Ultraviolet photosensitive alkali-free glass substrate and method for manufacturing the same

Abstract

The application discloses an ultraviolet photosensitive alkali-free glass substrate and a manufacturing method thereof, and belongs to the technical field of glass. The technical scheme is as follows: the components include the following components in percentage by mass: 62-72% of silicon dioxide, 8-12% of diboron trioxide, 10-16% of aluminum oxide, 2-5% of barium oxide, 1-3% of magnesium oxide, 1-3% of calcium oxide, 1-3% of strontium oxide, 2-5% of zinc oxide, 0.5-1.5% of tin dioxide and 2-4% of a photosensitive agent, wherein the photosensitive agent is silver fluoride and cerium tetrafluoride in a mass ratio of (1-2):(1-2). The application improves the through-hole manufacturing efficiency and precision, reduces the production cost, and is expected to promote the further development of semiconductor packaging technology.

Description

Technical Field

[0001] The present invention relates to the technical field of glass, and in particular to an ultraviolet-sensitive alkali-free glass substrate and a manufacturing method thereof. Background Art

[0002] Glass substrates are increasingly used in semiconductor packaging. As electronic devices continue to become smaller and more powerful, higher demands are placed on the density and reliability of semiconductor packaging. Alkali-free photosensitive glass substrates, due to their excellent chemical stability, low thermal expansion coefficient, and ability to be precisely formed using photolithography, have become a key material for semiconductor packaging.

[0003] During the chip packaging process, through-holes need to be made on the glass substrate to achieve functions such as electrical connections and physical connections between the chip and external components. Traditional through-hole production methods have many limitations on alkali-free glass substrates. For example, the mechanical drilling process can easily cause microcracks in the glass substrate, reducing the mechanical strength and reliability of the substrate. In addition, the drilling accuracy cannot meet the increasingly sophisticated semiconductor packaging requirements. Although the chemical etching process can control the shape and size of the through-holes to a certain extent, the etching rate is slow and the process is complex for alkali-free glass substrates. It can also easily cause uneven etching, affecting the quality of the through-holes. Laser drilling technology may cause thermal stress concentration in the glass when processing glass, causing deformation or defects in the glass substrate. At the same time, it has high equipment requirements and high costs. Therefore, it is urgent to develop an efficient and precise through-hole production method that can guarantee the performance of the glass substrate. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: to overcome the shortcomings of the existing technology, provide a UV-sensitive alkali-free glass substrate and a manufacturing method thereof, improve the efficiency and precision of through-hole production, reduce production costs, and is expected to promote the further development of semiconductor packaging technology.

[0005] The technical solution of the present invention is:

[0006] On the one hand, the present invention provides an ultraviolet-sensitive alkali-free glass substrate, comprising the following components in percentage by mass: 62-72% silicon dioxide, 8-12% boron trioxide, 10-16% aluminum oxide, 2-5% barium oxide, 1-3% magnesium oxide, 1-3% calcium oxide, 1-3% strontium oxide, 2-5% zinc oxide, 0.5-1.5% tin dioxide, and 2-4% photosensitizer, wherein the photosensitizer is silver fluoride and cerium tetrafluoride in a mass ratio of (1-2):(1-2).

[0007] Among them, silicon dioxide (SiO2), as the main body of the glass network, gives the glass substrate high strength, good chemical stability and thermal stability, and is the key cornerstone to ensure the reliable operation of the glass substrate in complex electronic packaging environments.

[0008] Boron trioxide (B2O3) can effectively lower the melting temperature of glass, improve processing performance, and enhance chemical stability, enabling it to resist corrosion from a variety of chemical substances and maintain the stability of the glass substrate performance.

[0009] A high content of aluminum oxide (Al2O3) significantly enhances the hardness, thermal shock resistance, and mechanical strength of glass substrates. Within the glass structure, it acts like a skeleton, strengthening the network structure and enabling the glass to withstand greater mechanical stress and temperature fluctuations, thereby improving the reliability and durability of electronic packaging.

[0010] Barium oxide (BaO) is mainly used to fine-tune the optical properties of glass, such as the refractive index, to meet the needs of optical transmission or display applications in electronic packaging. It also helps in glass molding and facilitates obtaining highly flat glass substrates.

