A high-frequency copper-clad plate with low thermal expansion

Abstract

The present application belongs to the technical field of communication materials, and particularly relates to a high-frequency copper-clad plate with low thermal expansion. The present application provides a high-frequency copper-clad plate with low thermal expansion, and a preparation method thereof comprises the following steps in sequence: S1, preparing a modified polyarylether resin; S2, preparing a uniform dispersion liquid of a polyarylether composition; S3, preparing a prepreg; and S4, preparing the final high-frequency copper-clad plate. In S1, the raw materials include a bisphenol hydroxyl type polyarylether resin containing a diphenyl octacyclic ring, glycidyl methacrylate and an alkali. In S2, the raw materials include the modified polyarylether resin, a polydiene resin, a bismaleimide resin, a crosslinking agent and an initiator. Finally, the most prominent advantage of the high-frequency copper-clad plate is: 1, extremely low thermal expansion coefficient; and 2, simple, efficient and safe preparation process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of communication materials, and particularly relates to a high-frequency copper-clad plate with low thermal expansion. BACKGROUND

[0002] Electronic products are rapidly developing towards miniaturization, lightness, thinness and multi-functionality. As the main carrier of electronic components and devices, the copper-clad plate has higher and higher integration and more and more obvious multi-layer trend, which requires the copper-clad plate to have extremely low thermal expansion coefficient.

[0003] The traditional method is to introduce a large amount of inorganic fillers into the plate base body to inhibit the thermal expansion process of the polymer base body. However, the reduction effect of the thermal expansion coefficient of the copper-clad plate brought by this scheme has obvious limit value. In addition, too much inorganic filler introduced into the plate base body will cause poor dispersibility of each material in the plate base body, resulting in many problems such as poor performance uniformity and reliability of the plate.

[0004] On the other hand, the low-frequency copper-clad plate appeared earlier, and its resin material is epoxy resin, phenolic resin and cyanate ester resin, etc. Its advantages are: high thermal-mechanical properties, low thermal expansion coefficient, low cost, easy processing and strong versatility. However, the dielectric constant and dielectric loss of the low-frequency copper-clad plate are generally high, which is not suitable for the current high-frequency and high-speed communication field, so the above-mentioned high-frequency copper-clad plate is developed.

[0005] Generally, the resin type used in the high-frequency copper-clad plate is polyarylether or polyolefin. Among them, the polyolefin used as the high-frequency copper-clad plate requires that the 1,2-vinyl content is greater than or equal to 85%. Such polyolefin is relatively expensive, so the high-frequency copper-clad plate of polyarylether is more common.

[0006] The polyarylether at the present stage can be divided into two categories: end-vinyl modified and side-vinyl modified. Compared with the former, the side-vinyl modified polyarylether not only has high cross-linking and curing degree, but also can realize self-curing, even without adding initiator. Therefore, the side-vinyl modified polyarylether has basically realized commercialization, and the field of end-vinyl modified polyarylether is relatively blank, and it is relatively difficult to prepare high-frequency copper-clad plate.

[0007] US3522326, US4923932 and US5218030 use organic metal compounds such as butyl lithium to first metalize polyphenyl ether, and then react with halogenated unsaturated hydrocarbons to finally graft unsaturated bonds to the polyphenyl ether main chain, thereby preparing end-vinyl modified polyphenyl ether resin which can be cured with epoxy resin.

[0008] However, butyl lithium is used in the above-mentioned methods, which has many disadvantages such as extremely strong reactivity, violent exothermic reaction, difficult process control and high risk.

[0009] Therefore, there is an urgent need for a safer, more efficient and lower cost end-vinyl modified polyarylether-based composition, and to prepare a high-frequency copper-clad plate.

[0010] In addition, in 2013, the research group of Jennifer Lu from the University of California, USA and the research group of Wang Changchun from Fudan University jointly discovered that polymers containing a dibenzo-octane ring structural unit have a unique reversible thermal shrinkage and cold expansion property, and the thermal expansion coefficient value can reach-1200ppm / K. (Nat. Chem., 2013, 5, 1035; Chinese Patent Application 201710360230.2; Chinese Patent Application 201910474075.6) This property is derived from the reversible conformational change of the dibenzo-octane ring structural unit from a boat form to a chair form.

