Copper clad laminate, resin composition for copper clad laminate, and spherical silicon and preparation method therefor

Abstract

The present application relates to the technical field of copper clad laminates, and discloses a copper clad laminate, a resin composition for the copper clad laminate, and spherical silicon and a preparation method therefor. The spherical silicon of the present application is composed of spherical silicon dioxide and zinc molybdate particles dispersedly grown on the surface of the spherical silicon dioxide in situ and has a diameter of less than 10 microns and a D50 of 0.6-6 microns. The content of zinc molybdate per unit area on the surface of the spherical silicon dioxide is 0.03-1 g / m2, and the size of the zinc molybdate particles is less than or equal to 400 nm. The preparation method comprises: enabling spherical silicon dioxide to come into contact with / be mixed with a soluble molybdate and a zinc salt in an aqueous reaction system; and reacting the soluble molybdate with the zinc salt in situ on the surface of the spherical silicon dioxide, so as to form spherical silicon chemically coated with zinc molybdate particles. In the present application, by directly synthesizing the zinc molybdate in situ on the surface of the spherical silicon dioxide by means of a hydrothermal method, the structural morphology of the obtained spherical silicon and the size of the zinc molybdate particles can be effectively controlled, thereby ensuring that the wear of a drill bit during the drilling of the copper clad laminate is effectively mitigated.

Description

A copper-clad laminate, a resin composition for copper-clad laminates, spherical silicon and its preparation method

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411609442.6, filed on November 12, 2024, entitled "A copper-clad laminate, a resin composition for copper-clad laminate, spherical silicon and a preparation process thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of electronic component technology, and more specifically, relates to a copper-clad laminate, a resin composition for copper-clad laminate, spherical silicon, and a method for preparing the same. Background Technology

[0004] Copper-clad laminate (CCL) is a sheet material made by impregnating electronic fiberglass cloth or other reinforcing materials with resin, covering one or both sides with copper foil, and then hot-pressing it. The performance of CCL largely determines the quality, performance, manufacturing level, manufacturing cost, and long-term reliability and stability of the printed circuit board (PCB).

[0005] In recent years, electronic products have trended towards greater precision and multifunctionality. The processing of copper-clad laminates (CCLs) has become more complex. To reduce the coefficient of thermal expansion, increasingly more fillers are being added. PCB manufacturing requires drilling, and because fillers generally have high hardness, high filler content leads to faster drill bit wear, increasing the difficulty and cost of drilling. Currently, the main method to reduce drill bit wear is by adding fillers such as talc and aluminum hydroxide. However, talc has a flaky structure and a large specific surface area, resulting in high adhesive viscosity, making it unsuitable for high-filler systems. Aluminum hydroxide releases water when heated to around 200℃, easily causing board breakage.

[0006] Zinc molybdate is a good lubricant material, characterized by its non-decomposition at high temperatures and absence of water of crystallization. Therefore, its application in printed circuit boards (PCBs) has been studied. For example, Chinese patent application No. 2015110289065 discloses a thermosetting resin composition, a prepreg containing it, a laminate, and a circuit carrier. It also discloses the use of a combination of zinc molybdate or ammonium molybdate with silica as an inorganic filler in the thermosetting resin composition, which can improve the drilling performance of the laminate to some extent. However, to achieve a good lubrication effect when zinc molybdate is added directly, small-sized zinc molybdate particles are best due to their good dispersibility. However, adding small-sized zinc molybdate particles leads to high viscosity and insufficient addition, while large-sized zinc molybdate particles are difficult to disperse in the material, resulting in poor lubrication of the drill bit during drilling. Furthermore, zinc molybdate is a weakly ionizing material; its ionization produces molybdate ions and zinc ions. Excessive amounts of these ions can reduce the resistance to ion migration in the manufactured copper-clad laminate, ultimately leading to its failure.

[0007] Chinese Patent Application No. 2022800372276 discloses a supported zinc dimolybdate hydroxide / silica composite and its use in polymer formulations. The preparation method includes: reacting a zinc compound (such as zinc oxide) and molybdenum trioxide in an aqueous system to form a reaction mixture, and contacting the reaction mixture with silica to form a supported zinc dimolybdate hydroxide / silica composite. At least 80% by weight of the zinc dimolybdate hydroxide in the resulting supported zinc dimolybdate hydroxide / silica composite is present in the form of Zn3Mo2O8(OH)2. The method of reacting MoO3 with the zinc compound in this patent is problematic because MoO3 is a solid substance that is difficult to dissolve in water. The synthesized zinc molybdate will contain unreacted molybdenum oxide, which weakens its effect of reducing drill bit wear. At the same time, molybdenum trioxide is a semiconductor material with poor insulation properties, and the presence of unreacted molybdenum oxide will also result in poor insulation of the copper-clad laminate.

[0008] In addition, the development of high-speed copper clad laminates has led to increasingly thinner copper clad laminates. If the filler size is too large, it will form protrusions on the surface of the copper clad laminate and may also affect the copper clad laminate processing equipment. Therefore, it is necessary to strictly control the size of the filler.

[0009] Application content

[0010] The first objective of this application is to provide a spherical silicon for copper clad laminates, which is composed of spherical silicon dioxide and zinc molybdate particles in situ dispersed on the surface of the spherical silicon dioxide, thereby solving the problem that the drilling performance of copper clad laminates is relatively poor and the filling amount of spherical silicon is relatively low when existing spherical silicon products are added to copper clad laminates.