[0011] Magnesium oxide (MgO) can improve the heat resistance of glass, reduce high-temperature softening and deformation, and synergize with other ingredients to enhance chemical stability, ensuring the long-term performance of the glass substrate remains stable.

[0012] Calcium oxide (CaO) plays a stabilizing role in the glass structure, enhancing the strength of the glass, optimizing the melting characteristics, making the glass structure more uniform during melting and forming, and ensuring the consistency of the quality of the glass substrate.

[0013] Strontium oxide (SrO) works together with other alkaline earth metal oxides to optimize the physical and chemical properties of glass, reduce the tendency of crystallization, and improve transparency and uniformity, which is crucial for the application of high-precision optical or electrical properties in electronic packaging.

[0014] Zinc oxide (ZnO) can improve the fluidity of glass, making the molding process smoother, helping to obtain a glass substrate with uniform thickness and smooth surface. At the same time, it can improve chemical stability and enhance the overall performance of the glass substrate.

[0015] Tin dioxide (SnO2) as a clarifier can effectively remove bubbles in glass melting, improve transparency and uniformity, and adjust electrical properties to meet the requirements of electronic packaging for glass electrical properties.

[0016] In the photosensitizer, silver fluoride (AgF) and cerium tetrafluoride (CeF4) decompose under ultraviolet light to produce Ce 3+ 、Ag + and Ce 3+ Has an empty orbital and can accept electron pairs to form coordination bonds; F - It is a strong ligand with lone pair electrons. In acidic solution, F - With Ce 3+ When they meet, they will bind to Ce through coordination bonds 3+Combine to form [CeF x ] 3-x The complex has a certain charge and has an electrostatic attraction with the silicon atoms in the glass component, which enables the complex to approach the silicon atoms. x ] 3-x After the complex combines with the silicon atom, due to F - The strong electronegativity will cause the electron cloud on the silicon atom to move to F through the induction effect. - The direction of the glass shifts, resulting in a decrease in the electron cloud density between the silicon atom and the adjacent oxygen atom, and a weakening of the bond energy of the silicon-oxygen bond. In an acidic environment, the hydrogen ions in the acid will also produce nucleophilic attacks on the glass. x ] 3-x The combination of the complex and silicon atoms will change the electron cloud density around the silicon atoms, which is more conducive to the nucleophilic attack of hydrogen ions, thereby accelerating the breaking of the silicon-oxygen bond. After the silicon-oxygen bond breaks, some soluble silicic acid or fluorosilicic acid and other products will be formed. These products will be carried away with the flow of the acid solution, so that new silicon atoms are continuously exposed on the glass surface and continue to react with the complex and acid, thereby accelerating the overall corrosion process of the glass and providing the core chemical power for high-precision through-hole production.

[0017] The silicon-oxygen bond is represented by Si-O-Si. When [CeF x ] 3-x After the complex combines with the silicon atom, an intermediate binding state is formed, which causes the electron cloud density around the silicon atom to change. The reaction is dynamically reversible, but it will proceed in a specific direction under subsequent conditions. In an acidic environment, hydrogen ions will carry out a nucleophilic attack on the above-mentioned intermediate binding state to form an unstable intermediate state. Similarly, this is also a dynamic equilibrium process, but it will proceed in the direction of the product under an etching environment. Eventually, the silicon-oxygen bond breaks, producing Si-OH (silanol group) and Si-F (silicon-fluorine bond compound). Because the product will be carried away by the solution, etc., the reaction is pushed to continue to the right, so this reaction is irreversible. Formation of silicic acid: The silanol group will react further. In an acidic environment, the silanol group reacts with hydrogen ions to form silicic acid. The simplified reaction formula is Si-OH+H + → H2SiO3. Formation of Fluorosilicic Acid: Silicon-fluorine compounds react with components in the solution. Assuming water is present, the simplified reaction equation for this reaction with water is 3Si-F + 3H2O → H2SiF6 + 2H2SiO3, forming soluble products such as fluosilicic acid. These soluble products are carried away by the flow of the acid solution, continuously exposing new silicon atoms on the glass surface. These continue to react with the complex and acid in a similar manner, accelerating the overall corrosion process of the glass.

