As the core of smart watches, the Smart Watch PCBA is characterized by ultra-high density, miniaturization and high reliability, which needs to integrate multiple functional modules in an extremely small space to realize health monitoring, time display, wireless communication and other functions. The PCBA usually adopts 4-layer, 6-layer or 8-layer design according to the functional complexity: entry-level models with basic step counting and Bluetooth functions use 4-layer PCBs to control costs; mid-range models with heart rate, blood oxygen and fast charging functions adopt 6-layer PCBs to optimize communication and sensing lines; high-end models with eSIM and ECG functions use 8-layer PCBs with blind and buried holes to adapt to complex functions.

The PCBA is equipped with a high-precision main control chip, a sensor module, a power management module and a communication module. The sensor module includes heart rate sensors, blood oxygen sensors and accelerometers, which can accurately collect human health data and motion data. The power management module adopts a high-efficiency low-dropout regulator to ensure stable power supply and long battery life. The communication module supports Bluetooth, Wi-Fi and eSIM, enabling functions such as call making and message receiving. In terms of manufacturing process, the PCBA adopts high-precision lithography technology, with a minimum line resolution of 0.05mm, and the surface is coated with acrylic or silicone to isolate sweat, moisture and dust, adapting to the long-term wearing scenario of smart watches. The surface treatment usually adopts immersion gold technology to ensure the oxidation resistance and corrosion resistance of the circuit.