[0011] The second objective of this application is to provide a modified spherical silicon for copper-clad laminates. By further modifying the spherical silicon chemically coated with the zinc molybdate particles, the compatibility between the spherical silicon filler and the resin can be further improved, and the hydroxyl content on the surface of the spherical silicon can be effectively controlled.

[0012] The third objective of this application is to provide a copper-clad laminate or a resin composition for copper-clad laminate that uses the above-mentioned spherical silicon or modified spherical silicon as a filler, thereby effectively improving the drilling performance of the copper-clad laminate.

[0013] The fourth objective of this application is to provide a method for preparing the above-mentioned spherical silicon or modified spherical silicon;

[0014] The fifth objective of this application is to provide a copper-clad laminate.

[0015] To achieve the above objectives, the technical solution provided in this application is as follows:

[0016] The first aspect of this application provides a spherical silicon for copper-clad laminates, which is composed of spherical silicon dioxide and zinc molybdate particles in situ dispersedly grown on the surface of the spherical silicon dioxide. The diameter of the spherical silicon dioxide particles is less than 10 micrometers, the D50 is 0.6 to 6 micrometers, and the size of the zinc molybdate particles on the surface of the spherical silicon dioxide is ≤400 nm.

[0017] The spherical silicon of this application is composed of spherical silicon dioxide and zinc molybdate particles that are in situ dispersed on the surface of the spherical silicon dioxide. On the one hand, it can effectively solve the technical problem that the improvement effect of direct physical mixing of silicon dioxide and zinc molybdate on the drilling wear resistance of copper-clad laminate is limited, and it will not affect the viscosity of the material. On the other hand, since the zinc molybdate particles are chemically grown in situ on the surface of spherical silicon dioxide, their bond with silicon dioxide is relatively strong and they are not easy to fall off.

[0018] It should also be noted that the distribution of zinc molybdate particles on the surface of spherical silica has a significant impact on the application effect of spherical silica in copper-clad laminates. In this application, the size of the zinc molybdate particles is ≤400nm, and the zinc molybdate content per unit area of ​​the spherical silica surface is 0.03-1g / m². 2 The zinc molybdate particles are highly dispersed on the surface of the spherical silica, which ensures that when the spherical silica is applied to copper-clad laminates, it can effectively improve the drilling performance of the copper-clad laminates, while not adversely affecting other application performance parameters such as the peel strength of the copper-clad laminates.

[0019] Furthermore, the pH of the spherical silica is 6-8, and the D50 of the spherical silica is 0.5-5 micrometers.

[0020] A second aspect of this application provides a method for preparing spherical silicon for copper-clad laminates, comprising:

[0021] Spherical silica is brought into contact with / mixed with soluble molybdate and zinc salt in an aqueous reaction system;

[0022] Soluble molybdate and zinc salt are reacted in situ on the surface of spherical silica to form spherical silica particles chemically coated with zinc molybdate particles;

[0023] The process involves reacting soluble molybdate and zinc salt in situ on the surface of spherical silica, with the following reaction conditions: reaction temperature of 130-180℃, reaction pressure of 1-8MPa, and reaction time of 1-8 hours.

[0024] This application employs a hydrothermal method and optimizes its specific process parameters to directly synthesize highly dispersed zinc molybdate particles in situ on the surface of spherical silica. This results in spherical silica formed by the chemical bonding of zinc molybdate particles and spherical silica. When applied to copper-clad laminates, this spherical silica allows for high filling and effectively reduces drill bit wear during drilling without affecting the material's viscosity. Furthermore, the bond between the zinc molybdate particles and silica in the spherical silica prepared in this application is relatively strong, making them less prone to detachment during subsequent processing. In addition, commercially available methods, such as grading or sieving, struggle to guarantee precise control of material size. This application, through hydrothermal synthesis, allows for precise control of the large particle content in the resulting spherical silica product, ensuring that the product does not contain particles larger than 10 micrometers.

[0025] It should be noted that the reaction conditions in this application are crucial, as they not only affect the in-situ synthesis of zinc molybdate particles and the morphology and particle size of the synthesized zinc molybdate particles, but also the bonding strength between zinc molybdate particles and silica. In particular, the control of the reaction temperature is critical. When the reaction temperature is too low, zinc molybdate particles cannot be synthesized in-situ on the surface of spherical silica; while when the reaction temperature is too high, the number of zinc molybdate particles will be small, and non-spherical zinc molybdate particles are easily formed and mixed in the spherical silica.

[0026] The reaction temperature, time, and pressure can be selected from any range within the above numerical range, or even any specific value within that range. For example, the reaction temperature can be 130-150℃, 145-160℃, or 165-180℃, or it can be 130℃, 140℃, 150℃, 155℃, 160℃, 167℃, 175℃, or 180℃.

[0027] Meanwhile, the soluble molybdates include, but are not limited to, ammonium molybdate, sodium molybdate, potassium molybdate, etc., and the soluble zinc salts include, but are not limited to, zinc sulfate, zinc nitrate, zinc chloride, etc., as long as the soluble molybdates can react with the zinc salts to form zinc molybdate, and will not have other negative impacts on the product performance.

[0028] Furthermore, the spherical silica raw material used has a D50 of 0.5-5 micrometers, and the spherical silica obtained after coating has a D50 of 0.6-6 micrometers, an electrical conductivity of ≤100 μS / cm, a pH of 6-8, and a zinc molybdate content per unit area on the surface of the spherical silica of 0.03-1 g / m². 2 The size of the zinc molybdate particles is ≤400nm.

