Reinforced composite PCB and preparation method thereof

Abstract

The invention discloses a reinforced composite PCB and a preparation method thereof, and belongs to the technical field of PCB preparation. The preparation method of the reinforced composite PCB comprises the following steps: step 1, processing an inner-layer core board to obtain a preprocessed inner-layer core board; 2, cutting, drilling and activating the modified composite film to obtain a treated modified composite film; and 3, sequentially carrying out stacking, hot pressing treatment, pressure relief, cooling, drilling, hole metallization treatment, outer layer pattern transfer, pattern electroplating, outer layer etching, resistance welding, surface treatment, molding and testing on a copper foil, a prepreg, the pretreated inner layer core plate, the prepreg, the treated modified composite film, the prepreg, the pretreated inner layer core plate, the prepreg and the copper foil. And the composite PCB is obtained. The circuit board prepared by the method has excellent thermal stability and mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of circuit board manufacturing technology, specifically relating to reinforced composite PCB circuit boards and their manufacturing methods. Background Technology

[0002] As electronic devices rapidly evolve towards higher frequencies, higher speeds, higher integration, and greater adaptability to harsh environments, the limitations of traditional PCBs in terms of material performance and structural functionality are becoming increasingly apparent. Conventional FR-4 substrates, due to their low glass transition temperature, are prone to interlayer delamination and signal attenuation in high-temperature or high-power applications; while single-layer or double-layer structures struggle to meet the wiring density and electromagnetic shielding requirements of complex circuits. Reinforced composite PCBs, through innovative material systems and lamination processes, combine high-modulus glass fiber, ceramic-filled resin, and metal thermally conductive layers with high-temperature resistant polyimide and low-loss polytetrafluoroethylene resin, forming a multilayer heterogeneous structure that combines mechanical strength, thermal management performance, and electrical properties. This makes it a key support for miniaturization and reliability in fields such as 5G communications, automotive electronics, and aerospace.

[0003] Patent CN108617086A discloses a composite multilayer PCB circuit board and its preparation method. The preparation method includes the following sequential steps: ingredient preparation, ball milling for pulping, casting, die cutting, metallization, lamination and hot pressing, adhesive removal and sintering, and conductivity testing. Circuitry is fabricated on the composite substrate by printing or vapor deposition / sputtering. Because it is prepared under low-temperature sintering conditions, the circuitry does not require particularly high-temperature resistant materials; conventional silver and copper metals can be used under inert gas protection. By using a composite of glass, ceramics, etc., and adjusting the proportions, the coefficient of thermal expansion of the circuit board can be achieved between 5 and 7, very close to that of silicon wafers, thus enabling co-board technologies such as flip-chip bonding. During the fabrication of the aforementioned PCB circuit boards, the interfacial bonding between different raw materials significantly affects the overall performance. If the interfacial bonding is not tight, or if there are defects or stress concentrations, it will hinder charge conduction and distribution, affecting the stability of the dielectric constant. At the same time, if the pressure, temperature, and other parameters are not precisely controlled during processes such as lamination and hot pressing, the internal structure is not dense and uniform enough, and there are weak areas in the microstructure of the material, it will reduce the overall mechanical strength of the circuit board, resulting in poor mechanical properties such as bending resistance and impact resistance, making it difficult to meet the stringent performance requirements of some high-end electronic devices. Summary of the Invention

[0004] The purpose of this invention is to provide an enhanced composite PCB circuit board and its preparation method, which solves the technical problems of high dielectric constant and poor mechanical properties of circuit boards in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The present invention provides a method for preparing an enhanced composite PCB circuit board, comprising the following steps: Step 1: Clean the inner core board, apply dry film, expose, develop, etch, remove film, inspect by AOI and blacken to obtain the pre-treated inner core board; Step 2: Cut, drill holes in, and activate the modified composite film to obtain the treated modified composite film; Step 3: The copper foil, prepreg, pretreated inner core board, prepreg, treated modified composite film, prepreg, pretreated inner core board, prepreg and copper foil are stacked in sequence, hot-pressed, depressurized, cooled, drilled, hole metallized, outer layer pattern transferred, pattern electroplated, outer layer etched, solder mask applied, surface treated, shaped, and tested to obtain a composite PCB circuit board.