[0011] Therefore, the technical problem to be solved by the present application is: based on the thermal shrinkage and cold expansion properties of the dibenzo-octane ring structure and the end-vinyl modification technology of the polyarylether-based composition, how to prepare a low-thermal-expansion and high-frequency copper-clad plate. SUMMARY

[0012] The present application provides a low-thermal-expansion high-frequency copper-clad plate, and the preparation method comprises the following steps in sequence: S1, preparing a modified polyarylether resin; S2, preparing a uniform dispersion liquid of a polyarylether composition; S3, preparing a prepreg; and S4, preparing the final high-frequency copper-clad plate. In S1, the raw materials include a bisphenol hydroxyl type polyarylether resin containing a dibenzo-octane ring, glycidyl methacrylate and an alkali. In S2, the raw materials include the modified polyarylether resin, a polydiene resin, a bismaleimide resin, a crosslinking agent and an initiator. Finally, the most prominent advantage of the high-frequency copper-clad plate is: 1, extremely low thermal expansion coefficient; and 2, simple, efficient and safe preparation process.

[0013] The technical solution adopted by the present application to solve the above problems is: a low-thermal-expansion high-frequency copper-clad plate, and the preparation method comprises the following steps in sequence:

[0014] S1, preparing a modified polyarylether resin;

[0015] S2, preparing a uniform dispersion liquid of a polyarylether composition;

[0016] S3, preparing a prepreg;

[0017] S4, preparing the final high-frequency copper-clad plate,

[0018] In S1, the raw materials include a bisphenol hydroxyl type polyarylether resin containing a dibenzo-octane ring, glycidyl methacrylate and an alkali,

[0019] In S2, the raw materials include the modified polyarylether resin, a polydiene resin, a bismaleimide resin, a crosslinking agent and an initiator.

[0020] Further preferred technical solutions are as follows: first, the biphenyl dibenzocyclooctane-containing hydroxyl type polyarylether resin is dissolved, then glycidyl methacrylate and an alkali are added, and then stirring and reaction are performed, followed by adding a poor solvent of the polyarylether and stirring and standing to precipitate the product, and finally, filtration, washing and drying are sequentially performed to obtain the modified polyarylether resin.

[0021] Further preferred technical solutions are as follows: in S1, the solvent used for dissolving is N,N-dimethylformamide, and the poor solvent is ethanol.

[0022] In S1 of the present application, the solvent used for dissolving can also be any one or a mixture of several of acetone, methyl ethyl ketone, methyl isobutyl ketone, N,N-dimethylacetamide and N-methyl pyrrolidone.

[0023] In S1 of the present application, the alkali is any one or a mixture of several of lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate and potassium carbonate, and the molar number thereof is ≤ the molar number of glycidyl methacrylate.

[0024] In S1 and S2 of the present application, the molar number of glycidyl methacrylate is 100-150% of the total molar number of phenolic hydroxyl groups in the uniform dispersion of the polyarylether composition.

[0025] Further preferred technical solutions are as follows: in S2, the modified polyarylether resin is first dissolved in toluene, and then the polydiene resin, the bismaleimide resin, the crosslinking agent and the initiator are added, and the uniform dispersion of the polyarylether composition is obtained after stirring and reaction.

[0026] In S2 of the present application, the polydiene resin is any one or a mixture of several of a single polydiene resin, an epoxy-grafted polydiene resin and a hydroxyl-terminated polydiene resin.

[0027] The number average molecular weight of the polydiene resin is 500-20,000, and at least 3 reactive carbon-carbon double bonds are contained on the side groups of a single high molecular chain.

[0028] In S2 of the present application, the “adding again” operation can also include existing common fillers, compatilizers and modified resins. The fillers are, for example, silicon oxide and aluminum oxide particles, the compatilizers are, for example, polyethylene, and the modified resins are, for example, diene-maleic anhydride copolymers.

[0029] Further preferred technical solutions are as follows: in S2, the solid content of the uniform dispersion of the polyarylether composition is 20-80 wt / v%.