[0018] On the other hand, the present invention provides a method for manufacturing the above-mentioned UV-sensitive alkali-free glass substrate. After uniformly mixing the various components, the components are sequentially melted, formed, and annealed to obtain a glass substrate. The glass substrate is exposed to UV light with a wavelength of 300-330 nm, and the exposure time is adjusted according to the exposure energy and the size of the glass substrate. Subsequently, the exposed glass substrate is placed in an acidic solution for etching, and the etching time is determined according to the thickness of the glass substrate and the required through-hole size. The etched glass substrate is cleaned and dried to remove residual etching solution and impurities, and then sintered to obtain the UV-sensitive alkali-free glass substrate.

[0019] Preferably, the components are placed in a high-speed mixer and stirred for 40-60 minutes. With the help of the strong stirring of the high-speed mixer, the components are ensured to be evenly dispersed, and local differences in the performance of the glass substrate due to agglomeration or uneven distribution of raw materials are prevented, thereby ensuring consistent and stable overall performance.

[0020] Preferably, the uniformly mixed raw materials are put into an electric melting furnace for melting at a melting temperature of 1550-1650°C for 3-5 hours. During melting, inert gas protection is continuously introduced to prevent oxidation of the raw materials. At the same time, stirring is performed at a speed of 90-130 r / min to fully melt the raw materials and form high-quality glass liquid without bubbles.

[0021] Preferably, an overflow molding process is used to prepare the original glass substrate, and the melted glass liquid is transported to the overflow tank. The glass liquid slowly flows down along the two sides of the tank wall and converges at the bottom to form a glass substrate; the overflow tank temperature is controlled to 980-1080°C, and the pulling speed is 100-300m / h to ensure that the thickness error of the glass substrate is within ±0.08mm, meeting the requirements of electronic packaging for the thickness accuracy of the glass substrate and ensuring product consistency and reliability.

[0022] Preferably, the formed glass substrate is annealed in an annealing furnace at a temperature of 600-700°C for 1.8-2.8 hours at a cooling rate of 13-22°C / hour. Annealing effectively eliminates residual stress within the glass, improving its mechanical strength and stability. This prevents cracking or deformation caused by stress concentration during subsequent processing and ensures the quality and performance of the glass substrate.

[0023] Preferably, the exposure energy is 220-380 mJ / cm 2 .

[0024] Preferably, during exposure, the exposure area is controlled by a mask, and silver fluoride and cerium tetrafluoride decompose under ultraviolet light to produce Ce 3+ 、Ag + and F - , forming a latent image and determining the etching pattern or through-hole position.

[0025] Preferably, the acidic solution is a hydrochloric acid solution.

[0026] Preferably, the sintering temperature is 530-630°C and the sintering time is 0.9-1.9 hours. High-temperature sintering can further stabilize the through-hole structure, enhance the overall strength of the glass substrate, remove residual defects, and obtain a UV-sensitive alkali-free glass substrate with high-precision through-holes, enabling its reliable application in the field of electronic packaging.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The UV-sensitive alkali-free glass substrate and its manufacturing method of the present invention improve the efficiency and precision of through-hole production. Compared with traditional mechanical drilling, chemical etching and laser drilling technologies, the method of the present invention simplifies the process flow and reduces the dependence on high-precision equipment, thereby reducing production costs and is expected to promote the further development of semiconductor packaging technology.

[0029] 2. The present invention utilizes the F produced by the photosensitizer under ultraviolet light - With Ce 3+ The formed complex effectively promotes the breaking of silicon-oxygen bonds, allowing the glass surface to evenly and quickly expose new silicon atoms to react with acid, thereby achieving efficient and precise through-hole production in UV-sensitive alkali-free glass substrates.

[0030] 3. The present invention ensures the uniformity and consistency of the thickness of the glass substrate and the aperture of the through-hole by precisely controlling various process parameters during the manufacturing process, thus meeting the high requirements of electronic packaging for precision and reliability.

[0031] 4. Compared with traditional etching processes, the photosensitive etching method adopted in the present invention reduces pollution to the environment and is more in line with the development trend of green manufacturing. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0033] Example 1

[0034] The UV-sensitive alkali-free glass substrate of this embodiment includes the following components in percentage by mass: SiO2 63%, B2O 39%, Al2O3 12%, BaO 3%, MgO 2%, CaO 2%, SrO 2%, ZnO 3%, SnO2 1%, AgF 1%, and CeF4 2%.

