Resin composition with ultralow dielectric loss, prepreg and copper-clad plate

Abstract

The invention discloses a resin composition with ultralow dielectric loss, which is prepared from the following main components in parts by weight: 5 to 50 parts of BCB resin containing perfluorocyclobutyl, 3 to 10 parts of hydrocarbon resin, 1 to 20 parts of assistant crosslinking agent, 1 to 40 parts of filler, 0.5 to 1.5 parts of surface treating agent and 0.05 to 0.5 part of initiator. A perfluorocyclobutyl structure is constructed on a BCB resin framework through a 2pi + 2pi cycloaddition reaction, the dielectric loss of the BCB resin is greatly reduced, the dielectric constant and the dielectric loss factor of the resin composition are remarkably reduced on the basis that the inherent excellent performance of the BCB resin is maintained, and then the hydrocarbon resin and the filler are added into a resin system in a matched mode, so that the BCB resin composition has the excellent dielectric constant and dielectric loss factor. The heat stability and the size stability are improved, so that a copper-clad plate prepared from the resin composition is particularly suitable for a 5G / 6G communication base station, a low-orbit satellite high-frequency assembly and a circuit substrate of high-performance computing equipment, and the harsh requirement of millimeter wave frequency band signal transmission on a dielectric material is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of copper-clad plate technology, in particular to a resin composition with ultra-low dielectric loss, a prepreg and a copper-clad plate. BACKGROUND

[0002] BCB resin has low dielectric constant, low moisture absorption, high thermal stability and chemical stability, and high film flatness, and in a wide frequency and temperature range, BCB resin exhibits very low dielectric constant and dielectric loss, which can reduce the wiring capacitance per unit length, reduce the mutual inductance between adjacent metals to a lower limit, and ultimately improve the transmission speed and quality of signals, making it very advantageous in electronic packaging applications. However, with the large-scale deployment of 5G communication worldwide and the accelerated research and development of 6G technology, the working frequency of electronic devices has entered the millimeter wave frequency band (30-300GHz). Under this technical background, the delay and energy loss problems of signal transmission become particularly prominent. High-frequency circuits have almost stringent performance requirements for the dielectric layer of copper-clad plates. When working at a frequency of 10GHz or above, the dielectric constant needs to be stable below 3.0, the dielectric loss factor needs to be below 0.001, and it also needs to have high glass transition temperature, low thermal expansion coefficient and excellent dimensional stability.

[0003] The Df value of the traditional BCB resin is generally 3.0 x 10 -3 The loss increases significantly above 30GHz, resulting in signal integrity degradation. Therefore, it is necessary to propose a new solution to solve the above problems. SUMMARY

[0004] Therefore, the present application aims to provide a resin composition with ultra-low dielectric loss, a prepreg and a copper-clad plate, which can effectively solve the problem that the dielectric constant and dielectric loss of the existing copper-clad plate are not low enough, the loss increases significantly above 30GHz, resulting in signal integrity degradation, and it is difficult to meet the requirements of millimeter wave frequency band signal transmission for dielectric materials.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A resin composition with ultra-low dielectric loss, by weight, it includes the following main components: BCB resin containing perfluorocyclobutyl group 5-50 parts, hydrocarbon resin 3-10 parts, co-crosslinking agent 1-20, filler 1-40 parts, surface treatment agent 0.5-1.5 parts and initiator 0.05-0.5 parts.

[0007] As a preferred solution, the structure of the BCB resin containing perfluorocyclobutyl group is as follows:

[0008]

[0009] As a preferred embodiment, the BCB resin containing perfluorocyclobutyl group is prepared by the following steps:

[0010] (1) 0.5 mol of 1-adamantanol and 0.525 mol of 4-bromophenol are dissolved in 1000 ml of diethyl ether, 12.1784 g of Amberlite catalyst treated with acetic acid and dried is added, heated with water bath at 100°C and stirred to reflux for 2 hours, then the Amberlite catalyst is recovered by filtration, followed by ethyl acetate extraction, then the diethyl ether is removed by distillation under reduced pressure to obtain product A;

