A high-Tg chip-on-board copper-clad laminate and a preparation method thereof

Abstract

This application discloses a high-Tg chip-on-board copper-clad laminate and a preparation method thereof. The copper-clad laminate comprises a substrate material, glass fiber cloth, and copper foil. The substrate material comprises the following raw materials in parts by weight: 100 parts of a composite epoxy resin, 20-25 parts of a sulfone curing agent, 30-150 parts of modified spherical silica, 4.5-24 parts of a white dye, and 0.15-3 parts of a dispersant. The composite epoxy resin comprises an E-type epoxy resin and a multifunctional epoxy resin in a mass ratio of (3-4):(6-7). The modified spherical silica has a naphthalene structure on its surface. The multifunctional epoxy resin contains numerous reactive sites, which can enhance crosslinking between the epoxy resin and the curing agent during the curing process, thereby increasing the glass transition temperature of the copper-clad laminate. The naphthalene structured compound molecules exhibit a planar structure, which can inhibit the free movement between the epoxy resin molecular chains and reduce the thermal expansion coefficient of the cured substrate material.

Description

Technical Field

[0001] The present application relates to the field of copper clad laminates, and in particular to a high-Tg chip-on-board copper clad laminate and a preparation method thereof. Background Art

[0002] COB light source is a high-efficiency integrated surface light source technology that directly attaches the light-emitting LED chip to a highly reflective mirror metal substrate. It has the characteristics of high reliability, convenience, electrical stability, and uniform light emission. Compared with traditional LEDs, the circuit design, optical design, and heat dissipation design of COB light sources are more scientific and reasonable, and are favored by today's lighting electronic products.

[0003] However, the heat dissipation of COB light sources is slightly worse than that of TOP products. Therefore, based on the requirements of chip packaging, the substrate used by COB light sources needs to have a high glass transition temperature, high heat resistance and a low thermal expansion coefficient. The performance of ordinary PCB substrates cannot meet the packaging requirements of COB light sources. Generally, the insulating substrate selected for COB light sources during packaging is a BT substrate, but the cost of BT substrates is high. Therefore, it is particularly important to prepare a substrate material with low cost, high glass transition temperature and low thermal expansion coefficient for the development of COB light sources. Summary of the Invention

[0004] In order to obtain a white copper clad laminate with high heat resistance, high glass transition temperature and low thermal expansion coefficient for COB light sources, the present application provides a high Tg chip-on-board copper clad laminate and a preparation method thereof.

[0005] In a first aspect, the present application provides a high Tg chip-on-board copper clad laminate, comprising a substrate material, glass fiber cloth, and copper foil, wherein the substrate material comprises the following raw materials in parts by mass:

[0006] 100 parts of composite epoxy resin;

[0007] 20-25 parts of sulfone curing agent;

[0008] 30-150 parts of modified spherical silica;

[0009] 4.5-24 parts of white dye;

[0010] Dispersant 0.15-3 parts;

[0011] The composite epoxy resin comprises an E-type epoxy resin and a multifunctional epoxy resin in a mass ratio of (3-4): (6-7); and the surface of the modified spherical silica comprises a naphthalene structure.

[0012] Preferably, the multifunctional epoxy resin includes one or a combination of multifunctional phenolic epoxy resin, glycidyl ester epoxy resin, and glycidyl amine epoxy resin.

[0013] Preferably, the sulfone curing agent is 4,4-diaminodiphenyl sulfone.

[0014] Preferably, the white colorant is titanium dioxide.

[0015] Preferably, the dispersant comprises one or a combination of polyphosphate, hydroxyl-functional alkyl ammonium salt of acidic copolymer.

[0016] By adopting the above technical solution, the base resin of the substrate material used in this application is epoxy resin, wherein the epoxy resin is a composite epoxy resin obtained by compounding an E-type epoxy resin and a multifunctional epoxy resin. Compared with the general epoxy resin system, the multifunctional epoxy resin contains more reactive sites and has greater reaction activity. By adding the multifunctional epoxy resin, the reaction cross-linking between the epoxy resin and the curing agent can be improved during the curing process, so that the bulk density of the obtained substrate material is increased, that is, the cross-linking density is greatly increased, and a copper-clad laminate with a dense structure is obtained, thereby increasing the glass transition temperature of the copper-clad laminate substrate material; and the curing agent added to the substrate material is a sulfone curing agent, which has good heat resistance, and a highly heat-resistant substrate material can be obtained.

[0017] At the same time, modified spherical silica is also introduced into the system. Through the filling effect of silica, the epoxy resin in the system is dispersed, thereby reducing the thermal expansion coefficient of the substrate material. At the same time, this application uses spherical silica. Compared with angular silica, spherical silica has a higher packing density and uniform stress distribution, which can increase the fluidity of the system, thereby increasing the amount of modified spherical silica added to the system.

