Production process for carrying out surface metallization on aluminum nitride ceramic substrate by using laser

Abstract

The invention discloses a production process for carrying out surface metallization on an aluminum nitride ceramic substrate by using laser, and relates to the technical field of ceramic material surface treatment, and the production process comprises the following steps: step 1, configuring a vacuum chamber of 10 square meters, and setting the vacuum degree of the vacuum chamber to 8 * 10 <-1 > Pa; 2, a pulse fiber laser engraving machine with the power of 20 W is prepared, a field lens F is set to be 254 mm, and the working range is 180 * 180 mm; thirdly, an aluminum nitride ceramic chip is prepared, the surface of the aluminum nitride ceramic chip is cleaned to be free of pollution, and the aluminum nitride ceramic chip is placed on a laser engraving focus by 0.5 mm; and 4, laser parameters are set as follows: the power is 95%, the speed is 1200 mm / s, the filling density is 0.005 mm, the surface metallized pattern is controlled by a computer, a pure aluminum layer of 10 Um can be formed on the aluminum nitride surface after engraving is completed, and the conductivity coefficient of the pure aluminum layer is the same as that of aluminum. Compared with the prior art, the method has the advantages that the bonding strength is improved; the thermal stability is enhanced; precise engraving is realized; and batch production is easy.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic material surface treatment, in particular to a production process for metallizing the surface of an aluminum nitride ceramic substrate by using laser. Background Art

[0002] As a new type of material, aluminum nitride ceramics have the characteristics of high thermal conductivity, high hardness and high dielectric properties, and have broad application prospects in the fields of electronics, aerospace, medical equipment, etc. In order to achieve the connection between aluminum nitride ceramics and other metal materials or enhance their electrical conductivity, it is usually necessary to metallize the surface of aluminum nitride ceramics. Existing ceramic surface metallization treatment methods mainly include coating and spraying metal coating. However, these methods have many shortcomings. For example, although the coating method can form a layer of metal film on the ceramic surface, the bonding strength between the metal film and the ceramic substrate is often low, and it is easy to fall off when subjected to external force or temperature changes. The spraying metal coating method has problems such as uneven coating thickness and poor thermal stability. Especially in the thermal vibration mode, the coating is more likely to crack and fall off, thereby affecting the overall performance of the ceramic substrate.

[0003] In patents in related fields, such as patent number CN201210554374.X, a method for metallizing ceramic surfaces is proposed, but this method still uses traditional coating technology, which has problems such as low bonding strength and easy detachment of the coating. Patent number CN201510448548.X proposes a method for spraying metal coatings, which improves the adhesion of the coating to a certain extent, but the thermal stability is still poor and cannot meet the application requirements in high temperature environments. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention proposes a production process for surface metallization of aluminum nitride ceramic substrates using laser, aiming to solve the problems of low bonding strength between the metal coating and the ceramic substrate, easy detachment of the coating and poor thermal stability.

[0005] Specifically, the technical solution provided by the present invention is: a production process for surface metallization of an aluminum nitride ceramic substrate using a laser, comprising the following steps:

[0006] Step 1: Configure a 10 square meter vacuum chamber and set the vacuum degree of the vacuum chamber to 8*10 -1 Pa;

[0007] Step 2: Prepare a 20W pulse fiber laser engraving machine, set the field lens F=254mm, and the working range 180*180mm;

[0008] Step 3: Prepare an aluminum nitride ceramic sheet, clean the surface to make it free of pollution, and place it 0.5mm from the focus of the laser engraving;

[0009] Step 4: Set the laser parameters to 95% power, 1200mm / s speed, and 0.005mm filling density. The surface metallization pattern is controlled by a computer. After engraving, a 10Um pure aluminum layer can be formed on the aluminum nitride surface. The conductivity of the pure aluminum layer is the same as that of aluminum.

[0010] The advantages of the present invention compared with the prior art are: (1) improving the bonding strength: the present invention adopts laser engraving technology, through which laser energy directly acts on the surface of the aluminum nitride ceramic sheet, so that a molecular bond is formed between the metal layer and the ceramic substrate, the bonding force is strong, and the bonding layer is stable and firm, which effectively solves the problem of low bonding strength between the metal coating and the ceramic substrate in the prior art; (2) enhancing thermal stability: because the metal layer and the ceramic substrate are tightly bonded, and the thickness of the metal layer is controlled to be below 10 μm, the entire structure is more stable in the thermal vibration mode, and is not easy to crack and fall off, thereby enhancing thermal stability; (3) achieving precise engraving: the present invention adopts a pulse fiber laser engraving machine, which has the characteristics of high precision and high efficiency, and can achieve precise engraving on the surface of the aluminum nitride ceramic sheet to meet the needs of various complex patterns and shapes; (4) easy to mass produce: the production process of the present invention is simple and easy to operate, and by adjusting the laser parameters and the computer control program, aluminum nitride ceramic sheets of different specifications and sizes can be batch metallized, reducing production costs and improving production efficiency. DETAILED DESCRIPTION

[0011] In a specific implementation, the present invention provides a surface metallization production process for aluminum nitride ceramic substrates, which specifically includes:

[0012] (1) Configure a 10 square meter vacuum chamber and set the vacuum degree of the vacuum chamber to 8×10^-1Pa to ensure the cleanliness of the environment during the laser engraving process and avoid the influence of impurities on the metallization layer.

