High-frequency heat-conducting copper-clad plate glue solution as well as preparation method and application thereof
By using PTFE resin powder and inorganic fillers of different types and particle sizes to build thermal conductivity in copper clad plates, the problems of low thermal conductivity and high dielectric loss in the prior art are solved, and copper clad plates with low dielectric loss and high thermal conductivity are realized for high-frequency and high-power circuits.
Patent Information
- Application Number
- CN202411733172.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-06-06
AI Technical Summary
Existing copper clad plates have low thermal conductivity and high dielectric loss in high frequency and high power applications, which cannot meet the needs of high frequency and high power circuits.
PTFE resin powder is used as the main resin, and different types and particle sizes of inorganic fillers, such as BN, boron nitride, aluminum nitride, silicon nitride and barium titanate, are added to build a thermal conductivity path to improve thermal conductivity, and at the same time adjust the dielectric constant to reduce dielectric loss.
It realizes low dielectric loss and high thermal conductivity of copper clad plate, suitable for high-frequency and high-power circuits, with excellent thermal conductivity and stable dielectric properties.
Smart Images
Figure BDA0005160811820000121
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of copper clad laminates, and in particular to a high-frequency heat-conducting copper clad laminate adhesive and a preparation method and application thereof. Background Art
[0002] Copper clad laminate is the basic material of the electronics industry, mainly used for processing and manufacturing printed circuit boards. The increasing demand for portability of computers and other related equipment, the application and development of multi-layer interconnection of ultra-large-scale integrated circuits, have increased the packaging density of circuit boards and highly concentrated the electronic components of integrated circuits, resulting in narrower line spacing, further increasing signal propagation delay and crosstalk. The development of electrical equipment towards high voltage and large capacity, especially the technological innovation of high frequency, digitalization and high-power electronic components, has led to the rapid accumulation of heat inside organic composite materials, accelerating the aging of resins, and seriously threatening the stability and reliability of equipment and high-power systems.
[0003] Traditional copper-clad laminates used for high frequency and high speed are generally made of epoxy resin as the main material, and their thermal conductivity is around 0.5w / (m·k), and no more than 1w / (m·k). Since the dielectric loss of epoxy resin itself is around 0.02, the dielectric performance of general thermal conductive FR4 boards is relatively poor, and traditional copper-clad laminates can no longer meet the current market demand.
[0004] Polytetrafluoroethylene (PTFE) has become one of the possible materials for preparing copper clad laminates due to its excellent insulation, dielectric properties, high heat resistance, weather resistance and other characteristics. However, the low thermal conductivity of PTFE itself limits its application in the copper clad laminate industry, so inorganic fillers are generally added in the prior art to improve the thermal conductivity of PTFE. However, the addition of inorganic fillers will increase the dielectric loss of the composite material. Therefore, it is imperative to develop a high-frequency and high-speed copper clad laminate with low dielectric loss and high thermal conductivity. Summary of the invention
[0005] The present invention aims to overcome the above-mentioned problems existing in copper clad laminates in the prior art, and provides a high-frequency thermal conductive copper clad laminate adhesive and a preparation method and application thereof. PTFE resin powder is used as the main resin, and inorganic fillers of different types and particle sizes are added to construct a thermal conductive path to increase the thermal conductivity. The copper clad laminate having both low dielectric loss and high thermal conductivity can be prepared by the adhesive, which can be applied to high-frequency and high-power circuits.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a high-frequency thermal conductive copper-clad laminate adhesive, which comprises, by weight, 50 parts of PTFE resin powder; 10 to 35 parts of BN slurry with a D50 of 5 to 15 μm; 10 to 25 parts of flake boron nitride with a D50 of 17 to 22 μm; 10 to 25 parts of spherical aluminum nitride with a D50 of 20 to 30 μm; 3 to 8 parts of barium titanate with a D50 of 1 to 2 μm; 5 to 35 parts of silicon nitride with a D50 of 3 to 7 μm; 3 to 4 parts of additives; and 5 to 40 parts of water.
