The alumina ceramic substrate is made like this! How much do you know? Alumina ceramic substrate processing and manufacturing process and forming method Is the alumina ceramic substrate processing and manufacturing process and method the same as ordinary circuit boards?
Alumina ceramic substrate processing technology At present, most of the alumina ceramic substrates on the market adopt thin film technology, thick film technology, DBC technology, HTCC technology and LTCC technology.
Alumina ceramic substrate thin film process The thin film method is the main method for metal film deposition in microelectronics manufacturing, and direct plating copper is the most representative. Direct copper plating (DPC), which mainly uses surface deposition processes such as evaporation and magnetron sputtering to metallize the substrate surface, first sputtering titanium, chromium and then copper particles under vacuum conditions, and finally thickening by electroplating, followed by ordinary pcb The process completes the circuit production, and finally increases the thickness of the circuit by electroplating/electroless plating.
The DPC process is suitable for most ceramic substrates. The metal has good crystalline properties, good flatness, the circuit is not easy to fall off, and the circuit position is more accurate, the line spacing is smaller, and the reliability is stable.
Alumina ceramic DBC process ceramic copper clad laminate, abbreviated as DBC, is composed of ceramic substrate, bonding layer and conductive layer. It refers to the direct bonding of copper foil to alumina or aluminum nitride ceramic substrate at high temperature The special process method on the surface has high thermal conductivity, high adhesion strength, excellent solderability and excellent electrical insulation performance, but it cannot pass through holes, is poor in accuracy, and has rough surface. Due to the line width, it can only be applied to spacing In large places, precision places cannot be made, and only mass production can not achieve small-scale production.
The HTCC process is the high-temperature co-firing process used, and the HTCC ceramic heating sheet is a high-temperature co-firing ceramic heating sheet, which is designed by using high melting point metal heating resistor pastes such as tungsten, molybdenum, molybdenum and manganese according to the heating circuit. It is required to be printed on 92～96% of alumina cast ceramic green body, 4～8% of sintering aids are then laminated and co-fired at a high temperature of 1500～1600℃, so as to have corrosion resistance and high temperature resistance. , Long life, high efficiency, energy saving, uniform temperature, good thermal conductivity, fast thermal compensation, etc., and it does not contain lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers and other harmful substances. It complies with EU RoHS and other environmental protection Claim.
The LTCC process is a low-temperature co-fired ceramic (LowTemperatureCo-firedCeramicLTCC) to make low-temperature sintered ceramic powder into a precise and dense green ceramic tape, and use laser drilling, microporous grouting, and precision conductor paste printing on the green ceramic tape. Make the required circuit patterns, and embed multiple passive components (such as low capacitance capacitors, resistors, filters, impedance converters, couplers, etc.) in the multilayer ceramic substrate, and then stack them together. The inner and outer electrodes can be Metals such as silver, copper, gold are used and sintered at 900°C to make high-density circuits that do not interfere with each other in three-dimensional space. It can also be made into three-dimensional circuit substrates with built-in passive components. ICs and other materials can be mounted on the surface. The source device is made into a passive/active integrated functional module, which can further miniaturize and increase the circuit density, and is especially suitable for high-frequency communication components.
Drilling: Mechanical drilling holes are used to form connecting pipes between metal layers.
Plated through holes: After drilling the copper wires between the connecting layers, the circuit between the layers is not opened. Therefore, a conductive layer must be formed on the hole wall to connect the wires. This process is commonly referred to as "PTH" in the industry. The process flow mainly includes 3 procedures: Desmear, chemical copper and copper electroplating.
Dry film pressing: making photosensitive etching photosensitive layer.
Outer layer exposure: After the photosensitive film is attached, the circuit board is similar to the inner layer of the production process, exposed again and developed. The main function of this kind of photographic film is to determine the area that needs to be electroplated, and the area that we cover is the area that does not need to be electroplated.
Magnetron sputtering: The energy and momentum exchange between the positive ions generated in the gas glow discharge process and the atoms on the target surface is used to move the material from the source material to the substrate to achieve thin film deposition.
Etching-Formation of external lines: A technique that uses chemical reaction or physical impact to remove material. The function of etching is reflected in the selective removal of specific patterns.
The method of nickel plating on alumina ceramic substrate is divided into nickel plating and electroless nickel plating.
Nickel electroplating is in an electrolyte composed of nickel salt (called main salt), conductive salt, pH buffer, and wet agent. Metallic nickel is used for the anode, and the cathode is the plated part. Direct current is applied to deposit on the cathode (plated part). The upper layer is uniform and dense nickel plating. Nickel has good chemical stability in the atmosphere and lye, and it is not easy to change color. It will only be oxidized when the temperature is above 600°C. It dissolves very slowly in sulfuric acid and hydrochloric acid, but easily soluble in dilute nitric acid. It is easy to passivate in concentrated nitric acid and therefore has good corrosion resistance. The nickel coating has high hardness, is easy to polish, has high light reflectivity and can increase the appearance. The disadvantage is that it has porosity. To overcome this shortcoming, multilayer metal plating can be used, and after nickel is the intermediate layer circuit is completed, the circuit board will be sent to stripping, etching and stripping.
The main task is to completely strip the plating resist and expose the copper to be etched to the etching solution. Since the top of the wiring area has been protected by tin, an alkaline etching solution is used to etch copper, but since the wiring has been protected by tin, the wiring in the wiring area can be maintained so that the wiring in the wiring area provides an integral wiring board.
The casting method refers to the manufacturing process of adding solvents, dispersants, binders, plasticizers and other substances to the ceramic powder to make the slurry evenly distributed, and then making ceramic sheets of different specifications on the casting machine. It is called the scraper forming method.
This process first appeared in the late 1940s and was used to produce ceramic chip capacitors.
The equipment is simple to operate, efficient in production, capable of continuous operation and high level of automation.
The density of the embryo body and the elasticity of the diaphragm are greater.
Mature technology.
The production specifications are controllable and the scope is wide.
The purity of the substrate in the production of alumina ceramic substrate is 90.0~99.5%. The higher the purity, the better the performance. Temperature control is an important aspect and technology to achieve high yield. For more questions about the production process of alumina ceramic substrates, you can consult Jin Ruixin Special Circuit. Jin Ruixin is a domestic ceramic circuit board manufacturer with more than ten years of experience, producing alumina ceramic substrates and aluminum nitride ceramic substrates. Nickel plating is divided into electroplating nickel and electroless nickel plating. Nickel electroplating is in an electrolyte composed of nickel salt (called main salt), conductive salt, pH buffer, and wet agent. Metallic nickel is used for the anode, and the cathode is the plated part. Direct current is applied to deposit on the cathode (plated part). The upper layer is uniform and dense nickel plating. Nickel has good chemical stability in the atmosphere and lye, and it is not easy to change color. It will only be oxidized when the temperature is above 600°C. It dissolves very slowly in sulfuric acid and hydrochloric acid, but easily soluble in dilute nitric acid. It is easy to passivate in concentrated nitric acid and therefore has good corrosion resistance.