[0011] (2) 0.6 mol of 4-bromobenzocyclobutene and 0.78 mol of pinacol diboronic acid are dissolved in 1000 ml of toluene, 0.012 mol of DPPF palladium dichloride and 0.9 mol of potassium acetate are added, heated to 80°C under nitrogen atmosphere, reacted for 10 hours, then cooled to room temperature, quenched with saturated ammonium chloride solution, then extracted with ethyl acetate, the organic phase is combined and washed with water, dried with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain product B;

[0012] (3) 0.6 mol of product A obtained in step (1) and 0.78 mol of product B obtained in step (2) are dissolved in 1000 ml of two-phase solvent composed of THF and ultrapure water, then 1.2 mol of potassium carbonate and 0.03 mol of PD2DBA3 are added in sequence, nitrogen is introduced into the container and the air in the container is exhausted, heated to 85°C under nitrogen atmosphere, stirred to reflux for 6 hours, then cooled to room temperature, the organic phase and the aqueous phase are separated, the aqueous phase is extracted with DCM solvent for 5 times, the organic phase is first washed with saturated sodium chloride solution, then washed with ultrapure water again, dried with anhydrous magnesium sulfate, filtered, and the solvent is concentrated under reduced pressure to obtain product C;

[0013] (4) 0.5 mol of product C obtained in step (3) is dissolved in 500 ml of DMSO, then 0.65 mol of 1,2-dibromotetrafluoroethane and 0.8 mol of potassium carbonate are added, heated to 100°C under nitrogen atmosphere, stirred to reflux for 5 hours, then the reflux device is removed, the residual 1,2-dibromotetrafluoroethane is evaporated to obtain an intermediate; then the intermediate is dissolved in acetonitrile, zinc powder is added, heated to reflux for 5 hours, the zinc powder is recovered by filtration, washed with ultrapure water, and the filter residue is dried to obtain product D;

[0014] (5) Product D obtained in step (4) is dissolved in DCM solvent, and the cyclobutane structure is constructed by ultraviolet light initiation, then purified by silica gel column chromatography to obtain product E;

[0015] (6) Diels-Alder reaction of the product E obtained in step (5) to obtain a BCB resin containing perfluorocyclobutyl groups.

[0016] As a preferred solution, the organic phase in step (3) is first washed with a saturated sodium chloride solution, then washed again with ultrapure water, dried with anhydrous magnesium sulfate, filtered, the solvent is concentrated under reduced pressure, and then purified by silica gel column chromatography to obtain product C.

[0017] As a preferred solution, the filler is silicon dioxide.

[0018] As a preferred solution, the filler is spherical silicon dioxide.

[0019] A prepreg is prepared by impregnating glass fibers in a resin glue solution prepared from the aforementioned resin composition with ultra-low dielectric loss, and baking the impregnated glass fibers in a 150℃ air drying oven for 5 minutes.

[0020] As a preferred solution, the glass fibers are Q-glass 1078 glass cloth.

[0021] A copper-clad plate is prepared from the aforementioned prepreg.

[0022] The present application has obvious advantages and beneficial effects compared with the prior art, and in particular, the above technical solutions can know that:

[0023] The perfluorocyclobutyl structure is constructed on the BCB resin skeleton through a 2π+2π cycloaddition reaction, which greatly reduces the dielectric loss of the BCB resin, so that the resin composition significantly reduces the dielectric constant and dielectric loss factor while maintaining the inherent excellent performance of the BCB resin. In addition, the addition of hydrocarbon resin and filler in the resin system improves the thermal stability and dimensional stability, so that the copper-clad plate prepared from the resin composition is particularly suitable for 5G / 6G communication base stations, low-orbit satellite high-frequency components and circuit substrates for high-performance computing devices, meeting the harsh requirements of millimeter wave frequency band signal transmission on dielectric materials.