[0007] The copper-clad laminate glue of the present invention uses PTFE resin as the main resin, adds inorganic fillers of different types and different particle sizes, constructs a heat-conducting path to increase thermal conductivity. The PTFE resin in the present invention is added in the form of powder. Compared with the PTFE dispersion, the amount of PTFE powder additive added is small, the dielectric loss of itself is less affected, and the slight demulsification phenomenon that occurs when more fillers are added to the PTFE dispersion can be avoided. Boron nitride is added in the form of BN slurry and flaky boron nitride respectively. The Dk value of BN is close to that of silicon oxide, but its thermal conductivity is much greater than that of silicon oxide, which is beneficial to the improvement of the thermal conductivity of the copper-clad laminate; the added BN slurry can solve the dispersion problem of BN in solution or water, and it can be diluted; but the particle size of BN in the BN slurry is small, and the BN slurry process with large particle size is difficult to achieve, so the present invention is compounded with large particle size flaky BN, which is convenient for constructing a heat-conducting path; flaky boron nitride has higher in-plane thermal conductivity and more stable dielectric properties. Adding barium titanate can adjust the dielectric constant and stabilize it near a fixed value; aluminum nitride and silicon nitride are inorganic fillers with high thermal conductivity and relatively excellent dielectric properties. Choosing spherical aluminum nitride for addition is conducive to reducing interface loss. The higher the degree of spheroidization, the lower the interface loss.
[0008] The present invention can obtain a copper-clad laminate with low dielectric loss and high thermal conductivity by selecting material types, shapes and particle sizes under the synergistic effect of various inorganic fillers. The copper-clad laminate prepared by the adhesive of the present invention has a dielectric constant controlled at 3.5±0.1 at 10GHz; a dielectric loss of less than 0.0015; a thermal conductivity of more than 1.5W / (m·k); and a peel strength of more than 1.8N / mm, and can be applied to high-frequency and high-power circuits.
[0009] Preferably, the solid content of the BN slurry is 15-25wt%.
[0010] Preferably, the auxiliary agent includes 2.5 to 3 parts of a surfactant, 0.5 to 1 part of a coupling agent, and 0.2 to 0.4 part of a defoaming agent.
[0011] In a second aspect, the present invention provides a method for preparing the above-mentioned high-frequency thermal conductive copper clad laminate adhesive, comprising the following steps: (1) adding PTFE resin powder to BN water slurry, stirring and dispersing evenly, then adding flake boron nitride, spherical aluminum nitride, barium titanate, and silicon nitride, stirring evenly to obtain an initial glue solution; (2) adding water to the initial glue solution to adjust the viscosity, and then stirring under negative pressure to obtain the high-frequency thermal conductive copper-clad laminate glue solution.
[0012] Preferably, in step (1), flake boron nitride, spherical aluminum nitride, barium titanate, and silicon nitride are added in order from small to large particle sizes.
[0013] Preferably, in step (1), after adding PTFE resin powder to the BN water slurry, a surfactant and a coupling agent are added, and then stirred and dispersed uniformly.
[0014] Preferably, in step (2), water is added to the initial glue solution to adjust the viscosity, and then a defoaming agent is added, followed by negative pressure stirring.
[0015] In a third aspect, the present invention provides an application of the above-mentioned high-frequency thermal conductive copper clad laminate adhesive in a high-frequency and high-speed copper clad laminate, and a preparation method of the high-frequency and high-speed copper clad laminate comprises the following steps: S1: coating the high-frequency thermal conductive copper-clad laminate adhesive on a glass sheet, and baking to obtain a prepreg; S2: stacking a number of prepregs, attaching copper foils to the upper and lower surfaces, and performing vacuum hot pressing to obtain the high-frequency and high-speed copper-clad laminate.
[0016] Preferably, during baking in S1, the material is first pre-dried at 150-200°C for 4-6 minutes, and then the temperature is raised to 330-350°C and baked for 10-20 minutes.
[0017] Preferably, the pressure during vacuum hot pressing in S2 is 3-20 MPa, and the temperature is 50-375° C.; the heating time during vacuum hot pressing is 1-3 h, and the heat preservation time is 1-3 h.
[0018] Therefore, the present invention has the following beneficial effects: (1) Taking PTFE resin as the main resin, adding inorganic fillers of different types, different morphologies and different particle sizes to construct a thermal conductive path to increase thermal conductivity. Under the synergistic effect of various inorganic fillers, a copper clad laminate with both low dielectric loss and high thermal conductivity can be obtained; (2) PTFE resin is added in the form of powder. Compared with PTFE dispersion, the amount of PTFE powder additive added is small, which has less impact on its own dielectric loss and can avoid the slight demulsification phenomenon that occurs when more fillers are added to the PTFE dispersion; (3) Boron nitride is added in the form of BN slurry and flake boron nitride. The added BN slurry can solve the dispersion problem of BN in solution or water, and it can be diluted. DETAILED DESCRIPTION
[0019] The present invention is further described below in conjunction with specific implementation methods.
