BS EN IEC 61188-6-2:2021 pdf free

BS EN IEC 61188-6-2:2021 pdf free.Circuit boards and circuit board assemblies一Design and use Part 6-2: Land pattern design一Description of land pattern for the most common surface mounted components (SMD).
There are two classes of land pattern relating to the assembly limitations of components and the intended soldering process:
• land pattern for wave soldering — For low density product applications, land patterns are designed to accommodate several types of wave soldering applicable to surface mounted components.
• land pattern for reflow soldering — The land patterns generated for all device families shall provide a robust solder attachment condition for reflow soldering.
6 Requirements
6.1 General requirements
The calculated land pattern geometry for an electronic component can be different depending upon the type of soldering process to be used. Wherever possible, land patterns should be defined in such a manner that are transparent to the attachment process being used. Land pattern designers can use the information contained herein to establish standard configurations not only for manual designs but also for computer-aided design systems.
Whether parts are mounted on one side or both sides of the board, subjected to wave soldering, reflow soldering, or other type of soldering, the land pattern and part dimensions should be optimized to insure proper solder joint and inspection criteria.
Although patterns are dimensionally defined and since they are a part of the circuit board geometry, they are subject to the reducibility levels and tolerances associated with plating, etching, assembly or other conditioning process. The producibility aspects also pertain to the use of solder mask and the registration required between the solder mask and the conductor patterns.
A correctly designed land pattern is essential to satisfy quality standards such as IEC 61191- 2:2017, which specifies generic requirements for the concept of land pattern design. The land pattern designer should design in accordance with the concept in this document, and they could adopt appropriate numeric values that were suitable for their purpose. The numeric values described in this document are the parameters that were selected as references to show the concept of land-pattern design.
6.2 The proposed land pattern dimension system
6.2.1 Land pattern design
Distance between lands measured from outside edges (Z) and distance between lands
measured from inside edges (G) are given by the following Formula (1) and Formula (2).
NOTE In Figure I e), the area surrounded by dashed lines is the courtyard.
Figure 1 shows a typical example of the relationship between the land pattern design and the component dimensions. The requirements contained in IEC 61188-6-4 about the relationship between dimensions shall apply.BS EN IEC 61188-6-2 pdf free download.