Processing Glass Substrate for Advanced Packaging using Laser Induced Deep Etching

This work presents a new concept for using glass as a component material in FOWLP. Glass exhibits excellent properties for advanced packaging applications, such as low loss tangent, low dielectric constant, CTE values between that of Si and a typical EMC, and a favorable Young's modulus for reducing warpage. Despite the great interest in the properties of glass, its use is still not widespread as traditional glass processing techniques have a detrimental impact on its properties while increasing the effective material cost. Here, we show that by using Laser Induced Deep Etching technology for processing glass, substrates can be produced in an economical manner while retaining all of the its excellent properties. Furthermore, this technology enables the processing of precise cavities with flexible features completely made of glass, capable of passively correcting die position errors occurring during the pick-and-place and EMC-related processes. In addition, issues such as warpage are highly reduced while allowing the integration of other features such as Through Glass Vias and Integrated Passive Devices in the same wafer.