What is BS EN 61188-5-5 — Components with gull-wing leads on four sides of PCB about?
BS EN 61188-5-5 is an international standard that focuses on attachment considerations and design methods for printed board assemblies.
BS EN 61188-5-5 provides information on land pattern geometries used for the surface attachment of electronic components with gull-wing leads on four sides.
The intent of BS EN 61188-5-5 is the information presented herein is to provide the appropriate size, shape, and tolerances of surface mount land patterns to ensure sufficient area for the appropriate solder fillet, and also allow for inspection, testing, and reworking of those solder joints.
Who is BS EN 61188-5-5 — Components with gull-wing leads on four sides of PCB for?
BS EN 61188-5-5 on Components with gull-wing leads on four sides of PCB 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 61188-5-5 — Components with gull-wing leads on four sides of PCB?
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 four sides.
BS EN 61188-5-4 proposes the land pattern dimensions based on a mathematical model, that establishes a platform for a solder joint attachment to the printed board. The existing models create a platform that can establish a reliable solder alloy used to make that joint (lead-free, tin-lead, etc.).
BS EN 61188-5-5 contains a specific set of criteria such that the information presented is consistent, providing information on the component, the component dimensions, the solder joint design, and the land pattern dimensions.
BS EN 61188-5-4 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 61188-5-4 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 helps the users to assign each land pattern with an identification number to indicate the characteristics of the specific robustness of the land patterns. It also helps users to organize the information so that it is most useful for their particular design.
