Low dielectric loss glass and preparation method thereof

Abstract

The invention relates to the technical field of glass, and particularly discloses low dielectric loss glass and a preparation method thereof, the low dielectric loss glass comprises the following components by weight: 65%-70% of SiO2, 6%-11% of B2O3, 10%-15% of CaF2 + MgF2, 5%-10% of Al2O3, 1%-3% of ZrO2, 1%-3% of Na2O, 1%-10% of RE2O3 and 0.1%-2% of Li2O. The low-dielectric-loss glass provided by the invention shows excellent electrical performance in high-frequency application, can effectively reduce signal loss, and is suitable for microwave communication equipment, a high-frequency circuit substrate, a radio frequency device (such as an antenna and a filter), a photoelectric integrated circuit and other application scenes requiring low dielectric constant and low dielectric loss under a high-frequency condition; the invention provides a new choice for research and development of high-performance electronic devices, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of glass, and in particular to low dielectric loss glass and a preparation method thereof. Background Art

[0002] In recent years, the rapid development of informatization and digitalization has driven the demand for more powerful computing capabilities for artificial intelligence and big data cloud computing. Consequently, semiconductor circuits are becoming increasingly integrated, placing new demands on packaging technology. Advanced packaging technologies offer higher I / O density, faster signal transmission speeds, and improved electrical and thermal performance. While improving chip performance, they also reduce power consumption and size, enhancing reliability and production efficiency.

[0003] The key to chip packaging lies in the number of wafers mounted on the chip substrate. The greater the number, the more transistors a chip can hold, resulting in greater functionality and improved performance. Therefore, accommodating more transistors within a limited footprint has become a constant pursuit for the industry. Currently, the most popular chip substrate is an organic material substrate, which has been used in chip packaging for many years due to its ease of processing and low production cost. With the increasing global demand for computing power and the continued development of advanced packaging technologies such as 2.5D / 3D and chiplets, chip requirements for signal transmission speed, power transmission efficiency, and substrate stability are also increasing. The plastic substrates (organic material substrates) currently used by the industry are reaching their capacity limits. Their relatively rough surface can affect the inherent performance of ultra-fine circuits, and in advanced packaging, they face issues such as solder joint reliability and package heat dissipation. Furthermore, organic materials can shrink or warp during the chip manufacturing process, leading to chip defects. As more silicon chips are packaged on plastic substrates, the risk of warping increases. Therefore, traditional organic material substrates are no longer able to meet the packaging requirements of high-performance chips.

[0004] In recent years, through-glass via (TGV) technology has become a research hotspot in the semiconductor industry. Glass substrates offer significant mechanical, physical, and optical advantages over traditional organic substrates. Furthermore, glass offers the following unique properties: Excellent electrical performance: Glass substrates can effectively reduce power loss and energy consumption during signal transmission, significantly enhancing chip transmission efficiency and computing power, improving chip performance. High flatness: The unique flatness of glass substrates significantly increases the depth of focus of photolithography, significantly increasing interconnect density between chips. The number of openings on a glass substrate with the same surface area far exceeds that on an organic substrate, allowing the spacing between TGVs to be less than 100μm, increasing interconnect density by more than 10 times. High-temperature resistance: Glass substrates offer enhanced thermal and mechanical stability, with a similar thermal expansion coefficient to that of the chip, making them less susceptible to deformation issues such as warping and cracking at high temperatures, thereby increasing chip reliability. Glass substrates can enable larger chip packages to accommodate more transistors. According to statistics, a glass substrate can accommodate 50% more transistors, significantly increasing packaging density. Therefore, glass substrates are more suitable for high-speed signal interconnection applications, which can reduce interconnection loss and distortion and increase signal transmission rate.

[0005] At present, TGV uses high-quality borosilicate glass and quartz glass as substrates, and realizes 3D interconnection through advanced technologies such as seed layer sputtering, electroplating filling, chemical mechanical planarization, RDL rewiring, and bump process. In various applications in the field of advanced packaging, tens of thousands of TGVs with a diameter of 10μm-100μm are usually required on each wafer and metallized to obtain the required conductivity. With the rapid development of wireless communication technology, especially in 5G and future communication technologies, higher requirements are placed on the dielectric constant and dielectric loss of glass materials under some specific high-frequency application conditions. The high frequency refers to a frequency exceeding 10GHz, even exceeding 20GHz, even exceeding 45GHz, and even exceeding 70GHz. The high-frequency applications include but are not limited to antenna devices, electronic packaging, filters, autonomous driving radar systems, high-frequency sensing and other fields.