[0020] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art.
[0021] Overall embodiment: A high-frequency heat-conductive copper-clad laminate adhesive, comprising, by weight, 50 parts of PTFE resin powder; 10 to 35 parts of BN slurry with a D50 of 5 to 15 μm; 10 to 25 parts of flake boron nitride with a D50 of 17 to 22 μm; 10 to 25 parts of spherical aluminum nitride with a D50 of 20 to 30 μm; 3 to 8 parts of barium titanate with a D50 of 1 to 2 μm; 5 to 35 parts of silicon nitride with a D50 of 3 to 7 μm; 3 to 4 parts of Additives: 5-40 parts of water.
[0022] As a specific implementation, the solid content of the BN slurry is 15-25wt%.
[0023] As a specific implementation, the auxiliary agent includes 2.5 to 3 parts of a surfactant, 0.5 to 1 part of a coupling agent, and 0.2 to 0.4 parts of a defoaming agent.
[0024] As a specific implementation, the surfactant is selected from one or more non-ionic surfactants; the coupling agent is selected from one or more silane coupling agents and phthalate coupling agents; the defoaming agent is selected from one or more silicone defoaming agents.
[0025] The method for preparing the above-mentioned high-frequency thermal conductive copper-clad laminate adhesive comprises the following steps: (1) adding PTFE resin powder to BN water slurry, stirring and dispersing evenly, then adding flake boron nitride, spherical aluminum nitride, barium titanate, and silicon nitride, stirring evenly to obtain an initial glue solution; (2) adding water to the initial glue solution to adjust the viscosity, and then stirring under negative pressure to obtain the high-frequency thermal conductive copper-clad laminate glue solution.
[0026] As a specific implementation, in step (1), flake boron nitride, spherical aluminum nitride, barium titanate, and silicon nitride are added in order from small to large particle sizes.
[0027] As a specific implementation manner, in step (1), after adding PTFE resin powder to the BN water slurry, a surfactant and a coupling agent are added, and then stirred and dispersed evenly.
[0028] As a specific implementation method, in step (2), water is added to the initial glue solution to adjust the viscosity, and then a defoaming agent is added, followed by negative pressure stirring.
[0029] The application of the above-mentioned high-frequency thermal conductive copper clad laminate glue in high-frequency and high-speed copper clad laminates, and the preparation method of high-frequency and high-speed copper clad laminates include the following steps: S1: coating the high-frequency thermal conductive copper-clad laminate adhesive on a glass sheet, and baking to obtain a prepreg; S2: stacking a number of prepregs, attaching copper foils to the upper and lower surfaces, and performing vacuum hot pressing to obtain the high-frequency and high-speed copper-clad laminate.
[0030] As a specific implementation manner, during baking in S1, the material is first pre-dried at 150-200° C. for 4-6 minutes, and then the temperature is raised to 330-350° C. and baked for 10-20 minutes.
[0031] As a specific implementation manner, the pressure during vacuum hot pressing in S2 is 3 to 20 MPa, and the temperature is 50 to 375° C.; the heating time during vacuum hot pressing is 1 to 3 hours, and the heat preservation time is 1 to 3 hours.
[0032] Embodiment 1: A method for preparing a high-frequency and high-speed copper-clad laminate, the steps are as follows: S1: Preparation of high frequency thermal conductive copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 15 parts of silicon nitride with a D50 of 5 μm, 10 parts of flake boron nitride with a D50 of 17 to 22 μm, and 15 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 8 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a high-frequency thermal conductive copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is raised from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain a high-frequency and high-speed copper clad laminate.
[0033] Embodiment 2: A method for preparing a high-frequency and high-speed copper-clad laminate, the steps are as follows: S1: Preparation of high frequency thermal conductive copper clad laminate adhesive: (1) At room temperature, take 10 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai), add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 3 parts of barium titanate with a D50 of 1 to 2 μm, 10 parts of silicon nitride with a D50 of 5 μm, 15 parts of flake boron nitride with a D50 of 17 to 22 μm, and 20 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 20 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a high-frequency thermal conductive copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is raised from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain a high-frequency and high-speed copper clad laminate.
