Browse Prior Art Database

Pyramid for Preform Positioning

IP.com Disclosure Number: IPCOM000101361D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 3 page(s) / 52K

Publishing Venue

IBM

Related People

Cipolla, TM: AUTHOR [+2]

Abstract

Disclosed is a fixture and process for positioning adhesive preforms onto raised sealband areas of electronic device closures.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 89% of the total text.

Pyramid for Preform Positioning

       Disclosed is a fixture and process for positioning
adhesive preforms onto raised sealband areas of electronic device
closures.

      Small adhesive preforms with large adhesive/surface area ratios
are easily aligned with pins (standard procedure).  When the
adhesive/ surface area ratio becomes small, and the preform large, it
is much harder to handle. This is the case for positioning a 2 mm
wide x 51 mm square preform onto a raised sealband area of a cap
(Fig. 1).

      The preform can either be tacky (as in a pressure-sensitive
adhesive) or non-tacky (as in a B-staged epoxy).  For both versions,
a non-sticky (e.g., TEFLON*) positioning surface is preferred.

      Positioning of a square preform can be done with a
pyramid-shaped fixture (Fig. 2).  The pyramid is machined (or molded)
to fit snugly inside the raised sealband area of the cap.  The
preform then slides down the pyramid, and is automatically positioned
as it descends (I.D.  of preform = O.D. of pyramid).

      For a tacky preform, hand pressure is sufficient to keep it
positioned on the cap sealband, and the pyramid can then be removed.
Subsequent positioning of this cap with preform on a substrate and
curing steps then follow.  For a non-tacky preform, the pyramid would
be kept in place while the assembly was heated.  The preform would
then tackify/flow onto the cap sealband.  After cooling, the pyramid
could then be removed, and subsequent...