阅读说明：本技术 一种氮化铝陶瓷覆铜板及其制备方法 (Aluminum nitride ceramic copper-clad plate and preparation method thereof ) 是由 张德库 罗小阳 唐飞 贺琼 唐甲林 于 2019-09-17 设计创作，主要内容包括：本发明公开一种氮化铝陶瓷覆铜板的制备方法,其中,所述方法包括步骤：在氮化铝陶瓷基底表面沉积金属钛层,在所述金属钛层表面沉积金属银层,采用金属烧结3D打印法在所述金属银层表面打印金属铜层,制得所述氮化铝陶瓷覆铜板。本发明提供的制备方法在改善了金属铜层与氮化铝陶瓷基板间的粘结性能的同时,制备方法简单,易于操作,生产成本低,有利于工业生产。(The invention discloses a preparation method of an aluminum nitride ceramic copper-clad plate, wherein the method comprises the following steps: depositing a metal titanium layer on the surface of the aluminum nitride ceramic substrate, depositing a metal silver layer on the surface of the metal titanium layer, and printing a metal copper layer on the surface of the metal silver layer by adopting a metal sintering 3D printing method to obtain the aluminum nitride ceramic copper-clad plate. The preparation method provided by the invention improves the bonding property between the metal copper layer and the aluminum nitride ceramic substrate, is simple, is easy to operate, has low production cost, and is beneficial to industrial production.)

1. A preparation method of an aluminum nitride ceramic copper-clad plate is characterized by comprising the following steps:

depositing a metal titanium layer on the surface of the aluminum nitride ceramic substrate;

depositing a metal silver layer on the surface of the metal titanium layer;

and printing a metal copper layer on the surface of the metal silver layer by adopting a metal sintering 3D printing method to obtain the aluminum nitride ceramic copper-clad plate.

2. The method for preparing the aluminum nitride ceramic copper-clad plate according to claim 1, wherein the step of depositing the metallic titanium layer on the surface of the aluminum nitride ceramic substrate comprises:

depositing a metal titanium layer on the surface of the aluminum nitride ceramic substrate by adopting a magnetron sputtering method, wherein the sputtering gas pressure of the magnetron sputtering method is as follows: 0.8-1.2Pa, sputtering power is as follows: 110-140W, and the sputtering target distance is 50-100 mm.

3. The method for preparing the aluminum nitride ceramic copper-clad plate according to claim 1, wherein the thickness of the metal titanium layer is 50-100 nm.

4. The method for preparing the aluminum nitride ceramic copper-clad plate according to claim 1, wherein the step of depositing the metallic silver layer on the surface of the metallic titanium layer comprises the following steps:

depositing a metal silver layer on the surface of the metal titanium layer by adopting a magnetron sputtering method, wherein the sputtering air pressure of the magnetron sputtering method is as follows: 0.8-1.2Pa, sputtering power is as follows: 110-140W, and the sputtering target distance is 50-100 mm.

5. The method for preparing the aluminum nitride ceramic copper-clad plate according to claim 1, wherein the thickness of the metal silver layer is 1-5 um.

6. The method for preparing the aluminum nitride ceramic copper-clad plate according to claim 1, wherein the step of printing the metal copper layer on the surface of the metal silver layer by using a metal sintering 3D printing method comprises the following steps:

copper powder is laid on the surface of the metal silver layer, and the first layer of copper powder is sintered at a first laser scanning speed to form a first layer of metal copper layer;

and sequentially paving copper powder on the surface of the first metal copper layer, sintering the paved copper powder at each time of paving the copper powder by adopting a second laser scanning speed until the thickness of the finally formed metal copper layer reaches a preset thickness threshold, and preparing the aluminum nitride ceramic copper-clad plate, wherein the second laser scanning speed is greater than the first laser scanning speed.

7. The method for preparing the aluminum nitride ceramic copper-clad plate according to claim 6, wherein the first laser scanning speed is 30-60 mm/s; and/or the second laser scanning speed is 60-120 mm/s.

8. The method for preparing the aluminum nitride ceramic copper-clad plate according to claim 1, wherein the thickness of the copper powder laid each time is 20-50 um.

9. The method for preparing the aluminum nitride ceramic copper-clad plate according to claim 1, wherein the thickness of the metal copper layer is 0.1-1.5 mm.

10. The aluminum nitride ceramic copper-clad plate is characterized by comprising an aluminum nitride ceramic substrate, a metal titanium layer, a metal silver layer and a metal copper layer which are sequentially stacked from bottom to top.

Technical Field

The invention relates to the field of manufacturing of ceramic copper-clad plates, in particular to an aluminum nitride ceramic copper-clad plate and a preparation method thereof.