[0006] Preferably, the method for preparing the modified composite film includes the following steps: Q1: 3,5-Di(trifluoromethyl)aniline was added to a container, followed by p-fluoronitrobenzene, cesium fluoride and dimethyl sulfoxide in sequence. The mixture was heated and stirred, cooled, and the reactants were added to cold water. The mixture was filtered, dried and recrystallized to obtain product 1. Q2: Add product 1, Pd / C and ethanol to a container in sequence, heat and stir to react, add hydrazine hydrate, heat to reflux to react, filter while hot, concentrate the filtrate, dry and recrystallize to obtain product 2. Q3: Add product 2 and biphenyltetracarboxylic dianhydride to N,N-dimethylacetamide, stir and mix, add tris(2-aminoethyl)amine and continue stirring, then add triethylamine and stir, then add to ice-cold deionized water and freeze dry to obtain product 3; Q4: Mix product 3, ice-cold deionized water and triethylamine to obtain a sol. Add carbon nanotubes to the deionized water and ultrasonically disperse to obtain a dispersion. Then add the dispersion to the sol, stir, age at room temperature, freeze, freeze dry under vacuum, and heat imidize to obtain a modified composite film.

[0007] The synthesis reaction formula for product 3 in the above process is as follows:

[0008] The mass spectrometry analysis results of product 1 were: m / z: 471.07 (100.0%), 472.07 (21.9%), 473.07 (3.3%), 472.06 (1.1%); the mass spectrometry analysis results of product 2 were: m / z: 411.12 (100.0%), 412.12 (21.8%), 413.12 (2.5%), 412.11 (1.1%).

[0009] Preferably, in Q1, the ratio of 3,5-bis(trifluoromethyl)aniline, p-fluoronitrobenzene, cesium fluoride, and dimethyl sulfoxide is (11.03-11.98) g : (13.78-14.58) g : (14.88-15.48) g : (220-260) mL, and the mixture is heated to 100-105℃ and stirred for 10-12 h.

[0010] Preferably, in Q2, the ratio of product 1, Pd / C, ethanol and hydrazine hydrate is (4.25-5.22) g : (0.22-0.36) g : (140-160) mL : (20-28) mL, the temperature is raised to 50-55℃ and stirred for 30-45 min, and the reaction is refluxed for 8-12 h.

[0011] Preferably, in Q3, the ratio of product 2, biphenyltetracarboxylic dianhydride, N,N-dimethylacetamide, tris(2-aminoethyl)amine, and triethylamine is (0.363-0.422) g : (0.288-0.299) g : (6.182-6.498) g : (0.007-0.015) g : (0.472-0.496) g, the mixing time is 5-7 h, the stirring is continued for 5-10 min, and triethylamine is added and stirred for 2-3 h.

[0012] Preferably, in Q4, the ratio of product 3, ice-deionized water, triethylamine, and carbon nanotubes is (0.25-0.33) g : (3.5-4.8) mL : (0.71-0.88) g : (0.015-0.032) g. The mixture is stirred for 6-8 hours, aged at room temperature for 5-8 hours, frozen for 10-12 hours, and freeze-dried at -80 to -85°C at a pressure of 2-5 Pa for 40-48 hours. The thermal imidization process involves heating at 80°C, 100°C, 200°C, and 300°C for 1 hour, respectively.

[0013] Preferably, in step three, the hot pressing process is as follows: at 110-150°C, a pressure of 0-50 psi is applied, followed by at 180-220°C, a pressure of 300-400 psi is applied, and the temperature and pressure are maintained for 60-90 minutes.