[0030] Further preferred technical solutions are that S3 is: first using the uniform dispersion of the polyarylether composition to impregnate the fiber cloth, and then baking and drying to obtain the prepreg.

[0031] Further preferred technical solutions are that S4 is: first folding the prepreg and the copper foil on the surface together, and then going through the lamination process to obtain the high-frequency copper-clad plate.

[0032] Further preferred technical solutions are that in S4, the prepreg and the copper foil further include a film, and the film is a polyolefin film.

[0033] In the present application, the film can also be a polyaromatic film, a polyamide film, and a polyether ketone film.

[0034] Further preferred technical solutions are that in S1, the diphenyl octacyclic ring-containing bisphenol hydroxyl type polyarylether resin has the following structure:

[0035] ,

[0036] wherein R1, R2, R3, and R4 are any one of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, and halogen atoms, a is an integer ≥0, and R is any one of structure 1 and structure 2 or a composite of the two:

[0037] , .

[0038] In the present application, the number average molecular weight of the diphenyl octacyclic ring-containing bisphenol hydroxyl type polyarylether resin is 1000-10000, and the concentration in the solvent used for dissolution is ≤75wt / v%.

[0039] Further preferred technical solutions are that in S2, the number average molecular weight of the polydiene resin is 500-20000, the crosslinking agent is any one of triallyl isocyanurate, triallyl cyanurate, divinylbenzene, trimethylolpropane trimethacrylate, and bismaleimide or a mixture of several thereof, and the initiator is any one of a mixture of several of peroxide and azo compound.

[0040] In S2 of the present application, the added weight of the crosslinking agent is 1-30% of the weight of the uniform dispersion of the polyarylether composition.

[0041] In S2 of the present application, the added weight of the initiator is 1-5% of the weight of the uniform dispersion of the polyarylether composition.

[0042] Compared with the prior art, the present application has the following beneficial effects.

[0043] First, a polyarylether resin with both hydroxyl and reactive carbon-carbon double bond groups on the end groups is prepared by reacting a relatively inexpensive bisphenol hydroxyl type polyarylether resin and glycidyl methacrylate, i.e. a modified polyarylether resin of thermosetting type. The entire preparation process is simple, efficient, safe and economical, and does not require the use of butyl lithium.

[0044] Second, a self-made bisphenol hydroxyl type polyarylether resin containing a structural unit of a reversible thermal shrinkage and cold expansion property of a dicyclic octane ring is used to ensure that the thermal shrinkage and cold expansion property of the dicyclic octane ring is effectively utilized in the copper-clad plate.

[0045] Third, a thermosetting polyarylether resin-based composition is prepared by taking advantage of the property of bismaleimide resin that it can react with both hydroxyl and reactive carbon-carbon double bond groups, so that the thermosetting effect is fully effective.

[0046] Fourth, the prepreg has the comprehensive advantages of uniform glue content, strong resin adhesion, smooth surface, and suitable toughness and adhesion.

[0047] Fifth, the thermosetting high-frequency copper-clad plate has excellent dielectric properties, high mechanical strength, extremely low thermal expansion coefficient, high copper foil peel strength, and good uniformity of each property. DETAILED DESCRIPTION

[0048] The following description is only a preferred embodiment of the present application, and does not limit the scope of the present application.

[0049] Example 1

[0050] 100 parts of a self-made bisphenol hydroxyl type polyarylether resin containing a structural unit of a reversible thermal shrinkage and cold expansion property of a dicyclic octane ring (number average molecular weight Mn = 942, weight average molecular weight Mw = 1727) was dissolved in 200 parts of toluene, and then glycidyl methacrylate and DMAP were added and stirred to mix uniformly. The molar ratio of glycidyl methacrylate to the phenolic hydroxyl groups contained in the bisphenol hydroxyl type polyarylether resin was controlled to be 1.05:1, and the amount of DMAP was 5 mol% of glycidyl methacrylate.

[0051] The above system was mechanically stirred at 90 o C for 24 hours, and then poured into excess methanol to precipitate the product. After filtration, methanol washing and drying, a thermosetting modified polyphenyl ether resin was obtained.

