Fluorine-containing coolant and use thereof

Abstract

This invention relates to the field of electrical functional materials technology, specifically to a fluorinated coolant and its applications. The general structural formula of the fluorinated coolant is CF3-[CR1R2]. m -[CR3R4] n -O-[(CR5R6)] p -C(R7R8) q -(CF2O) k ] t -CF3, where R1-R8 are independently -F and -C. X F 2X+1 The fluorinated coolant of this invention is a perfluoroether substance. By selecting specific groups and controlling the number and composition of substituents, a coolant with low dielectric constant, high volume resistivity and high breakdown voltage is obtained, which can be used in semiconductor, data center temperature control and other fields.

Description

Technical Field

[0001] This invention relates to the field of electrical functional materials technology, specifically to a fluorine-containing coolant and its applications. Background Technology

[0002] In temperature control applications such as semiconductors and data centers, temperature control solutions typically have multiple requirements, including viscosity, heat transfer capacity, chemical stability, environmental friendliness, and safety. Fluorinated coolants, currently widely used in the industry, offer advantages primarily due to their stable chemical properties, good heat transfer capacity, and safety as they have no flash point. Data center liquid cooling technology is rapidly evolving towards immersion solutions, with AI chips exceeding 1000W in power density. Traditional perfluoropolyether and hydrofluoroether coolants, due to their high dielectric constant (>2.5), are prone to causing high-frequency signal attenuation, making it difficult to meet the electrical signal stability requirements of 5G / 6G communication equipment. Furthermore, the temperature control liquid flows directly through equipment components, some of which are subjected to high voltages during operation to meet process requirements. If the temperature control liquid has a low breakdown voltage, liquid breakdown discharge can occur, leading to process failure and ultimately affecting overall production yield. Therefore, the insulation properties (breakdown voltage, volume resistivity) of coolant products are extremely important. However, commonly used fluorinated coolants currently struggle to balance high dielectric constant and high insulation. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention provides a coolant composition and its application.

[0004] This invention includes the following technical solutions:

[0005] On one hand, the present invention provides a fluorinated coolant, the general structural formula of which is CF3-[CR1R2]. m -[CR3R4] n -O-[(CR5R6) p -C(R7R8) q -(CF2O) k ] t -CF3, where R1-R8 are independently -F and -C. X F 2X+1 , m≥0, n≥0, p≥0, q≥0, k≥0, t≥0, X≥0, and all are integers.

[0006] Furthermore, the fluorinated coolant meets the following conditions:

[0007] CPI = 4 - 2.5 × -0.05σ, 2≤CPI≤4;

[0008] σ is an empirical parameter for the polarity of the substituent. ;

[0009] Rx and Ry are groups on the same carbon. If the two substituents Rx and Ry on the same carbon are the same, then σ(RxRy) = σ(Rx) = σ(Ry); if the two substituents Rx and Ry on the same carbon are different, then σ(RxRy) = σ(Rx) + σ(Ry).

[0010] σ(-F)=4, σ(-C) X F 2X+1 )= ;

[0011] S is the symmetry factor. If the two substituents on the same carbon are the same, then S = 0.6; if the two substituents on the same carbon are different, then S = 0.

[0012] Further, σ(-F)=4, σ(-CF3)=2, σ(-CF2CF3)=1.33, σ(-CF2CF2CF3)=1, σ(-CF2CF2CF2CF3)=0.8.

[0013] Furthermore, the dielectric constant of the fluorinated coolant is ≤3.0 (1KHz), and the volume resistivity is ≥5×10⁻⁶. 13 Ω·cm, breakdown voltage >40kV (2.45mm).

[0014] On the other hand, the present invention also provides the application of the above-mentioned fluorinated coolant in temperature control devices for semiconductors and data center servers.

[0015] The fluorinated coolant of the present invention is a perfluoroether substance. By selecting specific groups and controlling the number and composition of substituents, a coolant with low dielectric constant, high volume resistivity and high breakdown voltage can be obtained. It can be used in semiconductor, data center temperature control and other fields. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0017] This invention provides a fluorinated coolant, the general structural formula of which is CF3-[CR1R2]. m -[CR3R4] n -O-[(CR5R6) p -C(R7R8) q -(CF2O) k ] t-CF3, where R1-R8 are independently -F and -C. X F 2X+1 , m≥0, n≥0, p≥0, q≥0, k≥0, t≥0, X≥0, and all are integers.