[0014] As a preferred option, the reinforced composite PCB circuit board is prepared using the above-described preparation method.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: In the process of preparing PCB circuit boards, this invention adds a modified composite film, which can effectively improve its electrical performance, thermal stability, and mechanical properties. The trifluoromethyl structure contained in the modified composite film has a strong electronegativity, which can reduce the dielectric constant of the PCB circuit board and reduce signal transmission loss. After the product 3 is combined with carbon nanotubes, the cross-linked network structure suppresses leakage current, improves insulation resistance, and ensures circuit stability. At the same time, the product 3 has high temperature resistance, and the addition of carbon nanotubes can improve thermal conductivity, accelerate heat dissipation, and improve its thermal stability. Moreover, as a nano-reinforcing phase, carbon nanotubes combine with the product 3 through π-π interactions, thereby improving the mechanical properties of the modified composite film. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1: This example discloses a method for preparing a modified composite film, including the following steps: Q1: 11.51 g of 3,5-bis(trifluoromethyl)aniline was added to a container, followed by 11.03 g of p-fluoronitrobenzene, 15.02 g of cesium fluoride and 240 mL of dimethyl sulfoxide. The mixture was heated to 100 °C and stirred for 12 h. After cooling, the reactants were added to cold water, filtered, dried and recrystallized to obtain product 1. Q2: Add 4.87g of product 1, 0.29g of Pd / C and 150mL of ethanol to a container in sequence, heat to 53℃ and stir for 45min, then add 24mL of hydrazine hydrate, heat under reflux for 10h, filter while hot, concentrate the filtrate, dry and recrystallize to obtain product 2. Q3: Add 0.393g of product 2 and 0.294g of biphenyltetracarboxylic dianhydride to 6.273g of N,N-dimethylacetamide, stir and mix for 6h, then add 0.011g of tris(2-aminoethyl)amine and continue stirring for 5min, then add 0.483g of triethylamine and stir for 3h, then add to ice-cold deionized water and freeze dry to obtain product 3; Q4: Mix 0.29g of product 3, 3.2mL of ice-cold deionized water, and 0.78g of triethylamine to obtain a sol. Add 0.023g of carbon nanotubes to 10mL of deionized water and ultrasonically disperse to obtain a dispersion. Then add the dispersion to the sol and stir for 6h. Age at room temperature for 6h, freeze for 12h, freeze dry at -85℃ and 5Pa for 48h, and then perform thermal imidization treatment by heating at 80℃, 100℃, 200℃, and 300℃ for 1h respectively to obtain a modified composite film.

[0018] This embodiment discloses a method for preparing an enhanced composite PCB circuit board, including the following steps: Step 1: Clean the inner core board, apply dry film, expose, develop, etch, remove film, inspect by AOI and blacken to obtain the pre-treated inner core board; Step 2: Cut, drill holes in, and activate the modified composite film to obtain the treated modified composite film; Step 3: Copper foil, prepreg, pretreated inner core board, prepreg, treated modified composite film, prepreg, pretreated inner core board, prepreg and copper foil are stacked in sequence and hot-pressed. The process is as follows: apply a pressure of 30 psi at 120℃, then apply a pressure of 320 psi at 200℃, hold for 80 minutes, release pressure, cool, drill holes, metallize the holes, transfer the outer layer pattern, electroplate the pattern, etch the outer layer, apply solder mask, surface treat, form, and test to obtain the composite PCB circuit board.

[0019] Example 2: This example discloses a method for preparing a modified composite film, including the following steps: Q1: 11.03 g of 3,5-bis(trifluoromethyl)aniline was added to a container, followed by 13.78 g of p-fluoronitrobenzene, 14.88 g of cesium fluoride and 210 mL of dimethyl sulfoxide. The mixture was heated to 100 °C and stirred for 12 h. After cooling, the reactants were added to cold water, filtered, dried and recrystallized to obtain product 1. Q2: Add 4.25g of product 1, 0.27g of Pd / C and 160mL of ethanol to a container in sequence, heat to 53℃ and stir for 45min, then add 28mL of hydrazine hydrate, heat under reflux for 10h, filter while hot, concentrate the filtrate, dry and recrystallize to obtain product 2. Q3: Add 0.363g of product 2 and 0.288g of biphenyltetracarboxylic dianhydride to 6.182g of N,N-dimethylacetamide, stir and mix for 6h, then add 0.007g of tris(2-aminoethyl)amine and continue stirring for 5min, then add 0.472g of triethylamine and stir for 3h, then add to ice-cold deionized water and freeze dry to obtain product 3; Q4: Mix 0.25g of product 3, 3.5mL of ice-cold deionized water, and 0.88g of triethylamine to obtain a sol. Add 0.015g of carbon nanotubes to 10mL of deionized water and ultrasonically disperse to obtain a dispersion. Then add the dispersion to the sol and stir for 6h. Age at room temperature for 6h, freeze for 12h, freeze dry at -85℃ and 5Pa for 48h, and then perform thermal imidization treatment. The treatment process is as follows: heat treatment at 80℃, 100℃, 200℃, and 300℃ for 1h respectively to obtain a modified composite film.

