structure on the wettability of the photosensitive polymer film needs to be considered. This research aims to investigate the effects of surface morphology and molecular structure on the wettability of photosensitive polymer films. First of all, we prepare the different kinds of the photosensitive polyester acrylic films by the use of oligomer species, silver nitrate, dipentaerythritolhexaacrylate (DPHA) and tripropylene glycol diacrylate (TPGDA) as monomer, and Irgacure 500 as photo-initiator. And then we use atomic force microscopy (AFM) and contact angle meter to analyze the surface morphology and contact angle to examine the wettability of photosensitive polyester acrylic films. Finally, we change water by alkaline solution with different pH value to measure contact angle on the surface of polymer films. Based on above experiments, the significant findings of this study could be remarked as below: (1) Because cresol novolac epoxy acrylate has benzene ring in the chemical structure, so that difficult to affinity with water, resulting in that the contact angle reached 74.4 degrees, which was more than contact angle of polyester acrylic and tetrafunctional polyester acrylic by 18% and 14% respectively. (2) The root mean square roughness of alkali soluble metal / polymer composite film was increased from 0.126nm to 3.798nm, resulting in that the contact angle was increased by 51%, comparing with the polymer film, because of the polymer films are hydrophobic in this work.. (3) When the amount of the monomer increase from 0.7g to 2.1g, the root mean square roughness of photosensitive polyester acrylic film was increased from 0.236nm to 0.825nm, which the contact angle was increased from 65.4 to 71.9, because the more monomer can enhance the crosslinking density to rough the surface of the hydrophobic films. (4) When the amount of the photo-initiator increase from 0.07g to 0.35g, the root mean square roughness of photosensitive polyester acrylic films was increased from 0.345nm to 0.825nm, which the contact angle was increased from 68.6 to 71.9, resulting from the more photo-initiator can speed the reaction rate and the depth of hardening to rough the surface of hydrophobic films. (5) When photosensitive acrylic polyester film was exposed to ultraviolet light, it generated the free radicals to make intermolecular polymerization, crosslinking and grafting reaction to form a network structure, so that photosensitive acrylic polyester film is hard to be attacked by alkali solution, which contact angle was increased by 11%, comparing to polyester acrylic films without photo-initiator.