[0029] Furthermore, this also includes:

[0030] The reaction product is subjected to pressure filtration and washing; and / or

[0031] The material obtained after the reaction is dried; and / or

[0032] The materials obtained after the reaction are broken down and classified.

[0033] Furthermore, when the material obtained after the reaction is subjected to pressure filtration, it is repeatedly rinsed with pure water during the pressure filtration process until the conductivity of the material is ≤100us / cm; the drying temperature is 100-150℃.

[0034] Furthermore, this also includes:

[0035] Add spherical silica to water and stir until well mixed;

[0036] Then add an aqueous solution of soluble molybdate and zinc salt, and stir until homogeneous;

[0037] The concentration of the soluble molybdate aqueous solution is 1-8 mol / L, and the concentration of the soluble zinc salt aqueous solution is 1-8 mol / L.

[0038] A third aspect of this application also provides a modified spherical silicon for copper-clad laminates, the modified spherical silicon comprising modified spherical silicon dioxide and zinc molybdate particles in situ dispersedly grown on the surface of the silicon dioxide, wherein the structural formula of the surface groups of the modified spherical silicon dioxide is as follows:

[0039] Due to the increasingly stringent requirements for dielectric properties in current copper-clad laminates, a large amount of low-polarity resins are used, especially polyphenylene ether (PPE), a high-heat-resistant, high-reliability, and low-polarity resin. However, its compatibility with fillers is very poor. When the modified spherical silica described in this application is used as a filler, the compatibility between the filler and PPE resin can be effectively improved, especially in highly filled systems, thereby enhancing the peel strength of the copper-clad laminate. At the same time, the modified spherical silica has a relatively low hydroxyl content, thus avoiding the tendency of excessive hydroxyl content to polarize in an electric field, which would lead to increased dielectric loss. Therefore, it is beneficial to further reduce the dielectric loss of spherical silica products.

[0040] More preferably, the modified spherical silicon has a hydroxyl content of 0.1-10 hydroxyl groups / nm. 2 .

[0041] More preferably, the modified spherical silica has a diameter of less than 10 micrometers and a D50 of 0.6–6 micrometers; and / or the zinc molybdate content per unit area of ​​the modified spherical silica surface is 0.03–1 g / m². 2 The size of zinc molybdate particles is ≤400nm.

[0042] The fourth aspect of this application also provides a method for preparing any of the modifiers described in the third aspect, specifically including:

[0043] The modifier is contacted / mixed with the spherical silicon prepared by the process described in the first aspect or the second aspect of this application in a reaction solvent to react and obtain modified spherical silicon; wherein the reaction conditions include: a reaction temperature of 25-120℃, a reaction time of 1-9 hours, and the amount of modifier added is 0.2-3% of the total mass of the spherical silicon chemically coated with zinc molybdate particles, and the structural formula of the modifier is as follows:

[0044] Furthermore, the reaction solvent is 2-hexanol. Alcohols with shorter chains than 2-hexanol have lower boiling points, such as ethanol, and cannot meet the requirements of 120°C or higher temperatures. Alcohols with longer chains are also more expensive.

[0045] Furthermore, it also includes: pressure filtration, drying, or dispersion and classification of the modified spherical silica obtained from the reaction, or any combination thereof.

[0046] The fifth aspect of this application also provides a resin composition comprising a resin and a filler, wherein the filler comprises any of the spherical silicons described in the first aspect of this application, or spherical silicons prepared by any process described in the second aspect of this application, or any of the modified spherical silicons described in the third aspect of this application, or modified spherical silicons prepared by any preparation method described in the fourth aspect of this application.

[0047] Furthermore, the amount of spherical silica or modified spherical silica in the resin composition is 50-65%.

[0048] The sixth aspect of this application also provides a copper-clad laminate made from any of the resin compositions described in the fifth aspect of this application.

[0049] Furthermore, the copper-clad laminate made using the above-mentioned resin composition has a dielectric loss of 0.001-0.003 and a peel strength of 1.0-1.5 N / inch.

[0050] In summary, compared with the prior art, the technical solution provided in this application can achieve the following beneficial effects:

[0051] (1) This application provides a spherical silicon for copper-clad laminates. The spherical silicon is composed of spherical silicon dioxide and zinc molybdate particles in situ dispersedly grown on the surface of the spherical silicon dioxide. In particular, the distribution of zinc molybdate particles on the surface of the spherical silicon dioxide is optimized. When this spherical silicon is applied to copper-clad laminates, it can effectively increase the filler content, reduce drill wear during copper-clad laminate drilling, and the bond between the zinc molybdate particles and the silicon dioxide surface is relatively strong, making it less prone to detachment during subsequent applications. In addition, the spherical silicon dioxide particles mentioned in this application can be solid silicon dioxide particles or porous silicon dioxide particles, such as hollow silicon dioxide particles, porous silicon dioxide particles, honeycomb silicon dioxide particles, and mesoporous silicon dioxide particles; the spherical silicon can be white or black. The spherical silicon mentioned in this application can be prepared by any existing method for obtaining spherical silicon, such as the deflagration method, flame method, chemical method, etc. This application does not limit the method of obtaining spherical silicon, the color of the spherical silicon, or the pore structure.

[0052] (2) This application adopts a hydrothermal method and strictly controls its specific process parameters, thereby ensuring that highly dispersed zinc molybdate particles are directly synthesized in situ on the surface of spherical silica, and controlling the morphology and particle size of the synthesized zinc molybdate particles, while preventing the zinc molybdate particles from falling off, thereby ensuring the application effect of the spherical silica.

