Browse Prior Art Database

Fine Line Chip Carrier with Connected Power and Ground Planes

IP.com Disclosure Number: IPCOM000118521D
Original Publication Date: 1997-Mar-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

D'Aloisio, A: AUTHOR [+4]

Abstract

Disclosed is a design for a multilayer, organic, Ball Grid Array (BGA) chip carrier and the processes to build this chip carrier. This chip carrier includes fine line circuitry and connections to separate power and/or ground planes without the use of drilled-through holes.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 93% of the total text.

Fine Line Chip Carrier with Connected Power and Ground Planes

      Disclosed is a design for a multilayer, organic, Ball Grid
Array (BGA) chip carrier and the processes to build this chip
carrier.  This chip carrier includes fine line circuitry and
connections to separate power and/or ground planes without the use of
drilled-through holes.  The abbreviated process flow is as follows:
  o  pre-drill clearance holes in layers of glass cloth
      reinforced prepreg
  o  laminate a multilayer structure of copper and prepreg
      (the pre-drilled clearance holes fill with resin from
      the prepreg during lamination)
  o  thin one or more of the external copper layers to about 6 um
  o  circuitize the thinned copper to fine line circuit features,
      which include chip bonding pads, BGA ball pads, and the
      appropriate connecting circuit lines (provide openings in
      the copper above the resin-filled holes in the prepreg)
  o  laser ablate blind vias in the resin-filled holes down to a
      copper plane
  o  screen solder paste in the blind vias and attach BGA solder
      balls by a reflow process.

      The advantages of the chip carrier described above are thin
film, fine line circuitry that enables fine pitch BGA chip carriers,
connected power and ground planes without the need for drilled- and
plated-through holes, and laser ablated blind vias which are much
smaller than drilled-through holes; thu...