[0035] Example 2

[0036] The UV-sensitive alkali-free glass substrate of this embodiment includes the following components in percentage by mass: SiO2 63%, B2O 39%, Al2O3 12%, BaO 3%, MgO 1%, CaO 3%, SrO 3%, ZnO 2%, SnO2 1%, AgF 1.5%, and CeF4 1.5%.

[0037] Example 3

[0038] The UV-sensitive alkali-free glass substrate of this embodiment includes the following components in percentage by mass: SiO2 64%, B2O3 8%, Al2O3 12%, BaO 3%, MgO 2%, CaO 1%, SrO 2%, ZnO 4%, SnO2 1%, AgF 2%, and CeF4 1%.

[0039] Comparative Example 1

[0040] The alkali-free glass substrate of Comparative Example 1 includes the following components in percentage by mass: SiO2 65%, B2O 39%, Al2O3 12%, BaO 3%, MgO 2%, CaO 2%, SrO 2%, ZnO 3%, SnO2 1%, and AgF 1%.

[0041] Comparative Example 2

[0042] The alkali-free glass substrate of Comparative Example 2 comprises the following components in percentage by mass: SiO2 64%, B2O 39%, Al2O3 12%, BaO 3%, MgO 2%, CaO 2%, SrO 2%, ZnO 3%, SnO2 1%, CeF4 2%

[0043] Comparative Example 3

[0044] The alkali-free glass substrate of Comparative Example 3 includes the following components in mass percentage: SiO2 62%, B2O3 8%, Al2O3 10%, BaO 3%, MgO 2%, CaO 2%, SrO 2%, ZnO 3%, SnO2 1%, AgF 3.5%, and CeF4 3.5%.

[0045] Comparative Example 4

[0046] The UV-sensitive alkali-free glass substrate of Comparative Example 4 includes the following components in percentage by mass: SiO2 63%, B2O 39%, Al2O3 12%, BaO 3%, MgO 2%, CaO 2%, SrO 2%, ZnO 3%, SnO2 1%, AgF 0.5%, and CeF4 2.5%.

[0047] Comparative Example 5

[0048] The UV-sensitive alkali-free glass substrate of Comparative Example 5 includes the following components in mass percentage: SiO2 63%, B2O 39%, Al2O3 12%, BaO 3%, MgO 2%, CaO 2%, SrO 2%, ZnO 3%, SnO2 1%, AgF 2.5%, and CeF4 0.5%.

[0049] The method for manufacturing the alkali-free glass substrate of Examples 1-3 and Comparative Examples 1-5 comprises the following steps:

[0050] S1 Raw material mixing: Mix the components in a high-speed mixer for 50 minutes to obtain a uniformly mixed raw material;

[0051] S2 smelting: put the mixed raw materials into the electric melting furnace for smelting at 1600℃ for 4 hours, with argon protection in the furnace and stirring at 110r / min;

[0052] S3 molding: Using overflow molding technology, the overflow tank temperature is controlled at 1030 ° C, the pulling speed is 200 m / h, and the glass substrate with a thickness of 0.45 mm is produced;

[0053] S4 sends the formed glass substrate into an annealing furnace for annealing at 650°C for 2.2 hours with a cooling rate of 17°C / h;

[0054] S5: After cleaning and drying the annealed glass substrate, the mask is closely attached to the glass substrate and the UV light with a wavelength of 320nm and a power of 300mJ / cm 2 Energy exposure 35s;

[0055] S6: etching the glass substrate in a 6 wt.% hydrochloric acid solution for 20 min;

[0056] In S6 , the etched glass substrate is cleaned and dried, and then sintered at 580° C. for 1.5 hours to obtain an alkali-free glass substrate having through holes.

[0057] The performance of the alkali-free glass substrates of Examples 1-3 and Comparative Examples 1-5 was tested, and the test results are shown in Table 1:

[0058] Table 1 Performance test results of alkali-free glass substrates of Examples 1-3 and Comparative Examples 1-5

[0059] Test item Mask aperture (μm) Actual aperture (μm) Aperture accuracy (μm) Example 1 50 49-53 ±3 Example 2 50 46-51 ±4 Example 3 50 44-49 -6 Comparative Example 1 50 40-45 -10 Comparative Example 2 50 42-46 -8 Comparative Example 3 50 58-62 +12 Comparative Example 4 50 68-89 +39 Comparative Example 5 50 23-29 -27

