| 摘要 |
<p>PURPOSE:To obtain a ceramic chip carrier having ultrafine pad accurately in high density with an exposed part as a connecting pad by forming a hole at the pad forming position and introducing a metal material. CONSTITUTION:A through hole of approx. 0.3mm. in diameter is opened at a green sheet 11c of the third layer of a ceramic chip carrier 1, conductive paste is introduced to the hole, metallized to form vertical internal wirings 16, a through hole of desired size and shape is formed at the green sheet 11d of the uppermost layer, conductive paste is introduced, baked and internal wirings 16a (pad) are formed. The surface is polished, the top of the wirings 16a is flattened, and Ni-Au plated to complete a pad 17. According to this structure, the pad is not wasted by polishing, a carrier 11 can be mounted on a printed board or a ceramic board 18 with solder 19, the pad can be formed in a small size and high density, thereby improving the integration of the leadless chip carrier.</p> |
