| 摘要 |
An object is to form a solder layer which does not have a variation in the heights of a plurality of electrode portions arranged at a fine pitch regardless of the type of a solder material and realize stable bonding with an electronic component. Provided as means for solving the problem is a solder precoated substrate in which a plurality of electrode portions are arranged at a fine pitch in the opening portion of an insulating film covering the principal plane of the substrate, the electrode portion is precoated with solder, and the shape of the electrode portion simultaneously satisfies (i) and (ii) below: (i) the upper surface of the electrode portion (3) presents a rectangular shape in which the ratio of electrode length (L) to electrode width (W), (L/W), is equal to or less than 6.0 (note that L=W); and (ii) the thickness (t) of the electrode portion (3) is equal to or less than the electrode width (W).
|
