A circuit material and a printed circuit board

Abstract

The present invention provides a circuit material and a printed circuit board. The circuit material includes a dielectric substrate layer, a conductive metal layer, and a resin layer disposed between the dielectric substrate layer and the conductive metal layer; the dielectric substrate layer includes a reinforcing material and a resin composition coated on the reinforcing material, and the resin composition includes the following components: (A) 1,2-polybutadiene resin; (B) a thermosetting resin with unsaturated double bonds in the polymer chain; (C) an inorganic filler; (D) a flame retardant; (E) a free radical initiator. The circuit material provided by the present invention has a relatively high peel strength after high-temperature aging, and relatively small changes in the Dk and insertion loss of the resonant ring after high-temperature aging and after high-temperature and high-humidity treatment.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic materials, and particularly relates to a circuit material and a printed circuit board. Background Art

[0002] High-frequency copper clad laminates are applied in more and more scenarios, including antennas, radio frequencies, power amplifiers, filters, radars, etc. The application scenarios are becoming more and more complex, and end customers have higher and higher requirements for high-frequency copper clad laminates. It is required to still have a relatively high peel strength after high-temperature aging, and the changes in resonant ring Dk and insertion loss after high-temperature aging and high-temperature and high-humidity treatment should be small.

[0003] CN113597088A discloses a circuit material, a preparation method thereof and a circuit board. The circuit material includes a flexible conductive metal layer, a PET film, and an adhesive layer disposed between the flexible conductive metal layer and the PET film. The thickness of the adhesive layer is 0.4 - 1 mm; the adhesive layer is made of an adhesive, and the adhesive is made of raw materials comprising the following parts by weight: 80 - 120 parts of hydroxyl-terminated polydimethylsiloxane, 2 - 7 parts of tetraethyl orthosilicate, 2 - 7 parts of a catalyst, and 5 - 15 parts of coated titanium dioxide; its preparation method is: the adhesive is coated between the flexible conductive metal layer and the PET film, and is placed under the condition of 40 - 55 °C, and the adhesive is cured to form an adhesive layer, thus obtaining the finished circuit material. Although the circuit board prepared by this technical solution has good flexibility, processing performance and appearance performance, its comprehensive performance after high-temperature aging is poor.

[0004] CN111393724A discloses a resin composition, a prepreg and a circuit material using the same. The resin composition includes an unsaturated polyphenylene ether resin, a polyolefin resin, a rosin resin and an initiator; based on the total weight of the unsaturated polyphenylene ether resin, the polyolefin resin and the rosin resin being 100 parts by weight, the content of the rosin resin is 3 - 40 parts by weight; the polyolefin resin is selected from one or a combination of at least two of an unsaturated polybutadiene resin, an SBS resin and a styrene-butadiene resin. Through the mutual cooperation among the unsaturated polyphenylene ether resin, the polyolefin resin and the rosin resin, the obtained resin composition has good film-forming property, adhesiveness and dielectric properties. The circuit board using it has a relatively high interlayer peel strength and a relatively low dielectric loss, but its peel strength after high-temperature aging is poor, and the changes in resonant ring Dk and insertion loss after high-temperature aging and high-temperature and high-humidity treatment are also large.

[0005] In the prior art, due to the excellent dielectric properties of 1,2-polybutadiene resin after curing, high cross-linking with a very high glass transition temperature, and the raw materials being inexpensive and easily available, 1,2-polybutadiene resin is often used as the main resin to prepare high-frequency copper clad laminates. However, the electrical properties of hydrocarbon high-frequency copper clad laminates in the prior art deteriorate severely after high-temperature aging and high-temperature and high-humidity treatment, and cannot meet the requirements of increasingly complex application scenarios of end customers.

[0006] Therefore, how to provide a circuit board material with a higher peel strength after high-temperature aging and smaller changes in the resonant ring Dk and insertion loss after high-temperature aging and high-temperature and high-humidity treatment has become a technical problem to be solved urgently at present. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a circuit material and a printed circuit board. In the present invention, by designing the structure of the circuit material and the specific composition of the resin composition, and further by selecting 1,2-polybutadiene resin with specific properties, the circuit material prepared has a higher peel strength after high-temperature aging and smaller changes in the resonant ring Dk and insertion loss after high-temperature aging and high-temperature and high-humidity treatment.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] In the first aspect, the present invention provides a circuit material, which includes a dielectric substrate layer, a conductive metal layer, and a resin layer disposed between the dielectric substrate layer and the conductive metal layer;

[0010] The dielectric substrate layer includes a reinforcing material and a resin composition coated on the reinforcing material, and the resin composition includes the following components:

[0011] (A) 1,2-polybutadiene resin, in which the vinyl content at the 1,2 position is ≥90%, the number average molecular weight (Mn) is 3000 - 6000 g / mol, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) PDI is 1.02 - 1.08;

[0012] (B) A thermosetting resin with unsaturated double bonds in the polymer chain, and the number average molecular weight Mn ≥ 50000 g / mol;

[0013] (C) Inorganic filler;

[0014] (D) Flame retardant;

[0015] (E) Free radical initiator.

