What is BS EN 61249-2-43 - Materials for printed boards about?   
BS EN 61249-2-43 is an international standard that discusses materials for printed boards and other interconnecting structures, enabling performance and longevity in printed board assemblies.  
BS EN 61249-2-43 gives requirements for properties of non-halogenated epoxide cellulose paper reinforced core/woven E-glass reinforced surface laminate sheets of defined flammability (vertical burning test), copper-clad for lead-free assembly in thicknesses of 0.60 mm up to 1.70 mm.
In BS EN 61249-2-43, the flammability rating is achieved through the use of nonhalogenated fire retardants reacted as part of the epoxide polymeric structure. The glass transition temperature is defined to be 100 °C minimum.
Who is BS EN 61249-2-43 - Materials for printed boards for?  
BS EN 61249-2-43 on materials for printed boards is useful for:  
- Manufacturers of printed circuit boards (PCBs) 
- Manufacturers of electronic components and interconnecting structures 
- Manufacturers and suppliers of laminate sheets 
- Quality control and testing personnel 
- Inspection authorities 
Why should you use BS 61249-2-43 - Materials for printed boards?   
PCB is essential in all electronic devices, whether they are used for residential or industrial applications. In a multi-processor context, the interconnection arrangement can determine total system performance.  
BS EN 61249-2-43 provides you guidance on materials and construction, reference standards’ test methods to verify electrical properties along with their requirements, and non-electrical properties of the copper-clad laminate, facilitating the classification and application of materials in printed boards.
BS EN 61249-2-43 also provides you with methods for properties such as flexural strength, flammability, measling, water absorption, amongst others, and their respective requirements, ensuring the safety and performance of printed boards. 
If you are a manufacturer, you can also improve your quality management systems by adopting best industry practices for conformance and qualification inspection and exhibiting compliance with BS EN 61249-2-43 requirements. 
Compliance with requirements and tests provided by BS EN 61249-2-43 can thus demonstrate the reliability, quality, and performance of materials for printed boards and interconnecting structures.