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The Main Cause Of Circuit Boards And Fault

MOKO Technology Ltd | Updated: Jul 04, 2017

     The working principle of the circuit board: it is to use the insulating material of the substrate to separate the conductive layer of copper foil, so that the current flows along the predetermined route in various components such as work, amplification, attenuation, modulation, demodulation, coding and other functions. Circuit Boards Circuit board principle: structure. circuit board mainly by the pad, through hole, installation hole, wire, components, connectors, filling, electrical boundary, etc. The common plate-layer structure includes Single-layer Board (single layer PCB), double board (double layer PCB) and multilayer Board (multi layer PCB) three kinds. The main functions of each component are as follows: Solder PLATE: The metal hole used for welding component pins. Over hole: There is metal over hole and non-metallic over hole, wherein the metal is used to connect the component pins between each layer. Mounting holes: For fixing the circuit board. Conductor: The electrical Network copper film used to connect the pins of the components. Connectors: For the circuit board connection between the components. Filling: Deposited copper for ground network can effectively reduce impedance. Electrical boundary: Used to determine the size of the circuit board, all components on the circuit board can not exceed the boundary.
     The factors that make up the welding defects of PCB PCB processing factory analysis has the following three reasons: 1, the solderability of the circuit board hole affects the welding quality. The circuit board hole Solderability is not good, will produce virtual welding defects, affect the parameters of the circuit components, resulting in multilayer board components and inner-layer wire conduction instability, causing the entire circuit function failure. The so-called solderability is the metal surface by the molten solder wettability properties, that is, the solder on the metal surface to form a relatively uniform layer of continuous smooth adhesion film.Circuit Boards
     The main factors affecting solderability of printed circuit boards are: (1) The composition of solder and the nature of solder. Solder is an important part of the chemical process of welding, it consists of chemical materials containing flux, common low melting-point eutectic metal is-or Sn-Pb. The impurity content must be controlled in order to prevent impurities from being dissolved by the flux. The flux function is to help solder wetting the surface of the solder plate circuit by passing heat and removing rust. Generally used white rosin and isopropyl alcohol solvent. (2) The welding temperature and the surface cleanliness of the metal plate also affect solderability. When the temperature is too high, the diffusion speed of solder at this time has a very high activity, will make the circuit board and solder melts the surface of the rapid oxidation, resulting in welding defects, circuit board surface contaminated can also affect the weldability and thus create defects, these defects include tin beads, tin ball, open circuit, gloss, etc.Circuit Boards

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