SMD resistors are also business card type fixed resistors, which are one of the metal glass glaze resistors. It is a resistor made by mixing metal powder and glass glaze powder and printing on the substrate by screen printing. It is resistant to humidity and high temperature, and has a small temperature coefficient. It can greatly save the cost of circuit space and make the design more refined. Including: thick film smd resistor, thin film smd resistor and metal plate (or alloy plate) smd resistor.
Thin film smd resistor are made by vacuum evaporation, sputtering, chemical deposition and other methods, and metal film is plated on an insulating substrate, or thin films such as alloy film and metal oxide film are used as resistors. Upper electrode, resistance value It is made after adjustment and protection layer.
Generally speaking, compared with thick film smd resistor, the accuracy can be higher, suitable for use in higher frequency occasions, but the rated power will be lower. The biggest disadvantage is that the equipment is complex and the cost is high. Metal plate smd resistor are made of ready-made plate alloy materials, which are made after cutting, making electrodes, adjusting the resistance value, and covering with a protective layer. Compared with thick film smd resistor, the accuracy can be higher. Some, the rated power can also be made larger, the disadvantage is that the cost is higher.
At present, the thick film smd resistor are the most produced and used at home and abroad. Therefore, the manufacturing process of thick film smd resistor will be introduced in this section of the smd resistor manufacturing process.