Dap ground bond enhancement

Abstract

A variety of semiconductor package arrangements and packaging methods are described that improve the reliability of bonding wires that down bond a die to a die attach pad. In one aspect, selected portions of the top surface of a lead frame (which may be in panel form) are plated (e.g., silver plated) to facilitate wire bonding. The plating covers some, but not all of a die attach surface of the die attach pad. In some preferred embodiments, the plating on the die attach pad is arranged as a peripheral ring that surrounds an unplated central region of the die support surface. In other embodiments, the plating on the die attach pad takes the form of bars or other geometric patterns that do not fully cover the die support surface.; Unplated portions of the die support surface are roughened to improve the adherence of the die to the die attach pad, thereby reducing the probability of die attach pad delamination and the associated risks to down bonded bonding wires. The described lead frames may be used in a variety of packages. Most commonly, a die is attached to the die support surface of the die attach pad and electrically connected to the lead frame leads by wire bonding as appropriate. At least one of the die's bond pads (typically the ground bond pad(s)) is down bonded to the die attach pad. The die, the bonding wires and at least portions of the lead frame are then typically encapsulated with a plastic encapsulant material while leaving a contact surface of the die attach pad exposed to facilitate electrically coupling the die attach pad to an external device.

Description

technical field [0001] The present invention generally relates to lead frame based semiconductor packages. More particularly, this disclosure describes arrangements that enhance the reliability of bond wires electrically coupled to die attach pads. Background technique [0002] Many semiconductor packages utilize metal lead frames to provide electrical interconnection between the integrated circuit die and external components. I / O pads on the die (often referred to as "bond pads") are typically electrically connected to corresponding leads in a lead frame using extremely small wires called "bond wires." Typically, the die, bond wires, and portions of the leadframe are encapsulated in plastic for protection, while portions of the leadframe are exposed to facilitate electrical connection to external devices. [0003] Many leadframes include die attach pads (DAPs) that support the die during assembly of the package. In some packages, the die attach pads are exposed on a surf...

AI Technical Summary

Problems solved by technology

When die attach pad delamination occurs, the movement of the die relative to the die attach pad can sometimes detach or otherwise break the down bond wire from the die attach pad

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