What is BS EN 61188-5-4 — Components with J leads on two sides for PCBs about?
BS EN 61188-5-4 is an international standard that focuses on attachment considerations and design methods for printed board assemblies.
BS EN 61188-5-4 provides the component and land pattern dimensions for a small outline integrated circuits with “J“ leads on two sides (SOJ components) used in the reflow soldering process. The basic construction of the SOJ device is also covered.
Who is BS EN 61188-5-4 — Components with J leads on two sides for PCBs for?
BS EN 61188-5-4 on Components with J leads on two 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 61188-5-4— Components with J leads on two sides 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 61188-5-4 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 develop deviating land pattern dimensions based upon the methodology of IEC 61188-5-1, introducing its own special material, and assembling process conditions C, F, P, and perhaps its own special land protrusions and courtyard excesses dimensions, as required.
BS EN 61188-5-4 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.