[0016] In the present invention, by designing the structure of the circuit material and the specific composition of the resin composition, and further by selecting 1,2-polybutadiene resin with specific properties, the prepared circuit material has a relatively high peel strength after high-temperature aging, and the changes in Dk and insertion loss of the resonant ring after high-temperature aging and after high-temperature and high-humidity treatment are relatively small.

[0017] In the present invention, by selecting 1,2-polybutadiene resin with specific properties, when the vinyl content at the 1,2-position in the 1,2-polybutadiene resin is ≥90%, the number-average molecular weight (Mn) is 3000 - 6000 g / mol, it has a narrow molecular weight distribution, and the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), PDI, is 1.02 - 1.08, the prepared circuit material has good comprehensive properties.

[0018] If the vinyl content at the 1,2-position in the 1,2-polybutadiene resin is <90%, the curing crosslinking density of the circuit material (also known as the board) will deteriorate, thereby affecting the aging performance, and ultimately resulting in the values of the changes in Dk and insertion loss of the resonant ring of the circuit material exceeding the standard after aging at 188°C for 28 days.

[0019] If the number-average molecular weight (Mn) of the 1,2-polybutadiene resin is less than 3000 g / mol, the molecular weight is too small, and it is easy to produce glue flow and grooves during pressing, resulting in an inhomogeneous internal structure of the board, and ultimately resulting in the values of the changes in Dk and insertion loss of the resonant ring of the circuit material exceeding the standard after being treated at 85% RH and 85°C for 1000 hours; if the number-average molecular weight (Mn) of the 1,2-polybutadiene resin is greater than 6000 g / mol, the molecular weight is too large, and it is not easy to produce glue flow during pressing, resulting in dry flowers, and resulting in voids in the internal structure of the board, and ultimately resulting in the values of the changes in Dk and insertion loss of the resonant ring of the circuit material exceeding the standard after being treated at 85% RH and 85°C for 1000 hours.

[0020] At the same time, in the present invention, by controlling the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), PDI, of the 1,2-polybutadiene resin to be 1.02 - 1.08, it can meet the requirements that the changes in Dk and insertion loss of the resonant ring of the high-frequency electronic circuit substrate after aging and after high-temperature and high-humidity are both relatively small. When PDI is less than 1.02, it is very difficult for raw material suppliers to synthesize a polymer with an almost completely single molecular weight distribution; when PDI is greater than 1.08, the molecular weight distribution of the resin is relatively wide, and the fluctuation values of the Dk and insertion loss data measured for the circuit material are relatively large, and ultimately resulting in the values of the changes in Dk and insertion loss of the resonant ring of the circuit material exceeding the standard after aging at 188°C for 28 days and after being treated at 85% RH and 85°C for 1000 hours.

[0021] In the present invention, the vinyl content at the 1,2-position in the 1,2-polybutadiene resin is ≥90% (for example, it can be 90%, 91%, 92%, 93%, 94% or 95%, etc.), the number-average molecular weight (Mn) is 3000 - 6000 g / mol (for example, it can be 3000 g / mol, 3300 g / mol, 3500 g / mol, 3700 g / mol, 4000 g / mol, 4200 g / mol, 4600 g / mol, 5000 g / mol, 5200 g / mol, 5500 g / mol, 5700 g / mol or 6000 g / mol, etc.), and the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), PDI, is 1.02 - 1.08 (for example, it can be 1.02, 1.03, 1.04, 1.05, 1.06, 1.07 or 1.08, etc.).

[0022] The number-average molecular weight of the high-molecular-weight thermosetting resin with unsaturated double bonds can be 50000 g / mol, 60000 g / mol, 65000 g / mol, 70000 g / mol, 80000 g / mol, 90000 g / mol, 100000 g / mol, 110000 g / mol or 120000 g / mol, etc.

[0023] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0024] As a preferred technical solution of the present invention, the resin layer is an unmodified polyarylether layer.

[0025] Preferably, the raw materials for preparing the unmodified polyarylether layer include unmodified polyarylether, metal salts containing unsaturated bonds, and co-curable monomers.

[0026] The specific proportions of the raw materials and the preparation method in the unmodified polyarylether layer can refer to CN113072885A.

[0027] Preferably, the thickness of the resin layer is 5 - 20 μm, for example, it can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 12 μm, 13 μm, 14 μm, 15 μm, 18 μm or 20 μm, etc.

