Fabrication process circuit board with embedded passive component

A fabrication process of a circuit board with embedded passive component, comprising:

• providing a circuit unit having a first conductive layer, a second conductive layer and at least one passive component material layer, wherein the first conductive layer and the second conductive layer are respectively located on two opposite surfaces of the circuit unit, and the second conductive layer covers the passive component material layer, and the second conductive layer comprises at least one component area, and the passive component material layer is located over the component area of the second conductive layer;
• forming a first photoresist layer and a second photoresist layer, respectively covering the first conductive layer and the second conductive layer;
• patterning the first photoresist layer;
• performing a first etching process on the first conductive layer to form a first circuit layer;
• removing the patterned first photoresist layer and the second photoresist layer;
• forming a third photoresist layer and a fourth photoresist layer covering the first circuit layer and the second conductive layer respectively;
• patterning the fourth photoresist layer;
• and
• performing a second etching process and a third etching process on the second conductive layer to form a second circuit layer, wherein the second etching process uses an acid etchant, while the third etching process uses a alkaline etchant.