Search

CN-122002691-A - Multilayer aluminum core copper-clad plate adopting plasma oxidation-copper plating process and preparation method thereof

CN122002691ACN 122002691 ACN122002691 ACN 122002691ACN-122002691-A

Abstract

The invention discloses a multilayer aluminum core copper-clad plate of a plasma oxidation-copper plating process, and also discloses a preparation method of the copper-clad plate, comprising the steps of performing plasma anodic oxidation and copper plating treatment on the surface of an aluminum substrate to obtain a copper-clad plasma anodic aluminum oxide substrate; the method comprises the steps of manufacturing an inner layer circuit pattern on the surface of a copper-clad plasma anodized aluminum substrate, overlapping the inner layer circuit pattern with copper foil and prepreg, performing vacuum hot-pressing and curing to obtain a multilayer plate blank embedded with an aluminum core, forming through holes on the multilayer plate blank, performing activation and copper plating treatment to realize interlayer electrical interconnection, manufacturing an outer layer circuit pattern on the surface of the multilayer plate blank, preparing a solder mask layer on the surface of the circuit, and performing nickel-plating and gold-plating surface treatment to obtain the multilayer aluminum core copper-clad plate. The method solves the problems of weak interlayer bonding force, low heat dissipation efficiency, insufficient electrical interconnection reliability and the like of the aluminum core multi-layer board, and the prepared copper-clad plate can meet the use requirements of high-frequency and high-power electronic equipment.

Inventors

  • ZHOU RUI
  • JIANG MENGFAN
  • JIANG BAILING
  • WU XIAO
  • YUAN XIANG
  • HAO JUAN
  • LIU DONGJIE
  • GE YANFENG

Assignees

  • 西安理工大学

Dates

Publication Date
20260508
Application Date
20260211

Claims (10)