[0024] To make the structural features and effects of the present application clearer, the present application will be described in detail below with reference to specific examples. DETAILED DESCRIPTION

[0025] The present application discloses a resin composition with ultra-low dielectric loss, which comprises the following main components by weight: 5-50 parts of BCB resin containing perfluorocyclobutyl, 3-10 parts of hydrocarbon resin, 1-20 parts of auxiliary crosslinking agent, 1-40 parts of filler, 0.5-1.5 parts of surface treatment agent, and 0.05-0.5 parts of initiator; the BCB resin containing perfluorocyclobutyl can provide low dielectric properties and high Tg for the resin composition, the hydrocarbon resin can enhance the toughness of the resin composition, the filler is spherical silica which can improve the modulus and reduce the CTE; specifically, the structure of the BCB resin containing perfluorocyclobutyl is as follows:

[0026] and the BCB resin containing perfluorocyclobutyl is prepared by the following steps:

[0027] (1) 0.5 mol of 1-adamantanol and 0.525 mol of 4-bromophenol are dissolved in 1000 ml of diethyl ether, 12.1784 g of Amberlite catalyst treated with acetic acid activation and drying treatment is added, heated with water bath at 100℃ and stirred for refluxing for 2 h, then the Amberlite catalyst is recovered by filtration, followed by ethyl acetate extraction, then the diethyl ether is removed by reduced pressure distillation to obtain product A, and the reaction path is as follows:

[0028]

[0029] (2) 0.6 mol of 4-bromobenzocyclobutene and 0.78 mol of pinacol diboron acid are dissolved in 1000 ml of toluene, 0.012 mol of DPPF palladium dichloride and 0.9 mol of potassium acetate are added, heated to 80℃ under nitrogen atmosphere protection, reacted for 10 h, cooled to room temperature after the reaction is completed, then saturated ammonium chloride solution is added for quenching reaction, followed by ethyl acetate extraction, the organic phase is combined and washed with water, dried with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain product B, and the reaction path is as follows:

[0030]

[0031] (3) 0.6 mol of the product A obtained in step (1) and 0.78 mol of the product B obtained in step (2) were dissolved in 1000 ml of a two-phase solvent composed of THF and ultrapure water, and then 1.2 mol of potassium carbonate and 0.03 mol of PD2DBA3 were sequentially added. Nitrogen gas was introduced into the vessel and the air in the vessel was exhausted, and the vessel was heated to 85°C under a nitrogen atmosphere. The reaction was stirred under reflux for 6 h. After the completion of the reaction, the vessel was cooled to room temperature, and the organic phase and the aqueous phase were separated. The aqueous phase was extracted with DCM solvent 5 times. The organic phase was washed with saturated sodium chloride solution and then washed with ultrapure water again. The organic phase was dried over anhydrous magnesium sulfate, filtered, and the solvent was concentrated under reduced pressure. The product C was obtained by purification using a silica gel column, and the reaction path thereof is shown below.

[0032]

[0033] (4) 0.5 mol of the product C obtained in step (3) was dissolved in 500 ml of DMSO, and then 0.65 mol of 1,2-dibromotetrafluoroethane and 0.8 mol of potassium carbonate were added. The reaction was stirred under reflux at 100°C for 5 h under a nitrogen atmosphere. After removing the reflux device, the residual 1,2-dibromotetrafluoroethane was evaporated to obtain an intermediate. The intermediate was dissolved in acetonitrile, and zinc powder was added. The reaction was stirred under reflux at 100°C for 5 h. The zinc powder was recovered by filtration, and the filter residue was washed with ultrapure water and dried to obtain the product D. The reaction path thereof is shown below.

[0034]

[0035] (5) The product D obtained in step (4) was dissolved in DCM solvent, and the cyclobutane structure was constructed by ultraviolet light initiation. The product E was obtained by purification using a silica gel column, and the reaction path thereof is shown below.

[0036]

[0037] (6) The product E obtained in step (5) was subjected to Diels-Alder reaction to obtain a BCB resin containing a perfluorocyclobutyl group.