[0034] Embodiment 3: A method for preparing a high-frequency and high-speed copper-clad laminate, the steps are as follows: S1: Preparation of high frequency thermal conductive copper clad laminate adhesive: (1) At room temperature, take 35 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai), add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 8 parts of barium titanate with a D50 of 1 to 2 μm, 20 parts of silicon nitride with a D50 of 5 μm, 5 parts of flake boron nitride with a D50 of 17 to 22 μm, and 10 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) Add 0 parts of water to the initial glue solution, adjust the viscosity to 400-500 cps, stir evenly, add a defoamer, and stir under negative pressure to obtain a high-frequency thermal conductive copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is raised from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain a high-frequency and high-speed copper clad laminate.
[0035] Embodiment 4: A method for preparing a high-frequency and high-speed copper-clad laminate, the steps are as follows: S1: Preparation of high frequency thermal conductive copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 5 parts of silicon nitride with a D50 of 5 μm, 10 parts of flake boron nitride with a D50 of 17 to 22 μm, and 25 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 8 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a high-frequency thermal conductive copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is raised from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain a high-frequency and high-speed copper clad laminate.
[0036] Comparative Example 1 (the filler body is replaced with α-crystalline spherical alumina of different particle sizes): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 15 parts of spherical alumina with an α-crystal phase with a D50 of 5 μm, and 25 parts of spherical alumina with an α-crystal phase with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 8 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is raised from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain a high-frequency and high-speed copper clad laminate.
[0037] Comparative Example 2 (the filler body is replaced with aluminum nitride of different particle sizes): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 15 parts of spherical aluminum nitride with a D50 of 5 μm, and 25 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 8 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is increased from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain the copper clad laminate.
[0038] Comparative Example 3 (the filler body is replaced with flake boron nitride of different particle sizes): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 15 parts of flake boron nitride with a D50 of 1 to 3 μm, and 25 parts of flake boron nitride with a D50 of 17 to 22 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 14 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is increased from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain the copper clad laminate.
[0039] Comparative Example 4 (using α-crystalline spherical alumina to replace spherical aluminum nitride with the same particle size): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 15 parts of silicon nitride with a D50 of 5 μm, 10 parts of flake boron nitride with a D50 of 17 to 22 μm, and 15 parts of α-crystalline spherical alumina with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 8 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is increased from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain the copper clad laminate.
[0040] Comparative Example 5 (using α-crystalline spherical alumina to replace spherical silicon nitride with the same particle size): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 15 parts of spherical alumina with a D50 of 5 μm, 10 parts of flake boron nitride with a D50 of 17 to 22 μm, and 15 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 8 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is increased from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain the copper clad laminate.
[0041] Comparative Example 6 (using α-crystalline spherical alumina to replace flake boron nitride with the same particle size): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 20 parts of water by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.6 parts of KH550, and stir thoroughly to make the PTFE resin powder evenly dispersed in the water slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 15 parts of silicon nitride with a D50 of 5 μm, 5 parts of spherical aluminum oxide with an α-crystal phase with a D50 of 5 μm, 10 parts of spherical aluminum oxide with a D50 of 25 μm, and 15 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 8 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is increased from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain the copper clad laminate.
[0042] Comparative Example 7 (total filler addition amount is 40 parts): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.5 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 5 parts of silicon nitride with a D50 of 5 μm, 10 parts of flake boron nitride with a D50 of 17 to 22 μm, and 15 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 7 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is increased from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain the copper clad laminate.
[0043] Comparative Example 8 (total filler addition amount is 60 parts): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 0.8 parts of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 25 parts of silicon nitride with a D50 of 5 μm, 10 parts of flake boron nitride with a D50 of 17 to 22 μm, and 15 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 10 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is increased from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain the copper clad laminate.