Background

The aluminum nitride ceramic has the outstanding advantages of high heat conductivity coefficient, good chemical stability and the like, is an ideal material for the high-heat-conductivity ceramic copper-clad plate, but the metallization problem of the aluminum nitride ceramic is not solved all the time, and the aluminum nitride is difficult to be directly bonded with Cu at high temperature and in an oxygen atmosphere to prepare the aluminum nitride ceramic copper-clad plate. The existing manufacturing process of the aluminum nitride ceramic copper-clad plate mainly comprises a direct bonding method (DBC) and an active metal brazing method (AMB), wherein the direct bonding method is to directly laminate a copper foil and aluminum nitride ceramic to prepare a substrate, the preparation method is simple, and the substrate is widely applied to a power electronic module, but the ceramic copper-clad plate prepared by the method has the advantages that the bonding strength between a metal copper layer and the ceramic substrate is not high, meanwhile, the thickness of the metal copper layer is large, the quality of the copper layer is poor, the resistivity is high, a fine circuit is not easy to manufacture, the active metal brazing method depends on active metal brazing filler metal to realize the high-temperature metallurgical bonding of the aluminum nitride and the metal copper layer, the bonding strength is high, the reliability of cold and hot circulation is good, and the reliability of the process depends on a plurality of key factors such as the components of the active brazing filler metal, the brazing process, the process difficulty is high and the cost is high.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide an aluminum nitride ceramic copper-clad plate and a preparation method thereof, and aims to solve the problems of high difficulty and high cost of the preparation process of the existing aluminum nitride ceramic copper-clad plate and poor bonding performance between a metal copper layer and a ceramic substrate.

The technical scheme of the invention is as follows:

a preparation method of an aluminum nitride ceramic copper-clad plate is characterized by comprising the following steps:

depositing a metal titanium layer on the surface of the aluminum nitride ceramic substrate;

depositing a metal silver layer on the surface of the metal titanium layer;

and printing a metal copper layer on the surface of the metal silver layer by adopting a metal sintering 3D printing method to obtain the aluminum nitride ceramic copper-clad plate.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the following steps of:

depositing a metal titanium layer on the surface of the aluminum nitride ceramic substrate by adopting a magnetron sputtering method, wherein the sputtering gas pressure of the magnetron sputtering method is as follows: 0.8-1.2Pa, sputtering power is as follows: 110-140W, and the sputtering target distance is 50-100 mm.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the step of preparing a titanium layer, wherein the thickness of the titanium layer is 50-100 nm.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the following steps of:

depositing a metal silver layer on the surface of the metal titanium layer by adopting a magnetron sputtering method, wherein the sputtering air pressure of the magnetron sputtering method is as follows: 0.8-1.2Pa, sputtering power is as follows: 110-140W, and the sputtering target distance is 50-100 mm.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the step of preparing a metal silver layer, wherein the thickness of the metal silver layer is 1-5 um.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the following steps of printing a metal copper layer on the surface of the metal silver layer by adopting a metal sintering 3D printing method:

copper powder is laid on the surface of the metal silver layer, and the first layer of copper powder is sintered at a first laser scanning speed to form a first layer of metal copper layer;

and sequentially paving copper powder on the surface of the first metal copper layer, sintering the paved copper powder at each time of paving the copper powder by adopting a second laser scanning speed until the thickness of the finally formed metal copper layer reaches a preset thickness threshold, and preparing the aluminum nitride ceramic copper-clad plate, wherein the second laser scanning speed is greater than the first laser scanning speed.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the following steps that the first laser scanning speed is 30-60 mm/s; and/or the second laser scanning speed is 60-120 mm/s.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the step of paving copper powder with the thickness of 20-50um each time.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the step of preparing a copper-clad plate, wherein the thickness of the metal copper layer is 0.1-1.5 mm.

According to the preparation method of the aluminum nitride ceramic copper-clad plate, the thickness of copper powder is monitored in real time by a thickness measuring sensor when the copper powder is laid, and 3D printing is stopped when the printed copper powder is larger than the specified copper-clad thickness by 0.1 mm.

The preparation method of the aluminum nitride ceramic copper-clad plate comprises the steps of machining the prepared aluminum nitride ceramic copper-clad plate, measuring the thickness in real time by using a thickness measuring sensor, and stopping machining when the thickness of the machined aluminum nitride ceramic copper-clad plate is consistent with the thickness of a specified copper plate.

The aluminum nitride ceramic copper-clad plate is characterized by comprising an aluminum nitride ceramic substrate, a metal titanium layer, a metal silver layer and a metal copper layer which are sequentially stacked from bottom to top.

