DIN EN 62326-20:2016-12

This part of IEC 62326 specifies the properties of the printed circuit board for high-brightness LEDs. Many aspects of the PCB for high-brightness LEDs are identical with those of ordinary PCBs, therefore, some aspects of this standard also describe general aspects. The PCB for high-brightness LEDs specified in this standard shall comply with the specifications of Class A - Standard PCBs, Class B - Thermally conductive PCBs and Class C - Highly thermally conductive PCBs, respectively. The materials used for the PCB are not specified, but they shall be agreed between the user and the supplier depending on the application area of the PCB in question. The Design Rules and Tolerances clause covers the panel and board dimensions, overall board thickness, holes, conductors, printed contact, pad pattern, register mark and component positioning mark, and layer connection - copper metallization. The Quality clause covers the topics of distance between the conductor and the wall of a component mounting hole or a via hole, positional deviation between conductor layers of a multilayer PCB, minimum width of the connection area, surface treatment, defects in masking lacquer, terminal area of a land pattern, and defects in a terminal area for BGA/CSP assembly. The Performance Characteristics and Test Methods clause covers conductor resistance, current carrying capacity of the conductor and metallized via hole, and verification of component assembly and via holes. Informative Appendix A contains the classification and classes of printed circuit boards for high-brightness LEDs. Research on thermal conductivity and thermal transmittance has shown that the classification of PCBs for high-brightness LEDs is possible using these parameters. When using thermal conductivity, rosin-based PCBs for high-brightness LEDs can be classified into the two categories rosin-based PCBs for high-brightness LEDs with a thermal conductivity of more than 1 W/mK and rosin-based PCBs for high-brightness LEDs with a thermal conductivity of less than 1 W/mK. The responsible committee is DKE/K 682 "Aufbau- und Verbindungstechnik für elektronische Baugruppen" ("Packaging and interconnection technology for electronic assemblies") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.