As a material with outstanding performance, alumina substrate's surface treatment method is rather crucial for increasing its performance and fulfilling certain application conditions.
Polishing treatment
Polishing treatment is among the basic steps of surface treatment of alumina substrate. Polishing helps to remove minor defects and roughness from the surface of the substrate, therefore smoothing and brightening it. This is especially important for optical systems needing perfect polish and outstanding precision as well as for electrical devices.
Mechanical polishing reduces the uneven surfaces of the substrate by mechanical friction using abrasives and polishing solutions. The advantages of mechanical polishing are defined by fast processing speed and polishing surface fit-ability.
Chemical polishing is surface smoothing by chemical solutions dissolving the microscopic protrusions on the substrate. Chemical polishing is necessary for higher quality and polishing complex shapes and fine structures need.
Electrochemical polishing combines the characteristics of electrolysis and chemical polishing. The substrate surface melts under passing voltage in the electrolyte; a flat surface develops. For electrochemical polishing, high-finish surface treatment and high-precision are requirements.
After polishing, the flat and smooth surface of the alumina substrate considerably improves the reliability and performance of electronic devices by excellent surface quality.
Treatment with metalizing
Metalization treatment is to cover the surface of the alumina substrate with metal layer in order to raise its conductivity and connectivity. Metallization treatment has quite important applications in electronic packaging and integrated circuit manufacturing.
Sputtering deposition uses high-energy particles to bombard the target material, therefore spattering the target atoms across the surface of the substrate to produce a metal coating. Sputtering deposition is defined as favorable in high deposition rate, dense layer and strong adhesion as well as in metallization treatment of high-precision electronic devices.
Characteristic of homogeneous deposition and high film quality, chemical vapor deposition (CVD) chemically reacts to lay metal layer on the surface of the substrate. Large-area substrates suitable for metallization treatment fit CVD.
Physical vapor deposition, or PVD, is the method by which metal layer is produced on the surface of a substrate by physical processes including arc deposition and evaporation deposition. PVD appeals because of fast deposition speed and excellent film cleanliness; it is also suitable for metallization treatment of high-performance electronic devices.
After metallization treatment, good conductivity and connection of the aluminum oxide substrate enable to considerably raise the dependability and performance of electronic devices.
Treatments with gold and silver plating
Silver or gold plating treatments are to lay a coating of either metal on the surface of the aluminum oxide substrate, therefore improving its conductivity and corrosion resistance.
Chemical or electroplating silver plating covers the surface of the substrate with silver. Silver has fairly remarkable thermal and conductive characteristics. After silver plating, thermal conductive materials and high-frequency electronic devices discover suitable for the aluminum oxide substrate.
Either chemical or electroplating, gold plating covers the surface of the substrate with gold particles. Gold is conductive, corrosion-resistant, and somewhat stable. After gold plating, very dependable and extremely stable electronic equipment comprising highly precise connections and packaging substrates would find fit on the aluminum oxide substrate.
Silver and gold plating can greatly improve the conductivity and corrosion resistance of aluminum oxide substrates, hence prolonging their service life and reliability.
Ceramic coating treatment
High temperature resistance and insulating performance of the aluminum oxide substrate, ceramic coating treatment covers its surface with a layer of ceramic material to boost the wear resistance.
Plasma spraying uses high-temperature plasma to coat ceramic powder thickly onto the surface of a substrate. Perfect for high temperature and high wear resistance uses, plasma spraying offers outstanding thick coating adhesion, temperature resistance, and coating consistency.
Melting ceramic powder and then spraying it onto the surface of the substrate under heat sources like flame, arc or explosion generates a ceramic coating via thermal spraying. Appropriate for numerous application purposes, thermal spraying has the advantages of regulated coating thickness and dense covering.
The alumina substrate covered with ceramic coating defines by great wear resistance, high temperature resistance and insulating performance, and fit for high temperature, high wear and high insulating application settings.
Therapy's oxidizing effect
Oxidation treatment produces an oxide layer on the alumina substrate's surface, therefore improving its corrosion resistance, wear resistance, and insulating properties.
Dense oxide layer on the surface of the substrate produced by anodizing via electrochemical means Anodizing provides the advantages of thick oxide coating, strong adhesion and corrosion resistance, therefore improving the corrosion resistance and wear resistance of the substrate surface.
Thermal oxidation builds an oxide layer on the surface of the substrate at high temperature. Appropriate for enhancing the insulating and wear resistance of the substrate surface, thermal oxidation has the advantages of thick oxide coating and simple approach.
Excellent corrosion resistance, wear resistance, and insulating performance define the dependability of the aluminum oxide substrate following oxidation treatment and serve to extend its service life.
Laser direction
Precision processing on the surface of the aluminum oxide substrate employing a laser beam enhances surface performance and processing accuracy.
laser-based etching: Laser etching create fine patterns on the surface of the substrate by use of a high-energy laser beam. Given its extreme accuracy and non-contact processing, it is suitable for the production of micro-nanostructures and very precise electrical equipment.
Laser sintering is: Laser sintering melts and sinters the surface material of the substrate under a laser beam, therefore producing a thick surface layer. Two advantages of laser sintering—suitable for surface treatment of high-performance substrates—are perfect surface quality and excellent processing accuracy.
High-performance and high-precision requirements will be satisfied by excellent surface quality and processing accuracy of the aluminium oxide substrate after laser treatment.
Etching chemically
Chemical etching selectively etchers the surface of the aluminum oxide substrate using a chemical solution to produce a desired pattern and structure.
Chemical solutions help to smooth the substrate in wet etching. It provides inexpensive processing cost and a simple procedure and is suitable for etching of huge-area surfaces.
Drying etching is: via use of plasma or ion beams, dry etching surfaces the substrate via fine etching. It has the minimal damage and outstanding precision features and is suitable for etching complex structures.
After chemical etching, microelectronic devices and micro-nanostructures might find use for the specific surface pattern and structure of the alumina substrate.
Surface treatment methods greatly affect the performance of alumina substrates and satisfies certain application needs. From polishing, metallization, silver plating, gold plating to ceramic coating, oxidation treatment, laser treatment, chemical etching, each treatment type has particular advantages and uses. By choosing the appropriate surface treatment technique, one may significantly raise the conductivity, corrosion resistance, wear resistance, insulation performance, dependability of the alumina substrate, and so extend its service life. Surface treatment technology of alumina substrates will be upgraded as science and technology keep expanding, thus providing major support for technological innovation and development in many domains of life.