The PCB Four-layer Board segmentation by application reveals distinct demand drivers that collectively shape market size. Consumer Electronics dominates with roughly 40% of revenue, fueled by smartphones, tablets, and wearables that require compact, high‑performance interconnects. Automotive accounts for about 25%, reflecting rising adoption of advanced driver‑assistance systems (ADAS), infotainment, and electric‑vehicle power management where four‑layer boards provide the necessary thermal stability and signal integrity. Industrial applications contribute 15%, driven by automation, robotics, and IoT sensors that depend on robust boards for harsh environments. Medical devices hold a 12% share, as diagnostic imaging and patient‑monitoring equipment increasingly rely on multilayer PCBs for reliability and miniaturization. Finally, Telecommunications represents 8% of the market, supporting base‑station equipment and 5G infrastructure where high‑frequency performance is critical. Each segment’s proportion mirrors its capital intensity and growth outlook, together defining the overall market valuation.