In the first two articles of the TGV series, we exploredthe industrialization path of TGV technology, as well asthe specific processing results of Huachuang Hongdu’s TGV technology on Schott BF33 borosilicate glass.
△ A Comparison Table of Different Glass Compositions (Huachuang Hongdu Self-test)
Different glass substrates have varying characteristics, requiring targeted optimization of process conditions and parameters.This article will focus onCorning。 EAGLE XG®（ （Short for EXG） glass, exploring how our TGV technology adapts to its material characteristics, unlocking its advantages in high-frequency signal transmission and advanced packaging scenarios.
The TGV concept was first proposed by Corning Corporation, and the EXG glass it developed was also applied in early TGV research； it can be said that,whenever TGV is mentioned, EXG almost inevitably comes into play.This glass substrate, launched in 2006, contains no heavy metals； “XG” stands for “Extra Green,” highlighting its environmental friendliness.
△ Corning EXG Glass (Image from Corning’s Official Website)
As the industry’s first display glass substrate completely free of heavy metals, EXG is an ideal choice for liquid crystal display devices （LCD）,favored by leading panel manufacturers,featuring the followingtechnical characteristics:
△ Corning EXG Glass Material Information (Image from Corning Official Website)
Any product chosen by the market has its advantages, but it is also inevitable that it will have limitations.As a cost-effective choice for imported glass, EXG has a high process threshold； under the same thickness, the difficulty of through-hole processing is significantly higher than that of other glasses.
Taking a thickness of 0.5 mm as an example: the BF33 can process through-holes with a minimum diameter of 10 μm, while the EXG has a minimum aperture of approximately 30 μm at the same thickness； going any smaller makes it difficult to drill through。 This is mainly because the non-alkali metal composition of EXGrequires a narrower energy window during the laser modificationstage, and exhibits higher sensitivity to solution concentration and temperature during the wet etching stage.Therefore, EXG places greater emphasis on the fine control capabilities of the hole-forming process.
△ Super Fast Laser Light Source for Huachuang Hongdu TGV
In response to this challenge, Huachuang Hongdu’s TGV solution demonstrates clear advantages。 We have independently developed a specialized ultrafast laser source for TGV, which can flexibly optimize key performance indicators such as pulse width, beam quality, and pulse stability according to different needs.Based on customized light sources and independently controllable etching processes, we have achieved excellent via performance on Corning EXG:a minimum aperture of 30 μm for 0.5 mm thick substrates, with the potential to explore even smaller dimensions； The through-hole taper is 70%–80%, with smooth side walls free of burrs or cracks；The aperture consistencyis excellent, meeting the requirements for high-density interconnects.
△ Laser Induced – Glass Front (Left) Back (Right)(Huachuang Hongdu Microscopic Measurements)
△ The Glass Carved End Surface (Huachuang Hongdu Microscopic Measurements)
△ Demonstration of Perforation Effect (Huachuang Hongdu Microscopic Measurements)
Huachuang Hongdu“specialized custom laser light source + independently controllable etching process”solution takes“stable and controllable”as its core objective—laser modification provides selectivity,while wet etchingProvide efficiency, with both working together.
Based on the above pathways, we have demonstrated exceptional TGV processing capabilities on Corning EXG substrates,with specific technical indicators as follows:
The Conning EXG combines high cost-effectiveness, low dielectric loss, and clean characteristics, making it naturally suited for high-frequency, high-speed signal transmission scenarios.Huachuang Hongdu’s precision TGV processing technology can achievelow taper and high consistencythrough-holes, effectively avoiding issues such as micro-cracks, rough side walls, and thermal stress generated by traditional laser ablation or mechanical drilling, thereby providing a reliable foundation for high-end applications such as RF front-ends and optoelectronic co-packaging.
△ TGV Sample Display (Huachuang Hongdu Measured Photo)
The challenge of the TGV lies in whether it can maintain effect consistency under different materials, sizes, and batch conditions.The Huachuang Hongdu TGV solution has completed sample testing and process validation on multiple glass-based substrates from domestic and international material companies such as Corning, Schott, Rainbow, and Kaisheng. This has elevated the process capability from “adapting to a single material” to “generalized multi-material manufacturing,” providing a stable, controllable, and scalable TGV perforation solution for both imported and domestically produced glass.
