US 5,293,064 A · Lead frame and method of manufacturing a semiconductor device

Abstract

A lead frame for manufacturing a semiconductor device has at least one set of substantially parallel leads having inner ends for connection to a semiconductor chip, outer ends for external connection and central portions therebetween and an outer tiebar interconnecting the outer ends and having an elongated guide hole therein, the longer dimension of the guide hole being parallel to the leads. A lead bending die has a locating pin respectively corresponding to and received in sliding engagement in each guide hole. The die maintains a center portion of them lead frame in a first plane and, with each locating pin remaining in sliding engagement within the respective, elongated guide hole, bends the central portions of the leads thereby to dispose the respective outer ends of the leads in a second plane, displaced from the first plane. The outer tiebar and the sliding engagement of the locating pin in the guide hole serve to prevent undesirable deformation of the leads as a result of the bending operation. The central surface portion of the die further includes a recess for receiving at least a part of a package which seals a semiconductor chip therewithin. The lead frame may include plural sets of substantially parallel leads with corresponding outer tiebars and associated guide holes extending from respective, plural edges of the package.

Claims16

Dependent claims

A lead frame comprising:

at least one set of substantially parallel leads, the leads respectively having inner ends for connection to a semiconductor chip, outer ends for external connection, and central portions therebetween;
each set of substantially parallel leads having a corresponding outer tiebar interconnecting the respective outer ends of the leads;
and
each outer tiebar having at least one guide hole therein, of an elongated configuration and with the longer dimension thereof parallel to the leads, for engaging a locating pin during bending of the leads from a substantially planar initial configuration to a final configuration in which the respective leads of each set are bent in the corresponding central portions thereof thereby to dispose the respective outer ends of the leads of each set in a second plane, different from the first plane, the corresponding outer tiebar maintaining the interconnection of the outer ends of the leads of the at least one set in the initial configuration and during bending thereof into the final configuration and being severable therefrom after bending into the final configuration.

1 more element

A semiconductor device comprising:

a semiconductor chip;
a lead frame comprising:
at least one set of substantially parallel leads, the leads respectively having inner ends for connection to a semiconductor chip, outer ends for external connection, and central portions therebetween,
each set of substantially parallel leads having a corresponding outer tiebar interconnecting the respective outer ends of the leads, and
each outer tiebar having at least one guide hole therein, of an elongated configuration and with the longer dimension thereof parallel to the leads, for engaging a locating pin during bending of the leads from a substantially planar initial configuration to a final configuration in which the respective leads of each set are bent in the corresponding central portions thereof thereby to dispose the respective outer ends of the leads of each set in a second plane, different from the first plane, the corresponding outer tiebar maintaining the interconnection of the outer ends of the leads of the at least one set in the initial configuration thereof and during bending thereof and being severable therefrom after bending thereof into the final configuration thereof;
and
a package sealing the semiconductor chip therewithin and having at least one side, the at least one set of leads being respectively associated with and protruding from the at least one side of the package with the leads extending in substantially perpendicular relationship relatively to, and with the outer tiebar extending in substantially parallel relationship relatively to, the respectively associated at least one side of the package.

4 more elements

A lead frame comprising;

at least one set of substantially parallel connector and dummy leads each set including first and second outermost connector leads, a plurality of further connector leads disposed at intermediate positions between the first and second outermost connector leads and first and second dummy leads respectively disposed in spaced relationship, outwardly of and adjacent to the first and second outermost connector leads, the connector leads respectively having inner ends for connection to a semiconductor chip, outer ends for external connection and central portions extending therebetween and the dummy leads having first and second portions respectively corresponding to the central portions and the outer ends of the connector leads;
each set of substantially parallel connector leads and dummy leads having a corresponding outer tiebar interconnecting the respective outer ends of the corresponding connector leads and the second portions of the corresponding first and second dummy leads;
and
each outer tiebar having at least one guide hole therein, of an elongated configuration and with the longer dimension thereof parallel to the connector leads, for engaging a locating pin during bending of the connector leads from a substantially planar initial configuration to a final configuration in which the corresponding connector leads of each set are bent in the respective central portions thereof thereby to dispose the respective outer ends of the corresponding connector leads of each set in a second plane, different from the first plane, the corresponding outer tiebar maintaining the interconnection of the outer ends of the corresponding connector and dummy leads of the at least one set in the initial configuration thereof and during bending thereof and being severable therefrom after bending thereof into the final configuration thereof.