[0052] Take 100 parts of the above thermosetting modified polyphenyl ether resin, 30 parts of polybutadiene (Kewelly Ricon154), 5 parts of TAIC, 20 parts of bismaleimide resin, 5 parts of polybutadiene-maleic anhydride copolymer (Kewelly Ricon130MA8), 10 parts of epoxidized polybutadiene (JP100), 250 parts of silicon oxide, 10 parts of aluminum oxide, 30 parts of decabromodiphenyl ethane and 550 parts of toluene, stirring at 50℃ for 24h, fully dissolved-dispersed uniformly; Lower to room temperature, add 2.5 parts of dibenzoyl peroxide, further stirring uniformly.

[0053] The 1078 glass fiber cloth is impregnated with glue, and then baked and dried to obtain a prepreg, wherein the first stage baking temperature is 90℃, and the time is 5min, and the second stage baking temperature is 120℃, and the time is 2min.

[0054] Take 9 prepregs and stack them together, and attach loz copper foil on both sides, and laminate under the condition of pressure 45-75kg / cm 2 , temperature 220℃ for 4h to obtain a copper clad plate.

[0055] Example 2

[0056] The preparation process of the thermosetting modified polyphenyl ether resin is the same as that of Example 1.

[0057] Take 100 parts of the above thermosetting modified polyphenyl ether resin, 30 parts of polybutadiene (Kewelly Ricon154), 5 parts of TAIC, 20 parts of bismaleimide resin, 5 parts of polybutadiene-maleic anhydride copolymer (Kewelly Ricon130MA8), 10 parts of epoxidized polybutadiene (JP100), 250 parts of silicon oxide, 10 parts of aluminum oxide, 30 parts of decabromodiphenyl ethane and 550 parts of toluene, stirring at 50℃ for 24h, fully dissolved-dispersed uniformly; Lower to room temperature, add 2.5 parts of dibenzoyl peroxide, further stirring uniformly.

[0058] The 1078 glass fiber cloth is impregnated with glue, and then baked and dried to obtain a prepreg, wherein the first stage baking temperature is 90℃, and the time is 5min, and the second stage baking temperature is 120℃, and the time is 2min.

[0059] Take 9 prepregs and stack them together, and attach loz copper foil on both sides, and laminate under the condition of pressure 45-75kg / cm 2 , temperature 220℃ for 4h to obtain a copper clad plate.

[0060] Example 3

[0061] The preparation process of the thermosetting modified polyphenyl ether resin is the same as that of Example 1.

[0062] Take 100 parts of the thermosetting modified polyphenyl ether resin, 20 parts of bismaleimide resin, 10 parts of divinylbenzene, 10 parts of polybutadiene (Kraton Ricon 154), 5 parts of polybutadiene-maleic anhydride copolymer (Kraton Ricon 130MA8), 10 parts of epoxidized polybutadiene (JP100), 250 parts of silicon oxide, 10 parts of aluminum oxide, 30 parts of decabromodiphenyl ethane and 550 parts of toluene, stirring at 50℃ for 24h, fully dissolved-dispersed uniformly; Lower to room temperature, add 2.5 parts of dibenzoyl peroxide, further stirring uniformly.

[0063] The 1078 glass fiber cloth is impregnated with glue, and then baked and dried to obtain a prepreg, wherein the first stage baking temperature is 90℃, and the time is 5min, and the second stage baking temperature is 120℃, and the time is 2min.

[0064] Take 9 prepregs and stack them together, and attach loz copper foil on both sides, under the condition of pressure 45-75kg / cm 2 , temperature 220℃, laminated for 4h to prepare a copper clad plate.

[0065] Example 4

[0066] The preparation process of the thermosetting modified polyphenyl ether resin is the same as that of Example 1.

[0067] Take 100 parts of the thermosetting modified polyphenyl ether resin, 20 parts of bismaleimide resin, 10 parts of divinylbenzene, 10 parts of polybutadiene (Kraton Ricon 154), 5 parts of polybutadiene-maleic anhydride copolymer (Kraton Ricon 130MA8), 10 parts of epoxidized polybutadiene (JP100), 250 parts of silicon oxide, 10 parts of aluminum oxide, 30 parts of decabromodiphenyl ethane and 550 parts of toluene, stirring at 50℃ for 24h, fully dissolved-dispersed uniformly; Lower to room temperature, add 2.5 parts of dibenzoyl peroxide, further stirring uniformly.

