Low-dielectric sioc ceramic powder, preparation method and application thereof

Abstract

This invention relates to the field of inorganic materials technology, and more particularly to a low-dielectric SiOC ceramic powder, its preparation method, and its applications. The low-dielectric SiOC ceramic powder provided by this invention possesses low dielectric properties and high insulation, with a dielectric loss tangent < 0.0010 and a surface resistivity > 4 × 10⁻⁶. 14 Ω, volume resistivity > 5 × 10 12 Ω, conductivity Ec < 10 μS / cm, low dielectric SiOC ceramic powder crystal form is amorphous phase, no carbon crystallization peak, whiteness < 5%, density ≥ 2.0 g / cm³ 3 The low-dielectric SiOC ceramic powder prepared by this invention possesses low dielectric properties and high insulation. Furthermore, the low-dielectric SiOC ceramic powder has an amorphous phase and no carbon crystallization peaks. The evaluation results of the examples meet the requirements for low-dielectric SiOC ceramic powder used in electronic-grade applications such as high-frequency and high-speed circuits and packaging.

Description

Technical Field

[0001] This invention relates to the field of inorganic materials technology, and in particular to a low-dielectric SiOC ceramic powder, its preparation method, and its application. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] SiOC (silicon oxide carbon) ceramics are a class of polymer-derived ceramics (PDCs) composed of elements such as Si, O, and C. Their structure is typically amorphous, and they possess the characteristics of tunable composition and diverse properties. This material combines low density, high mechanical strength, excellent thermal stability, and oxidation resistance, making it promising for applications in extreme environments such as aerospace and nuclear engineering.

[0004] In terms of electrical properties, the coefficient of thermal expansion of SiOC ceramics (typically about 4 × 10⁻⁶) is... -6 K -1 The compatibility of SiOC ceramics with silicon helps improve their interface stability in applications such as semiconductor packaging. Furthermore, their dielectric properties can be further tuned through composition control, porous structure design, and process optimization to achieve lower dielectric constants and dielectric losses while maintaining high mechanical properties (e.g., flexural strength up to nearly 400 MPa). These performance advantages make SiOC ceramics a promising candidate for applications in high-frequency communication systems, microelectronic packaging, and high-performance antenna substrates.

[0005] The prior art discloses a semiconductor packaging material that uses T-unit polysiloxane as starting material particles, and then heat-treats the polysiloxane particles under non-oxidizing gas or vacuum to carbonize the alkyl inside the particles and condense the silanols on the surface. Then, it is calcined at 800-1100℃ to condense the remaining silanols to obtain a black silica powder. This preparation method has the following problems: there is a lot of carbon residue, and the powder has many pores, which makes it easy to absorb water from the air. When this powder is used as a filler for substrate materials, it will cause the substrate materials to have a large dielectric loss. Summary of the Invention

[0006] In view of this, the present invention provides a low dielectric SiOC ceramic powder, its preparation method and application.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a method for preparing low-dielectric SiOC ceramic powder, comprising the following steps: (1) The organosiloxane powder a was heat-treated at 600-1400℃ under an inert atmosphere to obtain powder b; (2) Powder b is placed in an atmosphere with a certain oxygen content and heat-treated at 600-1200℃ to obtain powder c; (3) The agglomerates in the heat-treated powder c are broken up to obtain low dielectric SiOC ceramic powder d.

[0008] Furthermore, the general structural formula of the organosiloxane powder a is -RSiO3. - The number of R groups is 1, wherein the R group is a C1-6 hydrocarbon group; preferably, R is a C1-6 alkyl, C1-6 alkenyl, or phenyl group; more preferably, R is any one of methyl, ethyl, propyl, butyl, phenyl, vinyl, or propenyl groups.

[0009] Further, in step (1), the heating step of heat treatment 1 is as follows: heat up to 600-700℃ at 5-20℃ / min and hold for 2-4h; then continue to heat up to the target temperature at the same rate and hold for 4-8h.

[0010] Furthermore, the heating rate is 5-15℃ / min. The faster the heating rate, the more easily the carbon element in organic compound a cracks and turns black.

