Browse Prior Art Database

Via Connection on Power Plane

IP.com Disclosure Number: IPCOM000114286D
Original Publication Date: 1994-Dec-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Shirai, M: AUTHOR [+3]

Abstract

This article describes a method to get reliable connection to power and grand plane through plated via hole connection in Surface Laminar Circuit (SLC) panel.

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This is the abbreviated version, containing approximately 100% of the total text.

Via Connection on Power Plane

      This article describes a method to get reliable connection to
power and grand plane through plated via hole connection in Surface
Laminar Circuit (SLC) panel.

      Generally, the power plane or the grand plane has large copper
area in layer.  To get connection to this copper plane, photo via
holes are made in an insulator on this large copper plane.  Fig. 1
shows the process steps and panel cross section at each step.  The
surface of the copper is usually oxidized to get good adhesion with
the insulator.  The panel is treated with an acid solution before
copper plating.  This acid may erode oxidized layer and might cause
separation between copper and the insulator.  This may cause poor
via-connection as shown in Fig. 1.

      To improve this poor connection, a part of the large copper
connection area is etched off at the bottom of the via hole, and then
the insulator layer is produced as shown in Fig. 2.  The insulator to
insulator interface is firmed and is not eroded by acid treatment, so
any separation does not occur.  As a result, good connection through
via hole is maintained.  The modified point is that there is an
insulator interface of the under layer in the bottom of the via hole.