However, how many types of patch resistor shapes are there? I don't think everyone knows much about it. In fact, the shape of patch resistor can be divided into three types: rectangular, cylindrical and irregular. According to categories, there are resistors, capacitors, inductors, transistors and small integrated circuits. Bian Xiao roughly sorted out the information and wrote it to share with you as follows.
Patch resistance shape
1. Rectangular resistor, also known as patch resistor, can be divided into substrate, electrode, resistive film and protective layer. Description and diagram of rectangular resistor are given below.
(1) substrate: the substrate should have good electrical insulation G8P- 14PDC 12 edges, high thermal conductivity and high mechanical strength. Generally, high purity (96%)al2o 3 ceramics are used as substrate materials. The process requires smooth surface and accurate marking, and ensures that the resistor and electrode paste are printed in place;
(2) Electrode: Chip resistors generally adopt a three-layer electrode structure, and the innermost layer is the inner electrode, which is the intermediate electrode connecting the middle layer resistor, and is a nickel (Ni) plated layer, also known as the barrier layer. Its main function is to improve the heat resistance of the resistor during welding and avoid the internal electrode from being dissolved. Located on the outermost layer is the external electrode, also known as the solderable layer. This layer can not only make the electrode have good weldability, but also prolong the storage life of the electrode. Usually, tin and lead are used as external electrodes. -Pb) alloy electroplating;
(3) Resistive film: Resistive film is a thick film resistor printed on ceramic substrate with resistive paste with certain resistivity and then sintered;
(4) Protective layer: The protective layer is located outside the resistive film and mainly plays a protective role. Usually it can be subdivided into envelope glass protective film, glass glaze coating and logo glass layer. Among them, the encapsulated glass protective film directly covers the resistive film, which is generally made of glass paste with low melting point and sintered by printing. On the one hand, it plays a protective role, on the other hand, it plays an insulating role, avoiding the failure caused by the contact between the resistor and the adjacent conductor or line. In addition, in the process of electroplating the middle electrode, the protective layer can also prevent the electroplating solution from corroding and damaging the resistance film;
2. Cylindrical resistors, also known as disc resistors, leadless resistors, leadless resistors, color ring resistors, etc. , is a kind of resistance element, which is mainly used in surface mount technology. Disc resistor is also a surface mount component, which is obviously superior to chip resistor in function, mechanical structure, electrical characteristics and safety, and its noise is lower than that of thick diaphragm resistor. Cylindrical MELF resistors are mainly used in high-order circuits with high power/high voltage surge/precision/high security requirements. The following figure is the structural diagram of cylindrical resistor.
3. Different shapes, also known as sampling resistor, sampling resistor and presser foot type manganin resistor, are made of alloy and manganin. They are door-shaped, U-shaped, M-shaped, spring-shaped, S-shaped, L-shaped, linear and so on. They mainly have the characteristics of low temperature coefficient of resistance, wide temperature range (below 480℃), good processability and good welding performance. Widely used in the production of electronic components in instruments, electronics and industrial equipment. It is also a kind of patch resistance, but the shape is larger, but the resistance range of 1 mOhm -200 mOhm can be selected.