| Summary: | 碩士 === 元智大學 === 化學工程學系 === 90 === This study researches into the factors of the plugging ink crack when it is used in the print circuit board by high-temperatured procedure.
We design a weight loss experiment. We can get the diffusion coefficient of plugging ink is 2.6*10-5 cm2/sec and the activity energy of plugging ink is 4735 kcal/mole. Therefore, there will be solvent left when the ink thickness is more than 3 mils and the ink is baked at 80℃ for 100 minutes.
The adhesion between copper and plugging ink is 913psi which is bigger than the stress by the chemical thermal expansion coefficient difference. Therefore, we prove that the plugging ink crack is not made up of the stress.
The ink thickness in the hole is more than 3mils while the solvent can’t be evaporated from the pre-baking process. Because the the temperature which is at 220℃-260℃ of the assembly process is more than the solvent boiling point (189℃), the solvent will rush out and make the ink crack.
|
|---|
