Printed circuit board
AssigneesSumitomo Electric Industries, Ltd., Sumitomo Electric Printed Circuits, Inc.
InventorsYosuke Fukaya, Koji Nitta, Shoichiro Sakai, Takuto Hidani, Yoshihito Yamaguchi
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Abstract
A printed circuit board includes a base film having a main surface, and an electrically conductive pattern disposed on the main surface. The electrically conductive pattern includes an electrically conductive base layer disposed on the main surface directly or indirectly, and a copper electroplating layer disposed on the electrically conductive base layer. The void density, being a value obtained by dividing a sum of areas of voids within a predetermined observation length at an interface between the electrically conductive base layer and the copper electroplating layer by the observation length, is more than 0.01 μm2/μm and 5.5 μm2/μm or less.
Claims6
A printed circuit board comprising:
- a base film having a main surface;
- and
- an electrically conductive pattern disposed on the main surface,
- wherein the electrically conductive pattern includes an electrically conductive base layer disposed on the main surface directly or indirectly, and a copper electroplating layer disposed on the electrically conductive base layer,
- wherein a void density is more than 0.01 μm2/μm and 5.5 μm2/μm or less, the void density being a value obtained by dividing a sum of areas of voids present in a range having a predetermined observation length at an interface between the electrically conductive base layer and the copper electroplating layer by the observation length, and
- wherein, when a thickness of the electrically conductive base layer is T (μm), the observation length is L (μm), and a sum of lengths of the voids present at the interface in the range having the observation length is VL (μm), a value of T×VL/L is 0.39 or less in the range having the observation length.
Dependencies are inferred from the claim text.