  1. 1. The multilayer aluminum core copper-clad plate is characterized by being formed by sequentially laminating a plurality of copper-clad plasma anodized aluminum substrates, wherein a prepreg is arranged between every two aluminum substrates as an adhesive layer, vertical interconnection is realized between each two conductive layers through metallized through holes, the copper-clad plasma anodized aluminum substrates are formed by sequentially depositing an anodized aluminum ceramic layer, an electroless copper plating base layer and an electroplating thickened copper layer on the aluminum substrates, circuit patterns are manufactured on the surfaces of copper plating layers of the aluminum substrates positioned inside, and circuit patterns are not manufactured on the surfaces of copper plating layers of the two aluminum substrates positioned at the outermost side.
  2. 2. The preparation method of the multilayer aluminum core copper-clad plate by the plasma oxidation-copper plating process is characterized by comprising the following steps of: step 1, performing plasma anodic oxidation and copper plating treatment on the surface of an aluminum substrate to obtain a copper-clad plasma anodic aluminum oxide substrate; step 2, manufacturing an inner layer circuit pattern on the surface of the copper-clad plasma anode alumina substrate, overlapping the inner layer circuit pattern with the prepreg, and performing vacuum hot-pressing and curing to obtain a multilayer plate blank embedded with an aluminum core; step 3, forming through holes on the multilayer plate blank, and performing activation and copper plating treatment to realize interlayer electrical interconnection; And 4, manufacturing an outer layer circuit pattern on the surface of the multilayer plate blank, preparing a solder mask layer on the surface of the circuit, and performing nickel plating and gold immersion surface treatment to obtain the multilayer aluminum core copper clad laminate.
  3. 3. The method for preparing the multilayer aluminum core copper-clad plate by the plasma oxidation-copper plating process according to claim 2, wherein the step 1 is specifically: Cleaning an aluminum substrate, carrying out laser drilling to form positioning holes with the aperture of 0.2-2 mm, carrying out plasma anodic oxidation treatment on the surface of the aluminum substrate to grow an anodic aluminum oxide ceramic layer with a micropore structure in situ, then carrying out copper ion erosion resistance treatment and steam hole sealing treatment on the ceramic layer in sequence, and finally carrying out electroless copper plating and copper electroplating to form a copper plating layer on the surface of the ceramic layer to obtain the copper-clad plasma anodic aluminum oxide substrate.
  4. 4. The method for preparing the multilayer aluminum core copper-clad plate by the plasma oxidation-copper plating process according to claim 3, wherein in the step 1, the thickness of the aluminum oxide ceramic layer is 5-100 μm, and the single-layer puncture resistance is more than 1000V; The copper ion corrosion resistance treatment process comprises the steps of immersing an aluminum substrate in an ammonium thiosulfate aqueous solution with the concentration of 70-150 g/L, and treating for 20-90 minutes at 50-100 ℃ and pH of 5.0-9.0; the steam hole sealing treatment process specifically comprises the steps of placing an aluminum substrate in a high-pressure steam tank, introducing saturated steam of 0.1-0.6 MPa, and treating for 10-60 minutes at 60-150 ℃.
  5. 5. The method for preparing the multilayer aluminum core copper clad laminate by the plasma oxidation-copper plating process according to claim 3, wherein in the electroless copper plating in the step 1, the copper plating solution comprises the following components of CuSO 4 ·5H 2 O1-100 g/L, ethylenediamine tetraacetic acid disodium salt 1-100 g/L, 37% formaldehyde 1-100 mL/L and 2,2' -bipyridine 1-100 mg/L, the copper plating process parameters comprise the specific copper plating solution pH value of 12.0-13.0, the plating temperature of 5-60 ℃ and the plating time of 5-60 minutes, and an electroless copper plating layer with the thickness of 0.5-20 mu m is formed; In the copper plating, the components and the contents of the components are specifically CuSO 4 ·5H 2 O1～300g/L、H 2 SO 4 1～100g/L、Cl - -100 mg/L, 0.1-1 mL/L of filling agent and 0.1-1 mL/L of brightening agent, the parameters of the plating process are that the cathode current density is 0.1-3.0A/dm < 2 >, the temperature is 5-60 ℃ and the time is 5-60 minutes, and the copper plating layer with the thickness of 10-50 mu m is formed.
  6. 6. The method for preparing the multilayer aluminum core copper clad laminate by the plasma oxidation-copper plating process according to claim 2, wherein in the step 2, the number of superposed layers is 3-100, and the total thickness of the aluminum core copper clad laminate within 10 layers is 1-1.2mm.
  7. 7. The method for preparing the multilayer aluminum core copper-clad plate by the plasma oxidation-copper plating process according to claim 2, wherein the step 2 is specifically as follows: forming an inner layer circuit pattern on a copper plating layer on the surface of the copper-clad plasma anode alumina substrate through the processes of pasting a photoresist dry film, ultraviolet exposure, sodium carbonate solution development, copper chloride solution etching and sodium hydroxide solution film removal, so as to obtain the plasma anode alumina substrate with the copper-clad pattern; and sequentially overlapping the copper-clad plasma anodized aluminum substrate, the prepreg, the plasma anodized aluminum substrate with the copper-clad pattern, the prepreg and the copper-clad plasma anodized aluminum substrate with the copper-clad pattern from top to bottom, and finally carrying out vacuum hot-press curing on the overlapped body to obtain the multilayer slab with the embedded aluminum core.
  8. 8. The preparation method of the multilayer aluminum core copper clad laminate by the plasma oxidation-copper plating process according to claim 2 or 7, wherein the specific process of vacuum hot press curing in the step 2 is that the heat preservation is carried out for 1-40 minutes at the pressure of 80-130 ℃ and 10-15 kgf/cm < 2> under the condition that the vacuum degree is lower than 1000Pa, the temperature is further raised to 150-220 ℃, the pressure of 25-30 kgf/cm < 2> is applied, and the heat preservation is carried out for 90-120 minutes, so that the hot press curing is completed.
  9. 9. The method for preparing the multilayer aluminum core copper-clad plate by the plasma oxidation-copper plating process according to claim 2, wherein the step 3 is specifically: The method comprises the steps of (1) forming a through hole with the diameter of 0.3-1.8 mm on a multilayer plate blank obtained in the step (2) through laser drilling, carrying out plasma cleaning treatment on a hole wall for 20-40 minutes, then carrying out chemical activation, namely immersing the plate blank in a colloid palladium activation solution for 3-5 minutes, then carrying out acceleration treatment in a dilute hydrochloric acid with the mass fraction of 3-5% for 0.5-1.5 minutes to enable the hole wall to absorb palladium catalysis centers, then carrying out electroless copper plating, namely immersing the activated plate blank in a copper plating solution, plating for 15-60 minutes at 50-60 ℃, depositing a conductive chemical copper layer with the thickness of 0.5-1.5 mu m on the hole wall and the surface of the plate blank, and finally carrying out electroplating copper thickening, namely taking the chemical copper layer as a cathode, electroplating for 5-60 minutes in an acidic copper sulfate electroplating solution at the cathode current density of 0.1-3.0A/dm <2 > and the temperature of 5-60 ℃, so that the copper plating thickness of the inner wall of the through hole reaches 5-60 mu m, and thus realizing interlayer electrical interconnection; The copper plating solution comprises, by weight, 1-100 g/L of CuSO 4 ·5H 2 O, 1-100 g/L of ethylenediamine tetraacetic acid disodium salt, 1-100 mL/L of 37% formaldehyde and 1-100 mg/L of 2,2' -bipyridine, and the plating solution comprises, by weight, 1-100 mg/L of CuSO 4 ·5H 2 O1～300g/L、H 2 SO 4 1～100g/L、Cl - , 0.1-1 mL/L of a leveling agent and 0.1-1 mL/L of a brightening agent.
  10. 10. The method for preparing the multilayer aluminum core copper-clad plate by the plasma oxidation-copper plating process according to claim 2, wherein the step 4 is specifically: The method comprises the steps of performing brushing and microetching treatment on an outer copper surface of a multilayer plate blank obtained in the step 3, forming an outer circuit pattern through the processes of pasting a photoresist dry film, ultraviolet exposure, sodium carbonate solution development, copper chloride solution etching and sodium hydroxide solution film removal, performing screen printing on a circuit surface with liquid photoresist ink, performing pre-baking, exposure and sodium carbonate solution development to form a bonding pad window, performing thermal curing at 100-160 ℃ for 50-70 minutes to form a solder mask, performing chemical nickel plating and gold immersion surface treatment on a bare bonding pad, namely performing plating in chemical nickel plating solution with the pH of 4.5-4.8 and the temperature of 50-90 ℃ for 5-30 minutes to form a nickel layer with the thickness of 1-10 mu m, performing treatment in displacement gold immersion solution with the pH of 5.8-6.2 and the temperature of 50-100 ℃ for 2-20 minutes to form a gold layer with the thickness of 0.05-0.1 mu m, and finally performing contour cutting by a numerical control milling machine, and performing electrical property test to obtain a multilayer aluminum core copper-clad plate.

