| abstract |
The present invention provides a planar coil having a high inductance and a method for manufacturing the same while reducing the DC resistance of the coil by reducing the conductor width from the outermost periphery to the innermost periphery. A planar coil including a conductor formed in a spiral shape by electrolytic copper plating. The conductor 3 has a conductor width that decreases from the outermost peripheral part of the spiral shape toward the innermost peripheral part, and the conductor width Wa of the outermost peripheral part of the spiral-shaped planar coil connected to the external terminal is the largest, The conductor width gradually decreases toward the center, and the conductor width Wb at the innermost periphery is the smallest. The ratio of the conductor width Wb of the innermost periphery to the conductor width Wa of the outermost periphery is 0.01 or more and less than 0.5. The conductor 3 is configured to be embedded in an insulator. Furthermore, since the surface layer of the conductor 3 is subjected to magnetic plating, the inductance value of the coil can be improved. [Selection] Figure 1 |