Multilayer printed wiring board

• US 7,973,249 B2
• Filed: 02/26/2010
• Issued: 07/05/2011
• Est. Priority Date: 07/07/2005
• Status: Active Grant

• Current Assignee: Ibiden Co., Ltd.
• Original Assignee: Ibiden Co., Ltd.
• Inventors: Nakamura, Takenobu, Mikado, Yukinobu, Aoyama, Masakazu, Takahashi, Michimasa
• Primary Examiner(s): Patel; Ishwarbhai B
• Application Number:
  US12/713,249
• Publication Number:
  US 20100155130A1
• Time in Patent Office: 494 Days
• Field of Search: 174262-266, 361792-796
• US Class Current: 174/264
• CPC Class Codes: H05K 1/115 Via connections; Lands around holes or via connections H05K1/112 takes precedence
• CPC Class Codes: H05K 2201/0394 Conductor crossing over a hole in the substrate or a gap between two separate substrate parts
• CPC Class Codes: H05K 2201/09563 Metal filled via plated through-hole filled with insulating material H05K2201/0959
• CPC Class Codes: H05K 2201/096 Vertically aligned vias, holes or stacked vias
• CPC Class Codes: H05K 2201/09709 Staggered pads, lands or terminals; Parallel conductors in different planes
• CPC Class Codes: H05K 2201/09863 Concave hole or via
• CPC Class Codes: H05K 2203/0733 Method for plating stud vias, i.e. massive vias formed by plating the bottom of a hole without plating on the walls
• CPC Class Codes: H05K 3/421 Blind plated via connections H05K3/422, H05K3/423 and H05K3/425 take precedence
• CPC Class Codes: H05K 3/423 characterised by electroplating method
• CPC Class Codes: H05K 3/4602 characterized by a special circuit board as base or central core whereon additional circuit layers are built or additional circuit boards are laminated
• CPC Class Codes: H05K 3/4652 Adding a circuit layer by laminating a metal foil or a preformed metal foil pattern H05K3/4647 takes precedence
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 with selective destruction of conductive paths
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base
• CPC Class Codes: Y10T 428/31511 Of epoxy ether

Abstract

A multilayer printed wiring board including insulating layers and conductor layers being stacked alternately on each other. The conductor layers are electrically connected to each other through viaholes formed in the insulating layers. Each of the viaholes is formed to bulge in a direction generally orthogonal to the direction of thickness of the insulating layer. The multilayer printed wiring board is to have electronic components such as a capacitor, IC and the like mounted on the surface layer thereof.

Claims

1. A multilayer printed wiring board comprising:

a plurality of insulating layers;

a plurality of conductor layers formed on the insulating layers, respectively; and

a plurality of viaholes formed in the insulating layers and stacked such that at least two of the conductor layers are electrically connected to each other through the viaholes,

wherein each of the viaholes has a barrel shape bulging in a direction generally orthogonal to a direction of thickness of the insulating layers, each of the viaholes comprises a plating material comprising an electrolytic plating material and an electroless plating layer in an opening in a respective one of the insulating layers such that the electrolytic plating material completely closes the opening, and the plurality of viaholes includes ones stacked offset and ones stacked aligned.

2. The multilayer printed wiring board according to claim 1, wherein each of the insulating layers is about 100 μ

m or less in thickness.

3. The multilayer printed wiring board according to claim 1, wherein each of the insulating layers is about 50 μ

m or less in thickness.

4. The multilayer printed wiring board according to claim 1, wherein the viaholes are stacked together to form a multistage stacked vias.

5. The multilayer printed wiring board according to claim 1, wherein the barrel shape of each of the viaholes is formed such that the barrel shape has a diameter of a largest bulged part which is about 1.1 to about 1.5 times larger than a diameter of the top and the bottom of the opening.