US 8,148,643 B2 · Multilayered printed circuit board and manufacturing method thereof

Abstract

An opening is formed in resin 20 by a laser beam so that a via hole is formed. At this time, copper foil 22, the thickness of which is reduced (to 3 μm) by performing etching to lower the thermal conductivity is used as a conformal mask. Therefore, an opening 20a can be formed in the resin 20 if the number of irradiation of pulse-shape laser beam is reduced. Therefore, occurrence of undercut of the resin 20 which forms an interlayer insulating resin layer can be prevented. Thus, the reliability of the connection of the via holes can be improved.

Claims10

Dependent claims

A multilayered printed circuit board comprising:

a plurality of interlayer insulating resin layers and a plurality of conductive layers alternately laminated with each other;
a coarsened layer formed on a surface of at least one of the conductive layers;
a plurality of via holes connecting the conductive layers to one another, each via hole being formed by providing an opening in a respective one of the interlayer insulating resin layers to expose the coarsened layer, such that interference fringes are provided as stripe pits and projections, formed on a side wall and arranged along a depth direction of the opening.

Dependencies are inferred from the claim text.

Facts

Application

11/875,486Filed 19 Oct 2007 · division

Priority

JP 10-2493823 Sep 1998

Published

US 2008/0173473 A124 Jul 2008

Granted

3 Apr 2012

Term ends

Not estimatedThe source records don’t support an estimate.

Classification46 codes

H05K 3/4652
By building the multilayer layer by layer, i.e. build-up multilayer circuits: adding a circuit layer by laminating a metal foil or a preformed…
B23K 26/389
By boring: of fluid openings, e.g. nozzles, jets
H05K 3/0035
Of organic insulating material: of blind holes, i.e. having a metal layer at the bottom
H05K 3/0038
Of organic insulating material: combined with laser drilling through a metal layer

Family

PCT/JP99/04142Parent of this continuation · filed 30 Jul 1999

Application09/797,916Parent of this division · filed 5 Mar 2001

Application10/356,464Parent of this division · filed 3 Feb 2003

US 2008/0173473 A1Pre-grant publication · published 24 Jul 2008

US 7,415,761 B2Parent of this division

US 6,591,495 B2Parent of this division

Application09/797,916Parent of this continuation

US 2001/0042637 A1Published application

US 2004/0025333 A1Published application

US 8,148,643 B2This patent

From the US filing history. Foreign family members aren’t listed.

Multilayered printed circuit board and manufacturing method thereof

Life of this patent

Multilayered printed circuit board and manufacturing method thereof

Life of this patent

Abstract

Claims10