[0006] Conventional glass materials have problems with dielectric loss and high dielectric constant in high-frequency applications, resulting in signal attenuation and energy loss. Therefore, it is particularly important to develop a low-dielectric-loss glass material with low dielectric loss and low dielectric constant at high frequencies. Summary of the Invention

[0007] In view of the problems of dielectric loss and high dielectric constant of traditional glass materials in high-frequency applications in the prior art, the present invention provides a low dielectric loss glass and a preparation method thereof.

[0008] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0009] A low dielectric loss glass comprises the following components by weight: SiO2 65%-70%, B2O3 6%-11%, CaF2+MgF2 10%-15%, Al2O3 5%-10%, ZrO2 1%-3%, Na2O 1%-3%, RE2O3 1%-10% and Li2O 0.1%-2%.

[0010] Compared with the prior art, the low dielectric loss glass provided by the present invention has a higher content of SiO2 (65%-70%) as a glass network former, which constructs a stable glass skeleton structure, reduces the polarization phenomenon inside the glass, and thus reduces the dielectric loss; the addition of B2O3 (6%-11%) further optimizes the glass network, which can effectively reduce the electronic polarization and ionic polarization of the glass, and cooperates with SiO2 to further improve the low dielectric properties of the glass, ensuring that the energy loss of the signal is maintained at a low level during high-frequency and high-speed signal transmission, greatly improving the speed and quality of signal transmission; the introduction of CaF2+MgF2 can effectively reduce the glass The thermal expansion coefficient makes the glass more dimensionally stable when the temperature changes; Al2O3 can enhance the glass network structure and increase the Young's modulus of the glass; RE2O3 and ZrO2 can aggregate anion clusters in the glass. Under the action of the electric field, the glass network structure changes due to this agglomeration behavior, which causes the degree of distortion of the electron cloud during the application of the external electric field to be significantly suppressed. At the same time, the kinetic process of the migration of foreign ions along the direction of the electric field is hindered, and the difficulty of migration is significantly increased, which also makes the migration of foreign ions along the direction of the electric field more difficult, thereby reducing the dielectric constant of the glass, and also improving the melting and clarification effect of the glass and increasing the Young's modulus of the glass.

[0011] Through specific composition design, the present invention enables the glass to have excellent low dielectric loss performance, good thermal stability, a suitable thermal expansion coefficient and outstanding mechanical properties. The prepared glass is suitable for antenna devices, electronic packaging, filters, autonomous driving radar systems, high-frequency sensing and other fields, and has high potential application value.

[0012] Specifically, the design principles of each component in the present invention are as follows:

[0013] Silicon dioxide is a glass-forming oxide, forming an irregular continuous network with silicon-oxygen tetrahedral structural units, which serves as the skeleton of the glass. If the SiO2 content is too low, the integrity of the glass network will be poor, the migration of foreign ions within the glass will become easier, and the ion displacement polarization and orientation polarization of polar bonds will increase, resulting in electromagnetic signal absorption and a subsequent decrease in electromagnetic wave transmittance. At the same time, the glass strength decreases and the chemical stability of the glass deteriorates. If the SiO2 content is too high, the glass will be difficult to melt, with high viscosity, difficulty in clarifying and homogenizing, and high production costs. Therefore, the present invention limits the SiO2 content to 65%-70%.

[0014] The addition of MgF2 and CaF2 to the glass composition of the present invention effectively reduces the glass's high-temperature viscosity, thereby improving its meltability and formability, facilitating manufacturing, and contributing to enhanced water resistance and chemical stability. However, excessive MgF2 and CaF2 content can lead to glass network fractures and deteriorate dielectric properties. The present invention employs a 10%-15% MgF2 + CaF2 content.

[0015] The Al2O3 added in the present invention is an intermediate oxide that can reduce the crystallization tendency of glass and increase its Young's modulus. Because aluminum oxide tetrahedra are more stable than boron oxide tetrahedra, aluminum ions in the glass structural unit preferentially acquire free oxygen to form aluminum oxide tetrahedra. Excess free oxygen then reacts with boron oxide triangles to transform into boron oxide tetrahedra. Therefore, the aluminum oxide content cannot be too high. Therefore, the present invention controls the addition of Al2O3 to between 5% and 10%.