[0018] In addition, the surface of the modified spherical silica also contains a naphthalene structure. The surface of the spherical silica is grafted with a compound containing a naphthalene structure. The molecules of the compound containing the naphthalene structure present a planar structure, which can inhibit the free activity between the main chains of the epoxy resin molecules, thereby reducing the thermal expansion coefficient of the substrate material after curing. However, the introduction of the naphthalene structure also makes it easier for the molecular chains of the epoxy resin to interact with each other, and will not affect the cross-linking density of the epoxy resin. This intermolecular interaction further increases the configuration of the stacking effect of the modified spherical silica, and can further increase the constraint on the molecular chain activity of the epoxy resin, reduce the thermal expansion coefficient of the material, and make the lower thermal expansion coefficient of the material in a good balance with the high glass transition temperature, thereby obtaining a copper clad plate material that meets the requirements of the COB light source substrate.

[0019] Preferably, the raw materials of the modified spherical silica include spherical silica, ethylene oxide, ethylene glycol and 2,6-naphthalene dicarboxylic acid in a mass ratio of 1: (0.8-1.2): (0.3-0.5): (0.4-0.5).

[0020] By adopting the above technical solution, ethylene oxide forms polyethylene glycol segments on the surface of the spherical silica under the initiation of ethylene glycol, and the terminal hydroxyl groups can further react with 2,6-naphthalene dicarboxylic acid, thereby introducing a naphthalene structure on the surface of the spherical silica. The introduction of the naphthalene structure helps to help the modified spherical silica reduce the thermal expansion coefficient of the substrate material while maintaining a high cross-linking density, thereby obtaining a substrate material with a high glass transition temperature.

[0021] At the same time, the naphthalene structure is connected to the surface of the spherical silica via polyethylene glycol segments. Since epoxy resin itself has poor toughness, adding a large amount of modified spherical silica can improve the strength of the substrate material to a certain extent, but the toughness of the substrate material is greatly reduced, resulting in a decrease in impact resistance and brittleness. Therefore, flexible polyethylene glycol segments are also attached to the surface of the modified spherical silica. The introduction of flexible segments not only facilitates the dispersion of the modified spherical silica in the epoxy resin system, but also allows it to intersperse between the molecular chains of the epoxy resin, improving the toughness of the substrate material and compensating for the reduced toughness caused by excessive inorganic fillers, thereby resulting in a substrate material with excellent performance.

[0022] Preferably, the spherical silica includes spherical silica with particle sizes of 1 μm, 3 μm, 5 μm, 10 μm and 20 μm.

[0023] Preferably, the mass of the spherical silica of different particle sizes in the total spherical silica is as follows: 1 μm spherical silica accounts for 15-25%; 3 μm spherical silica accounts for 20-30%; 5 μm spherical silica accounts for 30-40%; 10 μm spherical silica accounts for 20-30%; 20 μm spherical silica accounts for 5-15%.

[0024] By adopting the above technical solution, spherical silica is mixed with spherical silica of different particle sizes. After the spherical silica with larger particle size forms a stacking structure in the epoxy resin system, the spherical silica with smaller particle size can fill the pores formed between the larger spherical silica, further increasing the filling amount of the inorganic filler, i.e., the modified spherical silica, thereby obtaining a substrate material with a denser structure and reducing the thermal expansion coefficient of the substrate material.

[0025] Preferably, the modified spherical silica is prepared according to the following method:

[0026] S101. Spherical silica and an aminosilane coupling agent were added to solvent 1, and the temperature was raised to 100-110° C. under a nitrogen atmosphere, refluxed for 24 h, and then centrifuged, washed, and dried to obtain a coupling agent-modified spherical silica;

[0027] S102. The coupling agent-modified spherical silica and catalyst 1 are added to solvent 2, and after vacuum dehydration, ethylene oxide in an amount of 20 to 30% by weight of the total mass of ethylene oxide is introduced under a nitrogen atmosphere, and the reaction is stirred at 25 to 35 ° C for 3 to 5 hours to obtain pre-reacted spherical silica;

[0028] S103. Add pre-reacted spherical silica and catalyst 2 to ethylene glycol, stir and disperse, vacuum dehydrate, introduce remaining ethylene oxide under nitrogen atmosphere, increase the temperature to 130-135°C, adjust the reaction pressure to 0.6-0.8 MPa, react for 10-12 hours, reduce the reaction pressure to normal pressure, add 2,6-naphthalene dicarboxylic acid, continue stirring and reacting for 4-5 hours, and after the reaction is completed, obtain modified spherical silica through centrifugation, washing and drying.

[0029] Preferably, the aminosilane coupling agent includes one or a combination of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-aminopropyltriethoxysilane, and N-β (aminoethyl)-γ-aminopropylmethyldiethoxysilane.

[0030] Preferably, the mass ratio of the aminosilane coupling agent to the spherical silica is (0.6-0.7):1.

[0031] Preferably, solvent 1 includes one or a combination of anhydrous ethanol and toluene; solvent 2 includes one or a combination of acetone and dimethyl sulfoxide.

[0032] Preferably, catalyst 1 includes one or a combination of sodium hydroxide, potassium hydroxide, and triethylamine; catalyst 2 includes one or a combination of sodium hydroxide, potassium hydroxide, and sodium carbonate.