[0011] Furthermore, in step (1), the inert atmosphere is a nitrogen atmosphere or an argon atmosphere.

[0012] Heat treatment in an inert atmosphere can remove H and some C elements from the R-based powder, while transforming the remaining C elements from hydrocarbon groups into single amorphous phase particles. This step contributes to the formation of the crystalline phase and black color in SiOC ceramic powder. The heat treatment equipment is a common segmented atmosphere calcination device, such as an atmosphere furnace or vacuum sintering furnace.

[0013] Furthermore, in step (2), the heat treatment temperature is 600-1000℃.

[0014] Further, in step (2), the heating step of heat treatment 2 is as follows: heat up to 600-700℃ at 5-20℃ / min and hold for 2-4h; then continue to heat up to the target temperature at the same rate and hold for 4-8h.

[0015] Furthermore, in step (2), the heating rate is 5-15℃ / min.

[0016] Furthermore, in step (2), the atmosphere with a certain oxygen content is a mixture of oxygen and nitrogen, wherein the oxygen content by volume is 1-30%, preferably 5-20%. Through experiments, it has been found that controlling the oxygen content within this range can most effectively remove the carbon bonded to the surface, thereby reducing dielectric loss and improving insulation.

[0017] Step (2) involves partially reacting the carbon elements in powder b with carbon-containing gas to reduce dielectric loss while ensuring that the blackness remains basically unchanged compared to powder b. The equipment for heat treatment 2 is a common calcination equipment, such as a muffle furnace, a tube furnace, or a high-temperature and high-pressure sintering furnace.

[0018] Furthermore, in step (3), the depolymerization equipment is an air jet mill or a ball mill.

[0019] The deagglomeration process in step (3) avoids the agglomeration of SiOC ceramic powder, which can be fully dispersed when preparing SiOC ceramic blanks, reduce the generation of pores, and improve the density and yield of SiOC ceramics.

[0020] Secondly, the present invention provides low-dielectric SiOC ceramic powder prepared by the preparation method described in the first aspect.

[0021] Furthermore, the dielectric loss tangent is <0.0010; the surface resistivity is >4×10⁻⁶. 14 Ω, volume resistivity > 5 × 10 12 Ω; conductivity Ec < 10 μS / cm; the SiOC ceramic powder provided by this invention has low dielectric properties and high insulation.

[0022] Furthermore, the low-dielectric SiOC ceramic powder exhibits an amorphous phase with no carbon-containing crystallization peaks; whiteness <5% and density ≥2.0 g / cm³. 3 .

[0023] Thirdly, the present invention provides the application of the low dielectric SiOC ceramic powder described in the second aspect in electronic-grade scenarios; further, the electronic-grade scenarios include high-frequency high-speed circuits or packages.

[0024] Compared with the prior art, the present invention has achieved the following beneficial effects: This invention prepares low-dielectric SiOC ceramic powder by selecting specific raw materials and through a two-step heat treatment and depolymerization process. The low-dielectric SiOC ceramic powder prepared by this invention possesses low dielectric properties and high insulation, with a dielectric loss tangent < 0.0010 and a surface resistivity > 4 × 10⁻⁶. 14 Ω, volume resistivity > 5 × 10 12 Ω; electrical conductivity Ec < 10 μS / cm; and the low-dielectric SiOC ceramic powder has an amorphous phase with no carbon crystallization peaks; whiteness < 5%, density ≥ 2.0 g / cm³. 3The evaluation results of the embodiments meet the requirements of low dielectric SiOC ceramic powder for electronic-grade scenarios such as high-frequency and high-speed circuits and packaging. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0026] Figure 1 This is the XRD pattern of the low-dielectric SiOC ceramic powder prepared in Example 1 of this invention. Detailed Implementation

[0027] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0028] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0029] Example 1 In this embodiment, commercially available organosiloxane powder a1 is selected as the raw material, and the R group is phenyl.

[0030] Powder a1 is subjected to heat treatment 1 to obtain product b1. The specific operation of heat treatment 1 is as follows: the temperature is increased to 700℃ at a heating rate of 10℃ / min and held for 4h; then the temperature is increased to 1200℃ at the same heating rate and held for 4h, with argon atmosphere.

