Browse Prior Art Database

J-lead TAB

IP.com Disclosure Number: IPCOM000109475D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 1 page(s) / 34K

Publishing Venue

IBM

Related People

Hernandez, B: AUTHOR [+8]

Abstract

Solder joint integrity is greatly enhanced by solder fillets from a solder pad to a vertical or near vertical portion of a component lead. In TAB this area is called the heel fillet area and in destructive testing of soldered TAB leads a beam break is a desired mode of failure. That break consistently occurs outside of the fillet area. The only other area for fillet formation on TAB leads is at the toe and on either side of the beam in contact with the solder pad. As most TAB leads are less than .0015 inches thick the fillet formed at these points is negligible.

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J-lead TAB

      Solder joint integrity is greatly enhanced by solder fillets
from a solder pad to a vertical or near vertical portion of a
component lead.  In TAB this area is called the heel fillet area and
in destructive testing of soldered TAB leads a beam break is a
desired mode of failure.  That break consistently occurs outside of
the fillet area.  The only other area for fillet formation on TAB
leads is at the toe and on either side of the beam in contact with
the solder pad.  As most TAB leads are less than .0015 inches thick
the fillet formed at these points is negligible.

      The J-lead form can be imparted to both inner and outer leads.
By incorporating the forming operation prior to excising, the
integrity of the lead planarity can be assured.  Added benefits from
this shape include the ability to inspect visually without contacting
the beam and the J-lead shape allows some preloading to insure
lead/solder pad contact.

      Disclosed anonymously.