Browse Prior Art Database

Crossed Twin Circle Heat Blockage

IP.com Disclosure Number: IPCOM000106465D
Original Publication Date: 1993-Nov-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Hinrichsmeyer, K: AUTHOR [+2]

Abstract

This article describes a special formed heat blockage around a pin.

This text was extracted from an ASCII text file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 68% of the total text.

Crossed

Twin Circle

Heat Blockage

      This article describes a special formed heat blockage around a
pin.

      Present card and board designs have several power planes to
cover the high current requirements and for signal plane shielding.

More than one power plane are soldered to one pin.  The heat sink
action of this power plane sandwich has to be prevented.

      So far this is done by surrounding the pin by clearance holes
or by using a wagon wheel design.  The wagon wheel is a large
clearance land with 4 spokes connecting the pin in the plated through
hole to the copper power plane sandwich.

      The larger the clearance holes in the form of wagon wheels the
less current carrying capability of the power plane remains.

      Connections to power planes of a printed circuit card get a
copper free area around a pin in a plated through hole that is
designed to provide the highest heat blockage while causing a minimum
of electrical impact.  This is achieved by the use of the circle
connecting the inner and outer spokes.  The pin in the plated through
hole is surrounded by two polygons or circles of copper free area.
Each polygon or circle is at least bridged by one copper line,
whereby the copper line bridging the inner polygon or circle and the
line bridging the outer polygon or circle are as fare a part as
possible in this case 180 degrees.  The number of lines bridging the
polygons or circles can be increased as long as they are offset fro...