What is BS EN 61188-5-3 – Components with gull-wing leads for PCBs about?
BS EN 61188-5-3 is an international standard that focuses on attachment considerations and the design of the printed board and printed board assemblies.
BS EN 61188-5-3 provides information on land pattern geometries used for the surface attachment of electronic components with gull-wing leads on two sides.
The intent of BS EN 61188-5-3 is to provide the appropriate size, shape, and tolerances of surface mount land patterns to ensure sufficient area for the appropriate solder fillet. It also recommends the specification for inspection, testing, and reworking of those solder joints.
Who is BS EN 61188-5-3 – Components with gull-wing leads for PCBs for?
BS EN 61188-5-3 on Components with gull-wing leads for PCBs is useful for:
- Manufacturers of printed circuit boards (PCBs) 
- Manufacturers and suppliers of electronic components
- Designers of printed circuit boards (PCBs) 
- Quality control and testing personnel 
- Regulatory authorities
Why should you use BS EN 61188-5-3 – Components with gull-wing leads for PCBs?
BS EN 61188 series covers the technicalities for printed boards and printed board assemblies, and this part particularly deals with land patterns for components with gull-wing leads on two sides.
BS EN 61188-5-3 proposes the land pattern dimensions based upon the fundamental tolerance calculation combined with the given land protrusions and courtyard excesses. The courtyard includes all issues of the normal manufacturing necessities.
BS EN 61188-5-3 offers a threefold land pattern dimensioning (levels 1, 2, and 3) on the basis of
a threefold set of land protrusions and courtyard excesses: maximum (max.); median (mdn), and minimum (min.). It assigns each land pattern with an identification number to indicate the characteristics of the specific robustness of the land patterns. It also helps the users to organize the information so that it is most useful for their particular design.
BS EN 61188-5-3 is applicable for the solder paste application plus the reflow soldering process. For the application of the wave soldering process, the land pattern dimensions normally have to be modified.
