Strong demand and fierce competition are sometimes twin brothers. The supply of PCBS from mainland manufacturers has surged in response to growing demand for PCBS in consumer electronics, PC and peripheral devices, telecommunications, automobiles and home appliances. While building new plants or revamping production facilities to increase capacity, manufacturers are also trying to increase the number of PCB layers and become more competitive. With about 400-500 PCB manufacturers, mainland China is expected to become the world's largest production base for double-sided and multilayer PCBS. In 2004, the combined output of double-sided and multilayer PCBS reached 52 million square meters, accounting for 61% of the mainland's total PCB output. The China Printed Circuit Board Association estimates PCB supply in the region will continue to grow 20% annually as manufacturers expand capacity to meet strong demand in the telecommunications and automotive electronics sectors.