[0033] By adopting the above technical solution, spherical silica is used as a filler, and the reaction activity of the silanol groups on the surface with ethylene oxide is low. Therefore, the spherical silica is first modified, and the surface of the spherical silica is modified with an aminosilane coupling agent. The epoxy groups in part of the ethylene oxide react with the amino groups in the aminosilane coupling agent under the action of catalyst 1 to form reaction sites, and then the remaining ethylene oxide and ethylene glycol acting as an initiator are added. The addition of ethylene glycol enables the remaining ethylene oxide to be polymerized with the ethylene oxide already connected to the surface of the spherical silica as the reaction active site to form polyethylene glycol segments. Ethylene glycol as an initiator can obtain polyethylene glycol segments with terminal hydroxyl groups having a lower degree of polymerization. Furthermore, the terminal hydroxyl groups of the polyethylene glycol chain segments can react with the carboxyl groups contained in 2,6-naphthalene dicarboxylic acid under the action of catalyst 2, thereby introducing a naphthalene structure on the surface of the spherical silica, reducing the thermal expansion coefficient of the substrate material while maintaining a high glass transition temperature. At the same time, the toughness of the substrate material can also be adjusted to obtain a copper clad laminate substrate material with excellent performance.

[0034] Preferably, the raw materials of the substrate material further include 8 to 15 parts of nano-silicon dioxide.

[0035] By adopting the above technical solution, polyethylene glycol segments are introduced into the surface of the modified spherical silica to adjust the toughness of the substrate material. However, due to the large particle size of the spherical silica, the improvement in toughness is limited. Therefore, nano-silica can also be added to the system. The volume of nano-silica is small and will not affect the viscosity and glass transition temperature of the epoxy resin. Nano-silica can also further fill the pores of the modified spherical silica and reduce the thermal expansion coefficient of the substrate material. More importantly, the addition of nano-silica can improve the toughness of the epoxy resin.

[0036] After curing, epoxy resin will often suffer from high stress concentration caused by external mechanical impact, external tension or internal tension, which will lead to the destruction of the internal molecular network and the formation of cracks. After adding nano-silica, under high stress, partial debonding occurs between the epoxy resin and nano-silica. After debonding, plastic voids will grow in the epoxy resin matrix. The local plastic shear band in the epoxy resin is mainly caused by the stress concentration around the intermediate phase of the silica nanoparticles. Therefore, the addition of nano-silica can greatly improve the toughness of the epoxy resin and improve the overall performance.

[0037] In a second aspect, the present application also provides a method for preparing a high Tg chip-on-board copper clad laminate, which is prepared according to the following method:

[0038] S201 modified spherical silica, sulfone curing agent, white dye, nano-silica and dispersant were sequentially added to the composite epoxy resin, and stirred and dispersed to obtain a substrate material;

[0039] S202. The glass fiber cloth is impregnated in the substrate material and semi-cured at 150 to 180°C for 6 to 8 hours to obtain a prepreg;

[0040] S203. Place a copper foil on the upper and lower sides of the obtained prepreg, respectively, and press at a pressure of 0.6-0.9 MPa and a temperature of 160-190° C., and post-process to obtain a high-Tg chip-on-board copper clad laminate.

[0041] Preferably, the glass fiber cloth is alkali-free glass fiber cloth.

[0042] Preferably, the post-treatment temperature is 200-210° C., and the post-treatment time is 1.5-2.5 h.

[0043] By adopting the above technical solution, a high-Tg chip-on-board copper-clad laminate material with good performance can be obtained without adding nano-silicon dioxide in step S201.

[0044] In summary, this application has the following beneficial effects:

[0045] 1. The base resin of the substrate material used in this application is obtained by compounding E-type epoxy resin and multifunctional epoxy resin. The multifunctional epoxy resin contains many reactive sites and has high reactivity. By adding multifunctional epoxy resin, the reaction cross-linking between the epoxy resin and the curing agent can be improved during the curing process, so that the bulk density of the obtained substrate material is increased, that is, the cross-linking density is greatly increased, and a copper clad laminate with a dense structure is obtained, which can further increase the glass transition temperature of the copper clad laminate substrate material.

[0046] 2. A large amount of modified spherical silica is also added to the substrate material of the present application. The spherical silica has a higher packing density and uniform stress distribution, which can increase the amount of modified spherical silica added to the system. At the same time, the spherical silica is mixed with spherical silica of different particle sizes, which can further increase the filling amount of inorganic filler, i.e., modified spherical silica; the surface of the modified spherical silica also contains naphthalene structure and polyethylene glycol segment. The naphthalene structure can inhibit the free movement between the main chains of epoxy resin molecules and reduce the thermal expansion coefficient of the substrate material after curing. The flexible polyethylene glycol segment can improve the toughness of the substrate material and make up for the defect of decreased toughness caused by excessive inorganic fillers.

[0047] 3. Nano-silicon dioxide is also added to the substrate material of the present application, which will not affect the viscosity and glass transition temperature of the epoxy resin, can significantly improve the toughness of the epoxy resin, and reduce the impact of external stress on the performance of the epoxy resin. DETAILED DESCRIPTION

[0048] Preparation examples of raw materials and / or intermediates

[0049] Preparation Example 1: A modified spherical silica was prepared according to the following method:

[0050] S101. 100 g of spherical silica and 65 g of γ-aminopropyltrimethoxysilane were added to 500 ml of toluene. Under a nitrogen atmosphere, the temperature was raised to 110°C and refluxed for 24 h. The mixture was then centrifuged, washed, and dried to obtain coupling agent-modified spherical silica. S102. 100 g of the coupling agent-modified spherical silica and 0.5 g of sodium hydroxide were added to 250 ml of acetone. After vacuum dehydration, 25 g of ethylene oxide was introduced under a nitrogen atmosphere. The mixture was stirred at 30°C for 4 h to obtain pre-reacted spherical silica.

