Lead frames having rounded corners and related packages and methods
AssigneeMicrochip Technology Incorporated
InventorBehrooz Mehr
Life of this patent
Estimating the term…
Abstract
Lead frames for semiconductor device packages may include lead fingers proximate to a die-attach pad. A convex corner of the lead frame proximate to a geometric center of the lead frame may be rounded to include a radius of curvature of at least two times a greatest thickness of the die-attach pad. The thickness of the die-attach pad may be measured in a direction perpendicular to a major surface of the die-attach pad. A shortest distance between the die-attach pad and each one of the lead fingers having a surface area larger than an average surface area of the lead fingers may be at least two times the greatest thickness of the die-attach pad.
Claims20
A lead frame for a microelectronic device package, comprising:
- lead fingers proximate to a die-attach pad;
- wherein a convex corner of the lead frame proximate to a geometric center of the lead frame is rounded to comprise a radius of curvature of at least two times a greatest thickness of the die-attach pad, the thickness of the die-attach pad measured in a direction perpendicular to a major surface of the die-attach pad;
- and
- wherein a shortest distance between the die-attach pad and each one of the lead fingers having a surface area larger than an average surface area of the lead fingers is at least two times the greatest thickness of the die-attach pad.
A microelectronic device package, comprising:
- a lead frame comprising a die-attach pad on which a microelectronic die is supported and lead fingers electrically connected to bond pads of the microelectronic die;
- wherein a convex corner of the lead frame proximate to a geometric center of the lead frame is rounded to comprise a radius of curvature of at least two times a greatest thickness of the die-attach pad, as measured in a direction perpendicular to a major surface of the die-attach pad;
- and
- wherein a shortest distance between the die-attach pad and each one of the lead fingers having a surface area larger than an average surface area of the lead fingers is at least two times the greatest thickness of the die-attach pad.
A method of making a lead frame for a microelectronic device package, comprising:
- removing material from a strip of electrically conductive material to form a series of lead frames, each comprising a die-attach pad and lead fingers;
- forming a convex corner of each lead frame proximate to a geometric center of the lead frame to be rounded so as to comprise a radius of curvature of at least two times a greatest thickness of the die-attach pad, the thickness of the die-attach pad measured in a direction perpendicular to a major surface of the die-attach pad;
- and
- defining a shortest distance between the die-attach pad and each one of the lead fingers having a surface area larger than an average surface area of the lead fingers to be at least two times the greatest thickness of the die-attach pad.
Dependencies are inferred from the claim text.