[0013] (2) Prepare a pulse fiber laser engraving machine with a power of 20 W, set the field lens F = 254 mm, and the working range 180×180 mm to meet the needs of precise engraving of aluminum nitride ceramic sheets.

[0014] (3) Prepare an aluminum nitride ceramic sheet, clean its surface to remove contamination, and then place it 0.5 mm from the focus of the laser engraving to ensure that the laser energy can accurately act on the surface of the ceramic sheet.

[0015] (4) The laser parameters are set to 95% power, 1200 mm / s speed, and 0.005 mm filling density. The laser engraving machine is controlled by a computer to form a pure aluminum layer on the surface of the aluminum nitride ceramic sheet. The thickness of the pure aluminum layer is controlled to be less than 10 μm, and the conductivity is the same as that of pure aluminum.

[0016] The working principle of this process is based on the thermal effect of laser and the special properties of aluminum nitride ceramics. When the laser irradiates the surface of the aluminum nitride ceramic substrate, the ceramic surface absorbs the energy of the laser and the surface temperature rises rapidly. When the temperature reaches the thermal decomposition temperature of aluminum nitride, a thermal decomposition reaction will occur on the surface of aluminum nitride to precipitate metallic aluminum. In this process, precise control of laser parameters (such as power, speed, filling density, etc.) is crucial, as they determine the thickness, uniformity and conductivity of the metallization layer.

[0017] Specifically, the high-energy laser beam emitted by the laser engraving machine accurately scans the surface of the aluminum nitride ceramic substrate, and the laser energy is absorbed by the ceramic surface and converted into heat energy. As the temperature rises, the chemical bonds on the surface of the aluminum nitride ceramic break, and the aluminum atoms are released and rearranged on the ceramic surface to form a layer of pure aluminum metal. This metal layer is tightly bonded to the ceramic substrate through intermolecular forces, and has high bonding strength and thermal stability.

[0018] Embodiment 1

[0019] This embodiment proposes a specific implementation method of this process:

[0020] (1) Preparation

[0021] A 10 square meter vacuum chamber is configured to ensure that the chamber is clean and free of impurities to avoid introducing contaminants during the metallization process. The vacuum degree of the vacuum chamber is set to 8×10^-1Pa to create an environment conducive to laser engraving.

[0022] Prepare a 20W pulse fiber laser engraving machine, set the field lens F=254mm, and the working range 180×180mm. Ensure that the laser engraving machine can accurately control the scanning path and speed of the laser beam.

[0023] Prepare the aluminum nitride ceramic substrate and clean the surface to remove contaminants such as oil, dust, etc. The cleaned ceramic substrate should be placed at the focus of the laser engraving machine, 0.5mm away from the focus, to ensure that the laser energy can accurately act on the ceramic surface.

[0024] (2) Laser engraving stage

[0025] Set the laser parameters: power 95%, speed 1200mm / s, filling density 0.005mm. The selection of these parameters should be adjusted according to the thickness and size of the ceramic substrate and the required metallization layer thickness and conductivity. The laser engraving machine is controlled by a computer to accurately scan the aluminum nitride ceramic substrate according to the preset pattern and path. During the scanning process, the laser beam forms a uniform and dense pure aluminum metal layer on the ceramic surface.

[0026] (3) Subsequent processing stage

[0027] After laser engraving is completed, the aluminum nitride ceramic substrate is taken out of the vacuum chamber and necessary cleaning and drying treatment is carried out to remove surface residues and moisture. The metallization layer is quality tested, including thickness measurement, conductivity test, and bonding strength test, etc. to ensure that the metallization layer meets the design requirements and usage needs.

[0028] (4) Mass production

[0029] In order to achieve mass production, the parameters of the laser engraving machine and the computer control program can be adjusted to adapt to aluminum nitride ceramic substrates of different specifications and sizes. By optimizing the production process and improving production efficiency, production costs can be reduced to meet the needs of large-scale production.

[0030] The above shows and describes the basic principles and main features of the present invention and the advantages of the invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A production process for surface metallization of aluminum nitride ceramic substrates using laser, characterized in that The following steps are involved: Step 1: Configure a 10 square meter vacuum chamber and set the vacuum degree of the vacuum chamber to 8*10 -1 Pa; Step 2: Prepare a 20W pulse fiber laser engraving machine, set the field lens F=254mm, and the working range 180*180mm; Step 3: Prepare an aluminum nitride ceramic sheet, clean the surface to make it free of pollution, and place it 0.5mm from the focus of the laser engraving; Step 4: Set the laser parameters to 95% power, 1200mm / s speed, and 0.005mm filling density. The surface metallization pattern is controlled by a computer. After engraving, a 10Um pure aluminum layer can be formed on the aluminum nitride surface. The conductivity of the pure aluminum layer is the same as that of aluminum.