CN115948042A - Thermosetting resin composition, laminated board and high-frequency circuit substrate - Google Patents

Abstract

The invention provides a thermosetting resin composition, a laminated board and a high-frequency circuit substrate, wherein the thermosetting resin composition comprises a thermosetting resin and a phosphorus-containing flame retardant, the phosphorus-containing flame retardant has a structure shown in a formula I, the phosphorus-containing flame retardant with a specific structure is used in the invention, the flame retardant has good flame retardance, good heat stability and humidity resistance, excellent dielectric constant and dielectric loss tangent, good hydrolysis resistance and excellent process processability, and the flame retardant does not migrate at high temperature.

Description

Thermosetting resin composition, laminated board and high-frequency circuit substrate

Technical Field

The invention belongs to the technical field of laminated plates, and relates to a thermosetting resin composition, a laminated plate and a high-frequency circuit substrate.

Background

Printed circuit boards are widely used in numerous applications including, for example, industrial mainframe computers, communication equipment, electrical measurement equipment, defense and aerospace products, and household appliances, all of which require printed circuit boards as a foundation for supporting various electronic components. With the progress of technology, electronic products are rapidly developing towards the trend of miniaturization, multi-functionalization, high performance and high reliability. Therefore, the development of printed circuit boards is also directed to high precision, high density, high performance, fine pore formation, thinness, and multilayers. When surface components (e.g., active components or passive components) are mounted on the printed circuit board, a reflow process is performed to melt the lead-free solder and connect the surface components to the metal traces on the printed circuit board. The resin material used for manufacturing the insulating layer of the printed circuit board may be deformed due to a difference in thermal expansion coefficient after being subjected to thermal shock during reflow; therefore, the circuit board may warp and decrease flatness, resulting in poor subsequent soldering, such as non-wetting and other problems, and high density interconnections in the printed circuit board result in increased heat generation, and thus it is necessary to provide a solution for reducing the thermal expansion coefficient of the insulating layer and improving dimensional stability. On the other hand, when a printed circuit board is produced using the epoxy resin composition, various flame retardants, such as a halogen-containing flame retardant or a phosphorus-containing flame retardant, are generally added to the composition in order to promote the flame retardancy of the material. Due to environmental problems, halogen-containing flame retardants have been banned or limited in use. Further, phosphazene compounds such as SPB-100 available from tsukamur chemical corporation or condensed phosphoric acid esters such as PX-200 available from yakatsu chemical corporation have disadvantages of low melting point, low thermal decomposition temperature, high temperature ionization, and the like, and thus a circuit board made therefrom has a high thermal expansion coefficient, easily causes inner layer cracking during the circuit board manufacturing process, and thus reduces the yield. DI-DOPO phosphorus-containing compounds and Geneva PQ-60, which are commercially available from Yabao, have high melting points and good electrical properties, but tend to migrate at high temperatures, resulting in poor properties such as peel strength. Therefore, there is a need to develop a new flame retardant that satisfies both the heat resistance and good electrical properties of the material and also satisfies the problem that the flame retardant does not migrate at high temperatures.

Disclosure of Invention

In view of the disadvantages of the prior art, an object of the present invention is to provide a thermosetting resin composition, a laminate, and a high-frequency circuit board.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a thermosetting resin composition comprising a thermosetting resin and a phosphorus-containing flame retardant having a structure according to formula I:

the phosphorus-containing flame retardant with a specific structure is used in the invention, so that the flame retardant has good flame retardance, good thermal stability and moist heat resistance, excellent dielectric constant and dielectric loss tangent and excellent process processability.

In the present invention, the phosphorus-containing flame retardant is a reactive phosphorus-containing flame retardant containing a double bond, and when the resin composition is prepared into a cured product by thermal curing, since the phosphorus-containing flame retardant participates in a crosslinking reaction, the migration of the flame retardant at high temperature can be prevented. The molecular structure of the phosphorus-containing flame retardant disclosed by the invention has a rigid alicyclic chain, so that the material has high heat resistance and dielectric property, and the phosphorus-containing flame retardant does not contain a phosphoric ester bond and has good hydrolysis resistance.

Preferably, the phosphorus-containing flame retardant comprises 8% to 40% by weight of the total thermosetting resin composition, such as 8%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, preferably 10% to 30%, more preferably 15% to 25%. In the present invention, if the content of the phosphorus-containing flame retardant in the thermosetting resin composition is less than 1%, the flame-retardant effect is poor, and if the content of the phosphorus-containing flame retardant is more than 40%, the electrical properties of the material are deteriorated.