[0060] It can be seen from Table 1 that, compared with Comparative Example 1, when the UV-sensitive alkali-free glass substrates of Examples 1-3 are irradiated with UV light, AgF and CeF4 decompose to produce a certain amount of F - , these F - In acidic solution with Ce 3+ Formation of [CeFx ] 3-x The complex can effectively promote the breaking of silicon-oxygen bonds, so that new silicon atoms are continuously exposed on the glass surface to react with acid, thereby achieving glass corrosion and forming through holes. Although CeF4 is not added in Comparative Example 1, F4 generated by the decomposition of AgF under ultraviolet light - It can still react with certain components in the glass (such as trace metal ions or other impurities), affecting the stability of the silicon-oxygen bond to a certain extent, so that the silicon-oxygen bond can also break under the nucleophilic attack of the acid in the acidic solution. However, this reaction is relatively weak and lacks effective control, resulting in poor precision of the formed through-holes. And compared with Examples 1-3, it can be seen that with the increase of Ce 3+ The content decreases, and the pore size also becomes smaller. In Comparative Example 2, no AgF is added, and the pore size of the glass substrate is small. This is because the silver atoms generated after ultraviolet light irradiation form some tiny active sites inside the glass. These sites will have a certain impact on the local structure and performance of the glass, providing a certain active basis for subsequent reactions. In Comparative Example 3, the amount of photosensitizer added is too much, and too much photosensitizer will produce a large amount of F after ultraviolet light irradiation. - , resulting in out-of-control etching reaction, failure to form regular through-holes, and excessively large and uneven through-hole sizes. In Comparative Examples 4-5, the mass ratio of silver fluoride to cerium tetrafluoride was too large or too small, resulting in the decomposition of F under ultraviolet light. - or Ag + Relatively more, compared with Ce 3+ The formed complex [CeF x ] 3-x The more silicon oxides are present, the stronger the breaking effect of silicon-oxygen bonds is. During the etching process, the glass corrodes faster, and the aperture of the formed through-holes is larger and uneven.

[0061] In summary, the present invention can efficiently and accurately produce high-quality through holes on an ultraviolet-sensitive alkali-free glass substrate, and has broad application prospects in the fields of electronic packaging and the like.

Claims

1. UV-sensitive alkali-free glass substrate, characterized in that: The invention comprises the following components in percentage by mass: 62-72% silicon dioxide, 8-12% boron trioxide, 10-16% aluminum oxide, 2-5% barium oxide, 1-3% magnesium oxide, 1-3% calcium oxide, 1-3% strontium oxide, 2-5% zinc oxide, 0.5-1.5% tin dioxide and 2-4% photosensitizer, wherein the photosensitizer is silver fluoride and cerium tetrafluoride in a mass ratio of (1-2):(1-2).

2. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 1, wherein: After the components are evenly mixed, they are melted, formed, and annealed in sequence to obtain a glass substrate. The glass substrate is exposed to ultraviolet light with a wavelength of 300-330nm, and then the exposed glass substrate is placed in an acidic solution for etching. The etched glass substrate is cleaned, dried, and then sintered to obtain a UV-sensitive alkali-free glass substrate.

3. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 2, wherein: Place all components in a high-speed mixer and stir for 40-60 minutes.

4. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 2, wherein: The uniformly mixed raw materials are put into an electric melting furnace for melting at a temperature of 1550-1650°C for 3-5 hours. During melting, inert gas protection is continuously introduced and stirring is performed at a speed of 90-130 r / min.

5. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 2, wherein: The glass substrate original sheet is prepared by overflow molding process, the overflow tank temperature is controlled at 980-1080℃, and the pulling speed is 100-300m / h.

6. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 5, wherein: The formed glass substrate is sent to an annealing furnace for annealing at a temperature of 600-700°C, a time of 1.8-2.8 hours, and a cooling rate of 13-22°C / h.

7. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 2, wherein: Exposure energy is 220-380mJ / cm 2 .

8. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 2, wherein: During exposure, the exposure area is controlled by the mask.

9. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 2, wherein: The acidic solution is hydrochloric acid solution.

10. The method for manufacturing an ultraviolet-sensitive alkali-free glass substrate according to claim 2, wherein: The sintering temperature is 530-630°C, and the sintering time is 0.9-1.9h.