[0053] (3) This application also provides a modified spherical silicon, which is further modified by using a specific modifier to graft new groups on the surface of spherical silicon dioxide to effectively improve the compatibility between the spherical silicon filler and polyphenylene ether resin and improve the peel strength of copper clad laminate. At the same time, it can effectively control the hydroxyl content of spherical silicon, prevent the hydroxyl groups from polarizing in the electric field and causing an increase in dielectric loss, and further reduce the dielectric loss of the obtained spherical silicon.

[0054] (4) Using the spherical silicon or modified spherical silicon of this application as filler, and mixing it with resin and applying it to copper-clad laminate, compared with the prior art of adding talc to reduce drill bit wear during drilling, it can also effectively reduce the dielectric loss of copper-clad laminate and improve its PS strength. Attached Figure Description

[0055] Figure 1 is a scanning schematic diagram of the spherical silicon prepared in Example 1 of this application;

[0056] Figure 2 is the XRD pattern of the spherical silicon prepared in Example 1 of this application;

[0057] Figure 3 is a picture of the copper-clad laminate made of spherical silicon provided in Example 1 of this application after being drilled 1000 times;

[0058] Figure 4 is a scanning schematic diagram of the spherical silica coating before it is coated in Example 1 provided in this application;

[0059] Figure 5 is a scanning diagram of the direct physical mixing of spherical silica and zinc molybdate in Comparative Example 1 provided in this application.

[0060] Figure 6 is a picture of the drill bit after drilling 1000 times in Comparative Example 1 provided in this application;

[0061] Figure 7 is a scanning schematic diagram of the spherical silicon prepared in Example 2 of this application;

[0062] Figure 8 is a picture of the drill bit after drilling 1000 times in Embodiment 2 provided in this application;

[0063] Figure 9 is a picture of the drill bit after drilling 1000 times in Embodiment 3 provided in this application;

[0064] Figure 10 is a scanning schematic diagram of the spherical silicon in Embodiment 3 provided in this application;

[0065] Figure 11 is the infrared spectrum of the modifier used in Example 4 of this application;

[0066] Figure 12 is the infrared spectrum of the modified spherical silicon obtained in Example 4 of this application;

[0067] Figure 13 is a picture of the drill bit after drilling 1000 times in Embodiment 4 provided in this application;

[0068] Figure 14 is a scanning schematic diagram of talc powder in Comparative Example 5 provided in this application;

[0069] Figure 15 is a scanning spectrum of the spherical silicon obtained in Comparative Example 6 provided in this application;

[0070] Figure 16 is a scanning spectrum of the spherical silicon obtained in Comparative Example 7 provided in this application;

[0071] Figure 17 is a scanning schematic diagram of the spherical silicon obtained in Example 5 of this application;

[0072] Figure 18 is a scanning schematic diagram of the spherical silicon obtained in Example 6 of this application;

[0073] Figure 19 is a picture of the drill bit after drilling 1000 times in Embodiment 6 provided in this application.

[0074] Test method:

[0075] 1. Hydroxyl content test method: Test method for silanol content on fumed silica surface T / FSI 049—2020;

[0076] 2. Large particle test: Take 200g of powder and pass it through a 1000-mesh sieve. Then take the residue on the sieve and test it with a scanning electron microscope. Detailed Implementation

[0077] To further understand the content of this application, a detailed description of this application is now provided in conjunction with specific embodiments.

[0078] Example 1

[0079] This embodiment provides a method for preparing spherical silicon for copper-clad laminates, comprising:

[0080] Pure water was added to a polytetrafluoroethylene-lined hydrothermal reactor, followed by 10 kg of spherical silica (D50: 1.3 μm, SiO2 content: 99.82%). The mixture was then stirred at a speed of 30 Hz for 80 minutes.

[0081] Then add an aqueous solution of ammonium molybdate (6.2 mol / L), 10 L in volume, and stir at 30 Hz for 60 minutes.

[0082] Continue adding zinc sulfate aqueous solution (6.2 mol / L), 10 L in volume, then raise the temperature of the reactor (150℃) and the pressure (5 MPa), and release the material from the reactor after reacting for 6 hours;

[0083] The material inside the reactor is discharged and filtered using a filter press. During the filtration process, the material is repeatedly rinsed with pure water. When the conductivity of the material is reduced to ≤100 μS / cm, the material is discharged.

[0084] The washed materials are dried using a flash dryer at 130°C.

[0085] The dried material was dispersed and classified using a fluidized bed air classifier to obtain spherical silicon material with zinc molybdate coating. Its specifications are as follows: Zinc molybdate content per unit area: 0.08 g / m² 2 The surface-coated zinc molybdate has a size of 50-400 nm, the spherical silicon has an electrical conductivity of 50 μS / cm, and a hydroxyl content of 15 hydroxyl groups / nm. 2 D50 is 1.5 micrometers.

[0086] The scanning images and XRD patterns of the spherical silica prepared in this embodiment are shown in Figures 1 and 2, respectively. Figure 4 shows the spherical silica before coating, which has a relatively smooth surface. However, as can be seen from Figure 1, after coating, the surface of the spherical silica in this embodiment clearly shows the formation of particulate matter. In the XRD pattern of Figure 2, positions 32, 33, 34, 35, 48, 57, 63, 67, 68, and 69 correspond to the standard peaks of zinc molybdate, proving that zinc molybdate grows in situ on the surface of the spherical silica.

