Die-Let Protection Circuit for Post-Dicing Test Line Isolation

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Solution Overview

Problem

During the dicing operation of semiconductor wafers, electrical connections between test circuits and integrated circuit product die-lets are physically cut, but may not be fully isolated, leading to potential electrical leakage that can interfere with the correct operation of the die-lets.

Innovation Solution

A protection circuit is implemented on the die-lets, comprising a signal line, a logic block, and a resistive element, which monitors the signal line for changes during the dicing operation and generates an isolation signal to disconnect the input test circuits from the cut ends of the signal lines, ensuring electrical isolation and preventing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the dicing operation physically cuts the electrical connections between test circuit and die-lets, then the die-lets are separated for individual operation, but electrical leakage at the cut lines may interfere with correct operation of the die-lets

Engineering Contradiction:

Improveseparation of die-letsVSAvoidelectrical isolation

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The protection circuit is activated before the dicing operation to establish isolation signals in advance. The circuit monitors the integrity of signal lines and preemptively configures isolation mechanisms before the physical cut occurs, ensuring that when the dicing operation separates the die-lets, the electrical isolation is already in place to prevent leakage interference.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The protection circuit acts as an intermediary between the test circuit and the die-let circuits. It includes intermediate isolation elements that can be activated to break the electrical connection path, serving as a mediator that allows controlled separation while maintaining electrical isolation. The circuit translates the physical separation event into an electrical isolation state through intermediate signaling mechanisms.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the cut lines are not totally isolated electrically, then the dicing operation can be completed, but electrical leakage at the cut line may interfere with the correct operation of the die-let

Engineering Contradiction:

Improvedicing operation completionVSAvoidelectrical leakage

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The protection circuit converts the potentially harmful effect of incomplete electrical isolation at cut lines into a beneficial isolation mechanism. By monitoring the signal line status and detecting the dicing event, the circuit activates isolation signals that transform the leakage-prone cut lines into electrically isolated boundaries, turning the manufacturing reality of incomplete cuts into a controlled isolation feature.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The protection circuit applies preliminary anti-action by establishing isolation signals before electrical leakage can occur. The circuit detects the integrity status of signal lines and preemptively activates isolation mechanisms that counteract the potential harmful effects of incomplete cuts, preventing electrical leakage from interfering with die-let operation rather than attempting to correct it afterward.

Inventive Principle:

Principle #9Preliminary anti-action

3Reliability

If a protection circuit is implemented to isolate internal circuits from external cut lines, then electrical interference is prevented, but the device complexity increases

Engineering Contradiction:

Improveelectrical isolationVSAvoidprotection circuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The protection circuit is designed with multi-functionality to reduce overall device complexity. The same isolation signals and circuit elements serve multiple purposes: they detect the integrity of signal lines, monitor the dicing operation status, activate isolation mechanisms, and maintain proper electrical boundaries. This universal approach allows a single protection circuit structure to handle multiple isolation requirements across different signal lines simultaneously.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The protection circuit merges multiple isolation functions into a unified circuit structure. Instead of implementing separate isolation mechanisms for each signal line or function, the patent combines the monitoring, detection, and isolation activation functions into an integrated protection circuit that operates across multiple signal lines using shared circuit elements and common isolation signals, thereby reducing overall device complexity.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS20180096987A1Protection Circuit for Integrated Circuit Die-Let After Scribe Cut

Publication Date: 2018.04.05 SYNOPSYS INC

AI summary

A protection circuit for an integrated circuit product die or die-let (die-let) is responsive to whether the die-let has undergone a dicing operation or not. A test circuit on the die-let's semiconductor wafer can test and/or configure the die-let. After the dicing operation, the protection circuit generates a signal to isolate the cut input lines from the test circuit to prevent any interference with the normal operation of the integrated circuit product die-let.