- 學位論文
光硬化文字油墨特性探討
The Degradation of the Photo cured Legend Ink used in Printed Circuit Board
摘要
本研究主要以不同光啟始劑及不同單體組成之配方，並於添加二氧化鈦後，經由不同的曝光條件及耐焊260℃模擬PCB後段波焊製程等，探討各配方耐光性及耐熱性的差異，結果顯示各配方在UV-Vis穿透率漂錫前較漂錫後佳，隨著曝光能量增加，穿透率遞減，加入二氧化鈦後光無法穿透；以色度計測試結果，隨曝光能量愈高，使光澤值(L值)下滑，黃化值（b值）、總色差值（E）急速增加，漂錫後上述現象更加明顯，添加二氧化鈦後，則可降低Lab及E，可在漂錫前、後減緩變色現象；以TGA測試得知曝光能量愈高熱裂解溫度(Td)愈高，且熱裂解溫度(Td)漂錫後略高於漂錫前，添加二氧化鈦，會降低光反應使整體Td點降低；並以FTIR得知-OH、C=O、-CH3 族群吸收峰等亦會隨曝光能量愈高而減少，漂錫後上述吸收峰則明顯消減，添加二氧化鈦，光穿透性不佳，無法分析吸收峰變化。
並列摘要
The thermal stability of the photo-cured legend inks used in the printed circuit board is investigated with the color meter, gross meter, UV-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analyzer (TGA). The results of UV-Vis indicate that the transmittance of the ink decreases with increasing the UV light energy during the cure because of the possible premature photodegradation. The over-cured inks also have lower gross but larger color difference than the regularly cured ink. These degradation resulted differences become more significant after exposing the inks to the soldering temperature at 2600C. Nonetheless, the unwanted color change can be alleviated by adding titanium dioxides (TiO2) to the ink. From TGA analyses, it is concluded thatthe initial and maximal degradation temperatures of the ink increase with increasing the photo-curing energy due to a higher crosslinking density formed during the cure. The addition of TiO2 would lower the degradation temperature of the ink because its presence can adversely affect the photo-curing reaction. The results of FTIR confirm that the concentrations of -OH、C=O、-CH3 functional groups in the ink decrease with increasing the photo-energy and after the high temperature exposure.