[0087] This embodiment also provides a resin composition comprising the spherical silica and polyphenylene ether resin prepared in this embodiment, wherein the spherical silica filler content is 60%. The resin composition is applied to glass cloth (2116, Chongqing International Composite Materials) using a gluing machine (vertical gluing machine, Taiwan Yatai Metal Industry Co., Ltd.), with a glue content of 56%, under a vacuum press (800T-12, Weidi Electromechanical Technology Co., Ltd.), while the press is maintained at a constant temperature of 280°C and a vacuum degree of 10. -3 The material is pressed at 15 MPa to form a semi-cured sheet. Eight of these semi-cured sheets are stacked together, and copper foil (35 μm, from Kingboard Chemical Group) is placed on top and bottom of the stacked sheets. The mixture is then pressed under a vacuum press (Aest (Shanghai) Machinery Technology Co., Ltd.) at a constant temperature of 290℃ with a vacuum degree of 10 MPa. -3 Pa, press pressure 16 MPa, to produce copper-clad laminate.

[0088] The copper-clad laminate was drilled with a drill bit to test the wear of the drill bit. Figure 3 shows a picture after 1000 drilling cycles. As can be seen from the figure, the drill bit showed almost no wear after 1000 drilling cycles (very little white part on the surface). The peel strength of the copper-clad laminate produced in this embodiment is 0.8 N / inch.

[0089] Comparative Example 1

[0090] In this comparative example, spherical silica (D50: 1.3 μm, SiO2 content: 99.82%) was physically mixed with zinc molybdate. The mixing mass ratio was the same as that in Example 1. After physical mixing, the conductivity of the spherical silica product was 56 μS / cm, and the hydroxyl content was 28 hydroxyl groups / nm. 2 D50 is 1.5 micrometers.

[0091] The above mixture was used as a filler (the scanned image of the filler is shown in Figure 5, where non-spherical zinc molybdate with a size greater than 800 nm can be clearly seen in the spherical silica) and mixed with polyphenylene ether resin to prepare a resin composition and a copper-clad laminate. The filling amount of the filler and the specific manufacturing process of the copper-clad laminate are the same as in Example 1.

[0092] The fabricated copper-clad laminate was drilled with a drill bit to test drill bit wear. Figure 6 shows a picture after 1000 drilling cycles. As can be seen from the figure, the direct physical mixing of spherical silica and zinc molybdate has a relatively weak effect on improving drill bit wear during drilling, and there is more white part on the surface of the worn drill bit.

[0093] Example 2

[0094] The method for preparing spherical silicon for copper-clad laminates in this embodiment includes:

[0095] Pure water was added to a polytetrafluoroethylene-lined hydrothermal reactor, followed by 10 kg of spherical silica (D50: 1.2 μm, SiO2 content: 99.7%). The mixture was then stirred at a speed of 10 Hz for 120 minutes.

[0096] Then add an aqueous solution of ammonium molybdate (8 mol / L), 6 L in volume, stirring at 10 Hz for 120 minutes;

[0097] Continue adding zinc sulfate aqueous solution (8 mol / L), volume 6 L, then raise the temperature of the reactor (130℃) and pressure (8 MPa), and release the material from the reactor after reacting for 8 hours;

[0098] The material inside the reactor is discharged and filtered using a filter press. During the filtration process, the material is repeatedly rinsed with pure water. When the conductivity of the material is reduced to ≤100 μS / cm, the material is discharged.

[0099] The washed materials are dried using a flash dryer at 150°C.

[0100] The dried material was dispersed and classified using a fluidized bed air classifier to obtain spherical silicon material with zinc molybdate coating (as shown in Figure 7). Its specifications are as follows: Zinc molybdate content per unit area: 0.04 g / m². 2 Electrical conductivity: 35 μS / cm, hydroxyl group content: 13 per nm 2 The D50 is 1.3 micrometers, and the size of the zinc molybdate coating on the surface is 80-300 nm.

[0101] The spherical silicon prepared in this embodiment was mixed with polyphenylene ether resin to prepare a resin composition (the spherical silicon filling amount was 55%), and copper-clad laminate was made using this resin composition. The results showed that using the spherical silicon as a filler in this embodiment can effectively improve the drill bit wear during the drilling process of copper-clad laminate (Figure 8 shows a picture after 1000 drilling cycles), and the drill bit wear is relatively small; and the peel strength of the copper-clad laminate made in this embodiment is 0.9 N / inch.

[0102] Example 3

[0103] The method for preparing spherical silicon for copper-clad laminates in this embodiment includes:

[0104] Add pure water to a polytetrafluoroethylene-lined hydrothermal reactor, then add 10 kg of spherical silica (D50: 0.5 μm, SiO2 content: 99.8%), and then stir at a speed of 40 Hz for 10 minutes.

[0105] Then add an aqueous solution of ammonium molybdate (3 mol / L), 10 L in volume, and stir at 40 Hz for 10 minutes.

[0106] Continue adding zinc sulfate aqueous solution (3 mol / L), volume 10 L, then raise the temperature of the reactor (180℃) and pressure (1 MPa), and release the material in the reactor after reacting for 3 hours;

[0107] The material inside the reactor is discharged and filtered using a filter press. During the filtration process, the material is repeatedly rinsed with pure water. When the conductivity of the material is reduced to ≤100 μS / cm, the material is discharged.

[0108] The washed materials are dried using a flash dryer at 110°C.

