| 摘要 |
PROBLEM TO BE SOLVED: To improve connecting reliability of a semiconductor component mounted by soldering, by making elasticity of a stacking insulating layer low, while maintaining heat resistance and bonding strength of wiring, at the time of manufacturing a multilayer printed board by employing build up method. SOLUTION: On one or both planes of a printed board to be a base, an insulating layer composed of an acrylic rubber, an epoxy resin, a curing agent which can cure the epoxy resin, and an inorganic filler is formed. A prescribed region of the insulating layer is irradiated with laser beams to make a hole. Then, a wiring formed on the insulating layer and a wiring under the insulating layer are connected by the hole. |