[0028] In the present invention, by providing an unmodified polyarylether layer between the dielectric substrate layer and the conductive metal layer, with the unmodified polyarylether layer, not only can a relatively high peel strength be ensured between the dielectric substrate layer and the conductive metal layer after aging at 188°C for 10 days, but also through the cooperative effect between the unmodified polyarylether layer and the resin composition, through their synergistic effect, finally, the change values of the resonant ring Dk and the insertion loss after aging the circuit material at 188°C for 28 days are relatively small; the change values of the resonant ring Dk and the insertion loss of the circuit material after being treated at 85% RH and 85°C for 1000 hours are also relatively small. This is because the crosslinking density of hydrocarbon resins (including 1,2-polybutadiene resin and thermosetting resins with unsaturated double bonds in the polymer chain) is relatively high and the molecular chains are prone to aging. Without the unmodified polyarylether layer, after high-temperature aging, the surface of the hydrocarbon resin will carbonize and shrink, eventually forming tiny gaps with the copper foil. Not only will the peel strength be greatly reduced, but also the carbonization will cause the change values of the resonant ring Dk and the insertion loss after aging to exceed the standard. The carbonization and tiny gaps will cause the change values of the resonant ring Dk and the insertion loss after high-temperature and high-humidity treatment to exceed the standard.

[0029] As a preferred technical solution of the present invention, based on 100 parts by weight of the resin composition, the sum of the parts by weight of component (A) and component (B) is 15 - 25 parts, for example, it can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts or 25 parts, etc.

[0030] Preferably, the mass ratio of component (A) to component (B) is 2:1 - 3:1, for example, it can be 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1 or 3:1, etc.

[0031] In the present invention, based on 100 parts by weight of the total amount of the resin composition, the total amount of component (A) and (B) is 15 - 25 parts by weight, and the total amount of component (C) is 60 - 78 parts by weight. Such a resin ratio and filler ratio are the result of the formula comprehensively considering the dielectric properties of the product and the production processability. If the resin ratio is too small, the resin cannot fill the voids between the fillers, easily forming voids, and eventually causing the change values of the resonant ring Dk and the insertion loss of the circuit material after being treated at 85% RH and 85°C for 1000 hours to exceed the standard; if the resin ratio is too high, especially when using 1,2-polybutadiene hydrocarbon resin, the bonding sheet will be sticky, affecting the production processability and the appearance of the board, and the resin is prone to defects such as grooves, and finally will also cause the change values of the resonant ring Dk and the insertion loss of the circuit material after being treated at 85% RH and 85°C for 1000 hours to exceed the standard.

[0032] In the present invention, by adding a high molecular weight thermosetting resin with unsaturated double bonds to the resin composition formulation, it is possible to ensure that the high-frequency substrate has good thickness uniformity, thereby ensuring that the Dk of the resonant ring and the change value of insertion loss fluctuate less. Because the 1,2-polybutadiene resin with a number average molecular weight (Mn) of 3000-6000 g / mol will flow and produce defects such as grooves after being heated and pressurized, the thickness at the edge of the plate is too thin, and the thickness of the plate is unstable, which will lead to large fluctuations in the Dk of the resonant ring and insertion loss. When the ratio of 1,2-polybutadiene resin to the high molecular weight thermosetting resin with unsaturated double bonds is 2:1-3:1, the effect is the best. If the ratio of the high molecular weight thermosetting resin with unsaturated double bonds is too low, the purpose of improving thickness uniformity and defects such as grooves cannot be achieved, which will lead to the Dk of the resonant ring and the change value of insertion loss exceeding the standard after the circuit material is treated at 85% RH and 85 °C for 1000 hours; if the ratio of the high molecular weight thermosetting resin with unsaturated double bonds is too high, it is easy to not flow and produce dry flowers, resulting in voids in the internal structure of the plate, and ultimately leading to the Dk of the resonant ring and the change value of insertion loss exceeding the standard after the circuit material is treated at 85% RH and 85 °C for 1000 hours.

[0033] As a preferred technical solution of the present invention, the component (B) is selected from any one or a combination of at least two of an elastomeric block copolymer, an ethylene-propylene rubber, or a polybutadiene rubber.

[0034] Preferably, the elastomeric block copolymer is selected from any one or a combination of at least two of a styrene-butadiene diblock copolymer, a styrene-butadiene-styrene triblock copolymer, a styrene-(ethylene-butene)-styrene triblock copolymer, a styrene-isoprene diblock copolymer, a styrene-isoprene-styrene triblock copolymer, a styrene-(ethylene-propylene)-styrene triblock copolymer, or a styrene-(ethylene-butene) diblock copolymer.

[0035] As a preferred technical solution of the present invention, based on 100 parts by weight of the resin composition, the weight of the inorganic filler is 60-78 parts, for example, it can be 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, 70 parts, 72 parts, 74 parts, 76 parts, or 78 parts, etc.

[0036] Preferably, the D50 particle size of the inorganic filler is 2-20 μm, for example, it can be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 13 μm, 14 μm, 15 μm, 18 μm, or 20 μm, etc.

[0037] Preferably, the inorganic filler is selected from any one or a combination of at least two of silica, titanium dioxide, hollow glass beads, alumina, boron nitride, aluminum nitride, silicon nitride, silicon carbide, magnesium oxide, zinc oxide, barium titanate, strontium titanate, magnesium titanate, calcium titanate, potassium titanate, strontium barium titanate, lead titanate, glass powder, magnesium hydroxide, mica powder, talc powder, hydrotalcite, mullite, boehmite, kaolin, montmorillonite, calcium silicate or calcium carbonate.