[0031] Product b1 is subjected to heat treatment 2 to obtain product c1. The specific operation of heat treatment 2 is as follows: the temperature is increased to 600℃ at a heating rate of 5℃ / min and held for 2 hours; then the temperature is increased to 900℃ at the same heating rate and held for 4 hours. The atmosphere is a mixture of oxygen and high-purity air with an oxygen volume ratio of 10%.

[0032] The product c1 was then depolymerized using a ball mill to obtain product d1. The grinding media was made of alumina, and the ratio of grinding media to material was 10:1 (mass ratio). The ball milling time was 30 minutes.

[0033] The XRD pattern of the low-dielectric SiOC ceramic powder prepared in this embodiment is shown below. Figure 1 As shown, from Figure 1 As can be seen from the above, the products of this invention are all amorphous phases of silicon dioxide and carbon.

[0034] Example 2 In this embodiment, commercially available organosiloxane powder a2 is selected as the raw material, and the R group is methyl.

[0035] Powder a2 is subjected to heat treatment 1 to obtain product b2. The specific operation of heat treatment 1 is as follows: heating to 600℃ at a heating rate of 8℃ / min and holding for 2h; then heating to 800℃ at the same heating rate and holding for 4h, with argon atmosphere.

[0036] Product b2 is subjected to heat treatment 2 to obtain product c2. The specific operation of heat treatment 2 is as follows: the temperature is increased to 600℃ at a heating rate of 8℃ / min and held for 2 hours; then the temperature is increased to 1000℃ at the same heating rate and held for 2 hours. The atmosphere is a mixture of oxygen and high-purity air, with an oxygen volume ratio of 5%.

[0037] The product c2 was then depolymerized using a ball mill to obtain product d2. The grinding media was made of alumina, and the ratio of grinding media to material was 8:1 (mass ratio). The ball milling time was 45 minutes.

[0038] Example 3 In this embodiment, commercially available organosiloxane powder a3 is selected as the raw material, and the R group is a vinyl group.

[0039] Powder a3 was subjected to heat treatment 1 to obtain product b3. The specific operation of heat treatment 1 was as follows: heating to 700℃ at a heating rate of 12℃ / min and holding for 2h; then heating to 1000℃ at the same heating rate and holding for 8h, with argon atmosphere.

[0040] Product b3 is heat-treated 2 to obtain product c3. The specific operation of heat treatment 2 is as follows: the temperature is increased to 600℃ at a heating rate of 8℃ / min and held for 2 hours; then the temperature is increased to 800℃ at the same heating rate and held for 6 hours. The atmosphere is a mixture of oxygen and high-purity air with an oxygen volume ratio of 15%.

[0041] The product c3 was then depolymerized using a ball mill to obtain product d3. The grinding media was made of alumina, and the ratio of grinding media to material was 9.5:1 (mass ratio). The ball milling time was 20 minutes.

[0042] Comparative Example 1 Heat treatment 1 involves heating to 1200℃ at a rate of 10℃ / min and holding for 8 hours; heat treatment 2 involves heating to 900℃ at a rate of 5℃ / min and holding for 6 hours. Other procedures are the same as in Example 1. The product is N1.

[0043] Comparative Example 2 Heat treatment 1 involves heating to 800°C at a rate of 8°C / min and holding for 6 hours; heat treatment 2 involves heating to 1000°C at a rate of 8°C / min and holding for 4 hours. Other procedures are the same as in Example 2. The product is N2.

[0044] Comparative Example 3 This comparative example uses commercially available organosiloxane powder a4 as raw material, with R-group being H. Subsequent processes are the same as in Example 3, and the product is N3.

[0045] Comparative Example 4 The comparative example and Example 3 are identical in raw materials and processes, except that the heating rate for heat treatment 1 is 1℃ / min. The product is N4.

[0046] Comparative Example 5 This comparative example differs from Example 3 except that the raw material R is C7H. 16 Apart from that, all other processes are the same, and the product is N5.

