What is the Impact of PCB Pad Size on the Shape and Life of SMT Products?

There are many factors that affect the size of the bare pcb board pad. When designing the size of the pad, the range and tolerance of the component size, the need for the size of the solder joint, the accuracy, stability and process capability of the substrate (such as positioning and placement accuracy, etc.) should be considered.

The size of the printing circuit boards pad is determined by factors such as the shape and size of the component, the type and quality of the substrate, the capability of the assembly equipment, the type and capability of the process used, and the required quality level or standard.

The designed small circuit board pad size, including the size of the pad itself, the size of the solder mask or the solder mask frame, needs to consider the footprint of the component, the wiring under the component and the glue (in the wave soldering process) used for the design. Process requirements such as dummy disk or wiring.

Since a specific and effective comprehensive mathematical formula cannot be found when designing the blue circuit board pad size at present, users must also cooperate with calculations and experiments to optimize their own specifications, instead of using others’ specifications or calculated results. Users should establish their own design files and formulate a set of size specifications suitable for their actual situation.


The Users need to understand many aspects when designing custom printed circuit board pads, including the following sections.

1. Although there are international specifications for the packaging and thermal characteristics of components, their specifications vary greatly in some aspects for different countries, regions and manufacturers. Therefore, the selection of components must be restricted or the design specification must be graded.

2. It is necessary to have a detailed understanding of the quality of the aluminium pcb board (such as dimensional and temperature stability), materials, process capabilities of mimeograph and relative suppliers, and need to organize and establish their own substrate specifications.

3. It is necessary to understand the product manufacturing process and equipment capabilities, such as the size range of substrate processing, placement accuracy, screen printing accuracy, dispensing process, etc. Knowing this aspect can be of great help in pad design.