[0016] The RE2O3 and ZrO2 added in the present invention can aggregate anion clusters in the glass, effectively reducing the degree of deformation of the electron cloud in the glass network structure under the influence of an external electric field. They also make the migration of external ions along the electric field more difficult, thereby reducing the dielectric constant of the glass. They can also improve the melting and clarification of the glass and increase the Young's modulus of the glass. However, large amounts of RE2O3 and ZrO2 added in the present invention can cause crystallization of the glass. Therefore, the amount of RE2O3 added in the present invention is controlled to 1%-10% and 1%-3% respectively.

[0017] Li2O and Na2O are alkali metal oxides that can improve the melting and forming properties of glass and lower its liquidus temperature. However, alkali metal oxides can easily loosen the glass structure, increasing the dielectric constant and dielectric loss. Therefore, the present invention limits the Li2O content to 0.1%-2% and the Na2O content to 1%-3%.

[0018] Preferably, the content of CaF2 is 4%-5%, and the content of MgF2 is 5%-6%.

[0019] Preferably, the RE2O3 is one or more of La2O3, Y2O3, Ga2O3, Ce2O3 or Nd2O3.

[0020] Furthermore, the low dielectric loss glass has a dielectric constant of less than 4.2 at a frequency of 10 GHz, a dielectric loss of less than 0.002 at a frequency of 10 GHz, a dielectric strength greater than 25 kV / mm, and a thermal expansion coefficient of (4-6)×10 -6 / K.

[0021] The present invention also provides a method for preparing the above-mentioned low dielectric loss glass, which comprises at least the following steps:

[0022] Step a, weighing each component according to the designed ratio of the low dielectric loss glass, and mixing the weighed components uniformly to obtain a mixture;

[0023] Step b, heating and melting the mixture, removing bubbles, and obtaining molten glass;

[0024] Step c: shaping and annealing the molten glass to obtain low dielectric loss glass.

[0025] The preparation method is simple to operate, does not require complicated steps, does not require special equipment, is low in cost, and is suitable for industrial large-scale production.

[0026] Preferably, in step b, the melting temperature is 1500° C.-1700° C., and the melting time is 3 h-8 h.

[0027] Preferably, in step c, the melting temperature is 1650° C. and the melting time is 5 hours.

[0028] The optimal melting temperature and time can effectively promote the rapid melting and mixing of the raw materials.

[0029] For example, the raw materials may be melted by using a method of full oxygen combustion + electric melting.

[0030] Preferably, in step c, the annealing temperature is 500° C.-600° C., and the annealing time is 1 h-3 h.

[0031] Preferably, in step c, the annealing temperature is 550° C. and the annealing time is 2 h.

[0032] It should be noted that the present invention also includes a process of mechanically processing the glass after annealing. The mechanical processing can adopt various conventional mechanical processing methods in the field, such as cutting, grinding, polishing, etc. The glass prepared by mechanical processing can also be subjected to chemical strengthening treatment, etc., and conventional existing technologies in the field can be used. The present invention does not make special limitations.

[0033] Preferably, after annealing, the method further comprises the steps of grinding and polishing the obtained glass.

[0034] The low-dielectric-loss glass provided by the present invention exhibits excellent electrical properties in high-frequency applications and can effectively reduce signal loss. It is suitable for application scenarios such as microwave communication equipment, high-frequency circuit substrates, radio frequency devices (such as antennas and filters), and optoelectronic integrated circuits that require low dielectric constant and low dielectric loss under high-frequency conditions. It provides a new option for the research and development of high-performance electronic devices and has broad application prospects. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Example 1

[0037] An embodiment of the present invention provides a low dielectric loss glass, the weight percentage of which is as follows:

[0038] SiO2 65%, B2O3 11%, CaF2 5%, MgF2 5%, Al2O3 8%, ZrO2 1%, Na2O1%, La2O31%, Y2O3 2% and Li2O 1%.

[0039] The preparation steps of the above-mentioned low dielectric loss glass are as follows:

[0040] Step a, weighing each component according to the designed ratio of the low dielectric loss glass, and mixing the weighed components uniformly to obtain a mixture;

[0041] Step b, adding the mixture into a platinum-rhodium alloy crucible, heating to 1650° C. and maintaining the temperature for 5 hours, and stirring with a platinum rod to expel bubbles to obtain molten glass;

[0042] Step c: pouring the molten glass into a stainless steel mold for forming, then placing the formed glass into an annealing furnace, annealing at 550° C. for 2 hours, turning off the power, and cooling the furnace to room temperature to obtain low dielectric loss glass.

