Universal surface-mount semiconductor package
AssigneeAdventive IPBank
InventorsRichard K. Williams, Keng Hung Lin
Life of this patent
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Abstract
In the fabrication of semiconductor packages, a leadframe is formed by masking and etching a metal sheet from both sides, and a plastic block is formed over a plurality of dice attached to die pads in the leadframe. A laser beam is used to form individual plastic capsules for each package, and a second laser beam is used to singulate the packages by severing the metal conductors, tie bars and rails between the packages. A wide variety of different types of packages, from gull-wing footed packages to leadless packages, with either exposed or isolated die pads, may be fabricated merely by varying the patterns of the openings in the mask layers and the width of the plastic trenches created by the first laser beam.
Claims22
A method of fabricating a semiconductor package by using a leadframe, the leadframe comprising a plurality of die pads, a first semiconductor die being mounted on a first die pad, a second semiconductor die being mounted on a second die pad, the method comprising:
- forming a plastic block, the plastic block covering said first and second semiconductor dice;
- and
- directing a first laser beam against the plastic block and moving said first laser beam through a series of parallel adjacent scans, each of said series of scans removing a slice of said plastic block, so as to form a first plastic capsule and a second plastic capsule, said first plastic capsule covering said first semiconductor die, said second plastic capsule covering said second semiconductor die.
A method of fabricating a semiconductor package by using a leadframe, the leadframe comprising a plurality of die pads, a first semiconductor die being mounted on a first die pad, a second semiconductor die being mounted on a second die pad, the method comprising:
- forming the leadframe from a metal sheet, said method of forming the leadframe comprising partially etching a backside of said metal sheet in a first location so as to form a cantilever segment of a lead;
- forming, a plastic block, the plastic block covering said first and second semiconductor dice;
- and
- directing a first laser beam against the plastic block so as to remove a portion of said plastic block and thereby form a first plastic capsule and a second plastic capsule, said first plastic capsule covering said first semiconductor die, said second plastic capsule covering said second semiconductor die.
Dependencies are inferred from the claim text.