[0044] Comparative Example 9 (total filler addition amount is 70 parts): A method for preparing a copper clad laminate, comprising the following steps: S1: Preparation of copper clad laminate adhesive: (1) At room temperature, take 25 parts of BN slurry (solid content 20wt%, D50 3-12μm, purchased from Jiangxi Liankai) by weight, add 50 parts of PTFE resin powder (Dongyue, DF-161), 3 parts of Triton and 1 part of KH550, and stir well to make the PTFE resin powder evenly dispersed in the slurry; (2) adding 5 parts of barium titanate with a D50 of 1 to 2 μm, 35 parts of silicon nitride with a D50 of 5 μm, 10 parts of flake boron nitride with a D50 of 17 to 22 μm, and 15 parts of spherical aluminum nitride with a D50 of 25 μm to the dispersed water slurry in sequence, and stirring evenly to obtain an initial glue solution; (3) adding 12 parts of water to the initial glue solution, adjusting the viscosity to 400-500 cps, adding a defoamer after stirring evenly, and stirring under negative pressure to obtain a copper clad laminate glue solution; S2: Preparation of prepreg: Use a 150 μm wire rod to evenly coat the obtained high-frequency thermal conductive copper-clad laminate adhesive on a 3 mm thick high-temperature resistant glass sheet, preheat at 150° C. for 5 min in an oven, heat to 350° C. and bake for 15 min to obtain a prepreg; S3: Preparation of copper clad laminate: stack 9 semi-cured sheets with flat surfaces and uniform impregnation, then cover the upper and lower surfaces with 0.5oz copper foil, and place them in a vacuum hot press for vacuum hot pressing. The vacuum hot pressing method is as follows: first stage: the pressure is set to 10MPa, the temperature is increased from room temperature to 345℃, and the required time is 40min; second stage: when the temperature reaches 345℃, the pressure is set to 20MPa, the temperature is set to 375℃, and the required time is 20min; third stage: keep warm for 2h to obtain the copper clad laminate.
[0045] The properties of the copper clad laminates prepared in the above embodiments and comparative examples were tested, and the results are shown in Table 1.
[0046] Among them, the test method of each parameter is: Dielectric constant: IPC-TM-650 2.5.5.5 stripline; Dielectric loss: IPC-TM-650 2.5.5.5; Thermal conductivity: ASTM D5470; Peel strength: IPC-TM-650 2.4.8; Water absorption: IPC-TM-650 2.6.2.1.
[0047] Table 1: Copper clad laminate performance test results.
[0048] It can be seen from Table 1 that the copper clad laminates prepared by using the copper clad laminate adhesive of the present invention in Examples 1 to 4 have good thermal conductivity, low dielectric loss, and low water absorption.
[0049] In Comparative Example 1, the main body adopts α-crystalline spherical alumina filler. Although it has more excellent thermal conductivity and thermal stability, compared with nitride fillers, its thermal conductivity is relatively weak and its dielectric loss is relatively high.
[0050] In Comparative Example 2, the main body uses spherical aluminum nitride filler. Since aluminum nitride will undergo hydrolysis reaction in a humid environment, the water absorption test result is poor and does not meet the use requirements of high-frequency and high-speed copper clad laminates.
[0051] In Comparative Example 3, the main body uses flake boron nitride filler, which is a high thermal conductivity filler, but its flake structure affects its addition amount and dispersion. At the same addition amount, the thermal conductivity is not as high as that of Example 1. At the same time, due to the chemical inertness and low friction characteristics of boron nitride, the peel strength is greatly reduced at a high addition amount.
[0052] In the filler of Comparative Example 4, α-crystalline spherical alumina is used to replace spherical aluminum nitride of the same particle size in a precise one-to-one ratio. The dielectric losses of the two are similar, but spherical aluminum nitride has better thermal conductivity. Since aluminum nitride will undergo hydrolysis reaction in a humid environment, resulting in a relatively high water absorption rate, its usage needs to be controlled.
[0053] The filler of comparative example 5 uses α-crystalline spherical alumina to replace silicon nitride of the same particle size in an accurate one-to-one ratio. Compared with α-crystalline spherical alumina, silicon nitride has certain advantages in thermal conductivity and dielectric loss, and silicon nitride does not have the obvious disadvantages of aluminum nitride, so its addition amount can be controlled to control the overall filler addition amount to avoid greater negative effects.
[0054] The filler in comparative example 6 uses α-crystalline spherical alumina to replace the flake boron nitride with the same particle size in a precise one-to-one ratio. Compared with α-crystalline spherical alumina, boron nitride has greater advantages in thermal conductivity and dielectric loss, but boron nitride also has obvious disadvantages: 1. Too much addition affects the viscosity of the system; 2. Too much addition significantly reduces the peel strength. Therefore, like aluminum nitride, its usage needs to be controlled.
[0055] In the filler of comparative example 7, the amount of silicon nitride added was reduced to make the total amount of filler added 40 parts. Due to the reduction in the amount of filler added, the overall thermal conductivity was significantly reduced compared with that of example 1; at the same time, the peel strength was significantly improved.