[0043] Example 2

[0044] An embodiment of the present invention provides a low dielectric loss glass, the weight percentage of which is as follows:

[0045] SiO2 68%, B2O3 6%, CaF2 6%, MgF2 4%, Al2O3 7%, ZrO2 1.5%, Na2O1%, Y2O36% and Li2O 0.5%.

[0046] The preparation steps of the above-mentioned low dielectric loss glass are as follows:

[0047] Step a, weighing each component according to the designed ratio of the low dielectric loss glass, and mixing the weighed components uniformly to obtain a mixture;

[0048] Step b, adding the mixture into a platinum-rhodium alloy crucible, heating to 1500° C. and keeping the temperature for 8 hours, and stirring with a platinum rod to expel bubbles, to obtain molten glass;

[0049] Step c: pouring the molten glass into a stainless steel mold for forming, then placing the formed glass into an annealing furnace, annealing at 530° C. for 3 hours, turning off the power, and cooling the furnace to room temperature to obtain low dielectric loss glass.

[0050] Example 3

[0051] An embodiment of the present invention provides a low dielectric loss glass, the weight percentage of which is as follows:

[0052] SiO2 70%, B2O3 7%, CaF2 9%, MgF2 1%, Al2O3 5%, ZrO2 3%, Na2O3%, Ce2O31.9% and Li2O 0.1%.

[0053] The preparation steps of the above-mentioned low dielectric loss glass are as follows:

[0054] Step a, weighing each component according to the designed ratio of the low dielectric loss glass, and mixing the weighed components uniformly to obtain a mixture;

[0055] Step b, adding the mixture into a platinum-rhodium alloy crucible, heating to 1700° C. and keeping the temperature for 3 hours, and stirring with a platinum rod to expel bubbles, to obtain molten glass;

[0056] Step c: pouring the molten glass into a stainless steel mold for forming, then placing the formed glass into an annealing furnace, annealing at 570° C. for 2 hours, turning off the power, and cooling the furnace to room temperature to obtain low dielectric loss glass.

[0057] Example 4

[0058] An embodiment of the present invention provides a low dielectric loss glass, the weight percentage of which is as follows:

[0059] SiO2 65%, B2O3 6%, CaF2 9%, MgF2 6%, Al2O3 10%, ZrO2 1%, Na2O1%, Ga2O31% and Li2O 1%.

[0060] The preparation steps of the above-mentioned low dielectric loss glass are as follows:

[0061] Step a, weighing each component according to the designed ratio of the low dielectric loss glass, and mixing the weighed components uniformly to obtain a mixture;

[0062] Step b, adding the mixture into a platinum-rhodium alloy crucible, heating to 1600° C. and keeping the temperature for 6 hours, and stirring with a platinum rod to expel bubbles, to obtain molten glass;

[0063] Step c: pouring the molten glass into a stainless steel mold for forming, then placing the formed glass into an annealing furnace, annealing at 500° C. for 3 hours, turning off the power, and cooling the furnace to room temperature to obtain low dielectric loss glass.

[0064] Example 5

[0065] An embodiment of the present invention provides a low dielectric loss glass, the weight percentage of which is as follows:

[0066] SiO2 65%, B2O3 6%, CaF2 2%, MgF2 8%, Al2O3 5%, ZrO2 1%, Na2O1%, Y2O3 3%, Nd2O3 7% and Li2O 2%.

[0067] The preparation steps of the above-mentioned low dielectric loss glass are as follows:

[0068] Step a, weighing each component according to the designed ratio of the low dielectric loss glass, and mixing the weighed components uniformly to obtain a mixture;

[0069] Step b, adding the mixture into a platinum-rhodium alloy crucible, heating to 1680° C. and maintaining the temperature for 7 hours, and stirring with a platinum rod to expel bubbles to obtain molten glass;

[0070] Step c: pouring the molten glass into a stainless steel mold for forming, then placing the formed glass into an annealing furnace, annealing at 600° C. for 1 hour, turning off the power, and cooling the furnace to room temperature to obtain low dielectric loss glass.