[0020] This embodiment discloses a method for preparing an enhanced composite PCB circuit board, including the following steps: Step 1: Clean the inner core board, apply dry film, expose, develop, etch, remove film, inspect by AOI and blacken to obtain the pre-treated inner core board; Step 2: Cut, drill holes in, and activate the modified composite film to obtain the treated modified composite film; Step 3: Copper foil, prepreg, pretreated inner core board, prepreg, treated modified composite film, prepreg, pretreated inner core board, prepreg and copper foil are stacked in sequence and hot-pressed. The process is as follows: apply a pressure of 30 psi at 120℃, then apply a pressure of 320 psi at 200℃, hold for 80 minutes, release pressure, cool, drill holes, metallize the holes, transfer the outer layer pattern, electroplate the pattern, etch the outer layer, apply solder mask, surface treat, form, and test to obtain the composite PCB circuit board.

[0021] Example 3: This example discloses a method for preparing a modified composite film, including the following steps: Q1: 11.98 g of 3,5-bis(trifluoromethyl)aniline was added to a container, followed by 14.58 g of p-fluoronitrobenzene, 15.48 g of cesium fluoride and 260 mL of dimethyl sulfoxide. The mixture was heated to 100 °C and stirred for 12 h. After cooling, the reactants were added to cold water, filtered, dried and recrystallized to obtain product 1. Q2: 5.22g of product 1, 0.36g of Pd / C and 140mL of ethanol were added to a container in sequence. The mixture was heated to 53℃ and stirred for 45min. Then, 20mL of hydrazine hydrate was added and the mixture was heated under reflux for 10h. The mixture was filtered while hot, the filtrate was concentrated, dried and recrystallized to obtain product 2. Q3: Add 0.422g of product 2 and 0.299g of biphenyltetracarboxylic dianhydride to 6.498g of N,N-dimethylacetamide, stir and mix for 6h, then add 0.015g of tris(2-aminoethyl)amine and continue stirring for 5min, then add 0.496g of triethylamine and stir for 3h, then add to ice-cold deionized water and freeze dry to obtain product 3; Q4: Mix 0.33g of product 3, 4.8mL of ice-cold deionized water, and 0.71g of triethylamine to obtain a sol. Add 0.032g of carbon nanotubes to 10mL of deionized water and ultrasonically disperse to obtain a dispersion. Then add the dispersion to the sol and stir for 6h. Age at room temperature for 6h, freeze for 12h, freeze dry at -85℃ and 5Pa for 48h, and then perform thermal imidization treatment by heating at 80℃, 100℃, 200℃, and 300℃ for 1h respectively to obtain a modified composite film.

[0022] This embodiment discloses a method for preparing an enhanced composite PCB circuit board, including the following steps: Step 1: Clean the inner core board, apply dry film, expose, develop, etch, remove film, inspect by AOI and blacken to obtain the pre-treated inner core board; Step 2: Cut, drill holes in, and activate the modified composite film to obtain the treated modified composite film; Step 3: Copper foil, prepreg, pretreated inner core board, prepreg, treated modified composite film, prepreg, pretreated inner core board, prepreg and copper foil are stacked in sequence and hot-pressed. The process is as follows: apply a pressure of 30 psi at 120℃, then apply a pressure of 320 psi at 200℃, hold for 80 minutes, release pressure, cool, drill holes, metallize the holes, transfer the outer layer pattern, electroplate the pattern, etch the outer layer, apply solder mask, surface treat, form, and test to obtain the composite PCB circuit board.

[0023] Comparative Example 1: Compared with Example 1, Comparative Example 1 did not add the treated modified composite film during the preparation of the composite PCB circuit board, and all other conditions remained unchanged.