Has the advantages that: the invention designs a preparation method of an aluminum nitride ceramic copper-clad plate, which comprises the steps of sequentially depositing a metal titanium layer and a metal silver layer on a ceramic substrate, and then printing a metal copper layer on the surface of the metal silver layer by adopting a metal sintering 3D printing method to prepare the aluminum nitride ceramic copper-clad plate. According to the invention, the metal copper layer is prepared by adopting a metal sintering 3D printing method, the extreme energy of laser generates high temperature in the preparation process, so that eutectic reaction is generated between copper powder and the metal silver layer to generate a silver-copper liquid phase, and the high temperature also enables titanium melted into the silver-copper and the aluminum nitride ceramic substrate to generate chemical reaction on a contact interface, so that effective bonding between layers is realized, and the bonding property between the metal copper layer and the ceramic substrate is improved.

Drawings

FIG. 1 is a flow chart of a preferred embodiment of the preparation method of the aluminum nitride ceramic copper-clad plate of the invention.

FIG. 2 is a schematic structural diagram of an aluminum nitride ceramic copper-clad plate of the present invention.

Detailed Description

The invention provides an aluminum nitride ceramic copper-clad plate and a preparation method thereof, and the invention is further explained in detail below in order to make the purpose, technical scheme and effect of the invention clearer and more clear and definite. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, fig. 1 is a flow chart of a preferred embodiment of a method for manufacturing an aluminum nitride ceramic copper-clad plate according to the present invention, and as shown in the figure, the method includes the steps of:

s10, depositing a metal titanium layer on the surface of the aluminum nitride ceramic substrate;

s20, depositing a metal silver layer on the surface of the metal titanium layer;

and S30, printing a metal copper layer on the surface of the metal silver layer by adopting a metal sintering 3D printing method to obtain the aluminum nitride ceramic copper-clad plate.

Specifically, the existing manufacturing process of the aluminum nitride ceramic copper clad laminate mainly comprises a direct bonding method (DBC) and an active metal brazing method (AMB), wherein the direct bonding method is to directly laminate a copper foil and the aluminum nitride ceramic to prepare a substrate, the preparation method is simple, but the aluminum nitride ceramic copper clad laminate prepared by the method has poor quality, the bonding strength of a metal copper layer and the aluminum nitride ceramic is not high, and a fine circuit is not suitable to be manufactured, the active metal brazing method depends on active metal brazing filler metal to realize the high-temperature metallurgical bonding of the aluminum nitride and the copper foil, and has the advantages of high bonding strength, good cold-hot circulation reliability and the like, but the reliability of the process depends on a plurality of key factors such as active brazing filler metal components, brazing process, brazing layer tissue structure and the like to a great extent, the process difficulty is high, the cost is high, therefore, the existing manufacturing process of the aluminum nitride ceramic copper clad laminate has poor bonding strength of the metal copper, the preparation process has high difficulty, the preparation cost is high and the like.

Based on the problems of the existing manufacturing process of the aluminum nitride ceramic copper-clad plate, the embodiment provides a method for manufacturing the aluminum nitride ceramic copper-clad plate, which is characterized in that a metal titanium layer and a metal silver layer are sequentially deposited on an aluminum nitride ceramic substrate, and finally, a metal copper layer is printed on the surface of the metal silver layer by a metal sintering 3D printing method, so that the aluminum nitride ceramic copper-clad plate is manufactured. Therefore, the preparation method of the aluminum nitride ceramic copper-clad plate realizes effective bonding between layers and improves the bonding performance of the metal copper layer and the ceramic substrate.

In some embodiments, the step of depositing the metallic titanium layer on the surface of the aluminum nitride ceramic substrate comprises: depositing a metal titanium layer on the surface of the aluminum nitride ceramic substrate by adopting a magnetron sputtering method, wherein the sputtering gas pressure of the magnetron sputtering method is as follows: 0.8-1.2Pa, sputtering power is as follows: 110-140W, and the sputtering target distance is 50-100 mm.

In some embodiments, the metallic titanium layer has a thickness of 50-100 nm. The bonding strength between the aluminum nitride ceramic and the metal copper layer can be reduced due to the undersize thickness of the metal titanium layer, the thickness of the metal titanium layer is too large, in the process of printing the metal copper layer by adopting a metal sintering 3D printing method, titanium cannot be rapidly and completely melted in a silver-copper liquid phase to influence the bonding performance, a reaction layer formed by chemical reaction between the titanium layer and the aluminum nitride ceramic substrate is too thick easily, the etching process of the prepared aluminum nitride ceramic copper-clad plate in the subsequent use process is not facilitated, and the thermal fatigue performance of the ceramic copper-clad plate is influenced.

In some embodiments, the step of depositing a metallic silver layer on the surface of the metallic titanium layer comprises: depositing a metal silver layer on the surface of the metal titanium layer by adopting a magnetron sputtering method, wherein the sputtering air pressure of the magnetron sputtering method is as follows: 0.8-1.2Pa, sputtering power is as follows: 110-140W, and the sputtering target distance is 50-100 mm.

