Stepped Die Paddle for Multi-Chip Package Adhesive Control

Solution Overview

Problem

Existing single-chip packages have limited functionality and are costly and time-consuming to re-design for increased functionality, while multiple-chip packages face challenges in preventing electrical shorts and chip misalignment due to adhesive flow between chips.

Innovation Solution

A lead frame assembly with die paddles featuring recessed landing areas and steps or grooves to prevent adhesive flow between semiconductor chips, ensuring secure bonding and shared common ground for reduced ground noise, particularly beneficial for analog and high-frequency circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple chips are mounted on a single die paddle to increase functionality, then the functionality and versatility of the package is improved, but the risk of electrical shorts and chip misalignment due to adhesive flow increases

Engineering Contradiction:

ImprovefunctionalityVSAvoidelectrical short prevention

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The die paddle surface is segmented into multiple landing areas at different heights, creating physical separation between chips. This segmentation prevents adhesive applied to one chip from flowing to adjacent chips, thereby preventing electrical shorts while maintaining multiple chip functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from a two-dimensional flat die paddle surface to a three-dimensional stepped surface with multiple height levels. This dimensional change creates physical barriers that contain adhesive within specific chip mounting zones, preventing cross-contamination between chips while allowing multiple chips to coexist on the same paddle.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If multiple chips are mounted on a single die paddle to increase functionality, then the versatility of the package is improved, but the precision of chip alignment and bonding is worsened due to adhesive flow

Engineering Contradiction:

ImprovefunctionalityVSAvoidchip alignment

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The die paddle surface is segmented into multiple landing areas at different heights, creating physical separation between chips. This segmentation prevents adhesive applied to one chip from flowing to adjacent chips, thereby preventing electrical shorts while maintaining multiple chip functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from a two-dimensional flat die paddle surface to a three-dimensional stepped surface with multiple height levels. This dimensional change creates physical barriers that contain adhesive within specific chip mounting zones, preventing cross-contamination between chips while allowing multiple chips to coexist on the same paddle.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If a flat die paddle surface is used for mounting multiple chips, then the ease of manufacture is improved, but the ground noise increases due to lack of common ground proximity

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidground noise

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The invention transitions from a two-dimensional flat die paddle surface to a three-dimensional stepped surface with multiple height levels. This dimensional change creates physical barriers that contain adhesive within specific chip mounting zones, preventing cross-contamination between chips while allowing multiple chips to coexist on the same paddle.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively prevents electrical shorts and misalignment, allowing for the integration of different semiconductor chips with varying frequencies and technologies while maintaining low ground noise, enhancing the functionality and reliability of multiple-chip packages.

Implementation Method 1

The chip adhesive comprises a material that requires heating to activate its bonding property

Methodology Applied

Scientific EffectHeating to activate bonding: Heating

Data Source

PatentUS7982293B2Multi-chip package including die paddle with steps

Publication Date: 2011.07.19 INFINEON TECHNOLOGIES AG

AI summary

A lead frame assembly includes at least one die paddle. The die paddle includes a first landing area for receiving a first semiconductor chip and a second landing area for receiving a second semiconductor chip. One or more steps are provided between the first landing area and the second landing area.