A high dielectric constant temperature-stable composite dielectric substrate material and a preparation method thereof

Abstract

The application relates to the technical field of composite materials, and particularly discloses a high-dielectric-constant temperature-stable composite dielectric substrate material and a preparation method thereof. 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder is subjected to surface modification treatment by using a silane coupling agent; (2) the modified Sr 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder is subjected to surface modification treatment by using a silane coupling agent; (2) the modified Sr After the slurry obtained in the step (2) is vacuum-deaerated, a green ceramic tape is prepared through flow casting; (4) the green ceramic tape obtained in the step (3) is double-side copper-coated and then laminated and sintered to obtain the high-dielectric-constant temperature-stable composite dielectric substrate material. The preparation method can obtain the composite dielectric substrate material which has a high dielectric constant, a low dielectric constant temperature coefficient and high thermal stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite materials, and particularly relates to a high dielectric constant temperature-stable composite dielectric substrate material and a preparation method thereof. BACKGROUND

[0002] With the rapid development of information technology, traditional materials are increasingly difficult to meet the requirements of high frequency, high speed, high capacity, high thermal stability and high frequency bandwidth of products. High dielectric constant microwave circuit boards (9.0-20) are beneficial to reducing the size of the circuit board and are widely used in the fields of antennas, communication systems, amplifiers and satellite navigation. In the traditional printed circuit board industry, high-frequency copper-clad boards are mainly prepared by glass cloth impregnation method, and the dielectric constant range is less than 3.45, which is difficult to improve the dielectric constant of the board. To obtain a high dielectric constant (greater than 10), ceramic powder is added as a filler to improve the dielectric constant of the microwave circuit board and to improve the high integration and miniaturization of the device. The dielectric constant of the AD1000 product of Rogers Company is 10.2, but its stability is poor, and the dielectric constant temperature coefficient reaches-380ppm / ℃. The product is mainly glass cloth / PTFE, and the remaining products RO3010, RO3210, RT / durdid 6010.2LM are also composite materials of glass cloth / PTFE / ceramic, and the dielectric constant temperature coefficient is also large, which cannot meet the requirement of high thermal stability.

[0003] For the ceramic-filled hydrocarbon resin type microwave circuit board with more excellent performance, the ceramic content can be added to more than 85-90%, and the comprehensive performance of the board is good. For example, the TMM 13i product of Rogers Company is a ceramic-filled hydrocarbon resin type microwave circuit board, but its dielectric constant temperature coefficient is-70ppm / ℃. In order to solve the requirements of high dielectric constant and high thermal stability, the present application is proposed. SUMMARY

[0004] To solve the problems mentioned in the background art, the purpose of the present application is to provide a high dielectric constant temperature-stable composite dielectric substrate material and a preparation method thereof.

[0005] In order to achieve the above-mentioned target, the technical scheme of the present application is as follows:

[0006] The present application provides a preparation method of a high dielectric constant temperature-stable composite dielectric substrate material, comprising the following steps:

[0007] (1) : Sr 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder is subjected to surface modification treatment with a silane coupling agent, wherein Sr 3.85 Ca 0.15Bi4Ti7O 24 The ceramic powder is 97-99% by mass, and the silane coupling agent is 1-3% by mass;

[0008] (2) : the modified Sr 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder, the curing agent, the hydrocarbon resin and the curing agent diluent are ball-milled for 4-6 hours to obtain a slurry, wherein the hydrocarbon resin is 10-40% by mass, the modified Sr 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder is 80-89% by mass, the curing agent is 1-5% by mass, and the curing agent diluent is Sr 3.85 Ca 0.15 Bi4Ti7O 24 70% by mass of the total amount of the ceramic powder;

[0009] (3) : the slurry obtained in step (2) is vacuum-deaerated and then flow-casted to prepare a semi-cured sheet;

[0010] (4) : the semi-cured sheet obtained in step (3) is laminated and sintered after being double-sided copper-coated, the sintering temperature is 190-220 DEG C, the time is 3 hours, and the surface pressure is kept at 6 MPa throughout the process, to obtain a high dielectric constant temperature-stable composite dielectric substrate material.

[0011] Further, the silane coupling agent in step (1) is one or more of Z6124, Z6264, KH550 and KH560.

[0012] Further, the curing agent in step (2) is di-t-butyl peroxide or dibenzoyl peroxide, the curing agent diluent is one or more of toluene, xylene, cyclohexane and butyl acetate, and the hydrocarbon resin is one or more of polybutadiene, styrene-butadiene-divinylbenzene copolymer and polyisoprene.

[0013] Further, the ball-milling speed in step (2) is 350 r / min, the ball-milling beads are alumina balls, and the ball-to-material ratio is 5:1.

[0014] Further, the flow-casting speed in step (3) is 0.3 m / min, and the drying temperature is 40-50 DEG C.

[0015] The application further provides a high dielectric constant temperature-stable composite dielectric substrate material prepared by the above method.