Preferably, the thermosetting resin comprises 10% to 95% by weight of the total thermosetting resin composition, for example 10%, 15%, 18%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

Preferably, the thermosetting resin comprises a resin containing C = C double bonds.

Preferably, the resin containing C = C double bonds includes any one of or a combination of at least two of a polybutadiene resin and a derivative thereof, a styrene-butadiene-styrene block copolymer or a random copolymer, a polyphenylene ether resin containing double bonds, a resin containing at least one styrene functional group, a resin containing at least one vinyl or allyl functional group on an aromatic ring or an alicyclic ring, a resin containing an allyl functional group, a resin containing an isopropenyl functional group, and a resin containing a maleimide functional group.

Preferably, the C = C double bond containing resin comprises 0-95% but not 0, for example 0.5%, 1%, 3%, 5%, 10%, 15%, 18%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95% of the total weight of the thermosetting resin.

Preferably, the thermosetting resin composition further comprises a thermoplastic material.

Preferably, the thermoplastic material comprises SEBS resin and any one or combination of at least two of derivatives thereof or PPO resin.

Preferably, the thermoplastic material comprises 0% to 80%, for example 0.5%, 1%, 3%, 5%, 10%, 15%, 18%, 20%, 25%, 30%, 40%, 50%, 60%, 70% or 80% of the total weight of the thermosetting resin composition.

Preferably, the thermosetting resin composition further comprises an initiator.

Preferably, the initiator is selected from organic peroxides, azo-based radical initiators or carbon-based radical initiators.

Preferably, the initiator is selected from any one or a combination of at least two of t-butyl cumyl peroxide, dicumyl peroxide, benzoyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne or 1, 1-di (t-butylperoxy) -3, 5-dimethylcyclohexane, dicumyl or polydicumyl.

Preferably, the initiator comprises 0.1 to 3% by weight of the total thermosetting resin, for example 0.1%, 0.5%, 0.8%, 1%, 1.5%, 1.8%, 2%, 2.3%, 2.5%, 2.8% or 3%.

Preferably, the thermosetting resin composition further comprises a filler.

Preferably, the filler is selected from organic or inorganic fillers, preferably inorganic fillers, more preferably surface treated silica.

Preferably, the surface treatment agent for surface treatment is selected from any one of a silane coupling agent, an organosilicon oligomer or a titanate coupling agent or a combination of at least two thereof.

The surface treatment agent is preferably used in an amount of 0.1 to 5.0 parts by weight, for example, 0.1 part by weight, 0.5 part by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight or 5 parts by weight, preferably 0.5 to 3.0 parts by weight, and more preferably 0.75 to 2.0 parts by weight, based on 100 parts by weight of the inorganic filler.

Preferably, the inorganic filler is selected from any one of or a combination of at least two of non-metal oxide, metal nitride, non-metal nitride, inorganic hydrate, inorganic salt, metal hydrate, or inorganic phosphorus.

Preferably, the inorganic filler is selected from one or a combination of at least two of fused silica, crystalline silica, spherical silica, hollow silica, aluminum hydroxide, alumina, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, calcium silicate, or mica.

Preferably, the organic filler is selected from any one of or a combination of at least two of polyphenylene oxide powder, polyphenylene oxide microspheres, polytetrafluoroethylene powder, polyether ether ketone, polyphenylene sulfide or polyether sulfone powder.

Preferably, the filler has a median particle diameter of 0.01 to 50 μm, for example 0.01 μm, 0.05 μm, 0.1 μm, 0.5 μm, 1 μm, 3 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm or 50 μm, preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm.

Preferably, the inorganic filler is added in an amount of 5 to 300 parts by weight, for example, 5 parts by weight, 10 parts by weight, 20 parts by weight, 50 parts by weight, 80 parts by weight, 100 parts by weight, 150 parts by weight, 180 parts by weight, 200 parts by weight, 250 parts by weight, 280 parts by weight, or 300 parts by weight, preferably 5 to 200 parts by weight, and more preferably 5 to 150 parts by weight, based on 100 parts by weight of the sum of the addition amounts of the organic components other than the filler in the thermosetting resin.

In a second aspect, the present invention provides a prepreg comprising a reinforcing material and the resin composition of the first aspect attached to the reinforcing material by impregnation drying.

In a third aspect, the present invention provides a laminate comprising one or at least two stacked prepregs as described in the second aspect.

In a fourth aspect, the present invention provides a high-frequency circuit board comprising at least one prepreg according to the third aspect and a metal foil covering one or both sides of the laminated prepreg.