[0051] S103. Add 100 g of pre-reacted spherical silica and 2 g of sodium hydroxide to 40 g of ethylene glycol, stir and disperse, vacuum dehydrate, introduce 75 g of ethylene oxide under nitrogen atmosphere, increase the temperature to 130°C, adjust the reaction pressure to 0.8 MPa, react for 12 h, reduce the reaction pressure to normal pressure, add 45 g of 2,6-naphthalene dicarboxylic acid, continue stirring and react for 5 h, and after the reaction is completed, obtain modified spherical silica by centrifugation, washing and drying.

[0052] Among them, 100g of spherical silica includes 20g of spherical silica with a particle size of 1μm, 20g of spherical silica with a particle size of 3μm, 30g of spherical silica with a particle size of 5μm, 20g of spherical silica with a particle size of 10μm and 10g of spherical silica with a particle size of 20μm.

[0053] Preparation Example 2, a modified spherical silica, is different from Preparation Example 1 only in that the amount of ethylene oxide added in step S102 is 20 g, and the amount of ethylene oxide added in step S103 is 60 g.

[0054] Preparation Example 3, a modified spherical silica, is different from Preparation Example 1 only in that the amount of ethylene oxide added in step S102 is 30 g, and the amount of ethylene oxide added in step S103 is 90 g.

[0055] Preparation Example 4, a modified spherical silica, is different from Preparation Example 1 only in that the amount of ethylene glycol added is 30 g.

[0056] Preparation Example 5, a modified spherical silica, is different from Preparation Example 1 only in that the amount of ethylene glycol added is 50 g.

[0057] Preparation Example 6, a modified spherical silica, is different from Preparation Example 1 only in that the amount of 2,6-naphthalene dicarboxylic acid added is 40 g.

[0058] Preparation Example 7, a modified spherical silica, is different from Preparation Example 1 only in that the amount of 2,6-naphthalene dicarboxylic acid added is 50 g.

[0059] Preparation Example 8, a modified spherical silica, differs from Preparation Example 1 only in that 100 g of spherical silica includes 15 g of spherical silica with a particle size of 1 μm, 20 g of spherical silica with a particle size of 3 μm, 30 g of spherical silica with a particle size of 5 μm, 30 g of spherical silica with a particle size of 10 μm and 5 g of spherical silica with a particle size of 20 μm.

[0060] Preparation Example 9, a modified spherical silica, differs from Preparation Example 1 only in that 100 g of spherical silica includes 15 g of spherical silica with a particle size of 1 μm, 20 g of spherical silica with a particle size of 3 μm, 40 g of spherical silica with a particle size of 5 μm, 20 g of spherical silica with a particle size of 10 μm and 5 g of spherical silica with a particle size of 20 μm.

[0061] Preparation Example 10, a modified spherical silica, is different from Preparation Example 1 only in that the amount of 2,6-naphthalene dicarboxylic acid added is 30 g.

[0062] Preparation Example 11, a modified spherical silica, is different from Preparation Example 1 only in that the amount of 2,6-naphthalene dicarboxylic acid added is 60 g.

[0063] Preparation Example 12: A modified spherical silica was prepared according to the following method:

[0064] S101. 100 g of spherical silica and 0.5 g of sodium hydroxide were added to 250 ml of acetone, and after vacuum dehydration, 25 g of ethylene oxide was introduced under a nitrogen atmosphere and stirred at 30 ° C for 4 h to obtain pre-reacted spherical silica;

[0065] S102. Add 100 g of pre-reacted spherical silica and 2 g of sodium hydroxide to 40 g of ethylene glycol, stir and disperse, vacuum dehydrate, introduce 75 g of ethylene oxide under nitrogen atmosphere, increase the temperature to 130°C, adjust the reaction pressure to 0.8 MPa, react for 12 hours, reduce the reaction pressure to normal pressure, add 45 g of 2,6-naphthalene dicarboxylic acid, continue stirring and reacting for 5 hours, and after the reaction is completed, obtain modified spherical silica by centrifugation, washing and drying.

[0066] Among them, 100g of spherical silica includes 20g of spherical silica with a particle size of 1μm, 20g of spherical silica with a particle size of 3μm, 30g of spherical silica with a particle size of 5μm, 20g of spherical silica with a particle size of 10μm and 10g of spherical silica with a particle size of 20μm.

[0067] Preparation Example 13, a modified spherical silica, was prepared according to the following method:

[0068] S101. 100 g of spherical silica and 65 g of γ-aminopropyltrimethoxysilane were added to 500 ml of toluene. Under a nitrogen atmosphere, the temperature was raised to 110°C and refluxed for 24 h. The mixture was then centrifuged, washed, and dried to obtain coupling agent-modified spherical silica. S102. 100 g of the coupling agent-modified spherical silica and 0.5 g of sodium hydroxide were added to 250 ml of acetone. After vacuum dehydration, 25 g of ethylene oxide was introduced under a nitrogen atmosphere. The mixture was stirred at 30°C for 4 h to obtain pre-reacted spherical silica.

