| 摘要 |
PURPOSE:To realize minute size via-holes and improve the reliability of the via-holes. CONSTITUTION:7th-10th layers 15 are laminated. Through-holes (i) are drilled in this stage to form blind via-holes 16. 4th-6th layers 17 and 11th-13th layers 18 are laminated on and under the 7th-10th layers 15 respectively. Spot facing holes (ii) which reach the surface 21 of the 7th layer and the surface 22 of the 10th layer are drilled to form blind via-holes 19 and 20. In the same way, 1st-3rd layers 23 and 14-16 layers 24 are laminated respectively and spot facing holes (ii) which reach the surface 27 of the 4th layer and the surface 28 of the 13th layer are drilled to form blind via-holes 25 and 26. With this constitution, a multilayer printed wiring 29 which has through via-holes 30 and is composed of 16 layers can be provided. |