In some embodiments, the metallic silver layer has a thickness of 1-5 um. The ratio of silver in the silver-copper liquid phase formed when the thickness of the metal silver layer is too small is too low, so that the bonding performance between the metal silver layer and the metal copper layer and between the metal silver layer and the metal titanium layer is poor, and the heat dissipation is too much when the thickness of the metal silver layer is too large, so that the silver cannot be completely melted to form the silver-copper liquid phase, and further the melting of titanium element is influenced, and the bonding performance between the metal copper layer and the aluminum nitride ceramic substrate is influenced.

In some embodiments, the step of printing the metallic copper layer on the surface of the metallic silver layer by using a metal sintering 3D printing method comprises:

s310, paving copper powder on the surface of the metal silver layer, and sintering the first layer of copper powder at a first laser scanning speed to form a first layer of metal copper layer;

s320, sequentially paving copper powder on the surface of the first metal copper layer, sintering the paved copper powder at each time of paving the copper powder at a second laser scanning speed until the thickness of the finally formed metal copper layer reaches a preset thickness threshold, and then preparing the aluminum nitride ceramic copper-clad plate, wherein the second laser scanning speed is greater than the first laser scanning speed.

In this embodiment, as shown in fig. 1, a metal copper layer is printed on a surface of a metal silver layer by a metal sintering 3D printer, the metal sintering 3D printer forms a first metal copper layer by spreading copper powder on the surface of the metal silver layer and sintering the first copper layer at a first laser scanning speed, wherein during the first laser scanning, titanium metal reacts with aluminum nitride to form titanium nitride and aluminum, so that an effective bond is formed between the titanium metal layer and an aluminum nitride ceramic substrate, and at the same time, a part of titanium metal that does not react chemically melts in a silver-copper liquid phase, so that an effective bond is also formed between the titanium metal layer and the metal silver layer, and when scanning is performed at the first laser scanning speed, sufficient heat needs to be generated to ensure that the chemical reaction is sufficiently performed, so that a lower first laser scanning speed is selected, and copper powder is sequentially spread on the surface of the first metal copper layer, in the process of sintering the laid copper powder at the second laser scanning speed, a stable bonding structure is formed between the metal titanium layer and the metal silver layer between the metal titanium layer and the aluminum nitride ceramic substrate, so that the second laser scanning speed can be increased on the premise of meeting the requirement that each layer of copper powder can be fully sintered, and further, the production efficiency of the aluminum nitride ceramic copper-clad plate process is improved.

In some embodiments, the first laser scanning speed is 30-60 mm/s; and/or the second laser scanning speed is 60-120 mm/s. In the invention, on the premise that the quality of the prepared metal copper layer is not influenced, in order to improve the production efficiency, the first laser scanning speed is set to be 30-60mm/s, the second laser scanning speed is set to be 60-120mm/s, if the laser scanning speed is too low, the production efficiency is reduced, and if the laser scanning speed is too high, the quality of the prepared metal copper layer is influenced.

In some embodiments, the metallic copper layer has a thickness of 0.1 to 1.5 mm. According to the product requirements of the actually produced aluminum nitride ceramic copper-clad plate and the requirements of the metal layer etching process in the subsequent use process of the aluminum nitride ceramic copper-clad plate, the thicknesses of the aluminum nitride ceramic substrate, the metal titanium layer and the metal silver layer are combined, and the thickness of the metal copper layer is set to be 0.1-1.5 mm.

In some embodiments, the copper powder thickness is 20-50um per lay. In the invention, in order to ensure that each layer of laid copper powder can be fully sintered in the laser scanning process, the thickness of each laid copper powder is set to be 20-50um, when the thickness of the copper powder is lower than 20um, the production efficiency of preparing the ceramic copper-clad plate by laser 3D printing is influenced, and when the thickness of the copper powder is higher than 50um, the sintering effect of the laid copper powder is influenced.

In some embodiments, the copper powder thickness is monitored in real time by a thickness measuring sensor as the copper powder is laid, and 3D printing is stopped when the printed copper powder thickness is greater than the specified copper-clad thickness of 0.1 mm; and finally, machining the prepared aluminum nitride ceramic copper-clad plate, and measuring the thickness in real time by using a thickness measuring sensor, wherein when the machined thickness of the aluminum nitride ceramic copper-clad plate is consistent with the specified copper plate thickness, the machining is stopped.

In some embodiments, an aluminum nitride copper-clad plate is also provided, wherein, as shown in fig. 2, the aluminum nitride copper-clad plate comprises an aluminum nitride ceramic substrate 1, a metal titanium layer 2, a metal silver layer 3 and a metal copper layer 4 which are sequentially stacked from bottom to top.

The preparation method of the aluminum nitride ceramic copper-clad plate of the invention is further explained by the following specific embodiment: