What makes PCB's difficult to recycle?

Printed Circuit Boards (PCBs) are challenging to recycle due to their complex composition, which includes various materials like metals, plastics, and ceramics that are bonded together. The presence of hazardous substances, such as lead and brominated flame retardants, complicates the recycling process and necessitates stringent safety measures. Additionally, the small size and intricate design of PCBs make mechanical separation difficult and often require specialized technologies for efficient recovery of valuable materials.