[0038] Preferably, the silica includes fused silica and / or crystalline silica, and more preferably fused silica.

[0039] Preferably, the titanium dioxide includes rutile titanium dioxide and / or anatase titanium dioxide, and more preferably rutile titanium dioxide.

[0040] Preferably, the inorganic filler includes unmodified inorganic filler and / or inorganic filler surface-modified with ethylene or a coupling agent.

[0041] As a preferred technical solution of the present invention, based on 100 parts by weight of the resin composition, the weight parts of the flame retardant are 5 to 15 parts, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts, etc.

[0042] Preferably, the flame retardant includes a bromine-containing flame retardant and / or a phosphorus-containing flame retardant.

[0043] Preferably, the bromine-containing flame retardant includes any one or a combination of at least two of decabromodiphenyl ether, decabromodiphenylethane or ethylene bis(tetrabromophthalimide).

[0044] Preferably, the phosphorus-containing flame retardant includes any one or a combination of at least two of tris(2,6-dimethylphenyl)phosphine, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6-bis(2,6-dimethylphenyl)phosphinobenzene or 10-phenyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0045] As a preferred technical solution of the present invention, based on 100 parts by weight of the resin composition, the weight parts of the radical initiator are 0.5 to 1 part, for example, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part or 1 part, etc.

[0046] Preferably, the radical initiator includes an organic peroxide radical initiator and / or a carbon-based radical initiator.

[0047] Preferably, the organic peroxide free radical initiator includes any one of diisopropylbenzene peroxide, 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,5-di-tert-butylperoxy-2,5-dimethylhexane, 2,5-di-tert-butylperoxy-2,5-dimethylhexyne-3, di-tert-butyl peroxide or tert-butylperoxide isopropylbenzene, or a combination of at least two thereof.

[0048] Preferably, the carbon-based free radical initiator is selected from any one of 2,3-dimethyl-2,3-diphenylbutane, 2,3-dimethyl-2,3-di(4-methylphenyl)butane, 2,3-dimethyl-2,3-di(4-isopropylphenyl)butane, and 3,4-dimethyl-3,4-diphenylhexane, or a combination of at least two thereof.

[0049] As a preferred technical solution of the present invention, based on 100 parts by weight of the resin composition, the resin composition further includes 0.1 to 0.5 parts by weight of a coupling agent, for example, 0.1, 0.2, 0.3, 0.4 or 0.5 parts.

[0050] Preferably, the coupling agent comprises a vinyl coupling agent.

[0051] Preferably, based on 100 parts by weight of the resin composition, the resin composition further comprises 0.1 to 0.5 parts by weight of an auxiliary agent, for example, 0.1 part, 0.2 part, 0.3 part, 0.4 part or 0.5 part.

[0052] Preferably, the auxiliary agent includes any one of a crosslinking agent, an antioxidant, a heat stabilizer, an antistatic agent, an ultraviolet absorber, a pigment, a colorant or a lubricant, or a combination of at least two thereof.

[0053] Preferably, the cross-linking agent includes any one of triallyl cyanate (TAC), allyl isocyanate (TAIC), trimethallyl isocyanate (TMAIC), or a combination of at least two thereof.

[0054] It should be noted that the resin composition of the present invention can also be used in combination with various other polymers, as long as they do not damage the inherent properties of the resin composition. The various other polymers exemplarily include but are not limited to: liquid crystal polymers, thermoplastic resins, different flame retardant compounds or additives, etc.; and can be used alone or in combination as needed.

[0055] It should be noted that there are no special restrictions on the preparation method of the resin composition in the present invention, and the commonly used preparation methods in the art are applicable, including but not limited to: stirring and mixing. In the present invention, the particle size of the spherical silica is measured by a Malvern 3000 laser particle size analyzer; in the present invention, the molecular weight (including number average molecular weight Mn and weight average molecular weight Mw) of the thermosetting resin is measured by GB / T 21863-2008 and determined by gel permeation chromatography based on polystyrene calibration.

[0056] As a preferred technical solution of the present invention, the reinforcing material is an electronic grade glass fiber cloth.

[0057] Preferably, the conductive metal layer is a copper foil.

[0058] Preferably, the thickness of the copper foil is 9-150 μm, such as 9 μm, 12 μm, 20 μm, 30 μm, 40 μm, 50 μm, 70 μm, 90 μm, 110 μm, 120 μm, 130 μm or 140 μm, etc.

[0059] It should be noted that there are no specific restrictions on the preparation method of the circuit material in the present invention. Exemplarily, the preparation method of the circuit material includes the following steps:

[0060] (1) Dissolve or disperse the resin composition in a solvent to obtain a resin glue solution. After impregnating the reinforcing material with the resin glue solution and drying to remove the solvent, a prepreg is obtained;

[0061] (2) Coat the unmodified polyarylether layer on the copper foil and dry the solvent to obtain a resin-coated copper foil (RCC);

[0062] (3) Stack at least one prepreg together and place it between two resin-coated copper foils (RCC) in step (2), and then put it into a laminator and cure it by hot pressing to obtain the circuit material.