[0038] The present application also discloses a prepreg prepared by dipping glass fiber in the resin glue prepared from the aforementioned resin composition with ultra-low dielectric loss, and baking the dipped glass fiber in a 150℃ air-drying oven for 5 minutes. The glass fiber is Q-glass 1078 glass cloth. The present application also discloses a copper-clad plate prepared from the aforementioned prepreg. Specifically, the BCB resin containing perfluorocyclobutyl and the hydrocarbon resin are respectively dissolved in a butanone / xylene mixed solvent in a mass ratio of 2:1, and stirred until completely dissolved. The glue is clear, and then the auxiliary cross-linking agent, the surface treatment agent, the spherical silica, and the initiator are added in sequence. The mixture is stirred at high speed for 1 hour and then homogenized for 1 hour to ensure uniform dispersion. The resin glue is filtered through a 10μm filter cloth. The resin glue is then dipped onto the glass fiber, which is Q-glass 1078 glass cloth. The dipped glass fiber is baked in a 150℃ air-drying oven for 5 minutes to prepare the prepreg. The prepreg is laminated with a copper foil from Mitsui, which has a thickness of 35μm and a model of HVLP4. The laminated copper foil is cured in a vacuum hot press. The copper foil is first hot-pressed at 220℃ for 0.5 hours, then hot-pressed at 230℃ for 1 hour, and finally hot-pressed at 250℃ for 1 hour. The pressure of the hot-pressing is 10MPa.

[0039] The following examples and comparative examples are described below. The specific component proportions are shown in Table 1.

[0040]

[0041] Table 1

[0042] The performance of the above examples and comparative examples is tested according to the following test methods, and the test results are shown in Table 2.

[0043] The test method is as follows.

[0044] The Tg is tested by using a DMA device from TA. The test conditions are as follows: frequency 10Hz, amplitude 10μm, and temperature rising rate 10℃ / min.

[0045] The XY axis CTE is tested by using a TMA450 from TA. The test sample is Q-glass 1078*2, and the resin content is 70%. The CTE data temperature range is 50-160℃.

[0046] The dielectric properties (specifically, the dielectric constant Dk and the dielectric loss Df) of the laminated plates of the above examples and comparative examples are tested by using the separated dielectric resonator method. The test frequency is 10GHz.

[0047] The peel strength of each laminated plate is tested according to the IPC-TM-650 test method. In addition, each laminated plate is subjected to a 288℃ immersion tin test.

[0048]

[0049] Table 2

[0050] According to the analysis of the above data, the ultra-low dielectric loss resin composition prepared by using the formula of the present application has very low dielectric loss, which can meet the requirement of Df < 0.0006 @ 10 GHz, and at the same time ensures that the prepared copper-clad plate has very high glass transition temperature, Tg > 270℃. The comparison of Comparative Example 1 and Example 2, Comparative Example 2 and Example 3, Comparative Example 3 and Example 4, Comparative Example 4 and Example 5 is that the BCB resin used in the examples contains perfluorocyclobutyl, and the BCB resin used in the comparative examples does not contain perfluorocyclobutyl structure, and the rest of the components and amounts are the same, but the glass transition temperature and dielectric properties of the comparative examples are obviously worse than those of the examples. It can be seen that embedding perfluorocyclobutyl in the backbone of BCB resin solves the defect of high dielectric loss of conventional BCB resin at high frequency, avoids the significant increase of loss at the frequency band above 30 GHz as much as possible, and makes the signal transmitted by the copper-clad plate more complete.

[0051] The above is only a preferred embodiment of the present application, and does not limit the technical scope of the present application. Any slight modification, equivalent change and modification made according to the technical essence of the present application to the above embodiment are still within the scope of the technical solution of the present application.

Claims

1. A resin composition with ultra-low dielectric loss, characterized in that: The invention comprises the following main components in parts by weight: 5-50 parts of BCB resin containing perfluorocyclobutyl, 3-10 parts of hydrocarbon resin, 1-20 parts of auxiliary crosslinking agent, 1-40 parts of filler, 0.5-1.5 parts of surface treatment agent and 0.05-0.5 parts of initiator.

