Browse Prior Art Database

Lead Lock Method by Elastic/Non-Elastic Resin

IP.com Disclosure Number: IPCOM000119059D
Original Publication Date: 1997-Nov-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 77K

Publishing Venue

IBM

Related People

Yoshimura, A: AUTHOR

Abstract

Disclosed is a method describing a plastic package lead frame lock method using an elastic or non-elastic resin. This resin is applied to a lead frame inner side even though there is narrow spacing. Cured resin can protect bent lead, lead/die pad shift and tilting.

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This is the abbreviated version, containing approximately 77% of the total text.

Lead Lock Method by Elastic/Non-Elastic Resin

      Disclosed is a method describing a plastic package lead frame
lock method using an elastic or non-elastic resin.  This resin is
applied to a lead frame inner side even though there is narrow
spacing. Cured  resin can protect bent lead, lead/die pad shift and
tilting.

      Fig. 1 shows the structure of a plastic package inner
side.  The lead frame consists of (1) inner lead, (2) die pad and (3)
support bar.  The device is mounted on a die pad and device
Input/Outputs (I/Os) are far out via Au/Al wire to inner lead.
Elastic/non-elastic resins (4) are applied at inner lead and support
bar.

      Currently, the taping process is applied to lead lock but a
wide space is required for tape and process accuracy.  (The taping
process has a spacing regulation.)  If leads and support bars are
free, lead bent and die pad shift causes package electrical and
reliability problems.  However, this method does not have spacing
regulation and coplanality regulation.

      Fig. 2 shows the lead lock method using non-elastic
resin.  Resin (5) is applied on inner lead or support bar by potting
method.  Lead and support bar are locked after resin thermal cure.
Fig. 3 shows lead lock method using elastic resin.  Resin (6) is
applied by potting method same as non-elastic resin.  Potting resin
surface is leveled by (7) press unit.  This process can level up the
lead camp force and resin surface becomes smooth for lea...