[0063] It should be noted that the present invention has no special restrictions on the solvent in step (1), and commonly used organic solvents in the art are applicable, including but not limited to: alcohols such as methanol, ethanol, and butanol; ethers such as ethyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, diethylene glycol ethyl ether, and diethylene glycol butyl ether; ketones such as acetone, butanone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and mesitylene; esters such as ethoxyethyl acetate and ethyl acetate; nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The above solvents can be used alone or in combination of two or more.

[0064] Based on 100 parts by weight of the resin composition, the weight of the solvent is 40 to 80 parts, such as 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts or 80 parts, etc.

[0065] In a second aspect, the present invention provides a printed circuit board, which includes the circuit material as described in the first aspect.

[0066] Preferably, the printed circuit board is a high-frequency substrate.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] (1) In the present invention, through the design of the structure of the circuit material and the specific composition of the resin composition, further through the setting of the unmodified polyarylether layer and the selection of 1,2-polybutadiene resin with specific properties, the circuit material prepared has a higher peel strength after high-temperature aging, and the change values of the resonant ring Dk and insertion loss after high-temperature aging and high-temperature and high-humidity treatment are smaller. The peel strength of the circuit material after aging at 188°C for 10 days is ≥1.25 N / mm, the change value of the resonant ring Dk after aging at 188°C for 28 days is ≤0.05 (2 GHz), and the change value of the insertion loss is ≤0.05 dB / 5 inch (2 GHz); the change value of the resonant ring Dk after being treated at 85% RH and 85°C for 1000 hours is ≤0.05 (2 GHz), and the change value of the insertion loss is ≤0.05 dB / 5 inch (2 GHz).

[0069] (2) In the present invention, by further setting the content of each component in the resin composition within a specific range, the change values of the resonant ring Dk and insertion loss of the circuit material after high-temperature aging and high-temperature and high-humidity can be further reduced, and more excellent performance effects can be obtained. The change value of the resonant ring Dk of the circuit material after aging at 188°C for 28 days is ≤0.042 (2 GHz), specifically 0.035 to 0.042, and the change value of the insertion loss is ≤0.045 dB / 5 inch (2 GHz), specifically 0.038 to 0.045; the change value of the resonant ring Dk after being treated at 85% RH and 85°C for 1000 hours is ≤0.044 (2 GHz), specifically 0.033 to 0.044, and the change value of the insertion loss is ≤0.046 dB / 5 inch (2 GHz), specifically 0.036 to 0.046. Detailed Embodiments

[0070] To facilitate the understanding of the present invention, the following examples are listed. Those skilled in the art should understand that the examples are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0071] The sources of some components in the examples and comparative examples are shown in Table 1 below:

[0072] Table 1

[0073]

[0074]

[0075] Among them, in the conductive metal layer, having RCC refers to a copper foil with an unmodified polyarylether layer, and not having RCC refers to a copper foil without an unmodified polyarylether layer.

[0076] The raw materials for preparing the unmodified polyarylether layer in the following examples and comparative examples include 100 parts by weight of unmodified polyarylether, 15 parts by weight of a metal salt containing unsaturated bonds, 8 parts by weight of a co-curable monomer, 8 parts by weight of an elastomeric block copolymer, and 4 parts by weight of an initiator.

[0077] Examples 1 - 9

[0078] Examples 1 - 9 respectively provide a circuit material and a preparation method thereof. The circuit material includes a dielectric substrate layer, a conductive metal layer, and an unmodified polyarylether layer disposed between the dielectric substrate layer and the conductive metal layer;

[0079] The dielectric substrate layer includes a reinforcing material and a resin composition coated on the reinforcing material. The specific composition of the resin composition is shown in Table 2 and Table 3 below. The dosage unit of the resin composition in Table 2 and Table 3 is parts by weight.

[0080] The circuit material in Example 1 was prepared by the following method:

[0081] (1) Dissolve or disperse the resin composition in xylene to obtain a resin glue solution. After impregnating the reinforcing material with the resin glue solution and drying to remove the solvent, a prepreg is obtained;

[0082] (2) Coat the unmodified polyarylether layer on the copper foil and dry the solvent to obtain a copper foil with an unmodified polyarylether layer (RCC);

[0083] (3) Stack at least one prepreg together and place it between two copper foils (RCC) with an unmodified polyarylether layer obtained in step (2). Then put it into a laminator and cure it by hot pressing at a temperature of 245 °C and a pressure of 60 Kg / cm 2 to obtain the circuit material.

[0084] Comparative Examples 1 - 5

[0085] Comparative Examples 1 - 5 respectively provide a circuit material and a preparation method thereof. The specific composition of the resin composition and the specific composition materials of the circuit material are shown in Table 3 below. The dosage unit of the resin composition in Table 3 is parts by weight.

[0086] The circuit materials described in Comparative Examples 1-5 can be prepared with reference to the preparation method provided in Example 1.

