Segmented Die Flag with Interior Power Bar for Multi-Die Packages

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Solution Overview

Problem

In multi-die semiconductor packages, connecting bond pads located away from the periphery of the die flag is challenging due to the proximity of power bars, leading to longer bond wire lengths and issues like wire sag.

Innovation Solution

A lead frame with a partially segmented die flag and interior power bars between die pads allows for easier connections by providing power supply directly to interior bond pads, reducing the need for longer bond wires and eliminating peripheral power bars.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If power bars are located near the periphery of the die flag, then power supply is provided to peripheral bond pads, but bond pads located away from the periphery become difficult to connect and require longer bond wires

Engineering Contradiction:

Improveease of connectionVSAvoidbond wire length

Core Design Contradiction:

Ease of manufactureVSLength of moving object

Solution Approach 1:

The die flag is divided into multiple segments with interior spaces between them. Power bars are placed within these interior spaces, allowing bond pads located away from the periphery to connect to power bars without requiring long bond wires. This segmentation enables direct connection to interior bond pads while maintaining ease of manufacture.

Inventive Principle:

Principle #1Segmentation

2Reliability

If power bars are located near the periphery, then peripheral power supply is achieved, but interior bond pads require longer bond wires causing wire sag

Engineering Contradiction:

Improveconnection reliabilityVSAvoidwire sag

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The die flag is segmented to create interior spaces where power bars can be positioned close to interior bond pads. This reduces bond wire length and eliminates wire sag, improving connection reliability while removing the harmful effect of wire sag that occurs with peripheral power bar placement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Interior power bars act as intermediary connection points between the die flag structure and interior bond pads. This intermediary placement allows direct, short connections to interior bond pads without the need for long wires that would sag, thereby improving reliability and eliminating wire sag.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Power

If peripheral power bars are used, then power supply to peripheral areas is achieved, but package size cannot be reduced

Engineering Contradiction:

Improvepower supply capabilityVSAvoidpackage area

Core Design Contradiction:

PowerVSArea of stationary object

Solution Approach 1:

The die flag is segmented to create interior spaces that accommodate power bars within the package area rather than requiring peripheral placement. This allows power supply capability to be maintained while utilizing interior space, enabling reduction of the overall package area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Power bars are relocated from the peripheral two-dimensional boundary to the interior three-dimensional space of the die flag. This dimensional relocation allows power supply functionality to be achieved within the package footprint, enabling smaller package sizes.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS9196578B1Common pin for multi-die semiconductor package

Publication Date: 2015.11.24 CHIP PACKAGING TECH LLC

AI summary

A semiconductor package has multiple dies and an interior power bar that extends within an interior space formed within the die flag between the dies. The bond pads located on the interior side of each die are wire-bonded to the interior power bar. Some embodiments may have more than two dies and/or more than one interior power bar between each pair of adjacent dies.