Integrated Circuit Package Removal for Planar Die Surfaces
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Solution Overview
Problem
Conventional methods for removing packaging from integrated circuit dies are time-consuming, customized for each die, and often leave behind wiring and ball bonds, resulting in a non-planar surface and increased cross-sectional area, which can obscure inspection and cause contamination.
Innovation Solution
A method to completely remove the encapsulating package from integrated circuit dies while protecting the top surface with a portion of the package, allowing for batch processing and achieving a planar, undamaged surface suitable for bonding, using etching and mechanical lapping to remove wires and ball bonds, and then removing the remaining package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to remove packaging from integrated circuit dies, then the die is protected from damage during removal, but the top surface is obscured by remaining wiring and ball bonds, preventing visual inspection
Solution Approach 1:
The patent applies preliminary action by removing the wiring and ball bonds from the top surface of the die before completing the package removal process. This ensures that when the package is fully removed, the top surface is already clear of obstructions, enabling immediate visual inspection without requiring additional cleanup steps.
Solution Approach 2:
The package removal process is segmented into distinct phases: first removing the top portion of the package while the die remains protected by the bottom portion, then removing the wiring and ball bonds, and finally removing the bottom portion of the package. This segmentation allows for controlled exposure and inspection at different stages.
2Reliability
If conventional methods are used to remove packaging, then the die is protected during removal, but portions of the package must be preserved over the top surface to maintain planarity, increasing the final cross-sectional area
Solution Approach 1:
The patent removes wiring and ball bonds from the top surface before completing package removal, eliminating the need to preserve package material for planarity. This preliminary cleaning action allows the final cross-sectional area to match the actual die area without additional package material.
Solution Approach 2:
Instead of preserving package material to achieve planarity (conventional approach), the patent inverts the approach by removing all package material and achieving planarity through selective removal of wiring and ball bonds, then using the remaining package structure as a mask during the process.
3Reliability
If conventional customized processes are used for each die, then the die receives tailored protection and handling, but throughput is limited to one die at a time, reducing productivity
Solution Approach 1:
The patent employs a universal package removal process that can handle multiple different die types simultaneously using the same equipment and methodology. The process uses the package structure itself as a protective mask, making the approach applicable to various die configurations without requiring customization for each die type.
Solution Approach 2:
The patent combines multiple package removal operations into a single batch processing step where multiple dies are processed simultaneously in one reactor vessel. This merging of operations maintains customized protection for each die while achieving high throughput through parallel processing.
4Reliability
If conventional methods are used to remove packaging, then the die is protected during removal, but remaining package portions can flake off during subsequent processing and contaminate equipment
Solution Approach 1:
The patent performs preliminary removal of all package material, wiring, and ball bonds before the die enters subsequent processing steps. This ensures no package portions remain to flake off and contaminate equipment during later manufacturing operations.
Solution Approach 2:
The patent extracts and removes all potential contamination sources (package material, wiring, ball bonds) from the die structure in a systematic sequence, leaving only the clean die ready for subsequent processing without embedded contaminants.
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
This approach minimizes the cross-sectional area of the die, allows for visual inspection, and maintains the die's electrical characteristics, enabling efficient batch processing and integration into multi-chip modules with reduced size and contamination risks.
Implementation Method 1
A first portion of the package disposed over a top surface of the integrated circuit die and at least a portion of each of the plurality of wires are removed. A remaining portion of each of the plurality of wires and at least a portion of each ball bond are also removed
Implementation Method 2
the top surface of the integrated circuit die may be left suitably planar for bonding to other electronic devices or higher level system packaging
Data Source
AI summary
Packaging is substantially entirely removed from an integrated circuit die. The method allows the batch processing of several integrated circuit dies, such that packaging is removed from each die approximately simultaneously.