Circuit board, method of manufacturing base plate and method of manufacturing circuit board

A method of manufacturing a circuit board, comprising:

• providing a second substrate comprising a second base layer and a third copper coating formed on a side of the second base layer;
• providing a semi-finished protect, a method of manufacturing the semi-finished protect comprising:
• providing a first substrate, the first substrate comprising a first base layer, a first copper coating and a second copper coating covered on two sides of the first base layer;
• opening at least one first hole on the first substrate, the first hole penetrating the first base layer and the first copper;
• forming a first electroplated coating on the first copper coating, the first electroplated coating filling into the first hole to form a first connecting portion;
• opening at least one second hole on the first connecting portion and the first electroplated coating to form a plurality of second connecting pins;
• and
• etching the first copper coating and a portion of the first electroplated coating correspondingly to the first copper coating to form an inner line layer to gain a first semi-finished protect;
• bonding the second substrate on the first semi-finished protect, the second base layer being toward to the inner layer and filled into the second hole;
• opening a plurality of fourth holes on the second substrate, the plurality of holes penetrating the second substrate, the plurality of second connecting pins been exposed from the plurality of fourth holes;
• forming a second electroplated coating on the third copper coating;
• etching the second electroplated coating and the third copper coating to gain a first outer line layer, and further etching a second copper coating to gain a second outer line layer.