Patent ID: 7321496
Filing Date: 2008-01-22
Classification: H01L,H05K,Y10T

Abstract:
1. A flexible substrate comprising: a film; a first insulating resin layer on a front surface of said film, and a second insulating resin layer on a rear surface of said film, with said front surface and said rear surface facing in opposite directions; a front-sided wiring pattern embedded in said first insulating resin layer such that an exposed surface of said front-sided wiring pattern is flush with an outer surface of said first insulating resin layer, and a rear-sided wiring pattern embedded in said second insulating resin layer such that an exposed surface of said rear-sided wiring pattern is flush with an outer surface of said second insulating resin layer; and a via between said front-sided wiring pattern and said rear-sided wiring pattern, said via electrically interconnecting said front-sided wiring pattern and said rear-sided wiring pattern, wherein said first insulating resin layer and said second insulating resin layer are each thicker than said film; wherein a ratio of a thickness of said first insulating resin layer to a thickness of said film is within a range of from 1.2 to 6, and a ratio of a thickness of said second insulating resin layer to a thickness of said film is within a range of from 1.2 to 6, and further comprising: at least one of a passive element and an active element, along with wiring connected thereto, on at least one of said front face and said rear face of said film, with said wiring and said via being electrically connected to each other.