감광성 실버페이스트의 공정조건에 따른 물성 연구

Abstract

A characterization study according to process conditions of photosensitive silver paste

Yoon Hoe Kim

Department of Graphic Arts Engineering, Graduate School, Pukyong National University

Abstract

The same photosensitive silver pastes obtain different result values if each process condition is set differently. In order to study the material property according to the process condition of the photosensitive paste, the photosensitive paste was fixed to be one type and the experiment was performed. After printing the screen, the condition applied was changed in the order of pre-heat treatment process, UV exposure process and post-heat treatment and the following conclusion could be gained according to the result of it. The specific resistance and developing results according to the pre-heat treatment process came out different according to each process condition and thus it could be known that the pre-heat treatment process affects the specific resistance and developing. The specific resistance and the developing result had a certain direction. As the temperature was high and the time is short, the specific resistance was low and the developing was good. In the UV exposure process also, the specific resistance result was different according to the pre-heat treatment process condition even in the same UV exposure amount, but in overall, the specific resistance result was lower as the UV exposure amount becomes higher. In the 200 mJ/cm2, the pattern could not penetrated into deep places and inner hardening was not made and thus patterns were lost in the developing-washing process and in the 400 mJ/cm2, the exposure was too extensive and affected the developing, due to which the pattern got spreaded. As a result of it, as the UV exposure amount was big, the specific resistance came out low. In the post heat treatment process, the specific resistance was high as the temperature was high and the time was long and was lower in the 400 mJ/cm2 than in the 300 mJ/cm2, which is because since the exposure scope is large, the spreading of the pattern is big. When measuring the pencil hardness, the solid patterns were all 6H but the lined patterns were 3B~4B. In the adhesive strength measurement, there was no patterns lost, but when they were cross-cut in the 150℃ 400 mJ/cm2 and seen through a optical microscope, it could be seen that no light could penetrate into the cut part and thus the cut part was dark. This seems to have happened when some patterns entered into the cracks of sheath when cross-cutting them. In comparison with the case of the 150℃ 300 mJ/cm2, in the 400 mJ/cm2, the patterns seem to have been broken due to over cure. According to the above result, it could be known that the specific resistance, developing, adhesive strength and hardness were most excellent in the condition of 5 minutes of pre-heat treatment at 70 ℃, 300 mJ/㎠ of UV exposure amount and 20 minutes of post heat treatment process of 150 ℃.