Visual Die Traceability via Laser Scribing
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Solution Overview
Problem
Existing methods for tracking semiconductor dies, such as electrical die-ID, require additional silicon area, increase costs, necessitate probe testing, and can be unreliable due to failure mechanisms, limiting their use in certain devices.
Innovation Solution
A visual identification method is introduced, where unique marks encoding die coordinates, wafer, and lot information are printed on semiconductor dies using laser scribing, tip scrubbing, or inking, eliminating the need for electrical testing and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical die-ID method is used to store traceability information in NVM, then traceability information can be stored and accessed, but additional silicon area is required which increases COGS
Solution Approach 1:
The patent extracts the traceability information storage function from the electrical domain (NVM) and implements it in the mechanical/visual domain through physical markings on the die surface or package. This removes the requirement for additional silicon area while maintaining traceability capability.
Solution Approach 2:
Instead of storing data electronically in NVM, the patent creates physical copies of traceability information through visual markings (laser scribing, etching, or inking) on the die or package surface. This copying approach eliminates the need for electrical storage while preserving information accessability.
2Reliability
If electrical die-ID method is used, then traceability information can be stored, but probe testing is required which increases complexity
Solution Approach 1:
The patent removes the probe testing requirement by extracting the traceability function from the electrical testing domain and implementing it through visual marking processes that occur during standard manufacturing, eliminating the need for additional probe testing steps.
Solution Approach 2:
The patent replaces the electrical probing mechanism with mechanical/chemical marking processes (laser scribing, etching, or inking) that create visual identifiers during manufacturing, eliminating the need for electrical probe testing while maintaining traceability.
3Reliability
If non-volatile storage mechanisms are used, then traceability information can be stored, but extra mask layers are required which increases wafer manufacturing cost
Solution Approach 1:
The patent extracts the traceability function from the electrical storage domain (requiring mask layers) and implements it through post-fabrication marking processes. This extraction eliminates the need for additional mask layers during wafer manufacturing while maintaining traceability capability.
Solution Approach 2:
The patent performs traceability marking as a preliminary action during or after the manufacturing process itself (through laser scribing, etching, or inking), rather than requiring additional mask layers during fabrication. This timing choice reduces manufacturing complexity and cost.
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 method provides reliable and cost-effective die traceability without requiring additional die area or electrical access, enabling tracking even in devices without probe test insertion, and is applicable to a broader range of semiconductor processes.
Implementation Method 1
printing the unique visual identification mark on a given die may include laser scribing or tip scrubbing a plurality of bond pads or terminals of the given die
Implementation Method 2
printing the unique visual identification mark on a given die may include laser scribing or tip scrubbing a plurality of bond pads or terminals of the given die
Data Source
AI summary
Systems and methods for visual identification of semiconductor dies are described. In some embodiments, a method may include: receiving a semiconductor wafer having a plurality of dies and printing a unique visual identification mark on each of the plurality of dies. In other embodiments, a method may include receiving an electronic device comprising a die and a package surrounding at least a portion of the die and reading, from the electronic device, a unique visual identification mark that encodes a Cartesian coordinate of the die relative to a reference point on a semiconductor wafer.