This study examined surface modification of a solder resist and dry film resist by 60 Hz nonequilibrium atmospheric pressure plasma using O₂/N₂ gas. Surface modification is extremely important for fine-pitch printed wiring board (PWB) manufacturing processes. Results show that the 0.1% of O₂/N₂ mixing ratio was the best condition for surface modification at a 0.45 m/min PWB substrate transportation speed. The triplet oxygen atom (³P) density and the quintet nitrogen atom (⁴S) density were measured using vacuum ultraviolet absorption spectroscopy (VUVAS). The quintet nitrogen atom was measured using VUVAS for the first time ever reported. The gas temperature, electron density, and NO-γ intensity were also evaluated. A triplet oxygen atom with extremely high density of 4.7 × 10¹³ cm^-3 was obtained at a 0.1% O₂/N₂ mixing ratio, and the density value was higher than that of the conventional atmospheric pressure plasma such as dielectric barrier discharge (DBD) type. The behavior of the triplet oxygen atom density and NO-γ intensity as a function of O₂/N₂ mixing ratio correlated strongly with surface modification. The 60 Hz nonequilibrium atmospheric pressure plasma using low-cost O₂/N₂ gas with a 0.1% O₂/N₂ mixing ratio is expected to be useful for surface modification during fine-pitch PWB manufacturing.

抄録全体を表示