[0071] Comparative Example 1

[0072] The only difference between this comparative example and Example 1 is that the amounts of MgF2 and CaF2 in Example 1 are reduced, and the amounts of Al2O3 and Y2O3 are increased. The specific components are as follows:

[0073] SiO2 65%, B2O3 11%, CaF2 2%, MgF2 2%, Al2O3 10%, ZrO2 1%, Na2O1%, La2O31%, Y2O3 6% and Li2O 1%.

[0074] The preparation method of the above glass is exactly the same as that in Example 1 and will not be repeated here.

[0075] Comparative Example 2

[0076] The only difference between this comparative example and Example 1 is that the amount of MgF2 and CaF2 in Example 1 is increased, and the amount of SiO2 and Al2O3 is reduced. The specific components are as follows:

[0077] SiO2 60%, B2O3 11%, CaF2 8%, MgF2 8%, Al2O3 7%, ZrO2 1%, Na2O1%, La2O31%, Y2O3 2% and Li2O 1%.

[0078] The preparation method of the above glass is exactly the same as that in Example 1 and will not be repeated here.

[0079] According to ASTM D150, the glasses prepared in Examples 1-5 and Comparative Examples 1-2 were cut, ground, and polished. The samples were then cleaned with deionized water and dried to produce 100 mm × 100 mm × 0.5 mm glass samples. The dielectric loss of these samples was measured using a dielectric constant meter. The results are shown in Table 1.

[0080] Table 1

[0081]

[0082] The performance test method of the above low dielectric glass is as follows:

[0083] (1) Thermal expansion coefficient test: GB / T 16920-2015 Determination of the average linear thermal expansion coefficient of glass.

[0084] (2) Dielectric loss test: SJ / T 11043-1996 Test method for high-frequency dielectric loss and dielectric constant of electronic glass.

[0085] (3) Dielectric strength test: GB / T 1408.1-2006 Electric strength test methods of insulating materials Part 1: Tests at power frequency.

[0086] In summary, the present invention, through the combined effects of various components, enables the prepared glass products to have low dielectric loss and dielectric constant at high frequencies, and has low raw material costs, which facilitates large-scale production. It is suitable for high-frequency electronic devices and microwave communication equipment, providing a new option for the research and development of high-performance electronic devices and has broad application prospects.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A low dielectric loss glass, characterized in that: Its components by weight are: SiO2 65%-70%, B2O3 6%-11%, CaF2+MgF2 10%-15%, Al2O3 5%-10%, ZrO2 1%-3%, Na2O 1%-3%, RE2O3 1%-10% and Li2O 0.1%-2%.

2. The low dielectric loss glass according to claim 1, wherein: The content of CaF2 is 4%-5%, and the content of MgF2 is 5%-6%.

3. The low dielectric loss glass according to claim 1, wherein: The RE2O3 is one or more of La2O3, Y2O3, Ga2O3, Ce2O3 or Nd2O3.

4. The low dielectric loss glass according to claim 1, wherein: The low dielectric loss glass has a dielectric constant of less than 4.2 at a frequency of 10 GHz, a dielectric loss of less than 0.002 at a frequency of 10 GHz, a dielectric strength greater than 25 kV / mm, and a thermal expansion coefficient of (4-6)×10 -6 / K.

5. The method for preparing the low dielectric loss glass according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step a, weighing each component according to the designed ratio of the low dielectric loss glass, and mixing the weighed components uniformly to obtain a mixture; Step b, heating and melting the mixture, removing bubbles, and obtaining molten glass; Step c: shaping and annealing the molten glass to obtain low dielectric loss glass.

6. The method for preparing low dielectric loss glass according to claim 5, wherein: In step b, the melting temperature is 1500° C.-1700° C., and the melting time is 3 h-8 h.

7. The method for preparing low dielectric loss glass according to claim 5, wherein: In step c, the melting temperature is 1650° C. and the melting time is 5 hours.

8. The method for preparing low dielectric loss glass according to claim 5, wherein: In step c, the annealing temperature is 500° C.-600° C., and the annealing time is 1 h-3 h.

9. The method for preparing low dielectric loss glass according to claim 5, wherein: In step c, the annealing temperature is 550° C. and the annealing time is 2 h.

10. The method for preparing low dielectric loss glass according to claim 5, wherein: After annealing, the method further comprises the steps of grinding and polishing the obtained glass.

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