High-Speed Through-Hole Drilling in Teflon Films with a Visible Laser

Abstract

In this review, a nobel technique in laser high-speed drilling for Teflon films reinforced with SiO₂ particles has been introduced. The new laser drilling surpasses conventional techniques in simplicity, throughput and spatial resolution. The process consists of three simple steps. First, a thin absorbing layer (300 A gold) is deposited on a Teflon film to allow laser absorption. Second, the drilling is performed by pulsed laser irradiation at a rate of one hole per pulse. The irradiation does not completely open the holes in which debris still remains. Third, ultrasonic cleaning in water is used to remove the modified and weakly bound materials inside the drilled holes, leaving behind 50 μm diameter through holes in 25 μm thick teflon sheets. This new laser process is useful for packaging technology because of its drilling speed as high as 60, 000 holes per minute, and its inexpensive equipment cost.