Wettable lead ends on a flat-pack no-lead microelectronic package
AssigneeFreescale Semiconductor, Inc.
InventorsDwight L. Daniels, Alan J. Magnus, Pamela A. O'Brien
Life of this patent
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Abstract
Methods of manufacturing a flat-pack no-lead microelectronic package (2100) coat exposed base metal at a cut end of a lead frame of the package with solder (1001). One method coats the exposed base metal with solder when the package is in a strip (200, 300). Another method coats the exposed base metal with solder after the package is singulated. As a result, all portions of leads of the package that may receive solder during mounting of the package to a printed circuit board are solder wettable. A solder wettable lead end (504) on the package facilitates formation of a solder fillet during mounting of the package.
Claims20
A method of manufacturing a microelectronic package, comprising:
- providing a lead frame strip that includes a plurality of lead frames, the lead frame strip having saw lanes between the lead frames;
- encapsulating the lead frame strip;
- after encapsulating, removing metal of the lead frame strip along the saw lanes;
- after removing metal, applying solder to the lead frame strip;
- reflowing the solder;
- and
- singulating the lead frame strip into individual microelectronic packages after the reflowing.
A method of manufacturing a microelectronic package, comprising:
- providing a lead frame strip that includes a plurality of lead frames, the lead frame strip having saw lanes between the lead frames;
- encapsulating the lead frame strip;
- after encapsulating the lead frame strip, applying solder to the lead frame strip;
- reflowing the solder;
- removing metal of the lead frame strip and the solder along the saw lanes, thereby creating a surface of bare base metal;
- reflowing the solder;
- and
- singulating the lead frame strip into individual microelectronic packages.
A method of manufacturing a microelectronic package, comprising:
- a) providing a package that has at least one lead having a portion at a bottom of the package and a portion at a side of the package, wherein the at least one lead has a surface located in a plane approximately orthogonal to a plane of the bottom of the package;
- b) applying solder to a solder carrier;
- c) placing the package on the solder that is on the solder carrier, wherein cut lead ends of the package are aligned with the solder;
- d) placing a combination of the package, the solder and the solder carrier on a reflow carrier;
- and
- e) reflowing the solder until the surface of the at least one lead located in the plane approximately orthogonal to the plane of the bottom of the package becomes solder wettable.
Dependencies are inferred from the claim text.