2. The ultra-low dielectric loss resin composition according to claim 1, characterized in that: The structure of the perfluorocyclobutyl-containing BCB resin is shown below:

3. The ultra-low dielectric loss resin composition according to claim 2, characterized in that: The BCB resin containing perfluorocyclobutyl is prepared by the following steps: (1) 0.5 mol of 1-adamantanol and 0.525 mol of 4-bromophenol were dissolved in 1000 ml of ether, and 12.1784 g of AmberLite catalyst activated with acetic acid and dried was added. The mixture was heated in a water bath at 100°C and stirred under reflux for 2 h. The AmberLite catalyst was recovered by filtration, and then extracted with ethyl acetate. The ether was then removed by distillation under reduced pressure to obtain Product A. (2) 0.6 mol of 4-bromobenzocyclobutene and 0.78 mol of pinacol diboron were dissolved in 1000 ml of toluene, 0.012 mol of DPPF palladium dichloride and 0.9 mol of potassium acetate were added, and the mixture was heated to 80° C. under nitrogen atmosphere for 10 h. After the reaction was completed, the mixture was cooled to room temperature, saturated ammonium chloride solution was added to quench the reaction, and then extracted with ethyl acetate. The organic phases were combined, washed with water, dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain product B; (3) 0.6 mol of the product A obtained in step (1) and 0.78 mol of the product B obtained in step (2) were dissolved together in 1000 ml of a two-phase solvent consisting of THF and ultrapure water. Then, 1.2 mol of potassium carbonate and 0.03 mol of PD2DBA3 were added in sequence. Nitrogen was introduced into the container and the air in the container was exhausted. The mixture was heated to 85° C. under a nitrogen atmosphere and stirred under reflux for 6 h. After the reaction was completed, the mixture was cooled to room temperature, and the organic phase and the aqueous phase were separated. The aqueous phase was extracted 5 times with DCM solvent. The organic phase was first washed with a saturated sodium chloride solution and then washed again with ultrapure water. The mixture was dried over anhydrous magnesium sulfate, filtered, and the solvent was concentrated under reduced pressure to obtain product C. (4) 0.5 mol of the product C obtained in step (3) was dissolved in 500 ml of DMSO, followed by the addition of 0.65 mol of 1,2-dibromotetrafluoroethane and 0.8 mol of potassium carbonate, and the mixture was heated to 100° C. under a nitrogen atmosphere, stirred and refluxed for 5 h, and then the reflux device was removed and the residual 1,2-dibromotetrafluoroethane was evaporated to obtain an intermediate; the intermediate was then dissolved in acetonitrile, zinc powder was added, and the mixture was heated and refluxed for 5 h. The zinc powder was filtered and recovered, washed with ultrapure water, and the filter residue was dried to obtain product D; (5) dissolving the product D obtained in step (4) in DCM solvent, and constructing a cyclobutane structure by ultraviolet light initiation, and purifying by silica gel column chromatography to obtain product E; (6) subjecting the product E obtained in step (5) to a Diels-Alder reaction to obtain a BCB resin containing a perfluorocyclobutyl group.

4. The ultra-low dielectric loss resin composition according to claim 3, characterized in that: In the step (3), the organic phase is first washed with a saturated sodium chloride solution, then washed again with ultrapure water, dried over anhydrous magnesium sulfate, filtered, the solvent is concentrated under reduced pressure, and then purified by silica gel column chromatography to obtain product C.

5. The ultra-low dielectric loss resin composition according to claim 1, wherein: The filler is silicon dioxide.

6. The ultra-low dielectric loss resin composition according to claim 5, characterized in that: The filler is spherical silica.

7. A prepreg, characterized in that: The glass fiber is impregnated with a resin adhesive prepared from the ultra-low dielectric loss resin composition according to any one of claims 1 to 6, and after the impregnation is completed, the resin is placed in a blast drying oven at 150° C. and baked for 5 minutes.

8. The prepreg according to claim 7, wherein: The glass fiber is Q-glass 1078 glass cloth.

9. A copper clad laminate, characterized in that: The prepreg is made from the prepreg according to any one of claims 7 to 8.

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