[0087] Table 2

[0088]

[0089]

[0090] Table 3

[0091] Component Example 6 Example 7 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 A-1 17 A-2 17 A-3 A-4 A-5 A-6 10 20 19 15 17 A-7 A-8 17 A-9 17 B-1 4 9 5 9 7 7 7 7 7 B-2 C-1 75 60 65 65 65 65 65 65 65 C-2 C-3 C-4 C-5 D-1 10 10 10 10 10 10 10 10 10 D-2 E-1 E-2 1 1 1 1 1 1 1 1 1 F-1 6 6 6 6 6 6 6 6 6 F-2 T-1 2 T-2 2 2 2 2 2 2 2 2 T-3 T-4

[0092] The performance of the circuit materials provided in Examples 1-9 and Comparative Examples 1-5 was tested. The specific test methods are as follows:

[0093] (1) Dielectric constant (Dk) and dielectric loss (Df): Using the SPDR method, the dielectric constant (Dk) and dielectric loss (Df) of the board were tested at a frequency of 10 GHz.

[0094] (2) Peel strength (PS): After the board was aged at 188 °C for 10 days, the peel strength of the board was tested according to the IPC-TM-650 2.4.8 method. The unit of peel strength is N / mm.

[0095] (3) Resonant ring Dk: It was tested according to the design drawing and test method provided by the terminal, and the test frequency was 2 GHz. The test conditions were divided into three conditions: receiving state, after aging at 188 °C for 28 days, and after being treated at 85% RH and 85 °C for 1000 hours. The change value of the resonant ring Dk after aging at 188 °C for 28 days was the difference between the resonant ring Dk after aging at 188 °C for 28 days and the resonant ring Dk in the receiving state. The change value of the resonant ring Dk after being treated at 85% RH and 85 °C for 1000 hours was the difference between the resonant ring Dk after being treated at 85% RH and 85 °C for 1000 hours and the resonant ring Dk in the receiving state.

[0096] (4) Insertion loss: It was tested according to the design drawing and test method provided by the terminal, and the test frequency was 2 GHz. The unit of insertion loss is dB / 5inch. The test conditions were divided into three conditions: receiving state, after aging at 188 °C for 28 days, and after being treated at 85% RH and 85 °C for 1000 hours. The change value of the insertion loss after aging at 188 °C for 28 days was the difference between the insertion loss after aging at 188 °C for 28 days and the insertion loss in the receiving state. The change value of the insertion loss after being treated at 85% RH and 85 °C for 1000 hours was the difference between the insertion loss after being treated at 85% RH and 85 °C for 1000 hours and the insertion loss in the receiving state.

[0097] The test results of the laminates provided in the examples and comparative examples are shown in Tables 4 and 5:

[0098] Table 4

[0099]

[0100] Table 5

[0101]

[0102] As can be seen from the data in Table 4 and Table 5, in the present invention, through the design of the circuit material structure and the specific composition of the resin composition, and further through the setting of the unmodified polyarylether layer and the selection of 1,2-polybutadiene resin with specific properties, the circuit material prepared has a higher peel strength after high-temperature aging, and smaller changes in the Dk and insertion loss of the resonant ring after high-temperature aging and after high-temperature and high-humidity treatment. The peel strength of the circuit material after aging at 188°C for 10 days is ≥1.25 N / mm, the change value of the resonant ring Dk after aging at 188°C for 28 days is ≤0.05 (2 GHz), and the change value of the insertion loss is ≤0.05 dB / 5 inch (2 GHz); the change value of the resonant ring Dk after treatment at 85% RH and 85°C for 1000 hours is ≤0.05 (2 GHz), and the change value of the insertion loss is ≤0.05 dB / 5 inch (2 GHz).

[0103] In the present invention, by further setting the contents of the components in the resin composition within a specific range, the change values of the Dk and insertion loss of the resonant ring after high-temperature aging and after high-temperature and high-humidity can be further reduced, and more excellent performance effects can be obtained. The change value of the resonant ring Dk after aging the circuit material at 188°C for 28 days is ≤0.042 (2 GHz), specifically 0.035 - 0.042, and the change value of the insertion loss is ≤0.045 dB / 5 inch (2 GHz), specifically 0.038 - 0.045; the change value of the resonant ring Dk after treatment at 85% RH and 85°C for 1000 hours is ≤0.044 (2 GHz), specifically 0.033 - 0.044, and the change value of the insertion loss is ≤0.046 dB / 5 inch (2 GHz), specifically 0.036 - 0.046.

[0104] As can be seen from the comparison between Example 4 and Examples 6 - 7, if the addition amount of the resin (component (A) and component (B)) is too small (Example 6), the resin cannot fill the voids between the fillers, and voids are easily formed, ultimately resulting in the change values of the Dk and insertion loss of the resonant ring of the circuit material exceeding the standard after treatment at 85% RH and 85°C for 1000 hours; if the addition amount of the resin is too high (Example 7), especially when using 1,2-polybutadiene resin, the bonding sheet will be sticky, affecting the production processability and the appearance of the board, and the resin is prone to defects such as grooves, ultimately resulting in the change values of the Dk and insertion loss of the resonant ring of the circuit material exceeding the standard after treatment at 85% RH and 85°C for 1000 hours.