[0109] The dried material was dispersed and classified using a fluidized bed air classifier to obtain spherical silicon material with zinc molybdate coating (as shown in Figure 10). Its specifications are as follows: Zinc molybdate content per unit area: 0.03 g / m². 2 Electrical conductivity: 30 μS / cm; hydroxyl content: 12 hydroxyl groups / nm 2 The D50 is 0.6 micrometers, and the size of the zinc molybdate coating on the surface is 40-300 nm.

[0110] The spherical silicon prepared in this embodiment was mixed with polyphenylene ether resin to prepare a resin composition (the filling amount of spherical silicon was 60%), and copper-clad laminate was made using this resin composition. The results showed that using spherical silicon as a filler in this embodiment can effectively improve the drill bit wear during the drilling process of copper-clad laminate. The drill bit wear image after 1000 drilling cycles is shown in Figure 9, and the peel strength of the copper-clad laminate prepared in this embodiment is 0.7 N / inch.

[0111] Example 4

[0112] This embodiment is based on the spherical silicon prepared in Example 1, and further modified. The structural formula of the modifier used is:

[0113] One method for preparing the modifier is as follows:

[0114] 1000 parts by mass of CH3CH2CH2SiCl3 and 1000 parts by mass of Cl2 were reacted under light conditions and with AlCl3 as a catalyst to prepare ClCH2CH2CH2SiCl3.

[0115] The product is prepared by reacting 1000 parts by mass of 2,6-dimethylphenol with 1000 parts by mass of ClCH2CH2CH2SiCl3.

[0116] By reacting 3000 parts by mass of methanol with 1000 parts by mass of the above product through an alcoholysis reaction, the following product is obtained:

[0117] The structure of the synthesized organic compound can be identified by Fourier transform infrared (FT-IR) spectroscopy, as shown in Figure 11, at 1377.48 cm⁻¹. -1 and 2918.89cm -1 The absorption peak at 1602.64 cm⁻¹ is attributed to the bending vibration of the CH bond of the methyl group on the benzene ring. -1 and 1467.56cm -1 The absorption peak at 1304.81 cm⁻¹ is attributed to the stretching vibration of the carbon-carbon bonds in the benzene ring skeleton. -1 1184.99cm -1 and 1018.94cm -1 The absorption peak observed is attributed to the stretching vibration of the COC bonds in the polyphenylene ether backbone, at 1190 cm⁻¹. -1 2861.12cm -1 It is a Si-O-CH3 stretching vibration, 1602.64 cm⁻¹. -1 1494.71cm - 1 for The stretching vibration, 2098.00cm -1 The stretching vibration of the -CH2-CH2-CH2-Si bond at this point is 907.65 cm⁻¹. -1 855.91cm -1 829.09cm -1 728.27cm -1 694.32cm -1 This is a stretching vibration on the H-plane of the benzene ring, 958.80 cm. -1 This is a stretching vibration in the H-plane of the benzene ring. 1304.81 cm⁻¹ -1 This is a stretching vibration of the benzene ring skeleton, 3024.68 cm. -1 It is the stretching vibration of H on the benzene ring. Based on the above data, it can be determined that the synthesized substance is a modifier of the aforementioned structure.

[0118] The fabrication process of the modified spherical silicon in this embodiment specifically includes:

[0119] a. The modifier is added to the zinc molybdate-coated spherical silicon powder at a ratio of 0.2-3% of the mass of the spherical silicon, and 2-hexanol is added at the same time to submerge the material. The temperature of the reactor is 25-120°C, and the reaction time is 1-9 hours. Specifically, in this embodiment, the amount of modifier added is 1.5% of the mass of the zinc molybdate-coated spherical silicon powder, the reaction temperature is 80°C, and the reaction time is 5 hours.

[0120] b. Discharge the reacted slurry from the reactor, then filter it under pressure, and use a spray drying device to spray dry it at a temperature of 150°C, while collecting the vaporized 2-hexanol.

[0121] c. Finally, the spray-dried material is dispersed using a fluidized bed jet mill to obtain modified spherical silicon.

[0122] The structure of the obtained modified spherical silicon was identified by Fourier transform infrared (FT-IR) spectroscopy, and the results are shown in Figure 12. The structure is located at 1377.48 cm⁻¹. -1 and 2918.89cm -1 The absorption peak at 1602.64 cm⁻¹ is attributed to the bending vibration of the CH bond of the methyl group on the benzene ring. -1 and 1467.56cm -1 The absorption peak at 1304.81 cm⁻¹, 1184.99 cm⁻¹, and 1018.94 cm⁻¹ is attributed to the stretching vibration of the carbon-carbon bonds in the benzene ring backbone. The absorption peaks at 2861.12 cm⁻¹ are attributed to the stretching vibration of the COC bonds in the polyphenylene ether backbone. -1 The stretching vibration peak of Si-O-CH3 disappears, mainly due to the reaction between silane and hydroxyl groups on the surface of the spherical silicon material, at 1602.64 cm⁻¹. -1 1494.71cm -1 for:

[0123] The stretching vibration, 2098.00cm -1 The stretching vibration is the stretching vibration of the -CH2-CH2-CH2-Si bond, 907.65 cm⁻¹. -1 855.91cm -1 829.09cm -1 728.27cm -1 694.32cm -1 The point is a stretching vibration on the H-plane of the benzene ring, 958.80 cm. -1 This is a stretching vibration in the H-plane of the benzene ring. 1304.81 cm⁻¹ -1 This is a stretching vibration of the benzene ring skeleton, 3024.68 cm. -1 It is the stretching vibration of H on the benzene ring, with a new increase of 10¹⁰.²⁰ cm⁻¹. -1 The presence of Si-O-Si chemical bonds indicates that the silane reacts with the hydroxyl groups on the surface of the spherical silicon material to generate a new structural formula:

[0124] That is, the modified spherical silica obtained in this embodiment includes modified spherical silica and zinc molybdate particles dispersed in situ on the surface of silica. After modification treatment, the modifier reacts with the hydroxyl groups on the surface of the spherical silica to form...

