Substrate Integrated Waveguide on Glass with Vacuum-Filled Tin Through Glass Vias for Millimeter-Wave Applications

Area of Science:

• Materials Science
• Electrical Engineering
• Microwave Engineering

Background:

• Substrate Integrated Waveguides (SIWs) are crucial components in microwave and millimeter-wave systems.
• Conventional fabrication methods for vias in glass substrates can be slow and expensive.
• There is a need for efficient and cost-effective fabrication techniques for millimeter-wave devices on glass.

Purpose of the Study:

• To present a novel fabrication approach for SIWs on glass substrates using tin through-glass vias (TGVs).
• To demonstrate a rapid and cost-effective method for filling TGVs with tin.
• To evaluate the performance of fabricated SIWs for millimeter-wave applications.

Main Methods:

• Fabrication of TGVs in glass substrates using wafer-level glass reflow micromachining.
• Development of a custom vacuum suctioning system for rapid molten tin filling of TGVs.
• Characterization of the fabricated SIW, including insertion loss and cutoff frequency.

Main Results:

• Successful fabrication of SIWs on glass substrates with tin TGVs.
• Achieved a 3-dB cutoff frequency of 17.2 GHz for the fabricated SIW.
• Demonstrated an average insertion loss of 1.65 ± 0.54 dB in the 20-35 GHz range.

Conclusions:

• The proposed method offers a fast and cost-effective alternative for void-free TGV filling compared to traditional metallization.
• Glass substrates with tin TGVs show significant potential for fabricating high-performance millimeter-wave devices.
• This technique advances the development of integrated millimeter-wave circuits on glass platforms.