[0105] From the comparison between Example 4 and Examples 8-9, it can be seen that if the proportion of the high-molecular-weight thermosetting resin with unsaturated double bonds is too low (the addition amount of 1,2-polybutadiene resin is too high), the purpose of improving thickness uniformity and defects such as grooves cannot be achieved, which will lead to the excessive change values of the resonant ring Dk and insertion loss of the circuit material after being treated at 85% RH and 85 °C for 1000 hours; if the proportion of the high-molecular-weight thermosetting resin with unsaturated double bonds is too high (the addition amount of 1,2-polybutadiene resin is too low), it is easy to have no resin flow, resulting in dry flowers, leading to voids in the internal structure of the board, and finally resulting in the excessive change values of the resonant ring Dk and insertion loss of the circuit material after being treated at 85% RH and 85 °C for 1000 hours.

[0106] From the comparison between Example 4 and Comparative Examples 1-2, it can be seen that when the number-average molecular weight (Mn) of the 1,2-polybutadiene resin is less than 3000 g / mol, the molecular weight is too small, and it is easy to have resin flow and generate grooves during pressing, resulting in an incompact internal structure of the board, and finally leading to the excessive change values of the resonant ring Dk and insertion loss of the circuit material after being treated at 85% RH and 85 °C for 1000 hours; when the number-average molecular weight (Mn) of the 1,2-polybutadiene resin is greater than 6000 g / mol, the molecular weight is too large, and it is not easy to have resin flow during pressing, resulting in dry flowers, leading to voids in the internal structure of the board, and finally leading to the excessive change values of the resonant ring Dk and insertion loss of the circuit material after being treated at 85% RH and 85 °C for 1000 hours.

[0107] From the comparison between Example 4 and Comparative Examples 3-4, it can be seen that when the PDI is greater than 1.08, the molecular weight distribution of the resin is relatively wide, and the fluctuation values of the resonant ring Dk and insertion loss data measured for the circuit material are relatively large, finally leading to the excessive change values of the resonant ring Dk and insertion loss of the circuit material after aging at 188 °C for 28 days and after being treated at 85% RH and 85 °C for 1000 hours; when the 1,2-vinyl content in the 1,2-polybutadiene resin is less than 90%, the curing crosslinking density of the board will deteriorate, thus affecting the aging performance, and finally leading to the excessive change values of the resonant ring Dk and insertion loss of the circuit material after aging at 188 °C for 28 days.

[0108] From the comparison between Example 4 and Comparative Example 5, it can be seen that the conductive metal layer and the unmodified polyarylether layer disposed between the dielectric substrate layer and the conductive metal layer can not only ensure that the peel strength between the dielectric substrate layer and the conductive metal layer is ≥1.20 N / mm after aging at 188°C for 10 days, but also, through the synergistic effect between the unmodified polyarylether layer and the resin composition, finally achieve that the change value of the resonant ring Dk of the circuit material is ≤0.05 (2 GHz) and the change value of the insertion loss is ≤0.05 dB / 5 inch (2 GHz) after aging at 188°C for 28 days; the change value of the resonant ring Dk of the circuit material is ≤0.05 (2 GHz) and the change value of the insertion loss is ≤0.05 dB / 5 inch (2 GHz) after being treated at 85% RH and 85°C for 1000 hours. Without the unmodified polyarylether layer, after high-temperature aging, the surface of the hydrocarbon resin (Component (A) and Component (B)) will carbonize and shrink, and finally form tiny gaps with the copper foil, not only greatly reducing the peel strength, but also the carbonization will cause the change values of the resonant ring Dk and the insertion loss after aging to exceed the standard. The carbonization and tiny gaps cause the change values of the resonant ring Dk and the insertion loss after high-temperature and high-humidity treatment to exceed the standard.

[0109] In summary, in the present invention, through the design of the structure of the circuit material and the specific composition of the resin composition, further through the setting of the unmodified polyarylether layer, and by selecting 1,2-polybutadiene resin with specific properties, the circuit material prepared has a relatively high peel strength after high-temperature aging, and relatively small change values of the resonant ring Dk and the insertion loss after high-temperature aging and high-temperature and high-humidity treatment.

[0110] The above is only the preferred embodiment of the present invention, and does not impose any restrictions on the content of the composition of the present invention. For those of ordinary skill in the art, various corresponding changes and deformations can be made according to the technical solutions and technical concepts of the present invention. Any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence or composition or content of the present invention all fall within the scope of the technical solutions of the present invention.