[0018] The fluorinated coolant of the present invention is a perfluoroether substance. By selecting specific groups and controlling the number and composition of substituents, a coolant with low dielectric constant, high volume resistivity and high breakdown voltage can be obtained. It can be used in semiconductor, data center temperature control and other fields.

[0019] Specifically, in some embodiments of the present invention, the fluorinated coolant satisfies the following condition: CPI = 4 - 2.5 × -0.05σ, 2≤CPI≤4;

[0020] σ is an empirical parameter for the polarity of the substituent. ;

[0021] RxRy are groups on the same carbon atom, such as R1R2, R3R4, R5R6, R7R8; σ(-F)=4, this is the baseline value, σ(-C) X F 2X+1 )= As the carbon chain X increases, the polar contribution decreases. When X is 0, both groups on both sides are -F, and fluorine has high electronegativity, with a value of 4. If the two substituents Rx and Ry on the same carbon are the same, then σ(RxRy) = σ(Rx) = σ(Ry). Since the groups on both sides are the same, the symmetry is strong, and the results do not add up. If the two substituents Rx and Ry on the same carbon are different, then σ(RxRy) = σ(Rx) + σ(Ry). When the groups on both sides of the main chain are different, the symmetry deteriorates, the polarizability increases, and the polarity becomes the superposition of the polar contributions of the groups on both sides.

[0022] S is the symmetry factor. If the two substituents on the same carbon are identical, then S = 0.6. According to the symmetry cancellation effect, when two groups with the same electronegativity are spatially symmetrically distributed, their dipole moments are in opposite directions, reducing the overall polar contribution rate. Empirically, the polar contribution rate of such symmetrical substitution is about 40% of that of a single substituent. Therefore, the symmetry factor S = 0.6 is introduced (i.e., retaining 60% of the polar contribution). If the two substituents on the same carbon are different, then S = 0. Due to the differences in electronegativity and steric hindrance of different substituents, the dipole moment directions are unbalanced, and there is no cancellation effect in this case.

[0023] Specifically, in some embodiments of the present invention, σ(-F)=4, σ(-CF3)=2, σ(-CF2CF3)=1.33, σ(-CF2CF2CF3)=1, and σ(-CF2CF2CF2CF3)=0.8. When R is -F, the σ value is 4 (high symmetry, low polarizability); when R is -CF3, the σ value is 2 (steric hindrance suppresses dipole flipping); when R is -CF2CF3, the σ value is 1.33; when R is -CF2CF2CF3, the σ value is 1; and when R is -CF2CF2CF2CF3, the σ value is 0.8 (increased rigidity, reduced molecular chain segment motion).

[0024] Specifically, in some embodiments of the present invention, the dielectric constant of the fluorinated coolant is ≤3.0 (1KHz), and the volume resistivity is ≥5×10⁻⁶. 13 The breakdown voltage is >40kV (2.45mm) Ω·cm. This invention controls various properties of the coolant by regulating the general formula of fluorinated coolant. Specifically, for the dielectric constant, molecular polarizability is increased by controlling the oxygen atom density (k value), but the proportion of flexible segments needs to be limited by controlling the m, n, p, and q values; the greater the molecular polarity, the greater the dielectric constant. For the breakdown voltage, the propagation of electrical trees is suppressed synergistically by the main chain length (t value) and rigid units (m, n, p, q, k values); polar groups (such as dipoles) enhance electron scattering, suppressing electron avalanche and collisional ionization, thus slowing down the breakdown process. However, excessive molecular polarity can lead to treeing under the influence of an electric field, forming local charge accumulation, accelerating electrical tree growth, and causing a decrease in breakdown voltage. For volume resistivity, CRxRy segments (m, n, p, q values) can increase molecular symmetry and reduce ion migration channels; polar molecules easily form ion migration channels through hydrogen bonds or dipole-dipole interactions, reducing insulation. The fluorinated coolant of the present invention combines molecular structure and coolant performance, enabling the prediction of coolant performance based on the coolant's molecular structure.

[0025] On the other hand, the present invention also provides the application of the above-mentioned fluorinated coolant in temperature control devices for semiconductors and data center servers.

[0026] The fluorinated coolant of the present invention will be further described below with reference to specific embodiments.

[0027] Examples 1-24 and Comparative Examples 1-5 present fluorinated coolants with different molecular structures, as shown in Table 1.

[0028] Table 1

[0029]

[0030] The polarity of the substituents in each embodiment and comparative example is shown in Table 2.

