SMT assembly chip processing is with the development of electronic products to the development of high precision, fine pitch direction, and SMT chip processing components of the minimum pitch design needs to be able to ensure that the PCBA pads are not easy to short and also take into account the maintainability of the components.
Consequences of insufficient component-to-component spacing;
One of the pins of the Bottom side connector on the PCB is too close to the next via hole, resulting in a short circuit between the pin and the via hole, and the PCB is burned. The distance between the component mounting hole and the pad is too small. The through-hole itself is directly connected to the pad, and there is no solder resist between the hole and the pad and the spacing is not suitable for the wave soldering process, or the welding parameters, such as speed and welding time, are not adjusted properly, resulting in continuous welding.
Through-hole and mounting pad spacing is too small. Through-hole and mounting pad spacing is too small, resulting in solder joints less tin, cold welding, not welded, monumental and other defects.
Neighboring pads are connected too close to the over-hole, and there is a risk of bridging in processes such as manual reflow. If the hole is designed on the pad, or the pad is close to the hole, the solder will flow out of the hole during reflow, resulting in insufficient solder. The defect of setting a hole directly on the pad is that the solder paste melts and flows into the hole during reflow, resulting in a lack of tin on the component pads, thus forming a virtual solder and possibly causing a short circuit.
When there is no solder mask between the wires connecting the through-hole of the mounting pads, soldering defects such as solder joints with little solder, cold soldering, short circuits, unsoldered, and monumental soldering can result. The distance between the through-hole solder ring and the BGA pad is close, and although there is a solder mask, the solder ring is not covered with a solder mask resulting in a solder joint connected to the through-hole. Capacitor pads on the metal through-hole without solder mask, resulting in component pins less tin defects, affecting the reliability of components. Solder pad design after the hole, sealed with solder resist ink, solder joints virtual solder and can not be replaced.
Therefore, it is crucial to ensure a reasonable pitch design during the SMT placement process. Inadequate design can lead to soldering defects such as low solder joints, cold soldering, short circuits, etc., thus affecting the reliability of components and the normal operation of the PCB. Proper pitch design not only reduces these defects but also improves solder quality and ensures component maintainability. In addition, the proper spacing between the over-hole and the pad helps to optimize the process parameters of wave soldering and reflow soldering to avoid problems such as solder loss or false soldering and thus improve productivity and product quality. In short, electronic manufacturers must strictly control the spacing between pads and via holes and optimize the process when designing PCBAs in order to guarantee the stability and safety of their products.
