Dual-Contact IC Package Leads for High-Density Stacking

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Solution Overview

Problem

Conventional integrated circuit packages face challenges in miniaturization, increased packaging density, higher performance, and lower cost, particularly in portable devices, with limitations in testing individual dies and flexible stacking options due to limited I/O capabilities and assembly inefficiencies.

Innovation Solution

The integrated circuit package system features leads with both top and bottom contact portions, allowing for dual connectivity by partially exposing these contacts within the package encapsulation, enabling flexible stacking and improved assembly processes while maintaining low manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional multi-chip modules are used, then packaging density is improved, but assembly yield deteriorates due to inability to test individual dies before assembly

Engineering Contradiction:

Improvepackaging densityVSAvoidassembly yield

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent enables preliminary testing of individual integrated circuit dies before they are assembled into multi-chip modules. By providing test access structures that allow electrical connection to die bond pads prior to final assembly, the system permits identification and removal of defective dies, ensuring only known-good-dies are assembled into the final product.

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If leaded packages are used for stacking, then assembly is simplified, but I/O capability deteriorates due to limited input and output connections

Engineering Contradiction:

Improveassembly simplicityVSAvoidI/O capability

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent transitions from traditional lateral I/O connections in leaded packages to vertical I/O connections through the package structure. Test access structures and connection elements are positioned to provide electrical connections in the vertical dimension, enabling multiple I/O connections without increasing package footprint, thus supporting higher I/O counts for 3D stacking configurations.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Volume of moving object

If package size is reduced for miniaturization, then portability is improved, but manufacturing precision requirements worsen

Engineering Contradiction:

Improvepackage sizeVSAvoidalignment precision

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent employs nested structures where connection elements, test access structures, and electrical interconnects are integrated within the package encapsulation volume. Leads and contact structures are positioned within the package body rather than extending externally, reducing overall package dimensions while maintaining functional capabilities through compact, nested arrangements of electrical connection elements.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS7977782B2Integrated circuit package system with dual connectivity

Publication Date: 2011.07.12 STATS CHIPPAC LTD

AI summary

An integrated circuit package system includes: forming a lead having a both top contact portion and a bottom contact portion; connecting an integrated circuit die and the lead; and forming a package encapsulation, having a top side and a bottom side, over the integrated circuit die. The forming the package encapsulation includes partially exposing the top contact portion at the top side, and partially exposing the bottom contact portion along the bottom side with the bottom contact portion extending beyond a nonhorizontal portion of the package encapsulation.