Browse Prior Art Database

Leadless Multi-Chip Module-Laminate Carrier with Conductive Paste Filled Edge Vias

IP.com Disclosure Number: IPCOM000117543D
Original Publication Date: 1996-Mar-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Yokotsu, M: AUTHOR

Abstract

Disclosed is a circuit card for the leadless Multi-Chip Module-Laminate (Leadless MCM-L) carrier consists of laminate and conductive paste filled edge vias. The carrier brings the following advantages: a) lower cost than the leadless multi-chip module-ceramic (Leadless MCM-C) carrier b) higher mechanical reliability in comparison with the conventional edge vias.

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

Leadless Multi-Chip Module-Laminate Carrier with Conductive Paste
Filled Edge Vias

      Disclosed is a circuit card for the leadless Multi-Chip
Module-Laminate (Leadless MCM-L) carrier consists of laminate and
conductive paste filled edge vias.  The carrier brings the following
advantages:
  a) lower cost than the leadless multi-chip module-ceramic (Leadless
      MCM-C) carrier
  b) higher mechanical reliability in comparison with the
conventional
      edge vias.

      The Figure shows a fundamental structure of the leadless MCM-L
carrier.  The edge vias are completely filled with a conductive paste
composed of fine conductive powder and some organics.  Both pads and
edge surfaces of the edge vias are metal-plated to preserve the
solderability of the edge vias.  The edge vias have excellent
reliability superior to the conventional copper plated-through edge
vias which have become separated loosened, or lifted by the
mechanical stress during shearing of the edge via formation.  The
reasons for the excellent reliability are due to the lower mechanical
stress generated around the conductive paste-filled edge vias.  The
observation of the the cross section of the edge vias showed that
there were no substantial defects such as cracks, voids, burrs and
separations in the vias.