| 摘要 |
<p>PURPOSE:To increase the mounting density of parts, by transferring a part of electric parts group mounted on the outer wiring layers of a wiring board to an inner wiring layers. CONSTITUTION:Each of the four wiring layers, i.e., a first wiring layer 1, a second wiring layer 2, a third wiring layer 3 and a fourth wiring layer 4 is insulated by each insulating layer 5. In accordance with necessity of wiring, wirings using through holes and the like are arranged between the wiring layers. The first wiring layer 1 and the fourth wiring layer 4 being outer wiring layers are, in the same manner as prior wiring boards, constituted of wiring patterns 8, metal foils like lands for fixing components, and coating films 9 for insulating, and thereon electric components 6 are mounted. On the other hand, the second wiring layer 2 and the third wiring layer 3 being inner wiring layers are constituted of wiring patterns 8 and thin type electric elements 7, such as resistors, capacitors and semiconductors formed by thick film art and thin film art.</p> |
