The physical properties of deposited film in acid copper plating were studied. Effects of addition agents on the mechanical properties of the deposit film were studied, besides, the excess deposit over the Faraday equivalent was measured. As a result it is found that the addition agents can be classified into three groups as follows.
1) Absorption type addition agent:
Greater change of physical properties and more excess deposit over the Faraday equivalent than in the case of plating in the bath without addition agents were observed.
2) With complex salt type addition agent:
The change of physical properties and the excess deposit over the Faraday equivalent were not observed.
3) Intermediate type addition agent:
The effects of the addition agent lay between those of 1) and 2).