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Circuit Rework with Embedded Wire Tube

IP.com Disclosure Number: IPCOM000123042D
Original Publication Date: 1998-Apr-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 75K

Publishing Venue

IBM

Related People

Hasegawa, N: AUTHOR

Abstract

Disclosed is a rework method for Blind Via Hole and Interstitial Via Hole on Printed Wiring Board (PWB) which is composed from a glass fiber, epoxy resin and photo sensitive dielectric resin. This method can rework defective Blind Via Holes and Interstitial Via Holes on PWB.

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Circuit Rework with Embedded Wire Tube

        Disclosed is a rework method for Blind Via Hole and
Interstitial Via Hole on Printed Wiring Board (PWB) which is composed
from a glass fiber, epoxy resin and photo sensitive dielectric
resin.  This method can rework defective Blind Via Holes and
Interstitial Via Holes on PWB.

        Figure 1 shows the Blind Via Hole and figure 2 shows the
Interstitial Via Hole on PWB before rework operation.  Firstly,
defective copper/materials at the Blind Via Hole and/or the
Interstitial Via Hole  on PWB shall be mechanically removed by
drilling as shown in figure 3 and figure 4.  Secondly, eutectic
solder sheets or solder balls shall be  placed into the Via Hole as
illustrated in figure 5 and figure 6. For  rework of non-functional
area, the eutectic solder sheets or balls shall  not be applied.
Thirdly, either of tubes in figure 7 and figure 8 shall  be inserted
into the Via Holes.  For functional Via Hole rework, the tube with
embedded copper wire in figure 7 shall be used.  The inserted
embedded wire tubes shall be heated by an appropriate heater or hot
air for soldering connection.  Then, epoxy resin shall be poured
along with the edge of embedded wire tube and cured at an appropriate
temperature.  For non-functional Via Hole rework, the tube without
embedded copper wire in figure no.8 shall be used.  After setting the
non-embedded wire tube into the Via Hole, epoxy resin shall be poured
along with the edge of...