Description

Multilayer aluminum core copper-clad plate adopting plasma oxidation-copper plating process and preparation method thereof Technical Field The invention belongs to the technical field of copper-clad plate processing, and relates to a multilayer aluminum core copper-clad plate by a plasma oxidation-copper plating process, and a preparation method of the copper-clad plate. Background With the rapid development and wide application of technologies such as fifth-generation mobile communication (5G), new energy automobile electronic control systems, high-end servers, high-power density power electronic devices and the like, electronic components and integrated circuits are rapidly evolving towards high frequency, high power, high integration and miniaturization, which puts forward unprecedented severe requirements on Printed Circuit Boards (PCBs) serving as core supports and interconnection carriers of electronic systems, namely, not only needing to bear increasingly complex high-density wiring, but also having to have excellent heat dissipation performance, excellent high-frequency signal integrity and strong mechanical reliability. In the application fields with very urgent heat dissipation requirements, such as high-power LED lighting modules, vehicle-mounted power modules, radio frequency power amplifiers and the like, the traditional epoxy glass cloth copper-clad plate (FR-4) has become a heat dissipation bottleneck due to lower heat conductivity (generally lower than 0.5W/(m.K)), and is easy to cause the rise of the junction temperature of a chip, thereby seriously affecting the performance, the service life and the reliability of a device. For this reason, metal-based copper-clad laminates have been developed and widely used, and aluminum-based copper-clad laminates are most commonly used, and their typical structure is in the form of a sandwich of a copper foil circuit layer, a high-thermal-conductivity insulating medium layer, and a metal aluminum substrate. The aluminum substrate (generally adopting 1060, 5052 or 6061 alloy) has the advantages of excellent heat conductivity (about 200W/(m.K)), light weight, moderate cost, easy processing and the like, and can rapidly conduct the heat generated by the circuit layer to the radiator or the shell, thereby effectively solving the problem of the diffusion of point heat sources. In the existing mechanical splicing mode of commonly used aluminum substrate and traditional multilayer board, the method takes the single/double-sided aluminum substrate with finished wiring as a daughter board, and the single/double-sided aluminum substrate and the traditional FR-4 multilayer board are pressed together at high temperature and high pressure through an adhesive sheet. The fundamental problem is that the aluminum substrate and the FR-4 layer have large difference in Coefficient of Thermal Expansion (CTE), and huge interfacial thermal stress can be generated in the temperature cycle or reflow soldering process, so that reliability faults such as interlayer separation, welding spot cracking and the like are extremely easy to cause. Meanwhile, the heat is transferred from the top chip to the bottom aluminum plate through the FR-4 layer, so that the heat dissipation path is long, the thermal resistance is large, the heat dissipation efficiency is greatly reduced, and the heat dissipation advantage of the aluminum core cannot be fully exerted. Another learner tries to directly realize hole metallization interconnection on an aluminum core, which is the most direct but most difficult technical idea, and the fundamental challenge is that aluminum has active chemical properties, namely, on one hand, a compact aluminum oxide insulating layer is extremely easy to form on the surface of aluminum, so that a copper layer deposited subsequently has extremely weak bonding force and is easy to peel off under thermal stress, and on the other hand, aluminum is incompatible with various liquid medicines (particularly strong alkaline solution) in PCB processing, corrosion can occur, and the yield is low. Although early researches have focused on the technology of electroless plating on aluminum, the problems of complex pretreatment process of aluminum surface, insufficient binding force and reliability of plating layers are not solved satisfactorily for a long time, and become a key technical bottleneck for restricting the realization of high-reliability electrical interconnection of aluminum cores. Disclosure of Invention The invention aims to provide a multilayer aluminum core copper-clad plate by a plasma oxidation-copper plating process, which has the characteristics of strong interlayer binding force, high electrical interconnection reliability and high heat dissipation efficiency. The invention further aims at providing a preparation method of the aluminum core copper-clad plate. The technical scheme includes that the multilayer aluminum core copper-clad plate is formed by sequentia