[0056] In the filler of Comparative Example 8, the amount of silicon nitride added was increased so that the total filler addition amount was 60 parts. Due to the increase in the amount of filler added, the proportion of PTFE resin was relatively reduced, the peel strength was significantly reduced, the thermal conductivity was improved but not significantly, and the overall performance was not as good as Example 1.
[0057] In the filler of Comparative Example 9, the amount of silicon nitride added was increased to a total amount of 70 parts. Due to the large increase in the amount of filler added, the agglomeration of fillers increased significantly during the configuration process, which destroyed the construction of the thermal conductive path and seriously affected the thermal conductivity. At the same time, due to the excessive addition of fillers, the peel strength decreased significantly, and the comprehensive performance was far inferior to that of Example 1.
Claims
1. A high-frequency thermal conductive copper-clad laminate adhesive, characterized in that: The components include, by weight: 50 parts of PTFE resin powder; 10-35 parts of BN slurry with a D50 of 5-15 μm; 10-25 parts of flake boron nitride with a D50 of 17-22 μm; 10-25 parts of spherical aluminum nitride with a D50 of 20-30 μm; 3-8 parts of barium titanate with a D50 of 1-2 μm; 5-35 parts of silicon nitride with a D50 of 3-7 μm; 3-4 parts of additives; and 5-40 parts of water.
2. The high-frequency thermal conductive copper-clad laminate adhesive according to claim 1 is characterized in that: The solid content of the BN slurry is 15-25wt%.
3. The high-frequency thermal conductive copper-clad laminate adhesive according to claim 1 is characterized in that: In parts by weight, the auxiliary agent includes 2.5 to 3 parts of a surfactant, 0.5 to 1 parts of a coupling agent, and 0.2 to 0.4 parts of a defoaming agent.
4. A method for preparing a high-frequency thermal conductive copper-clad laminate adhesive as claimed in any one of claims 1 to 3, characterized in that: The steps include: (1) Add PTFE resin powder to BN water slurry, stir and disperse evenly, then add flake boron nitride, spherical aluminum nitride, barium titanate, and silicon nitride, stir evenly to obtain an initial glue solution; (2) Water is added to the initial glue solution to adjust the viscosity, and then negative pressure stirring is performed to obtain the high-frequency thermal conductive copper clad laminate glue solution.
5. The method for preparing the high-frequency thermal conductive copper-clad laminate adhesive according to claim 4, characterized in that: In step (1), flake boron nitride, spherical aluminum nitride, barium titanate, and silicon nitride are added in order from small to large particle sizes.
6. The method for preparing the high-frequency heat-conducting copper-clad laminate adhesive according to claim 4 or 5, characterized in that: In step (1), PTFE resin powder is added to the BN water slurry, followed by the addition of a surfactant and a coupling agent, and then the mixture is stirred and dispersed evenly.
7. The method for preparing the high-frequency thermal conductive copper-clad laminate adhesive according to claim 4, characterized in that: In step (2), water is added to the initial glue solution to adjust the viscosity, and then a defoaming agent is added, followed by negative pressure stirring.
8. An application of the high-frequency thermal conductive copper-clad laminate adhesive as claimed in any one of claims 1 to 3 in high-frequency and high-speed copper-clad laminates, characterized in that: The preparation method of high-frequency and high-speed copper-clad laminate comprises the following steps: S1: coating the high-frequency thermal conductive copper-clad laminate adhesive on a glass sheet, and baking to obtain a prepreg; S2: stacking a number of prepregs, attaching copper foils to the upper and lower surfaces, and performing vacuum hot pressing to obtain the high-frequency and high-speed copper-clad laminate.
9. The application of the high-frequency heat-conducting copper-clad laminate glue according to claim 8 in high-frequency and high-speed copper-clad laminates, characterized in that: When baking in S1, pre-dry at 150-200°C for 4-6 minutes, then heat to 330-350°C and bake for 10-20 minutes.
10. The application of the high-frequency heat-conducting copper-clad laminate adhesive according to claim 8 in high-frequency and high-speed copper-clad laminates, characterized in that: The pressure during vacuum hot pressing in S2 is 3~20MPa, and the temperature is 50~375℃; the heating time during vacuum hot pressing is 1~3h, and the heat preservation time is 1~3h.