Claims

1. A circuit material, characterized in that, the circuit material comprises a dielectric substrate layer, a conductive metal layer, and a resin layer disposed between the dielectric substrate layer and the conductive metal layer; the dielectric substrate layer comprises a reinforcing material and a resin composition coated on the reinforcing material, and the resin composition comprises the following components: (A) 1,2-polybutadiene resin, wherein the vinyl content at the 1,2-position in the 1,2-polybutadiene resin is ≥90%, the number average molecular weight is 3000 - 6000 g / mol, and the ratio of the weight average molecular weight to the number average molecular weight PDI is 1.02 - 1.08; (B) a high molecular weight thermosetting resin with unsaturated double bonds, and the number average molecular weight Mn ≥ 50000 g / mol; (C) an inorganic filler; (D) a flame retardant; (E) a radical initiator; the resin layer is an unmodified polyarylether layer; at a test frequency of 2 GHz, the change value of the resonant ring Dk of the circuit material after aging at 188°C for 28 days is ≤0.05, and the change value of the insertion loss is ≤0.05 dB / 5 inch.

2. The circuit material according to claim 1, characterized in that, based on 100 parts by weight of the resin composition, the sum of the weight parts of the component (A) and the component (B) is 15 - 25 parts.

3. The circuit material according to claim 1, characterized in that, the mass ratio of the component (A) to the component (B) is 2:1 - 3:

1.

4. The circuit material according to claim 1, characterized in that, the component (B) is selected from any one or a combination of at least two of an elastomeric block copolymer, an ethylene-propylene rubber, or a polybutadiene rubber.

5. The circuit material according to claim 4, characterized in that, the elastomeric block copolymer is selected from any one or a combination of at least two of a styrene-butadiene diblock copolymer, a styrene-butadiene-styrene triblock copolymer, a styrene-(ethylene-butene)-styrene triblock copolymer, a styrene-isoprene diblock copolymer, a styrene-isoprene-styrene triblock copolymer, a styrene-(ethylene-propylene)-styrene triblock copolymer, or a styrene-(ethylene-butene) diblock copolymer.

6. The circuit material according to claim 1, characterized in that, based on 100 parts by weight of the resin composition, the weight part of the inorganic filler is 60 - 78 parts.

7. The circuit material according to claim 1, characterized in that, the D50 particle size of the inorganic filler is 2 - 20 μm.

8. The circuit material according to claim 1, characterized in that, the inorganic filler is selected from any one or a combination of at least two of silica, titanium dioxide, hollow glass beads, alumina, boron nitride, aluminum nitride, silicon nitride, silicon carbide, magnesium oxide, zinc oxide, barium titanate, strontium titanate, magnesium titanate, calcium titanate, potassium titanate, strontium barium titanate, lead titanate, glass powder, magnesium hydroxide, mica powder, talc powder, hydrotalcite, mullite, boehmite, kaolin, montmorillonite, calcium silicate, or calcium carbonate.

9. The circuit material according to claim 1, characterized in that, Based on 100 parts by weight of the resin composition, the weight parts of the flame retardant are 5 to 15 parts.

10. The circuit material according to claim 1, characterized in that the flame retardant includes a bromine-containing flame retardant and / or a phosphorus-containing flame retardant.

11. The circuit material according to claim 1, characterized in that Based on 100 parts by weight of the resin composition, the weight parts of the radical initiator are 0.5 to 1 part.

12. The circuit material according to claim 1, characterized in that the radical initiator includes an organic peroxide radical initiator and / or a carbon-based radical initiator.

13. The circuit material according to claim 12, characterized in that the organic peroxide radical initiator includes any one or at least two combinations of dicumyl peroxide, 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,5-di-tert-butylperoxy-2,5-dimethylhexane, 2,5-di-tert-butylperoxy-2,5-dimethylhex-3-yne, di-tert-butyl peroxide or tert-butylcumyl peroxide.

14. The circuit material according to claim 12, characterized in that the carbon-based radical initiator is selected from any one or at least two combinations of 2,3-dimethyl-2,3-diphenylbutane, 2,3-dimethyl-2,3-bis(4-methylphenyl)butane, 2,3-dimethyl-2,3-bis(4-isopropylphenyl)butane, 3,4-dimethyl-3,4-diphenylhexane.

15. The circuit material according to claim 1, characterized in that Based on 100 parts by weight of the resin composition, the resin composition further includes 0.1 to 0.5 parts by weight of a coupling agent.

16. The circuit material according to claim 15, characterized in that the coupling agent includes a vinyl coupling agent.

17. The circuit material according to claim 1, characterized in that Based on 100 parts by weight of the resin composition, the resin composition further includes 0.1 to 0.5 parts by weight of an auxiliary agent.

18. The circuit material according to claim 17, characterized in that the auxiliary agent includes any one or at least two combinations of a crosslinking agent, an antioxidant, a heat stabilizer, an antistatic agent, an ultraviolet absorber, a colorant or a lubricant.

19. The circuit material according to claim 1, characterized in that the reinforcing material is an electronic-grade glass fiber cloth.

20. The circuit material according to claim 1, characterized in that the conductive metal layer is a copper foil.

21. The circuit material according to claim 20, characterized in that the thickness of the copper foil is 9 to 150 μm.

22. A printed circuit board, characterized in that the printed circuit board includes the circuit material according to any one of claims 1-21.

23. The printed circuit board according to claim 22, characterized in that the printed circuit board is a high-frequency substrate.

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