Vertical Interconnect
Vertical conductive channels pass through glass substrates to enable high density electrical connections in advanced packages. These through glass vias offer lower signal attenuation and better thermal stability than traditional organic or silicon-based interconnects. The use of glass as a base material provides excellent high-frequency properties and a coefficient of thermal expansion that closely matches silicon dies.
Signal Efficiency
Electrical performance in millimeter-wave applications is enhanced by the insulating properties of the substrate. Because glass has a very low loss tangent, through glass vias exhibit minimal parasitic capacitance and low insertion loss compared to through-silicon vias. This allows for faster data transfer rates and lower power consumption in the final device.
The holes are typically formed using laser drilling or chemical etching and then filled with copper using an electrochemical plating process. These interconnects enable the stacking of multiple layers in a small footprint, which is necessary for modern mobile and wearable electronics.
Thermal Management
Reliability of the package depends on the ability of the structure to withstand temperature changes. Through glass vias provide a stable path for heat dissipation, although the thermal conductivity of glass is lower than that of silicon. Engineers must design the layout to ensure that heat from the active components can reach the external heat sinks without causing mechanical stress.
The hermetic nature of glass also protects the internal circuits from moisture and environmental gases.