[0125] The modified spherical silicon prepared in this embodiment was mixed with polyphenylene ether resin to prepare a resin composition, and copper-clad laminate was fabricated using this resin composition. The filling amount of modified spherical silicon and the specific fabrication process of the copper-clad laminate were the same as in Example 1. The results showed that the modified spherical silicon of this embodiment could not only effectively improve the drill bit wear during the drilling process of the copper-clad laminate (as shown in Figure 13 after 1000 drilling cycles), but also effectively improve the compatibility between the filler and the polyphenylene ether resin, and increase the peel strength of the copper-clad laminate to 1.4 N / inch. The hydroxyl content on the surface of the obtained modified spherical silicon was 3.3 hydroxyl groups / nm. 2 .

[0126] Comparative Example 2

[0127] Based on Example 4, the coupling agent was changed to vinyl silane, while the rest remained unchanged. The resulting modified spherical silicon was mixed with resin and used to make copper-clad laminate. The peel strength of the resulting copper-clad laminate was 0.9 N / inch (vinyl silane has a certain effect on improving peel strength).

[0128] Comparative Example 3

[0129] Based on Example 4, the coupling agent was replaced with epoxy silane, while the rest remained unchanged. The resulting modified spherical silicon was mixed with resin and used to make copper-clad laminate. The peel strength of the resulting copper-clad laminate was 0.72 N / inch.

[0130] Comparative Example 4

[0131] Based on Example 4, the coupling agent was replaced with aminosilane, while the rest remained unchanged. The resulting modified spherical silicon was mixed with resin and used to make copper-clad laminate. The peel strength of the resulting copper-clad laminate was 0.74 N / inch.

[0132] Comparative Example 5

[0133] Based on Example 4, the spherical silica was replaced with talc powder of the same particle size. Since talc powder has a distinct lamellar structure (as shown in Figure 14), the talc powder material coated with zinc molybdate became very viscous and completely unusable.

[0134] Comparative Example 6

[0135] The main difference between Comparative Example 1 and Example 1 is that the hydrothermal reaction temperature is 120°C, as shown in Figure 15, and zinc molybdate is basically not formed on the surface of the spherical silicon.

[0136] Comparative Example 7

[0137] The main difference between Comparative Example 1 and Example 1 is that the hydrothermal reaction temperature is 185°C. As shown in Figure 16, if the temperature is too high, less zinc molybdate is formed on the surface of the spherical silicon, resulting in non-spherical zinc molybdate particles mixed in the spherical silicon.

[0138] Example 5

[0139] This embodiment is based on the spherical silicon prepared in Example 2, and further modified. The modifier used is the same as in Example 4, and the modification process is basically the same as in Example 4. The main difference is that in this embodiment, the amount of ammonium molybdate and zinc sulfate added during the preparation of spherical silicon is 6.2 mol / L, and the volume is 20 L. The zinc molybdate content per unit area of ​​the modified spherical silicon obtained in this embodiment is 1.0 g / m². 2 The reaction temperature was 150℃ and the reaction time was 1 hour.

[0140] Conclusion: The hydroxyl content on the surface of the obtained modified spherical silicon is 7 hydroxyl groups / nm. 2 The peel strength of the copper clad laminate is 1.1 N / inch, but the high zinc molybdate content will cause the PS to be slightly lower, as shown in SEM image 17.

[0141] Example 6

[0142] This embodiment is based on the spherical silica prepared in Example 3, and further modified. The modifier used is the same as in Example 4, and the modification process is basically the same as in Example 4. The main difference is that in this embodiment, the amount of ammonium molybdate and zinc sulfate added during the preparation of spherical silica is 6.2 mol / L, with a volume of 5 L. The zinc molybdate content per unit area on the surface of the modified spherical silica obtained in this embodiment is 0.03 g / m². 2 The reaction temperature was 150℃ and the reaction time was 6 hours.

[0143] The test results are as follows: the hydroxyl content on the surface of the obtained modified spherical silicon is 4 per nm. 2 The peel strength of the copper-clad laminate is 1.3 N / inch. The SEM is shown in Figure 18. The wear of the drill bit after 1000 drilling cycles is shown in Figure 19. The surface wear is relatively small.

[0144] Example 7

[0145] The preparation method of the modified spherical silicon in this embodiment is basically the same as that in Example 4. The main difference is that the amount of modifier added in this embodiment accounts for 0.5% of the mass of zinc molybdate-coated spherical silicon powder, the reaction temperature is 150°C, and the reaction time is 1 hour.

[0146] The test results are as follows: the hydroxyl content on the surface of the obtained modified spherical silicon is 8 hydroxyl groups / nm. 2 The peel strength of the copper-clad laminate is 1.0 N / inch.

