TGV（Through-Glass Via）technology High Quality Borosilicate Glass Quartz

TGV(Through-Glass Via)technology High quality borosilicate glass quartz

Technical introduction

In the field of advanced packaging, Through-Glass Via (TGV) is widely considered by the semiconductor industry as a key technology for next-generation 3D integration, mainly due to its broad application spectrum. TGV can be applied in areas such as optical communications, RF front ends, optical systems, MEMS advanced packaging, consumer electronics, and medical devices. Both silicon-based and glass-based via metallization technologies are emerging vertical interconnect technologies applied in wafer-level vacuum packaging, providing a new technical approach for achieving the shortest and smallest chip-to-chip distances with excellent electrical, thermal, and mechanical properties.

Glass through-hole technology, TGV, enables the manufacture of highly miniaturized and integrated high-performance electronic components. It can also be used for glass interposers, smart glass substrates, and microstructured glass substrates. Glass substrates supporting TGV can integrate glass and metal into a single wafer.

TGV is made from high-quality borosilicate glass and fused quartz. By using high-quality glass wafer materials and advanced interconnect technologies (such as redistribution layers), it provides a highly reliable packaging solution.

Redistribution Layer (RDL) technology can form circuits on glass substrates through processes such as seed layer sputtering, photolithography, and semi-additive electroplating, thus connecting TGV. This technology provides a low-loss output end for chip-to-package interconnections and costs less than traditional silicon-based interposers.

Additionally, TGV itself has advantages such as low substrate loss, high density, quick response, and low processing costs. These benefits make it applicable in areas such as millimeter-wave antennas, RF front ends, chip interconnects, and 2.5/3D packaging. Morimaru Electronics currently has a full set of high aspect ratio (7:1) via filling processes and R&D capabilities, including laser modification, wet etching, high-coverage seed layer sputtering, through/blind via metal filling, and CMP planarization.

Material parameter

Material advantage

Through-Glass Via (TGV) technology utilizes different types of glass materials, such as quartz glass and borosilicate glass, each offering unique advantages. Quartz glass is highly valued for its exceptional optical transparency, making it suitable for optoelectronic applications, and its strong thermal stability, which maintains physical and chemical stability even at very high temperatures, ideal for high-temperature processing environments. It also features a low thermal expansion coefficient, which ensures minimal dimensional changes with temperature fluctuations, beneficial for precision manufacturing. Moreover, quartz glass is chemically stable against most substances, preventing degradation over long-term use, and has high mechanical strength, making it suitable for environments requiring high durability and damage resistance. On the other hand, borosilicate glass is more cost-effective compared to quartz glass, with a manufacturing process that is less expensive, making it an economical choice. It offers good thermal stability sufficient for most electronic packaging needs and a moderate thermal expansion coefficient that maintains enough dimensional stability for environments with mild temperature changes. Borosilicate glass is relatively easier to process and shape, suitable for complex electronic component designs, and possesses good chemical stability, capable of withstanding various chemical environments. The choice between these two types of glass materials depends on the application requirements and cost-effectiveness. Quartz glass is more appropriate for high-end applications that demand extremely high optical performance, thermal stability, or chemical stability, such as in aerospace and military fields, whereas borosilicate glass is a more economical option, suitable for large-scale industrial applications and consumer electronics, especially when cost and manufacturability are the primary considerations.

Main application scenarios of TGV

1. Glass-based 3D integrated passive components

2. Embedded glass base fan out of the package

3. TGV integrated antenna

4. Multi-layer glass based system level packaging

As the semiconductor industry chain develops, the advantages of Through-Glass Via (TGV) have been increasingly recognized by industry insiders. Currently, TGV is mainly applied in areas such as RF front-ends, optoelectronics, biomedicine, electronic gas amplifiers, and consumer electronics. The growth rate of China's TGV market far exceeds the global average. With future government support and semiconductor industry initiatives, the cost of TGV is expected to continue to decrease. The prospects for the development of the TGV market are filled with boundless potential.

Similarly, the TGV market faces challenges as core high-end equipment and the chemical solutions for copper interconnects are still dominated by advanced foreign companies. During the industrialization process of the TGV market, domestic equipment manufacturing and materials industries will encounter significant opportunities.

As the technology industry continues to pursue enhanced computing capabilities, more semiconductor giants are venturing into the field of heterogeneous integration. This technology encapsulates multiple chiplets within a single package through internal interconnect methods. Glass substrates, favored for their unique mechanical, physical, and optical properties, enable more transistor connections within a single package and offer faster signal transmission speeds. For chip architects, this means the ability to integrate more chiplets within a package, thereby improving performance, density, and flexibility, while also reducing costs and power consumption. Compared to other substrates, glass substrates have a smoother surface that does not adversely affect circuit products. Additionally, glass substrates exhibit excellent thermal performance and physical stability, and are more resistant to high temperatures.