[0069] S103. Add 100 g of pre-reacted spherical silica and 2 g of sodium hydroxide to 40 g of ethylene glycol, stir and disperse, and then dehydrate under vacuum. In a nitrogen atmosphere, introduce 75 g of ethylene oxide, increase the temperature to 130°C, and adjust the reaction pressure to 0.8 MPa. After reacting for 12 h, reduce the reaction pressure to normal pressure, and then obtain modified spherical silica through centrifugation, washing, and drying.

[0070] Among them, 100g of spherical silica includes 20g of spherical silica with a particle size of 1μm, 20g of spherical silica with a particle size of 3μm, 30g of spherical silica with a particle size of 5μm, 20g of spherical silica with a particle size of 10μm and 10g of spherical silica with a particle size of 20μm.

[0071] Preparation Example 14, a modified spherical silica, differs from Preparation Example 1 only in that the spherical silica is replaced by an equal amount of angular silica, wherein 100g of angular silica includes 20g of angular silica with a particle size of 1μm, 20g of angular silica with a particle size of 3μm, 30g of angular silica with a particle size of 5μm, 20g of angular silica with a particle size of 10μm and 10g of angular silica with a particle size of 20μm.

[0072] Preparation Example 15, a modified spherical silica, is different from Preparation Example 1 only in that 100 g of spherical silica includes 100 g of spherical silica with a particle size of 10 μm.

[0073] Preparation Example 16, a modified spherical silica, is different from Preparation Example 1 only in that 100 g of spherical silica includes 100 g of spherical silica with a particle size of 3 μm.

[0074] Example

[0075] Example 1: A high Tg chip-on-board copper clad laminate was prepared according to the following method:

[0076] S201. 350 g of E51 epoxy resin and 650 g of multifunctional novolac epoxy resin (model F-51) were mixed to obtain a composite epoxy resin, and then 900 g of the modified spherical silica prepared in Preparation Example 1, 230 g of 4,4-diaminodiphenyl sulfone, 150 g of titanium dioxide (model R-996), 120 g of nano-silica (average particle size of 20 nm) and 22 g of dispersant (model BYK-W969) were added in sequence, and the mixture was stirred and dispersed to obtain a substrate material;

[0077] S202. Impregnating a glass fiber cloth (model 7628 glass fiber cloth) in the substrate material, curing at 140°C for 3 h, then raising the temperature to 160°C for 3 h, and then raising the temperature again to 180°C for 2 h to obtain a prepreg.

[0078] S203. Place a copper foil on each of the upper and lower sides of the obtained prepreg, and press at a pressure of 0.8 MPa and a temperature of 180°C to obtain a high-Tg chip-on-board copper-clad laminate. The post-processing process is specifically: temperature of 200°C, and processing time of 2 hours.

[0079] Example 2 is a high Tg chip-on-board copper clad laminate, which differs from Example 1 only in that the added amount of E51 epoxy resin is 300 g; the added amount of multifunctional novolac epoxy resin is 700 g.

[0080] Example 3 is a high Tg chip-on-board copper clad laminate, which differs from Example 1 only in that the added amount of E51 epoxy resin is 400 g; the added amount of multifunctional novolac epoxy resin is 600 g.

[0081] Example 4 is a high Tg chip-on-board copper clad laminate, which differs from Example 1 only in that the amount of 4,4-diaminodiphenyl sulfone added is 200 g.

[0082] Example 5, a high Tg chip-on-board copper clad laminate, differs from Example 1 only in that the amount of 4,4-diaminodiphenyl sulfone added is 250 g.

[0083] Example 6, a high Tg chip-on-board copper-clad laminate, is different from Example 1 only in that the amount of modified spherical silica prepared in Preparation Example 1 added is 40 g.

[0084] Example 7, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the amount of modified spherical silica prepared in Preparation Example 1 added is 150 g.

[0085] Example 8, a high Tg chip-on-board copper clad laminate, differs from Example 1 only in that the amount of titanium dioxide added is 50 g and the amount of dispersant added is 1.5 g.

[0086] Example 9, a high Tg chip-on-board copper clad laminate, differs from Example 1 only in that the amount of titanium dioxide added is 240 g and the amount of dispersant added is 30 g.

[0087] Example 10, a high Tg chip-on-board copper clad laminate, differs from Example 1 only in that the amount of nano-silicon dioxide added is 80 g.

[0088] Example 11, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the added amount of nano-silicon dioxide is 150 g.

[0089] Example 12, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 2.

[0090] Example 13, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 3.

[0091] Example 14, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 4.

[0092] Example 15, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 5.

[0093] Example 16, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 6.

[0094] Example 17, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of modified spherical silica prepared in Preparation Example 7.

[0095] Example 18, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 8.

[0096] Example 19, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 9.

[0097] Example 20, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of modified spherical silica prepared in Preparation Example 10.

[0098] Example 21, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of modified spherical silica prepared in Preparation Example 11.

[0099] Example 22, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of modified spherical silica prepared in Preparation Example 12.

[0100] Example 23, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of modified spherical silica prepared in Preparation Example 16.

[0101] Example 24, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of modified spherical silica prepared in Preparation Example 17.