[0024] Performance testing: The composite PCB circuit boards prepared in Examples 1-3 and Comparative Example 1 were subjected to performance tests. The dielectric constant, thermal decomposition temperature and mechanical properties of the samples were tested according to GB / T4722-2017. The test results are shown in Table 1. Table 1

[0025] The data in Table 1 show that composite PCB circuit boards with excellent mechanical properties, thermal stability, and low dielectric constant can be prepared according to the preparation methods of Examples 1-3. A comparison between Comparative Example 1 and Examples 1-3 reveals that the addition of the modified composite film can effectively improve the mechanical properties, thermal stability, and dielectric constant of the composite PCB circuit board.

[0026] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0027] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a reinforced composite PCB circuit board, characterized in that, Includes the following steps: Step 1: Clean the inner core board, apply dry film, expose, develop, etch, remove film, inspect by AOI and blacken to obtain the pre-treated inner core board; Step 2: Cut, drill, and activate the modified composite film to obtain the treated modified composite film; Step 3: The copper foil, prepreg, pretreated inner core board, prepreg, treated modified composite film, prepreg, pretreated inner core board, prepreg and copper foil are stacked in sequence, hot-pressed, depressurized, cooled, drilled, hole metallized, outer layer pattern transferred, pattern electroplated, outer layer etched, solder mask applied, surface treated, shaped, and tested to obtain a composite PCB circuit board.

2. The method for preparing the reinforced composite PCB circuit board according to claim 1, characterized in that, The method for preparing the modified composite film includes the following steps: Q1: 3,5-Di(trifluoromethyl)aniline was added to a container, followed by p-fluoronitrobenzene, cesium fluoride and dimethyl sulfoxide in sequence. The mixture was heated and stirred, cooled, and the reactants were added to cold water. The mixture was filtered, dried and recrystallized to obtain product 1. Q2: Add product 1, Pd / C and ethanol to a container in sequence, heat and stir to react, add hydrazine hydrate, heat to reflux to react, filter while hot, concentrate the filtrate, dry and recrystallize to obtain product 2. Q3: Add product 2 and biphenyltetracarboxylic dianhydride to N,N-dimethylacetamide, stir and mix, add tris(2-aminoethyl)amine and continue stirring, then add triethylamine and stir, then add to ice-cold deionized water and freeze dry to obtain product 3; Q4: Mix product 3, ice-cold deionized water and triethylamine to obtain a sol. Add carbon nanotubes to the deionized water and ultrasonically disperse to obtain a dispersion. Then add the dispersion to the sol, stir, age at room temperature, freeze, freeze dry under vacuum, and heat imidize to obtain a modified composite film.

3. The method for preparing the reinforced composite PCB circuit board according to claim 2, characterized in that, In Q1, the ratio of 3,5-bis(trifluoromethyl)aniline, p-fluoronitrobenzene, cesium fluoride and dimethyl sulfoxide is (11.03-11.98) g : (13.78-14.58) g : (14.88-15.48) g : (220-260) mL.

4. The method for preparing the reinforced composite PCB circuit board according to claim 2, characterized in that, In Q2, the ratio of product 1, Pd / C, ethanol and hydrazine hydrate is (4.25-5.22) g : (0.22-0.36) g : (140-160) mL : (20-28) mL.

5. The method for preparing the reinforced composite PCB circuit board according to claim 2, characterized in that, In Q3, the ratio of product 2, biphenyltetracarboxylic dianhydride, N,N-dimethylacetamide, tris(2-aminoethyl)amine and triethylamine is (0.363-0.422) g : (0.288-0.299) g : (6.182-6.498) g : (0.007-0.015) g : (0.472-0.496) g.

6. The method for preparing the reinforced composite PCB circuit board according to claim 2, characterized in that, In Q4, the ratio of product 3, ice-deionized water, triethylamine and carbon nanotubes is (0.25-0.33) g : (3.5-4.8) mL : (0.71-0.88) g : (0.015-0.032) g.

7. The method for preparing the reinforced composite PCB circuit board according to claim 1, characterized in that, In step three, the hot pressing process is as follows: at 110-150℃, a pressure of 0-50psi is applied, followed by at 180-220℃, a pressure of 300-400psi is applied, and the temperature and pressure are maintained for 60-90 minutes.

8. A reinforced composite PCB circuit board, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

Images