KR-102962944-B1 - HIGHLY INTEGRATED MICRO HOLES PROCESSING METHOD FOR GLASS INTERPOSER

Abstract

The present invention relates to a method for processing highly integrated micro-holes for a glass interposer, which is improved to contribute to the miniaturization and high integration of semiconductor packaging. The present invention provides a method for processing highly integrated micro-holes for a glass interposer, comprising: (a) forming at least one first hole in a glass substrate through laser processing; (b) passing an etching solution through the first hole to etch the first hole first, and removing the leaching layer formed during the first etching by ionizing with ultrasound to form a second hole with a larger diameter than the first hole; (c) washing and drying the second hole; and (d) radiating X-rays into the second hole to detach residue attached to the second hole, thereby forming a third hole with a larger diameter than the second hole.

Inventors

• 채영훈

Assignees

• 경북대학교 산학협력단

Dates

Publication Date

20260508

Application Date

20240628

Claims (10)

1. (a) a laser first hole drilling step of forming at least one first hole in a glass substrate through laser processing; (b) a second hole expansion etching step, wherein, after the first laser hole drilling step, an etching solution is passed through the first hole to etch the first hole, and an ionizing treatment is performed using ultrasound to remove the leaching layer formed during the first etching, thereby forming a second hole with a larger diameter of the first hole; (c) an expansion 2-hole washing and drying step for washing and drying the 2-hole after the second hole expansion etching step; and (d) After the expansion 2-hole washing and drying step, a third hole expansion X-ray radiation step is included in which X-rays are radiated to the second hole to cause residue attached to the second hole to detach, thereby forming a third hole with a diameter larger than that of the second hole. The second hole formed by the above second hole expansion etching step is larger than the diameter of the first hole, and The third hole formed by the above third hole expansion X-ray radiation step is larger than the diameter of the second hole, and The X-ray in the above third hole expansion X-ray radiation stage includes 5W stationary X-rays, and The second hole formed by the second hole expansion etching step is 6 to 15 μm, and A method for processing highly integrated micro-holes for a glass interposer, characterized in that the third hole formed by the third hole expansion X-ray radiation step is 16 to 20 μm.
2. In paragraph 1, A method for processing highly integrated micro-holes for a glass interposer, characterized in that the first hole is 5㎛ or less.
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5. In paragraph 1, A method for processing highly integrated micro-holes for a glass interposer, characterized in that, in step (b) above, the etching solution is flowed by applying a predetermined pressure, and the process is carried out in a vacuum container so that the etching solution circulates and flows.
6. In paragraph 1, A method for processing high-density micro-holes for a glass interposer, characterized by performing the above washing with pure or ultrapure water.
7. In paragraph 1, A method for processing highly integrated micro-holes for a glass interposer, characterized in that the laser is a femtosecond laser.
8. In paragraph 1, A method for processing highly integrated micro-holes for a glass interposer, characterized in that the above etching solution contains HF.
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10. In paragraph 1, A method for processing highly integrated micro-holes for a glass interposer, characterized by further including a step of repeating steps (c) and (b) in reverse order after step (d).

Description

Highly Integrated Micro Hole Processing Method for Glass Interposers The present invention relates to a method for processing highly integrated micro-holes for a glass interposer, and more specifically, to an improved method for processing highly integrated micro-holes for a glass interposer that can contribute to the miniaturization and high integration of semiconductor packaging. For example, optical components often use a method of connecting them with conductive wires on a two-dimensional plane for high-speed signal transmission. However, the electrical connection using the aforementioned wire is limited in the transmission of high-speed signals and is not a suitable method for integration and miniaturization. To improve this, leading overseas optical component companies are developing technology that enables the stacking of optical components by applying an interposer equipped with through-vias on the substrate. The interposer equipped with the above-mentioned through-electrode is primarily manufactured by using a method of forming through-holes in a substrate made of silicon or glass using semiconductor etching, laser processing, etc., and filling them with a conductive material. In addition, for high-frequency characteristics and electrode integration density for high-speed signal transmission, a smaller diameter of the through-electrode is advantageous. Meanwhile, glass interposers are seeing increasing demand, particularly in the mobile communications semiconductor and AI chip packaging markets requiring high-speed, high-performance, and low-power operation, due to their superior price competitiveness and thermal and electrical properties compared to conventional silicon. However, in order to use the aforementioned glass as a competitive interposer, crack-free operation, high aspect ratio, and high-speed processing are essential; yet existing technologies, such as mechanical, chemical, and laser ablation (LA)—which removes material from the focused area on the sample surface by focusing a laser—had problems such as crack formation and long processing times. In addition, glass is a hard and brittle amorphous solid composed mainly of SiO2 (65–75%) and other oxides and additives such as Al2O3. When a hole is formed in such glass using only an etching process with an etching solution (HF), the following chemical reaction occurs. SiO2 + 6HF → SiF6 + 2H2O Specifically, the initial HF solution etches the glass and renders the byproducts precipitated on the glass surface insoluble. And as time passes, the size of the above insoluble by-products increases and accumulates, hindering glass etching. As a result, the surface becomes rough, the etching speed slows down over time, and as shown in Fig. 1, residues are generated and an hourglass shape (waist dia.) with a narrowed central part is formed. In addition, if the proportion of the oxide components in the glass is high, the oxides do not dissolve in the HF, so a large amount of precipitates are formed during etching. On the other hand, as 2.5D or 3D packaging technology advances, silicon interposer technology is being utilized to efficiently connect multiple devices. However, with the recent emergence of the need for glass interposers, which are more cost-competitive and superior in high-frequency bands, Intel announced in June 2023 that it would invest in the commercialization of glass interposers, following Corning and Schott. The present invention, described below, relates to a method for processing highly integrated micro-holes for a commercially viable glass interposer. FIG. 1 is a microscopic cross-sectional photograph of an example in which a hole is formed in glass by an etching solution according to the prior art. FIG. 2a is a flowchart sequentially illustrating a method for processing highly integrated micro-holes for a glass interposer according to the present invention. FIG. 2b is a process diagram sequentially showing a method for processing highly integrated micro-holes for a glass interposer according to the present invention. FIG. 3 is a drawing of a hole processed using a laser to apply a highly integrated micro-hole processing method for a glass interposer according to the present invention. FIGS. 4 to 6 are detailed views of (a), (b), and (c) of FIG. 2b. FIG. 7 is a plan view of a glass interposer manufactured by a high-density micro-hole processing method for a glass interposer according to the present invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. FIG. 2a shows a flowchart sequentially illustrating a method for processing highly integrated micro-holes for a glass interposer according to the present invention. And FIG. 2b shows a process diagram sequentially illustrating a method for processing highly integrated micro-holes for a glass interposer according to the present invention. In addition, FIG. 3 shows a hole processing diagram us