[0068] The 1078 glass fiber cloth is impregnated with glue, and then baked and dried to obtain a prepreg, wherein the first stage baking temperature is 90℃, and the time is 5min, and the second stage baking temperature is 120℃, and the time is 2min.

[0069] Take 9 prepregs and stack them together, and attach loz copper foil on both sides, under the condition of pressure 45-75kg / cm 2 , temperature 220℃, laminated for 4h to prepare a copper clad plate.

[0070] Prepreg performance test results

[0071]

[0072] Copper clad plate performance test results

[0073]

[0074] The embodiments of the present application are described in detail above, but the present application is not limited to the above-described embodiments, and various modifications can be made within the knowledge of those skilled in the art without departing from the spirit of the present application. These are modifications without creativity, and are protected by the patent law within the scope of the claims of the present application.

Claims

1. A low thermal expansion high frequency copper clad board, characterized by The preparation method comprises the following steps in sequence: S1, preparing a modified polyarylether resin; S2, preparing a uniform dispersion of a polyarylether composition; S3, preparing a prepreg; S4, preparing a final high-frequency copper-clad plate, In S1, the raw materials include a bisphenol hydroxyl type polyarylether resin containing a dicyclic octane ring, glycidyl methacrylate, and DMAP, In S2, the raw materials include the modified polyarylether resin, a polydiene resin, a bismaleimide resin, a crosslinking agent, and an initiator, In S1, the bisphenol hydroxyl type polyarylether resin containing a dicyclic octane ring is first dissolved, then glycidyl methacrylate and DMAP are added, and then the mixture is stirred and reacted at 90℃ for 24 hours, with the molar ratio of glycidyl methacrylate to the phenolic hydroxyl groups contained in the bisphenol hydroxyl type polyarylether resin controlled at 1.05:1, and the amount of DMAP accounted for 5mol% of glycidyl methacrylate, followed by the addition of a poor solvent for the polyarylether and stirring and standing to allow the product to precipitate, and finally filtration, washing, and drying in sequence to obtain the modified polyarylether resin, In S2, the modified polyarylether resin is first dissolved in toluene, and then the polydiene resin, the bismaleimide resin, the crosslinking agent, and the initiator are added, and a uniform dispersion of the polyarylether composition is obtained after stirring and reaction, In S1, the bisphenol hydroxyl type polyarylether resin containing a dicyclic octane ring has the following structure: ， wherein R1, R2, R3, and R4 are any one of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, and halogen atoms, a is an integer greater than or equal to 0, and R is any one of structure 1 or structure 2 or a combination of the two: 、 。 2. The low-CTE high-frequency copper-clad plate according to claim 1, characterized in that: In S1, the solvent used for dissolution is N,N-dimethylformamide, and the poor solvent is ethanol.

3. The low-CTE high-frequency copper-clad plate according to claim 1, characterized in that: In S2, the uniform dispersion of the polyarylether composition has a solid content of 20-80wt / v%.

4. The low-CTE high-frequency copper-clad plate according to claim 1, characterized in that In S3, the uniform dispersion of the polyarylether composition is first used to impregnate a fiber cloth, and then the fiber cloth is baked and dried to obtain the prepreg.

5. The low-CTE high-frequency copper-clad plate according to claim 1, characterized in that In S4, the prepreg and a copper foil on the surface are first laminated together, and then a lamination process is performed to obtain the high-frequency copper-clad plate.

6. The low-CTE high-frequency copper-clad plate according to claim 5, characterized in that: In S4, a film is further included between the prepreg and the copper foil, and the film is a polyolefin film.

7. The low-CTE high-frequency copper-clad plate according to claim 1, characterized in that: In S2, the number average molecular weight of the polydiene resin is 500-20000, the crosslinking agent is any one of triallyl isocyanurate, triallyl cyanurate, divinylbenzene, trimethylolpropane trimethacrylate, and bismaleimide or a mixture of several thereof, and the initiator is any one of a peroxide and an azo compound or a mixture of several thereof.

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