In the field of advanced packaging, TSV must be used in the Interposer in 2.5D packaging or 3D packaging, but many people have recently heard that the word of glass pores (TGV). The potential of glass pores (TGV) is huge, and it may be regulars in advanced packaging technology in the future. This article will briefly describe the application and development trend of glass pores (TGV) in advanced packaging.

  The glass substrate is the next -generation chip substrate, and the core material is made of glass. The key technology of glass substrate packaging is TGV. The glass substrate industry chain includes production, raw materials, equipment, technology, packaging, detection, application and other links, and the upstream is the production, raw materials, and equipment links. Due to the unique physical chemical attributes, the glass substrate has shown huge potential in the field of electronic component materials.

  In order to pursue the limit of Moore's law, Intel, Samsung, Nvidia, TSMC and other large factories entered the glass substrate. Intel was the first to introduce glass substrates for advanced packaging to promote the progress of Moore's law.

In July 2023, an Intel engineer held a test glass core substrate panel in the Intel assembly and test technology development factory in Chandler, Arizona. (Picture source: Intel Company)

Samsung regards the glass substrate as the future of chip packaging, and set up a "Legion" to develop glass substrates. Nvida's GB200 may use glass substrates and plans to put into operation. TSMC has set up a special team to explore FOPLP technology and vigorously invest in the development of glass substrates.

The global IC packaging substrate market is developing rapidly, and it is expected to reach 31.54 billion US dollars in 2029. The glass substrate is the latest trend, and the penetration rate is expected to reach more than 50%within 5 years. The global glass substrate market has broad space, and it is expected to increase to $ 11.3 billion in 2031. The size of the Chinese glass substrate market has continued to expand, reaching 33.3 billion yuan in 2023. Corning accounts for 48%of the global market, with a share of 48%. The cost advantage of domestic manufacturers has a significant advantage, the glass substrate has accelerated, and the market space is huge. In the second half of 2024, the layout of TGV enterprises was accelerated!

The Through-GLASS VIA (TGV) interconnection technology can be traced back to 2008, derived from 2.5D/3D integrated TSV rotary board technology, mainly used to solve the TSV rotor board due to silicon lining loss, which brings high consumption of high consumption of silicon lining. Frequent or high -speed signal transmission characteristics degradation, high material cost and complex process. In recent years, technology has become increasingly improved. Each header company has begun to lay out and produces some samples in different fields including: sensors, CPUs, GPUs, AI, display panels, medical devices, advanced semiconductor packaging, etc.

The advantages of glass pores (TGV) and Silicon Tongkou (TSV) are mainly reflected in:

1) Excellent high -frequency electrical characteristics. Glass material is a kind of insulator material. The dielectric constant is only about 1/3 of the silicon material. The loss factor is 2-3 levels of magnitude lower than the silicon material.Ensure the integrity of the transmission signal;

2) Large -sized ultra -thin glass lining is easy to obtain. Glass manufacturers such as Corning, Asahi, and Schott can provide large -size (> 2m × 2m) and ultra -thin (<50µm) panel glass and ultra -thin flexible glass materials.

3) Low cost. Benefiting from large -sized ultra -thin panel glass is easy to obtain and does not need to be deposited insulating layer. The production cost of glass transfer board is only about 1/8 of the silicon -based transfer board;

4) Simple process process. There is no need to deposit the insulating layer on the surface of the substrate and the inner wall of the TGV, and there is no need to lose weight in the ultra -thin rotary board;

5) Strong mechanical stability. Even when the thickness of the bolts is less than 100µm, the warning is still smaller;

6) Wide in application fields, is an emerging vertical interconnection technology applied in the field of wafer-level packaging. It provides a new type of technical way to achieve the shortest distance between the chip and chips. Thermalism and mechanical properties have unique advantages in the fields of radio frequency chips, high -end MEMS sensors, and high -density system integration. It is one of the first choice for the next generation of 5G and 6G high -frequency chips

通格微展出射频IC载板

厦门云天展出的微流控晶圆

工艺流程简介：

Figure 1, (A) Prepare glass wafers, (B) forms TGV, (C) PVD blocking layer, seed layer, double-sided electroplating-sedimentary copper, (D) annealing and CMP chemical mechanical polishing, and the surface copper layer ( e) PVD coating and light engravings, (F) laying RDL heavy wiring layer, (G) to remove glue and CU/TI etching, (H) forms a passivation layer (dielectric layer).

First of all, the material detection and make glass pores (TGV). The pores of TGV mainly include sandblasting, ultrasonic drilling, wet etching, deep reactive ion etching, light -sensitive etching, laser etching, laser induction depth etching, and focusing on holes. After the hole is formed, it needs to be detected and cleane

Figure 2 Comparison of ordinary laser drilling process and laser induction deep etching process (picture source: LPKF)

采用等离子Plasma蚀刻形成通孔（图片来源：友威科技）

1: Tongtong rate -leakage point and not connected. Pore diameter size: Specification-10/30/50/70/100, the peridal diameter requires a ratio of more than 60%than the inner diameter. Defective judgment standards: area; real circle (95%card control); diameter (± 5um). 

2: Forex in the holes: Is there any?

3: Panel defects: cracks, poor ETCH (concave pits), stolen goods, scratches.

Secondly, through the method of physical gas sedimentation (PVD), the obstacle block, seed layer;

Third, electroplating up from the bottom to achieve seamless filling of TGV;

图 玻璃芯基板的横截面图像

Note: The above is the craftsmanship of the hole, and the following is the facial process.

Finally, through the temporary key, the back is grinding, chemical mechanical polishing (CMP) to expose copper, and the key combined to form a glass pore (TGV) process technology metal filling board. In the process, semiconductor processes such as cleaning, detection are also needed.

source：艾邦半导体网