Browse Prior Art Database

TAB OLB Frame

IP.com Disclosure Number: IPCOM000109149D
Original Publication Date: 1992-Jul-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 56K

Publishing Venue

IBM

Related People

Cohrs, DA: AUTHOR [+5]

Abstract

The TAB frames that are readily available consist of .001 inch thick metal leads on an insulating film having twice that thickness. Lead width and spacing is continually shrinking while the total number of leads continues to increase. When a frame is excised and formed it becomes an extremely fragile and flexible component that must be held in a planar mode to allow alignment to a mating footprint on a circuit board. Each of the TAB parts will need a corresponding thermode to hold and affect solder reflow. The thermodes can be very expensive and also can require an extensive lead time from conception to actual debug. For early hardware the required thermode can be replaced with the invention that is described here.

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TAB OLB Frame

      The TAB frames that are readily available consist of .001 inch
thick metal leads on an insulating film having twice that thickness.
Lead width and spacing is continually shrinking while the total
number of leads continues to increase.  When a frame is excised and
formed it becomes an extremely fragile and flexible component that
must be held in a planar mode to allow alignment to a mating
footprint on a circuit board.  Each of the TAB parts will need a
corresponding thermode to hold and affect solder reflow.  The
thermodes can be very expensive and also can require an extensive
lead time from conception to actual debug.  For early hardware the
required thermode can be replaced with the invention that is
described here.

      The engineering drawing shows the tool in cross section with a
TAB frame resting on solder coated pads of a printed circuit board.
The critical component of the tool is the glass placement frame.  A
piece of optically flat glass that is .125 inches thick is machined
to remove material allowing the TAB frame to fit through the hole
with the heel area in close proximity to the glass.  To accurately
machine the glass and maintain visual acuity, ultrasonic machining
was necessary.  While the TAB frame shown in the photograph is a
rectangle, ultrasonic machining will allow fine and intricate cut
outs to be made.  The vacuum tube is held in a vertical position by
the bridge and is free to move up and down.  Initially the...