Preferably, the metal foil is a copper foil, a nickel foil, an aluminum foil, or a SUS foil, etc.

Compared with the prior art, the invention has the following beneficial effects:

the phosphorus-containing flame retardant with a specific structure is used in the invention, so that the flame retardant has good flame retardance, good thermal stability and moist heat resistance, excellent dielectric constant and dielectric loss tangent, good hydrolysis resistance and excellent process processability, and the flame retardant does not migrate at high temperature.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Preparation example 1

Synthesis of phosphorus-containing flame retardant

28.44g of bis (4-bromophenyl) phosphine oxide (0.0790 mol) were charged into a 25mL three-necked reaction flask equipped with a Dean-Stark trap, a hopper and thermocouple, and nitrogen inlet and outlet, and 4.69g of 1, 4-cyclohexanediol (0.0404 mol) and 0.300g of sodium iodide (0.00200 mol) were added. The reaction mixture was heated to 210 ℃ and the addition of p-xylene (entrainer) through the feed hopper was started. I.e. immediately with p-xylene and 1, 4-cyclohexanediol. After 2 hours at 200 ℃ 1.651 g of 1, 4-cyclohexanediol were added. The reaction was stirred for an additional 1 hour, then the mixture was diluted with xylene and the slurry was filtered while stirring for half an hour at 133 ℃, washed with acetone and dried overnight at 120 ℃ to give a white solid a with a molecular weight of 800.

A flask was charged with 7.96g of white solid A,5g of ethylene, 16.8g of tris (o-methylphenyl) phosphine, 7.692g of palladium acetate, 571mL of triethylamine and 350mL of acetonitrile, sealed and stirred at 85 ℃ for 24 hours under an argon atmosphere. Cooling and spin-drying the solvent. Washing with a large amount of deionized water for 3-5 times, and vacuum drying at 80 deg.C for 24h to obtain phosphorus-containing flame retardant with molecular weight of 588.

Examples

As shown in Table 1, other resins, fillers, a reactive halogen-free flame retardant and an initiator in the composition are uniformly mixed in a solvent according to a certain proportion, the solid content of a glue solution is controlled to be 65%, the glue solution is impregnated by 1035L glass fiber cloth, the proper thickness is controlled, then the glue solution is baked for 4min in an oven at 130 ℃ to prepare a prepreg, then 10 prepregs are stacked together, 18 mu m HVLP copper foils are stacked on two sides of the prepreg, the curing temperature is 210 ℃, and the curing pressure is 40kg/cm ² The copper-clad plate is prepared under the condition that the curing time is 120min, and the composition of the resin composition and the performance test standard of the copper-clad plate are shown in table 1.

TABLE 1

Physical properties of the copper foil substrates manufactured in the examples and comparative examples were evaluated according to the following methods:

1. glass transition temperature (. Degree. C.): the samples were tested with a dynamic viscosity Analyzer (DMA) Rheometric RSAIII.

2.T300: the heat resistance of the material was tested according to IPC-TM-650.2.4.24.1 standard.

Ps/thermal stress: the peel strength after thermal stress between the copper foil and the circuit carrier plate was tested according to the IPC-TM-650.4.8C standard test.

4. Dielectric constant Dk (10 GHz): the Dielectric constant Dk at a frequency of 10GHz was measured with a Dielectric Analyzer (Dielectric Analyzer) HP Agilent E4991A.

5. Loss factor Df (10 GHz): the loss factor Df at a frequency of 10GHz was measured with a Dielectric Analyzer (Dielectric Analyzer) HP Agilent E4991A.

6. Flame retardancy: the test was carried out according to UL 94.

PCT/6h: the plate from which the copper foil was etched was made into a 100mm × 100mm size sample, three pieces. The plate samples were cooked for 360min at 105 ℃ and 103.4Kpa using an autoclave and then tested for immersion in a tin furnace at 288 ℃ for delamination and plate explosion time. When the time is less than 300s, recording the specific time; the test was stopped after 5min, with a recording time > 300s. O represents that the sample has no delamination and cracking within 300s and the moist heat resistance passes; x represents that the sample has been subjected to layered board explosion within 300s, and the moist heat resistance test is failed.

As can be seen from the data in Table 1, the resin compositions of examples 1 to 6 can enable the copper clad laminate to have Tg of more than 220 ℃, dk (10 GHz) is less than 3.55, df (10 GHz) is less than 0.0015, PS is more than 0.50N/mm, higher peel strength is achieved, delamination and board explosion do not occur within 300s, the moisture and heat resistance is good, T300 is more than 60min, the heat resistance is good, and the flame retardance is good.