[0102] Example 25, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that no nano-silicon dioxide is added.

[0103] Comparative Example

[0104] Comparative Example 1 is a high Tg chip-on-board copper-clad laminate, which differs from Example 1 only in that the amount of modified spherical silica prepared in Preparation Example 1 added is 20 g.

[0105] Comparative Example 2, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the amount of modified spherical silica prepared in Preparation Example 1 added is 160 g.

[0106] Comparative Example 3, a high Tg chip-on-board copper clad laminate, differs from Example 1 only in that the added amount of E51 epoxy resin is 500 g; the added amount of multifunctional phenolic epoxy resin is 500 g.

[0107] Comparative Example 4 is a high Tg chip-on-board copper clad laminate, which differs from Example 1 only in that the added amount of E51 epoxy resin is 200 g; the added amount of multifunctional phenolic epoxy resin is 800 g.

[0108] Comparative Example 5 is a high Tg chip-on-board copper-clad laminate, which differs from Example 1 only in that the added amount of E51 epoxy resin is 1000 g; and no multifunctional phenolic epoxy resin is added.

[0109] Comparative Example 6, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 13.

[0110] Comparative Example 7, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 14.

[0111] Comparative Example 8, a high Tg chip-on-board copper-clad laminate, differs from Example 1 only in that the modified spherical silica prepared in Preparation Example 1 is replaced by an equal amount of the modified spherical silica prepared in Preparation Example 15.

[0112] Performance testing

[0113] 1. Thermal stability test: According to the relevant records on glass transition temperature in GB / T 4722-2017 "Test method for lamination of steel-clad copper foil for printed circuits", the glass transition temperature of the copper clad laminates obtained in the examples and comparative examples was tested by differential scanning calorimetry.

[0114] 2. Thermal expansion coefficient test: According to ISO 11359-2-2021 "Thermomechanical analysis of plastics (TMA) Part 2: Determination of linear thermal expansion coefficient and glass transition temperature", the thermal expansion coefficients of the prepregs obtained in the examples and comparative examples were tested before and after the glass transition temperature.

[0115] 3. Mechanical properties test: According to the relevant records on bending strength in GB / T 4722-2017 "Test method for lamination of rigid copper foil for printed circuits", the bending properties of the copper clad laminates obtained in the examples and comparative examples were tested.

[0116] The above test results are shown in Table 1.

[0117] Table 1 Performance test results of copper clad laminate

[0118]

[0119]

[0120] According to Table 1, in combination with Example 1 and Examples 2 to 11, it can be seen that the glass transition temperature, thermal expansion coefficient before and after the glass transition temperature, and bending strength in the warp and weft directions of Examples 2 to 11 are not significantly different from those of Example 1, indicating that the heat resistance, thermal expansion performance, and toughness of Examples 2 to 11 are not significantly different from those of Example 1. This may be because the only difference between Examples 2 to 11 and Example 1 is that the raw material ratios in the substrate material preparation process are different within the required range, indicating that changing the raw material ratio of the substrate material within the required range has no significant effect on the performance of the resulting copper clad laminate.

[0121] Combining Example 1 and Examples 12 to 17, it can be seen that the glass transition temperature, thermal expansion coefficient before and after the glass transition temperature, and bending strength in the warp and weft directions of Examples 12 to 17 are not significantly different from those of Example 1, indicating that the heat resistance, thermal expansion performance, and toughness of Examples 12 to 17 are not significantly different from those of Example 1. This may be because the only difference between Examples 12 to 17 and Example 1 is that the raw material ratios of the modified spherical silica used in the substrate material are different within the required range during preparation, indicating that changing the raw material ratio of the modified spherical silica within the required range has no significant effect on the performance of the resulting copper clad laminate.

[0122] Combining Example 1, Example 18, and Example 19, it can be seen that the glass transition temperature, the thermal expansion coefficient before and after the glass transition temperature, and the bending strength in the warp and weft directions of Example 18 and Example 19 are not significantly different from those of Example 1, indicating that the heat resistance, thermal expansion performance, and toughness of Example 18 and Example 19 are not significantly different from those of Example 1. This may be because the only difference between Example 18 and Example 19 and Example 1 is that the particle size ratio of the modified spherical silica used in the preparation process of the substrate material is different within the required range, indicating that changing the particle size ratio of the modified spherical silica within the required range has no significant effect on the performance of the resulting copper clad laminate.

[0123] Combining Example 1, Example 20, and Example 21, it can be seen that the thermal expansion coefficient of Example 20 before and after the glass transition temperature is increased compared to Example 1, and the bending strength in the warp and weft directions of Example 21 is decreased compared to Example 1, indicating that the thermal expansion performance of Example 20 is decreased, and the toughness of Example 21 is decreased. The reason may be that the amount of 2,6-naphthalene dicarboxylic acid added to the modified spherical silica used in the substrate material of Example 20 during the preparation process is less than the required range, and the naphthalene structure on the surface of the modified spherical silica is reduced, the ability to inhibit the free movement between the main chains of the epoxy resin molecules is reduced, and the thermal expansion performance of the material is reduced; the amount of 2,6-naphthalene dicarboxylic acid added to the modified spherical silica used in the substrate material of Example 21 during the preparation process is more than the required range, indicating that the ability to inhibit the free movement between the main chains of the epoxy resin molecules is increased, the rigidity of the material is too large, and the toughness is reduced.

