Metallization process of alumina ceramics

Metallization process of alumina ceramics

2021-11-12 16:16:28 37

[Introduction] In practical applications, will often encounter alumina ceramics and metal materials sealing process, to achieve a perfect ceramic-metal sealing, the most important step is to do a good job of alumina ceramic metallization process, it is good or bad affect the final sealing effect.

 Al2O3 ceramics have the advantages of highest mechanical strength, high hardness, good electrical insulation performance, low high frequency loss, high thermal conductivity, good vacuum hermeticity, etc. And the production of alumina ceramics is rich in raw material earth reserves, low price, mature production process, so the application of alumina ceramics is very wide.

In practice, will often encounter alumina ceramics and metal materials sealing process, to achieve a perfect ceramic - metal sealing, the most important step is to do a good job of alumina ceramic metallization process, it is good or bad affect the final sealing effect.


The main methods of ceramic metallization are chemically plated Ni-P method, electroplated Ni-P alloy method, high temperature sintering by Ag(Ni) method, Mo-Mn sintering method, vacuum evaporation coating method and vacuum sputtering coating method, etc.

1、Chemical plating Ni-P method

Chemical Ni-P plating, also known as electroless plating or autocatalytic plating, is a kind of self-catalytic reduction deposition of Ni layer on the surface of activated parts using a reducing agent without adding external current, and when the Ni layer is deposited on the surface of activated parts, the process will continue automatically because Ni has autocatalytic ability. Generally, the Ni layer obtained by chemical coating is an alloy coating, commonly known as Ni-P alloy.

Although the chemical coating layer is corrosion resistant, good wear resistance, high hardness, less porosity, and does not require power, there are many disadvantages, such as poor film bonding, low tensile strength, high cost of plating solution, and complex process.

2、Electroplating Ni method

Electroplating is an electrochemical process and a redox process. Electroplating Ni is to immerse the part in a solution of Ni salt as the cathode, and the metal Ni plate as the anode, and when the DC power is connected, a metal Ni coating will be deposited on the part. The electroplating Ni method was discovered by Brenner and others in 1950, and it is the electroplating Ni method that is used by Koch in the United States.

Although the electroplated Ni film layer and ceramic bonding force, internal stress is small, but the obvious disadvantage is that the cleanliness of the surface of the metalized porcelain parts and the purity of the plating solution is greatly affected, resulting in more defects in the metalized porcelain parts after plating, such as peeling, blistering, pockmarks, black spots, etc., and at the same time is extremely vulnerable to the impact of different locations in the plating pendant and plating cylinder, resulting in poor uniform plating ability.

3、Sintering by Ag(Ni) method

Be silver method is a layer of Ag slurry on the ceramic surface, consisting of Ag salt fusion and adhesive, and then sintered at high temperature to reduce Ag ions to singlet Ag, Ag layer can be reduced by triethanolamine silver carbonate, can also be obtained by adding ammonia to silver nitrate after reduction with formaldehyde or formic acid. The main problem of the current Ag layer and Ni layer is that the film layer is thin, discontinuous, non-uniform, and poor resistance to melt corrosion.

4、Mo-Mn sintering method

5、Vacuum evaporation coating method

Evaporation coating method is carried out in 0.13Pa vacuum, with resistance evaporation source or electron beam heating evaporation, so that aluminum and copper become gas phase atoms or molecules then deposited on the ceramic substrate, the following figure is its working schematic. Vacuum evaporation of silver and copper is a clean process, the international famous electric pottery enterprises represented by Japan Murata and Kyodo started to use single machine type vacuum evaporation technology for metallization in the beginning of this century. But the metal film layer and ceramic bonding is poor, easy to cause the silver-absorbing copper or electrode early off, and the thickness of the metal film layer is not easy to control, poor uniformity and consistency, and low material utilization.


6、Vacuum sputtering coating method

Vacuum sputtering coating in 1.3 ~ 0.013Pa vacuum, the deposition layer material as the target cathode, add negative bias pressure 2 ~ 3kV, pass argon gas, generate glow discharge, argon ion bombardment target material, target atoms escape, deposition on the surface of the substrate.


Compared with the above processes, the sputtering coating method is not only environmentally friendly, but also simple and low-cost, which is the main development direction of the metallization process in the future.

The quality of ceramic metallization mainly depends on the quality of the ceramic itself and the metallization process, and the specific influencing factors are metallization formula, metallization temperature and holding time, metallization microstructure, metallization coating thickness and coating method, etc. For many years, ceramic metallization has been a popular topic, and scholars at home and abroad have conducted in-depth research on it. There are still controversies in the mechanism of metallization, and the performance of metallization, such as the bending resistance, tensile strength, and airtightness of the finished ceramic metallization, still needs to be improved.

Reference sources.

[1] Wang Ling et al. Research progress on the method, mechanism and influencing factors of ceramic metallization

[2] Ma Yuanyuan et al. Research progress of alumina ceramic metallization technology

[3] Ding Shuhua et al. Mechanistic study of alumina ceramic metallization



was established in June 2001, is a national high-tech enterprise specializing in the research and development, production and operation of ultra-precision grinding and polishing materials in China, and is a pioneer in the industry with a number of international and domestic independent intellectual property rights, many years of experience in product technology development and many customer applications.

GRISH provides customers with specialized and customized grinding and polishing solutions, as well as a variety of complementary and serialized precision grinding and polishing material products, processes and equipment, focusing on solving customers' high-end needs of ultra-precision grinding and polishing, and helping customers succeed!

Its ultra-precision polishing film & polishing tape, electrostatic flocking abrasive tape & polishing tape, 3D three-dimensional bump abrasive, single crystal & polycrystalline & polycrystalline like - diamond micro powder and corresponding abrasive solution, CMP polishing solution, abrasive additives and other ultra-precision polishing consumables developed and produced by GRISH are widely used in optical communication, automotive, semiconductor, LED, sapphire, ceramics, LCD, 3C electronics, rollers, oral medicine and other industries, and have been exported to many countries and regions such as USA, UK, Germany, Russia, Japan, Korea, India, Brazil, etc.


Welcome to visit and consult us !!!



With specialized, serialized and

matching and customized products.

Precise service to help customers succeed!

【Precision Polishing Nano Material Expert--Grish 】

【Specializing in precision grinding & polishing for 20 years】

Sample Apply