| 摘要 |
<p>PURPOSE:To form a plastic chip carrier at a low cost, by forming solder projections at through holes of a plurality of matrixes which are formed from the surfaces to the rears of package bases to form each solder bump, thereby causing the solder bump to serve as a point of contact. CONSTITUTION:Each copper plated through hole is formed at a substrate 2 through systems of electroless copper-plating and electrolytic copper plating and circuit formation is carried out by using substractive processing. Further, a solder resist 4 is formed at both sides of the substrate 2 by using a printing process or a baking process and so on. After that, high purity Ni-Au plating process 5 and 6 for wire bonding are carried out at required places. Then, solder projections 7 are performed to each through hole by using a dip brazing process, a wave soldering, a reflow process, and the like. The solder projections allow a package to perform hermetic seal and the package having input/output terminals is formed toward the rear of the substrate.</p> |