[0124] Combining Example 1 and Example 22, it can be seen that the glass transition temperature and the bending strength in the warp and weft directions of Example 22 are lower than those of Example 1, and the thermal expansion coefficient before and after the glass transition temperature is higher than that of Example 1, indicating that the heat resistance, thermal expansion performance, and toughness of Example 22 are lower than those of Example 1. This may be because the modified spherical silica used in the substrate material of Example 22 was not pretreated with an aminosilane coupling agent during the preparation process, resulting in a decrease in the binding force between silica and ethylene oxide, a decrease in the polyethylene glycol segments and naphthalene structures on the surface, and a corresponding decrease in the thermal expansion performance and toughness.

[0125] Combining Example 1, Example 23, and Example 24, it can be seen that the thermal expansion coefficients of Example 23 and Example 24 before and after the glass transition temperature are increased compared to Example 1, indicating that the thermal expansion performance of Example 23 and Example 24 is decreased compared to Example 1. This may be because the modified spherical silica used in Example 23 and Example 24 is prepared from spherical silica of the same particle size. Compared with mixing silica of different particle sizes, the dispersion performance of silica in the system is reduced, the density of the structure is reduced, and the thermal expansion performance is significantly reduced.

[0126] Combining Example 1 and Example 25, it can be seen that the bending strength in both the warp and weft directions of Example 25 is significantly lower than that of Example 1, indicating that the toughness of Example 25 is lower than that of Example 1. This may be because the substrate material used in Example 25 was not added with nano-silicon dioxide during the preparation process. Nano-silicon dioxide can not only regulate the porosity of the inorganic filler in the substrate material, but also compensate for the stress defects of the epoxy resin under external stress, thereby improving the toughness of the resulting copper clad laminate.

[0127] Combining Example 1, Comparative Example 1 and Comparative Example 2, it can be seen that the glass transition temperatures of Comparative Example 1 and Comparative Example 2 are lower than those of Example 1, the thermal expansion coefficient of Comparative Example 1 before and after the glass transition temperature is significantly increased compared with that of Example 1, and the bending strength in the warp and weft directions of Comparative Example 2 is significantly lower than that of Example 1. The reason for this may be that the difference between Comparative Example 1 and Comparative Example 2 is that the amount of modified spherical silica added to the substrate material during the preparation process is outside the required range. When the amount of modified spherical silica added is reduced, as shown in Comparative Example 1, the effect of enhancing the thermal expansion properties of the substrate material is weakened, and the reduction of polyethylene glycol segments causes the toughness of the obtained copper clad laminate to decrease. When the amount of modified spherical silica added is increased, as shown in Comparative Example 2, the increase in excessive inorganic filler, even with the regulation of the toughness of the material by polyethylene glycol segments and nano-silica, will result in a large rigidity of the material and a significant decrease in the toughness of the obtained copper clad laminate.

[0128] Combining Example 1, Comparative Example 3, Comparative Example 4 and Comparative Example 5, it can be seen that the glass transition temperature of Comparative Examples 3 to Comparative Example 5 is lower than that of Example 1, among which the glass transition temperature of Comparative Example 5 is lowered most significantly; the thermal expansion coefficients of Comparative Examples 3 to Comparative Example 5 before and after the glass transition temperature are higher than that of Example 1, and the bending strength in the warp and weft directions of Comparative Examples 3 to Comparative Example 5 is lower than that of Example 1, among which the decrease in Comparative Example 4 is the most obvious. The reason may be that, in the preparation process of the substrate materials in Comparative Examples 3 to 5, the proportion of the multifunctional epoxy resin in the composite epoxy resin is not within the required range. Among them, the amount of multifunctional epoxy resin added in Comparative Example 3 is small, and the cross-linking density of the material decreases accordingly, and the glass transition temperature decreases. In Comparative Example 5, no multifunctional epoxy resin is added, and the cross-linking density decreases more significantly, and the glass transition temperature decreases significantly. In Comparative Example 4, the amount of multifunctional epoxy resin added is increased, and the excessive cross-linking density leads to excessive rigidity of the material. The dispersibility of inorganic fillers and nano-silica in the system also decreases, and the toughness of the obtained copper clad laminate decreases.

[0129] In combination with Example 1 and Comparative Example 6, it can be seen that the thermal expansion coefficient of Comparative Example 6 before and after the glass transition temperature is significantly increased compared to Example 1, indicating that the thermal expansion performance of Comparative Example 6 is significantly decreased compared to Example 1. The reason may be that the surface of the modified spherical silica in Comparative Example 6 does not contain a naphthalene structure. The naphthalene structure can not only inhibit the free movement between the main chains of the epoxy resin molecules and reduce the thermal expansion coefficient of the substrate material after curing, but also the introduction of the naphthalene structure makes it easier for the molecular chains of the epoxy resin to interact with each other. Losing the effect of the naphthalene structure will cause the thermal expansion performance of the substrate material to be significantly decreased.

