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US 7,071,424 B1Granted
Multilayer printed wiring board having filled-via structure
AssigneeIbiden Co., Ltd.
InventorsSeiji Shirai, Kenichi Shimada, Motoo Asai
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AssigneeIbiden Co., Ltd.
InventorsSeiji Shirai, Kenichi Shimada, Motoo Asai
Estimating the term…
The present invention provides a multilayer printed wiring board having a filled viahole structure advantageously usable for forming a fine circuit pattern thereon, and having an excellent resistance against cracking under a thermal shock or due to heat cycle. The multilayer printed wiring board is comprised of conductor circuitry layers and interlaminar insulative resin layers deposited alternately one on another, the interlaminar insulative resin layers each having formed through them holes each filled with a plating layer to form a viahole. The surface of the plating layer exposed out of the hole for the viahole is formed substantially flat and lies at a substantially same level as the surface of the conductor circuit disposed in the interlaminar insulative resin layer. The thickness of the conductor circuitry layer is less than a half of the viahole diameter and less than 25 μm. The inner wall of the hole formed in the interlaminar insulative resin layer is roughened and an electroless plating layer is deposited on the roughened surface. An electroplating layer is filled in the hole including the electroless plating layer to form the viahole. The interlaminar insulative resin layer is formed from a composite of a fluororesin showing a high fracture toughness and a heat-resistant thermoplastic resin, a composite of fluororesin and thermosetting resin or a composite of thermosetting and thermoplastic resins.
A multilayer printed wiring board comprising conductor circuit layers each having a respective thickness and a surface and interlaminar insulative resin layers deposited alternately one on another, the interlaminar insulative resin layers each having through-holes having an inner wall substantially filled up with a plating layer having a substantially flat surface to form a viahole having a diameter;
A multilayer printed wiring board comprising conductor circuit layers each having a respective thickness and a surface and interlaminar insulative resin layers deposited alternately one on another, the interlaminar insulative resin layers each having through-holes having an inner wall substantially filled up with a plating layer having at least one surface to form a viahole having a diameter, wherein depressions are formed on a central surface portion of the plating layer surface extending out of the through-holes, and wherein the thickness of said conductor circuit layer is less than a half of the viahole diameter and less than 25 μm and wherein at least one of the surfaces of the conductor circuits is roughened to a depth of 1 to 10 μm.
A multilayer printed wiring board comprising conductor circuit layers each with at least one surface wherein at least one of the surfaces of the conductor circuit layer is roughened to a depth of 1 to 10 μm and interlaminar insulative resin layers deposited alternately one on another, the interlaminar insulative resin layers each having through-holes, having an inner wall wherein the inner wall is roughened, substantially filled up with a plating layer to form a viahole, wherein:
A multilayer printed wiring board comprising conductor circuit layers and interlaminar insulative resin layers deposited alternately one on another, the interlaminar insulative resin layers each having through-holes, having an inner wall, substantially filled up with a plating layer to form a viahole, said interlaminar insulative resin layers being formed from a composite of fluororesin and heat-resistant thermoplastic resin, composite of fluororesin and thermosetting resin, or a composite of thermosetting resin and heat-resistant thermoplastic resin wherein depressions are formed in the central surface portion of the plating layer surface extending out of the through holes.
Dependencies are inferred from the claim text.