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Dense Circuit Board Structure Using Electrically Conductive Adhesive Wiring

IP.com Disclosure Number: IPCOM000118697D
Original Publication Date: 1997-May-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 116K

Publishing Venue

IBM

Related People

Gaynes, MA: AUTHOR [+3]

Abstract

Disclosed is a process to use an Electrically Conductive Adhesive (ECA) material in conjunction with a photo imageable or laser machineable polymer to produce a circuit card. Fig. 1 illustrates the steps required to produce an ECA card. Here, a thin insulator (1) is drilled (2) with small diameter through holes. The epoxy member would be hot roll laminated both sides, with a photo imageable or laser machinable polymer (3). If the photo-imageable material is used, it will be exposed and developed, forming the circuit lines (4). If laser machining is used, it must have depth control as not to nick the line beneath it. Both sides are squeegeed by a special nozzle to fill the cavities left behind with conductive adhesive (5).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 61% of the total text.

Dense Circuit Board Structure Using Electrically Conductive Adhesive
Wiring

      Disclosed is a process to use an Electrically Conductive
Adhesive (ECA) material in conjunction with a photo imageable or
laser machineable polymer to produce a circuit card.  Fig. 1
illustrates the  steps required to produce an ECA card.  Here, a thin
insulator (1) is drilled (2) with small diameter through holes.  The
epoxy member would  be hot roll laminated both sides, with a photo
imageable or laser machinable polymer (3).  If the photo-imageable
material is used, it will be exposed and developed, forming the
circuit lines (4).  If laser  machining is used, it must have depth
control as not to nick the line beneath it.  Both sides are squeegeed
by a special nozzle to fill the cavities left behind with conductive
adhesive (5).  The panel would be  baked at a low temperature (80
degrees C) for 15 minutes to drive off some  of the solvent and to
harden the ECA.  Additional layers of the photo-imageable epoxy would
be laminated as needed to build the desired  structure.  The layers
alternate as shown in Fig. 1 between the via and  circuit line (6).
Eventually the outer surface can be mated with a component, chip (8),
passive device, or a connector.  These are all connected to their
respective pads by pressing the leads (7) into the mushy ECA
material.

      Fig. 2 illustrates a flip chip interconnection having a Sn-cap,
or a eutectic Sn-Pb cap, or any other suitable...