IC Package Stacking Material for Yield and Footprint

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Solution Overview

Problem

Integrated circuit package yields and reliability are compromised due to the fragility of small electrical connections during manufacturing and handling, with existing solutions failing to adequately address the need for improved die attach and footprint in densely stacked packages.

Innovation Solution

A substrate-based integrated circuit package system that includes a base assembled package and a top package stacked with organic material serving as stand-off and insulation, eliminating damage to delicate connectors and reducing the need for additional processing steps like second die attach and post cure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If integrated circuits are stacked to reduce footprint, then dimensional density is improved, but manufacturing yield and reliability deteriorate due to damage to fragile electrical connections

Engineering Contradiction:

Improvedimensional footprintVSAvoidmanufacturing yield

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent applies a protective coating material (such as epoxy, polyimide, or silicone) over the electrical connections before the stacking process. This protective layer acts as a cushion that absorbs mechanical stresses and prevents damage to the fragile connections during handling and manufacturing, thereby maintaining high manufacturing yield while enabling compact stacked configurations.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent employs composite material structures combining different protective coating materials with specific properties (flexibility, adhesion, mechanical strength) to create a multi-layer protective system. This composite approach allows the protective layer to simultaneously protect against mechanical damage, provide thermal management, and maintain electrical isolation, resolving the contradiction between compact stacking and reliability.

Inventive Principle:

Principle #40Composite materials

2Reliability

If protective packaging is applied to protect fragile circuits, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improveprotection of electrical connectionsVSAvoidpackaging structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The protective coating material performs multiple functions simultaneously: it protects electrical connections from mechanical damage, provides thermal management pathways, ensures electrical isolation, and facilitates the stacking process. This multi-functionality reduces the need for separate protective components, thereby maintaining reliability while minimizing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the protective packaging function with the interconnect structure by integrating the protective coating directly into the stacking assembly process. This consolidation eliminates the need for separate protective housings or enclosures, reducing overall device complexity while maintaining comprehensive protection of fragile electrical connections.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS8026582B2Integrated circuit package system with internal stacking module adhesive

Publication Date: 2011.09.27 STATS CHIPPAC MANAGEMENT PTE LTD

AI summary

An integrated circuit package system comprising: providing a substrate; forming a base assembled package over the substrate; forming a top package over the base assemble package; and applying a top package stacking material for stand-off or insulation to the base assembled package and the top package.