removed by photo etching the al film 14 on the through hole conductor 4 is removed by an 8 aqueous sodium hydroxide naoh solution thereafter washing with water and drying are carried out to form the contact hole 15 under the state shown in fig7 c incidentally the diameter of this contact hole is about 110 u03bcm after the remaining resist on the al film 14 on the wiring substrate is removed the substrate is dipped into a copper pyrophosphate plating solution and a copper film 18 is formed on the entire surface of the al film 14 in a thickness of about 20 u03bcm by electro plating as shown in fig7 d at this time the through hole conductor 4 in the contact hole 15 is directly bonded to the copper film 18 on the bond surface 9 the wiring substrate 6 on which the copper film 18 is formed in this manner is washed with water and dried and a positive type resist 20 is coated on the copper film 18 before the copper film 18 is oxidized thereafter the resist 20 at the portion corresponding to the position of the solder bond portion 8 of the micro lead is removed in the shape of a circle having a diameter of about 110 u03bcm then after an about 0 5 u03bcm thick ni layer 25 is formed by ordinary electro plating on the portion where the resist is removed and the copper film 18 is exposed as shown in fig7 e a 1 u03bcm thick au gold layer 22 is formed next in order to form the micro lead 7 shown in fig1 the remaining resist film on the cu film 18 of the wiring substrate 42 is removed and a negative type resist 49 is.