Pre-cut plating lines on lead frames and laminate substrates for saw singulation
AssigneeTexas Instruments Incorporated
InventorsErma Gallenero Gardose, Liya Flores Aquino
Life of this patent
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Abstract
Described herein is a technology or a method for pre-fabricating pre-cut plating lines on a lead frame with use of a pre-cut etchback process to minimize burrs during a semiconductor package singulation process. A package includes: a chip, and a lead frame that mounts the chip. The lead frame further includes pre-fabricated pre-cut plating lines that are etched back on the lead frame to form an opening slot on a periphery of the lead frame. The opening slot allows a saw blade to cut through a prepreg material, without touching or cutting a conductive material of the lead frame.
Claims17
A method of forming a semiconductor package comprising:
- an etchback process on a lead frame that comprises:
- forming a stack including a prepreg material, a conductive layer, and a solder mask on a lead frame;
- exposing a top surface of the prepreg material;
- and
- creating pre-cut plating lines;
- mounting a chip on the lead frame;
- making electrical connections from the chip to leads on the lead frame;
- and
- cutting through the pre-cut plating lines, wherein an edge of the semiconductor package after cutting, includes a portion of the prepreg material exposed in a slot between an edge of the lead and the edge of the semiconductor package.
A method of forming a semiconductor package comprising:
- an etchback process on a lead frame that comprises:
- forming a stack of prepreg material, a conductive layer, and a solder mask;
- patterning a masking layer on the stack;
- forming a mask opening on the masking layer;
- etching back the solder mask and the conductive layer within the formed mask opening to expose a top surface of the prepreg material;
- and
- dissolving the masking layer, thereby creating pre-cut plating lines;
- mounting a chip on the lead frame;
- making electrical connections from the chip to leads on the lead frame;
- and
- cutting through the etched back pre-fabricated pre-cut plating lines.
Dependencies are inferred from the claim text.