Comparative example 1 has a reduced peel strength and reduced flame retardancy due to the use of a small amount of the reactive flame retardant, comparative example 2 has a reduced peel strength, poor wet heat resistance and poor heat resistance due to the use of a relatively high amount of flame retardant A, comparative example 3 has a poor Df due to the use of PQ-60 flame retardant, and comparative example 4 has a reduced peel strength due to the use of a flame retardant XP-7866.

The applicant states that the present invention is illustrated in detail by the above embodiments, but the present invention is not limited to the above embodiments, that is, the present invention is not meant to be implemented by relying on the above embodiments. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims (10)

1. A thermosetting resin composition comprising a thermosetting resin and a phosphorus-containing flame retardant having a structure represented by formula I:

2. the thermosetting resin composition of claim 1, wherein the phosphorus-containing flame retardant comprises 8 to 40% by weight, preferably 10 to 30% by weight, more preferably 15 to 25% by weight of the total thermosetting resin composition.

3. The thermosetting resin composition according to claim 1 or 2, wherein the thermosetting resin is 10 to 95% by weight based on the total weight of the thermosetting resin composition.

4. The thermosetting resin composition of any one of claims 1-3, wherein the thermosetting resin comprises a resin containing C = C double bonds.

5. The thermosetting resin composition of any one of claims 1 to 4, wherein the resin containing C = C double bonds comprises any one of or a combination of at least two of polybutadiene resin and derivatives thereof, styrene-butadiene-styrene block copolymer or random copolymer, polyphenylene ether resin containing double bonds, resin containing at least one styrene functional group, resin containing at least one vinyl or allyl functional group on aromatic or alicyclic ring, resin containing allyl functional group, resin containing isopropenyl functional group, resin containing maleimide functional group;

preferably, the C = C double bond containing resin is 0-95% by weight of the total thermosetting resin excluding 0.

6. The thermosetting resin composition of any one of claims 1-5, further comprising a thermoplastic material;

preferably, the thermoplastic material comprises SEBS resin and any one or combination of at least two of derivatives thereof or PPO resin;

preferably, the thermoplastic material accounts for 0-80% of the total weight of the thermosetting resin composition.

7. The thermosetting resin composition of any one of claims 1-6, further comprising an initiator;

preferably, the initiator is selected from organic peroxides, azo radical initiators or carbon radical initiators;

preferably, the initiator is selected from any one or a combination of at least two of t-butyl cumyl peroxide, dicumyl peroxide, benzoyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne or 1, 1-di (t-butylperoxy) -3, 5-dimethylcyclohexane;

preferably, the initiator accounts for 0.1 to 3 percent of the total weight of the thermosetting resin;

preferably, the thermosetting resin composition further comprises a filler.

Preferably, the filler is selected from organic fillers or inorganic fillers, preferably inorganic fillers, further preferably surface-treated inorganic fillers, more preferably surface-treated silica;

preferably, the surface treatment agent for surface treatment is selected from any one of or a combination of at least two of a silane coupling agent, an organosilicon oligomer or a titanate coupling agent;

preferably, the surface treatment agent is used in an amount of 0.1 to 5.0 parts by weight, based on 100 parts by weight of the inorganic filler;

preferably, the inorganic filler is selected from any one of or a combination of at least two of non-metal oxide, metal nitride, non-metal nitride, inorganic hydrate, inorganic salt, metal hydrate or inorganic phosphorus;

preferably, the inorganic filler is selected from one or a combination of at least two of fused silica, crystalline silica, spherical silica, hollow silica, aluminum hydroxide, alumina, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, calcium silicate or mica;

preferably, the organic filler is selected from any one of or a combination of at least two of polyphenylene oxide powder, polyphenylene oxide microspheres, polytetrafluoroethylene powder, polyether ether ketone, polyphenylene sulfide or polyether sulfone powder;

preferably, the median particle diameter of the filler is 0.01 to 50 μm;

preferably, the inorganic filler is added in an amount of 5 to 300 parts by weight based on 100 parts by weight of the sum of the addition amounts of the organic components except for the filler in the thermosetting resin.

8. A prepreg comprising a reinforcing material and the thermosetting resin composition according to any one of claims 1 to 7 attached to the reinforcing material after drying by impregnation.

9. A laminate comprising one or at least two superimposed prepregs according to claim 8.

10. A high-frequency circuit board comprising at least one prepreg according to claim 8 and a metal foil covering one or both sides of the laminated prepreg.