1. Arrange the order of assembly according to the characteristics of the product and the equipment conditions of the enterprise. If it is hand-inserted and soldered, it is necessary to install components that need to be fixed, such as heat sinks, brackets, clips, etc. of the power device, and then install the components fixed by soldering. Otherwise, the printed board will be deformed by force during mechanical fastening to damage other components that have already been installed. In the case of automatic mechanical equipment insertion and soldering, you should install those components with lower height, such as jumper of circuit, resistorOne type of component, after installing those components with higher height, such as axial (vertical) plug-in capacitor, transistor, etc., for valuable The key components, such as large-scale integrated circuits and high-power devices, should be put in the final assembly, install radiators, brackets, clips, etc., close to the welding process, so as not only can prevent the pre-installed components from interfering with the loading and unloading. The components are also beneficial to avoid losing precious components due to the vibration of the transmission system.
2, the installation of various components, should try to make their tag (marked with color code or character Value, accuracy, etc.) face up or in an easy-to-read direction, and note that the markings are in the same direction (from left to right or top to bottom), which is beneficial for the inspection personnel to visually inspect; horizontally mounted components, try to Make the lengths of the leads at both ends equal and symmetrical. Place the components in the center of the two holes and arrange them neatly. The color ring resistance of the vertical installation should be highly consistent. It is best to let the starting color ring up to check the installation error. Leave too long to avoid short-circuiting with other components. For components with polarity, ensure correct orientation when inserting.
3. When the components are vertically assembled on the printed circuit board, the number of components per unit area is large, which is suitable for the space inside the casing. Compact and dense components. However, the vertical assembly has poor mechanical properties and weak anti-vibration capability. If the components are tilted, it is possible to contact adjacent components and cause a short circuit. In order to isolate the leads from each other, a method of adding an insulating plastic tube is often employed. In the same electronic product, the color of the sleeves of the leads of the components should be the same, which is convenient for distinguishing different electrodes. Because this type of assembly requires manual operation, it is not used in high-grade electronic products except for those small-cost civilian products.
4. When mass-produced electronic products under non-specialized conditions, it is usually done by manually installing components in parallel with the welding operation. It should be assembled first with mechanically fixed components, first soldering those heat-resistant components, such as connectors, small transformers, resistors, capacitors, etc.; then assembling components that are more afraid of heat, such as Various semiconductor devices and components for plastic packaging.