Patent ID: 7911318

Claim:
A circuit board, comprising: a plurality of dielectric substrates; a resistive layer formed on first portions of a top surface or a bottom surface of at least one of the dielectric substrates; a wiring layer formed on second portions of the dielectric substrate for providing electrical connection; and at least one via hole formed in a thickness direction of the at least one of the dielectric substrates on which the resistive layer is formed, and extending through at least a portion of a body of the resistive layer, the via hole extending through the dielectric substrate from the top surface of the dielectric substrate to the bottom surface of the dielectric substrate, or through the dielectric substrate from the bottom surface of the dielectric substrate to the top surface of the dielectric substrate, wherein the resistance value of the resistive layer is variable depending on a size of the via hole, wherein the via hole comprises at least one of a hollow portion, an insulating material that fills the via hole, an electroplated metal material, or a metal material that fills the via hole, wherein the via hole is plated with conductive materials, or coated with the conductive materials, or filled with the conductive materials.