[0147] Example 8

[0148] This embodiment is based on the spherical silicon prepared in Example 3, and further modified. The modifier and modification process used are basically the same as in Example 4. The main difference is that the amount of modifier added in this embodiment accounts for 3% of the mass of zinc molybdate coated spherical silicon powder, the reaction temperature is 150℃, and the reaction time is 6 hours.

[0149] The test results are as follows: the hydroxyl content on the surface of the obtained modified spherical silicon is 2 hydroxyl groups / nm. 2 The peel strength of the copper-clad laminate is 15 N / inch.

[0150] In summary, this application utilizes a hydrothermal method to directly synthesize zinc molybdate in situ on the surface of spherical silica. Specifically, the optimized control of reaction temperature, pressure, and time effectively controls the structural morphology of the resulting spherical silica and the size of the zinc molybdate particles, thereby significantly reducing drill wear during copper-clad laminate (CCL) drilling, decreasing the wear rate from the current 5% to 2%. Simultaneously, it effectively ensures the strong bond between the zinc molybdate particles and silica, preventing detachment. Further modification of the resulting spherical silica not only improves its compatibility with the resin and enhances the peel strength of the CCL, but also further reduces the dielectric loss of the CCL.

Claims

1. A spherical silicon for copper clad laminate, wherein, The spherical silica is composed of spherical silica and zinc molybdate particles dispersedly grown in situ on the surface of the spherical silica, the diameter of the zinc molybdate particles is less than 10 microns, the D50 is 0.6-6 microns, and the zinc molybdate content per unit area of the surface of the spherical silica is 0.03-1 g / m 2 , the size of the zinc molybdate particles is ≤400 nm.

2. The spherical silica for copper-clad plates as claimed in claim 1, wherein, The spherical silica has a pH of 6-8, an electrical conductivity of ≤100 μS / cm, and a D50 of 0.5-5 μm.

3. A method for preparing a spherical silicon for a copper clad plate, wherein, include: Spherical silica is brought into contact with / mixed with soluble molybdate and zinc salt in an aqueous reaction system; Soluble molybdate and zinc salt are reacted in situ on the surface of spherical silica to form spherical silica particles with dispersed chemical coating; The process involves reacting soluble molybdate and zinc salt in situ on the surface of spherical silica, with the following reaction conditions: reaction temperature of 130-180℃, reaction pressure of 1-8MPa, and reaction time of 1-8 hours.

4. The method for preparing spherical silicon for copper-clad laminates as described in claim 3, wherein, The D50 of the spherical silica raw material used is 0.5-5 microns, the D50 of the spherical silica obtained after coating is 0.6-6 microns, the conductivity is ≤100 us / cm, the pH is 6-8, and the zinc molybdate content per unit area of the surface of the spherical silica is 0.03-1 g / m 2 The size of the zinc molybdate particles is ≤400 nm.

5. The method of producing spherical silicon for copper-clad plates according to claim 3 or 4, wherein Also includes: The resulting material after the reaction is subjected to pressure filtration and washing.

6. The method for preparing spherical silicon for copper-clad laminates as described in claim 5, wherein, The material obtained after the reaction is dried.

7. The method for preparing spherical silicon for copper-clad laminates as described in claim 6, wherein, The materials obtained after the reaction are broken down and classified.

8. The method for preparing spherical silicon for copper-clad laminates as described in claim 5, wherein, When the material obtained after the reaction is subjected to pressure filtration, it is repeatedly rinsed with pure water during the pressure filtration process until the conductivity of the material is ≤100us / cm.

9. The method for preparing spherical silicon for copper-clad laminates as described in claim 6, wherein, And / or the drying temperature is 100-150℃.

10. A modified spherical silica for a copper clad plate, wherein, The modified spherical silica comprises modified spherical silica and zinc molybdate particles in-situ dispersedly grown on the surface of the silica, wherein the structural formula of the surface group of the modified spherical silica is as follows:

11. The modified spherical silica for copper clad plate according to claim 10, wherein The modified spherical silica has a hydroxyl content of 0.1-10 / nm 2 ; and / or the modified spherical silica has a diameter of less than 10 microns, with a D50 of 0.6-6 microns.

12. The modified spherical silica for copper clad plate according to claim 10, wherein The content of zinc molybdate per unit area of the surface of the modified spherical silica is 0.03-1 g / m 2 The size of the zinc molybdate particles is ≤400 nm.

13. A method for preparing a modified spherical silica for a copper-clad plate as claimed in any one of claims 10 to 12, wherein, include: The modifier is brought into contact / mixed with the spherical silicon as described in claim 1 or 2, or the spherical silicon prepared by any one of claims 3-9, in a reaction solvent to react and obtain modified spherical silicon; wherein the reaction conditions include: a reaction temperature of 25-120°C, a reaction time of 1-9 hours, and the amount of modifier added is 0.2-3% of the total mass of the spherical silicon chemically coated with zinc molybdate particles, and the structural formula of the modifier is as follows:

14. A resin composition comprising a resin and a filler, wherein, The filler includes the spherical silicon as described in claim 1 or 2, or the spherical silicon prepared by the preparation method described in any one of claims 3-9, or the modified spherical silicon as described in any one of claims 10-12, or the modified spherical silicon prepared by the preparation method described in claim 13.

15. The resin composition of claim 14, wherein, The composition contains 50-65% spherical silica or modified spherical silica.

16. A copper clad board wherein, The copper-clad laminate is made of the resin composition of claim 14 or 15, wherein the dielectric loss of the copper-clad laminate is 0.001-0.003 and the peel strength is 1.0-1.5 N / inch.

Images