[0031] Table 2

[0032]

[0033] The dielectric constant, volume resistivity, and breakdown voltage of the fluorinated coolants in each embodiment and comparative example were tested, among which:

[0034] Dielectric constant testing method: The test is conducted using an LCR digital bridge dielectric constant meter. The stainless steel sample test cup is cleaned and dried with anhydrous ethanol. After rinsing with the sample to be tested, the test begins. Approximately 50 mL of sample is measured and added to the lower sample cup (lower electrode). The lower sample cup is placed on the electrode base, and then the upper sample cup is slowly lowered in, ensuring that the position of the electrode insertion port and the lower cup opening does not change. Ensure that the conductive base and the outer surface of the lower cup are free of moisture or other contaminants. After connecting the electrodes and turning on the instrument, the test begins, and the capacitance test result C is recorded. The relative dielectric constant is calculated using C / X (where X is the empty cup capacitance).

[0035] Volume resistivity test method: Using a high insulation resistance meter, clean and dry the stainless steel sample test cup with anhydrous ethanol. After rinsing with the sample to be tested, begin the test. Measure 50 mL of sample into the lower sample cup (lower electrode) using a beaker. Place the lower sample cup on the electrode base, ensuring the cup opening mark faces the tester. Slowly lower the upper sample cup, ensuring the electrode insertion position and the lower cup opening position do not change. The conductive base and the outer surface of the lower cup must be free of moisture or other liquids. Secure the electrode, turn on the instrument, and begin the test. Adjust the test range until the pointer reads between 1 and 10, and record the resistance reading R. Calculate the resistivity using R*733.

[0036] Breakdown voltage test method: An insulation dielectric strength tester is used. After cleaning and drying the sample cup with anhydrous ethanol, ensure the electrode spacing meets requirements. Rinse the sample cup with the sample to be tested before starting the test. Add approximately 300 mL of sample to the sample cup, ensuring the sample liquid level completely covers the test electrodes. Place the sample cup into the test chamber, close the chamber's plastic cap, and turn on the instrument. Set the stirring, settling time, and number of tests. Click "Start Test" and record the average breakdown voltage based on the instrument output.

[0037] The qualified standards for fluorinated coolants are: dielectric constant ≤ 3.0 (1KHz), volume resistivity ≥ 5×10⁻⁶. 13 Ω·cm, breakdown voltage ≥40kV (2.45mm).

[0038] The test results for each embodiment and comparative example are shown in Table 3.

[0039] Table 3

[0040]

[0041] As can be seen from the test results in Table 3, the fluorinated coolant of the present invention can obtain a coolant with low dielectric constant, high volume resistivity or high breakdown voltage by selecting specific groups and controlling the number and composition of substituents; when the fluorinated coolant satisfies 2≤CPI≤4, a coolant with low dielectric constant, high volume resistivity or high breakdown voltage can be obtained.

[0042] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the nature and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention.

Claims

1. A fluorine-containing coolant, characterized in that, The general structural formula of the fluorinated coolant is CF3-[CR1R2]. m -[CR3R4] n -O-[(CR5R6) p -C(R7R8) q -(CF2O) k ] t -CF3, where R1-R8 are independently -F and -C. X F 2X+1 , m≥0, n≥0, p≥0, q≥0, k≥0, t≥0, X≥0, and all are integers.

2. The fluorinated coolant according to claim 1, characterized in that, The fluorinated coolant meets the following condition: CPI = 4 - 2.5 × -0.05σ, 2≤CPI≤4; σ is an empirical parameter for the polarity of the substituent. ; Rx and Ry are groups on the same carbon. If the two substituents Rx and Ry on the same carbon are the same, then σ(RxRy) = σ(Rx) = σ(Ry); if the two substituents Rx and Ry on the same carbon are different, then σ(RxRy) = σ(Rx) + σ(Ry). σ(-F)=4,σ(-C X F 2X+1 )= ; S is the symmetry factor. If the two substituents on the same carbon are the same, then S = 0.6; if the two substituents on the same carbon are different, then S = 0.

3. The fluorinated coolant according to claim 2, characterized in that, σ(-F)=4, σ(-CF3)=2, σ(-CF2CF3)=1.33, σ(-CF2CF2CF3)=1, σ(-CF2CF2CF2CF3)=0.

8.

4. The fluorinated coolant according to any one of claims 1-3, characterized in that, The dielectric constant of the fluorinated coolant is ≤3.0 (1KHz), and the volume resistivity is ≥5×10⁻⁶. 13 Ω·cm, breakdown voltage >40kV (2.45mm).

5. The application of the fluorinated coolant according to any one of claims 1-4 in temperature control devices for semiconductors and data center servers.

Images