Journal Article

Study of Through Glass Via (TGV) Using Bessel Beam, Ultrashort Two-Pulses of Laser and Selective Chemical Etching

Ahn, Sanghoon, Kim, Jonghyeok, Kim, Byungjoo, Kim, Sungil, Choi, Jiyeon

2023

Overview

Selective laser etching is a promising candidate for the mass production of glass interposers. It comprises two steps: local modification by an ultrashort-pulsed laser and chemical etching of the modified volume. According to previous studies, when an ultrashort-pulsed laser beam is irradiated on the sample, electron excitation occurs, followed by phonon vibration. In general, the electron excitation occurs for less than a few tens of picoseconds and phonon vibration occurs for more than 100 picoseconds. Thus, in order to compare the electric absorption and thermal absorption of photons in the commercial glass, we attempt to implement an additional laser pulse of 213 ps and 10 ns after the first pulse. The modified glass sample is etched with 8 mol/L KOH solution with 110 °C to verify the effect. Here, we found that the electric absorption of photons is more effective than the thermal absorption of them. We can claim that this result helps to enhance the process speed of TGV generation.

• Publisher: MDPI AG,MDPI
• Subject: Bessel beam / burst-mode laser / Chemical etching / Chemical reactions / Energy / Excitation / Glass substrates / High speed trains / Internet of Things / Laser beams / Laser etching / Mass production / Micromachining / Phonons / Photon absorption / Photons / Plasma etching / Pulsed lasers / Scanning electron microscopy / selective laser-induced etching / spatial light modulator / Thermal absorption / ultrashort pulsed laser / Vibration