[0016] The beneficial effects of the present invention are as follows: by using the solution provided by the present invention, a composite dielectric substrate material with a high dielectric constant, a low dielectric constant temperature coefficient and high thermal stability can be obtained. Specific parameters will be described in the embodiments. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the protection scope of the present invention.

[0018] Example 1:

[0019] A method for preparing a high dielectric constant temperature-stable composite dielectric substrate material includes the following steps:

[0020] (1) Sr 3.85 Ca 0.15 Bi4Ti7O 24 Ceramic powder is surface modified using a silane coupling agent, wherein Sr 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder has a particle size fraction of 97%, and the silane coupling agent used is KH550 with a mass fraction of 3%.

[0021] (2) The modified Sr from step (1) 3.85 Ca 0.15 Bi4Ti7O 24 Ceramic powder, curing agent, hydrocarbon resin, and curing agent diluent were ball-milled for 6 hours to obtain a slurry. The hydrocarbon resin was polybutadiene with a mass fraction of 13 wt%, and Sr... 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder has a mass fraction of 85 wt%, and the curing agent is di-tert-butyl peroxide with a mass fraction of 2%. The curing agent is diluted with toluene and the addition amount is Sr. 3.85 Ca 0.15 Bi4Ti7O 24 The total amount of ceramic powder is 70 wt%, the ball milling time is 5 h, the speed is 350 r / min, alumina balls are used as grinding beads, and the ball-to-powder ratio is 5:1;

[0022] (3) After vacuum degassing the slurry obtained in step (2), a semi-cured sheet is prepared by casting. The casting speed is 0.3 m / min and the drying temperature is 42℃.

[0023] (4) The prepreg obtained in step (3) is coated with copper on both sides and then laminated and sintered at a temperature of 190°C for 3 hours, with a surface pressure of 6MPa throughout the process, to obtain a high dielectric constant temperature stable composite dielectric substrate material.

[0024] Example 2:

[0025] The difference from Example 1 is that the sintering temperature in step (4) is 200°C.

[0026] Example 3:

[0027] The difference from Example 1 is that the sintering temperature in step (4) is 210°C.

[0028] Example 4:

[0029] The difference from Example 1 is that the sintering temperature in step (4) is 220°C.

[0030] The properties of composite dielectric substrate materials prepared at different sintering temperatures are shown in Table 1:

[0031]

[0032] Table 1

[0033] As shown in Table 1, the composite dielectric substrate materials prepared by the preparation method provided by the present invention all have high dielectric constants and low dielectric constant temperature coefficients.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high dielectric constant temperature-stable composite dielectric substrate material, characterized in that, Includes the following steps: (1): Sr 3.85 Ca 0.15 Bi4Ti7O 24 Ceramic powder is surface modified using a silane coupling agent, wherein Sr 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder has a mass fraction of 97%–99%, and the silane coupling agent has a mass fraction of 1%–3%. (2): The modified Sr from step (1) 3.85 Ca 0.15 Bi4Ti7O 24 Ceramic powder, curing agent, hydrocarbon resin, and curing agent diluent are ball-milled for 4-6 hours to obtain a slurry, wherein the hydrocarbon resin has a mass fraction of 10wt%-40wt% and a well-modified Sr. 3.85 Ca 0.15 Bi4Ti7O 24 The ceramic powder has a mass fraction of 80wt%–89wt%, the curing agent has a mass fraction of 1wt%–5wt%, and the amount of solvent added to dilute the curing agent is Sr. 3.85 Ca 0.15 Bi4Ti7O 24 70 wt% of the total ceramic powder content; (3): After vacuum degassing the slurry obtained in step (2), a semi-cured sheet is prepared by casting. (4): The prepreg obtained in step (3) is coated with copper on both sides and then laminated and sintered. The sintering temperature is 190~220℃ and the time is 3 hours. The surface pressure is maintained at 6MPa throughout the process to obtain a high dielectric constant temperature stable composite dielectric substrate material.

2. The method for preparing a high dielectric constant temperature-stable composite dielectric substrate material according to claim 1, characterized in that, The silane coupling agent in step (1) is one or more of Z6124, Z6264, KH550, and KH560.

3. The method for preparing a high dielectric constant temperature-stable composite dielectric substrate material according to claim 1, characterized in that, The curing agent in step (2) is di-tert-butyl peroxide or benzoyl peroxide, the curing agent diluent is one or more of toluene, xylene, cyclohexane, and butyl acetate, and the hydrocarbon resin is one or more of polybutadiene, styrene-butadiene-divinylbenzene copolymer, and polyisoprene.

4. The method for preparing a high dielectric constant temperature-stable composite dielectric substrate material according to claim 1, characterized in that, In step (2), the ball milling speed is 350 r / min, alumina balls are used as grinding beads, and the ball-to-material ratio is 5:

1.

5. The method for preparing a high dielectric constant temperature-stable composite dielectric substrate material according to claim 1, characterized in that, In step (3), the casting speed is 0.3 m / min and the drying temperature is 40~50℃.

6. A high dielectric constant temperature-stable composite dielectric substrate material, characterized in that, Prepared according to the preparation method described in any one of claims 1-5.

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