[0047] The dielectric loss tangent, surface resistance, volume resistivity, conductivity, density, and whiteness of the products of Examples 1-3 and Comparative Examples 1-5 were tested, and the test results are summarized in Table 1.

[0048] Evaluation methods 1. Dielectric loss tangent: SiOC ceramic powder and paraffin powder are mixed and pressed into plates in a certain proportion. The dielectric loss tangent is tested using the SPDR test method commonly used in the copper clad laminate industry, and then converted into intrinsic parameters of the powder according to the proportion.

[0049] 2. Surface resistance and volume resistance: SiOC ceramic powder was tested using a high resistance meter according to the requirements of GB / T 1410.

[0050] 3. Whiteness: Tested using a digital whiteness meter, the blue light whiteness value is read.

[0051] 4. Conductivity: Tested in the water extract using a conductivity meter.

[0052] 5. Density: Based on Archimedes' principle, the density is tested using a specific gravity bottle method.

[0053] 6. Crystal form: The SiOC ceramic powder was ground and then tested using an X-ray diffractometer.

[0054] Table 1. Summary of results data from Examples 1-3 and Comparative Examples 1-5

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing low-dielectric SiOC ceramic powder, characterized in that, Includes the following steps: (1) The organosiloxane powder a was heat-treated at 600-1400℃ under an inert atmosphere to obtain powder b; (2) Powder b is placed in an atmosphere with a certain oxygen content and heat-treated at 600-1200℃ to obtain powder c; (3) The agglomerates in the heat-treated powder c are broken up to obtain low dielectric SiOC ceramic powder d; The structure general formula of the organic siloxane powder is -RSiO3 - ; wherein the number of R groups is 1, wherein R group is a C1-6 hydrocarbon group; The heating steps for heat treatment 1 are as follows: heat up to 600-700℃ at a rate of 5-20℃ / min and hold for 2-4 hours; then continue to heat up to the target temperature at the same rate and hold for 4-8 hours. The heating steps for heat treatment 2 are as follows: heat up to 600-700℃ at a rate of 5-20℃ / min and hold for 2-4 hours; then continue to heat up to the target temperature at the same rate and hold for 4-8 hours.

2. The preparation method according to claim 1, characterized in that, R can be a C1-6 alkyl group, a C1-6 alkenyl group, or a phenyl group.

3. The preparation method according to claim 2, characterized in that, R is any one of methyl, ethyl, propyl, butyl, phenyl, vinyl, and propenyl.

4. The preparation method according to claim 1, characterized in that, In step (1), the heating rate is 5-15℃ / min.

5. The preparation method according to claim 4, characterized in that, In step (1), the inert atmosphere is either nitrogen or argon.

6. The preparation method according to claim 1, characterized in that, In step (2), the heat treatment temperature is 600-1000℃; And / or, in step (2), the heating rate is 5-15℃ / min; And / or, in step (2), the atmosphere with a certain oxygen content is a mixture of oxygen and nitrogen, wherein the oxygen content accounts for 1-30% of the volume.

7. The preparation method according to claim 6, characterized in that, The oxygen content is 5-20% by volume.

8. The preparation method according to claim 1, characterized in that, In step (3), the depolymerization equipment is an air jet mill or a ball mill.

9. Low-dielectric SiOC ceramic powder prepared by the preparation method according to any one of claims 1-8.

10. The low-dielectric SiOC ceramic powder as described in claim 9, characterized in that, Dielectric loss tangent < 0.0010; Surface resistivity > 4 × 10⁻⁶ 14 Ω, volume resistivity > 5 × 10 12 Ω; conductivity Ec < 10 μS / cm.

11. The low-dielectric SiOC ceramic powder as described in claim 9, characterized in that, The low-dielectric SiOC ceramic powder has an amorphous phase and no carbon crystallization peaks; whiteness <5%, density ≥2.0 g / cm³. 3 .

12. The application of the low-dielectric SiOC ceramic powder as described in any one of claims 9-11 in electronic-grade applications, characterized in that, The electronic-grade scenario includes high-frequency, high-speed circuits or packages.

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