[0130] Combining Example 1 and Comparative Example 7, it can be seen that the glass transition temperature and the bending strength in the warp and weft directions of Comparative Example 7 are significantly lower than those of Example 1, and the thermal expansion coefficient before and after the glass transition temperature is significantly increased compared to Example 1, indicating that the heat resistance, thermal expansion performance, and toughness of Comparative Example 7 are significantly lower than those of Example 1. The reason for this may be that the spherical silica used in Comparative Example 7 has not been modified. First, the naphthalene structure loses its enhancing effect on the thermal expansion performance of the material and the enhanced interaction with the molecular weight of the epoxy resin; second, the polyethylene glycol loses its ability to regulate the toughness of the substrate material, resulting in a significant decrease in the thermal expansion performance and toughness of the resulting copper clad laminate.

[0131] Combining Example 1 with Comparative Example 8, it can be seen that the glass transition temperature and the bending strength in the warp and weft directions of Comparative Example 8 are lower than those of Example 1, while the thermal expansion coefficient before and after the glass transition temperature is higher than that of Example 1, indicating that the heat resistance, thermal expansion performance, and toughness of Comparative Example 8 are all lower than those of Example 1. This may be because angular silica is used in Comparative Example 8. Compared with spherical silica, angular silica has a lower bulk density and uneven stress distribution, and cannot achieve the good modification effect of spherical silica.

[0132] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high Tg chip-on-board copper-clad laminate, comprising a substrate material, glass fiber cloth and copper foil, characterized in that: The substrate material includes the following raw materials in parts by mass: 100 parts of composite epoxy resin; 20-25 parts of sulfone curing agent; 30-150 parts of modified spherical silica; 4.5-24 parts of white dye; Dispersant 0.15-3 parts; 8-15 parts of nano silicon dioxide; The composite epoxy resin comprises an E-type epoxy resin and a multifunctional epoxy resin in a mass ratio of (3-4): (6-7); the surface of the modified spherical silica comprises a naphthalene structure, which is connected to the surface of the spherical silica via a polyethylene glycol segment; The raw materials of the modified spherical silica include spherical silica, ethylene oxide, ethylene glycol and 2,6-naphthalene dicarboxylic acid in a mass ratio of 1: (0.8-1.2): (0.3-0.5): (0.4-0.5); the spherical silica includes spherical silica with particle sizes of 1 μm, 3 μm, 5 μm, 10 μm and 20 μm.

2. The high Tg chip-on-board copper clad laminate according to claim 1, characterized in that: The multifunctional epoxy resin includes one or a combination of multifunctional phenolic epoxy resin, glycidyl ester epoxy resin, and glycidyl amine epoxy resin.

3. The high Tg chip-on-board copper clad laminate according to claim 1, characterized in that: The mass of spherical silica of different particle sizes accounts for 15-25% of the total spherical silica; 3-μm spherical silica accounts for 20-30%; 5-μm spherical silica accounts for 30-40%; 10-μm spherical silica accounts for 20-30%; and 20-μm spherical silica accounts for 5-15%.

4. The high Tg chip-on-board copper clad laminate according to claim 1, characterized in that: The modified spherical silica is prepared according to the following method: S101. Spherical silica and an aminosilane coupling agent were added to solvent 1, and the temperature was raised to 100-110° C. under a nitrogen atmosphere, refluxed for 24 h, and then centrifuged, washed, and dried to obtain a coupling agent-modified spherical silica; S102. The coupling agent-modified spherical silica and catalyst 1 are added to solvent 2, and after vacuum dehydration, ethylene oxide in an amount of 20 to 30% by weight of the total mass of ethylene oxide is introduced under a nitrogen atmosphere, and the reaction is stirred at 25 to 35 ° C for 3 to 5 hours to obtain pre-reacted spherical silica; S103. Add pre-reacted spherical silica and catalyst 2 to ethylene glycol, stir and disperse, vacuum dehydrate, introduce remaining ethylene oxide under nitrogen atmosphere, increase the temperature to 130-135°C, adjust the reaction pressure to 0.6-0.8 MPa, react for 10-12 hours, reduce the reaction pressure to normal pressure, add 2,6-naphthalene dicarboxylic acid, continue stirring and reacting for 4-5 hours, and after the reaction is completed, obtain modified spherical silica through centrifugation, washing and drying.

5. The high Tg chip-on-board copper clad laminate according to claim 4, characterized in that: The aminosilane coupling agent includes one or a combination of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-aminopropyltriethoxysilane, and N-β (aminoethyl)-γ-aminopropylmethyldiethoxysilane.

6. The high Tg chip-on-board copper clad laminate according to claim 1, characterized in that: The sulfone curing agent is 4,4-diaminodiphenyl sulfone.

7. The method for preparing a high Tg chip-on-board copper clad laminate according to any one of claims 1 to 6, characterized in that: Prepared according to the following method: S201 modified spherical silica, sulfone curing agent, white dye, nano-silica and dispersant were sequentially added to the composite epoxy resin, and stirred and dispersed to obtain a substrate material; S202. The glass fiber cloth is impregnated in the substrate material and semi-cured at 150 to 180°C for 6 to 8 hours to obtain a prepreg; S203. Place a copper foil on the upper and lower sides of the obtained prepreg, respectively, and press at a pressure of 0.6-0.9 MPa and a temperature of 160-190° C., and post-process to obtain a high-Tg chip-on-board copper clad laminate.

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