| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that reliability decreases as wire bondability and electric characteristics deteriorate owing to microfabrication of wiring in a relay substrate although pad pitches of electrode pad need to be fine as a chip size is reduced by increasing the density of a semiconductor chip and a structure using the relay substrate is proposed because of a processing limit of a lead of a lead frame type package. SOLUTION: The relay substrate 1 is constituted by stacking a plurality of wiring boards 4, 5 and 6 each having conductor wiring 3 formed on an insulating resin film 2 in a staircase shape, and one end of the conductor wiring 3 forming a connection terminal of an outer lead 14 of the lead frame and the other end of the conductor wiring 3 forming a connection terminal for an electrode pad 12 of a semiconductor chip 11 are exposed on each of the wiring boards 4, 5 and 6 stacked in the staircase shape. COPYRIGHT: (C)2009,JPO&INPIT
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