SEMICONDUCTOR DEVICE, LEAD FRAME, AND METHOD OF MANUFACTURING LEAD FRAME
Provided is a lead frame that may prevent resin cracks from occurring in a semiconductor device. When a lead frame ( 3 ) is formed through press working, punching burrs ( 3 d ) are formed on tips of inner leads ( 3 b ) to serve as anchors with respect to a resin ( 5 ). The punching burrs ( 3 d ) are acute-angled projecting portions formed in a direction of a bottom surface of the semiconductor device.
1 . A lead frame, comprising:
a tab on which a semiconductor chip is to be mounted;
inner leads arranged around the tab;
outer leads extending from the inner leads; and
punching burrs comprising acute-angled projecting portions formed in a downward direction on tips of the inner leads.
2 . A lead frame according to claim 1 , wherein the acute-angled projecting portions are configured to protrude from a surface opposing a conductive-wire connection surface of the inner leads, and an outer surface of the acute-angled projecting portions form an edge surface of the tips the inner leads.
3 . A lead frame according to claim 1 , wherein the acute-angled projecting portions have a length that is half a thickness of the outer leads or shorter.
4 . A method of manufacturing a lead frame, comprising:
preparing a metallic plate formed of a predetermined material; and
punching, through use of a mold, the metallic plate into a lead frame comprising a tab and leads, and forming acute-angled projecting portions in a downward direction, which have a predetermined angle on end portions of inner leads of the lead frame.
5 . A semiconductor device, comprising:
a semiconductor chip;
a tab on which the semiconductor chip is mounted;
inner leads arranged around the tab;
outer leads extending from the inner leads;
punching burrs comprising acute-angled projecting portions formed in a downward direction on tips of the inner leads;
conductive wires configured to electrically connect pads formed on a front surface of the semiconductor chip, and the inner leads to each other; and
a resin for encapsulating the semiconductor chip, the inner leads, and the conductive wires.