Optimizing Detection Thresholds in Anomaly Prediction Models

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Solution Overview

Problem

Current anomaly detection methods in semiconductor manufacturing often fail to accurately predict component defects during pre-tests, leading to delayed identification of issues and significant production waste, as they rely solely on anomaly scores without considering explainability values, resulting in incorrect classifications and increased rejection rates.

Innovation Solution

A computer-implemented method that optimizes the detection threshold of a prediction model by incorporating anomaly scores and explainability values, such as Shapley values, to improve predictive accuracy and identify contributing parameters, allowing for early detection of process problems and reduced waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If anomaly detection relies solely on anomaly scores without explainability values, then the detection process is simple and fast, but predictive accuracy decreases and incorrect classifications increase

Engineering Contradiction:
Improvepredictive accuracyVSAvoiddetection process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines anomaly scores and explainability values into a unified detection framework. The detection threshold is optimized by integrating both types of information, allowing the system to leverage the simplicity of anomaly scores while incorporating the interpretive power of explainability values to improve predictive accuracy and reduce incorrect classifications.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent optimizes the detection threshold as a可调 parameter by analyzing the relationship between anomaly scores and explainability values. This parameter optimization enables the system to adapt to different operating conditions and maximize predictive accuracy while maintaining a balance between detection sensitivity and false positive rates.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the detection threshold is set to be highly sensitive, then more anomalies are detected, but false positive rate increases and rejection rate increases

Engineering Contradiction:
Improveanomaly detection reliabilityVSAvoidproduction waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent employs feedback mechanisms where the detection results, including both anomaly scores and explainability values, are used to continuously optimize the detection threshold. This feedback loop allows the system to learn from past decisions and adjust the threshold to minimize false positives while maintaining high anomaly detection reliability, thereby reducing unnecessary rejections and production waste.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The detection threshold is not fixed but dynamically adjusted based on the combined information from anomaly scores and explainability values. This dynamic adjustment enables the system to adapt to varying operational conditions and maintain optimal performance, balancing sensitivity and specificity to reduce both missed anomalies and false alarms.

Inventive Principle:
Principle #15Dynamics

3Loss of substance

If pre-test evaluation is performed to detect anomalies early, then production waste is reduced, but detection accuracy must be sufficient to avoid premature rejection

Engineering Contradiction:
Improveproduction wasteVSAvoiddetection accuracy
Core Design Contradiction:
Loss of substanceVSMeasurement precision

Solution Approach 1:

The patent performs preliminary anomaly detection during the pre-test evaluation phase by analyzing both anomaly scores and explainability values. This early detection capability allows the system to identify potential anomalies before they lead to defective products, enabling early intervention and reducing production waste while maintaining sufficient detection accuracy through the combined use of multiple evaluation metrics.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS20240280626A1Computer-Implemented Method for Optimizing a Detection Threshold of a Prediction Model
Publication Date: 2024.08.22 ROBERT BOSCH GMBH
  • US20240280626A1 patent drawing
  • US20240280626A1 patent drawing
  • US20240280626A1 patent drawing

AI summary

A computer-implemented method for optimizing a detection threshold of a prediction model used to determine an anomaly of a component is disclosed. The detection threshold indicates the criterion above which the prediction model classifies a component as anomalous. The method includes (i) providing the prediction model, (ii) providing a plurality of pre-test results determined for a plurality of test parameters for a plurality of components, respectively, (iii) providing a final test result for each of the plurality of components, wherein the respective final test result indicates whether the respective component has an anomaly in a final test, (iv) calculating a respective anomaly result for each of the plurality of components by evaluating the respective pre-test results by the prediction model, (v) calculating a respective explainability value for each of the plurality of test parameters for each of the plurality of components by the prediction model, and (vi) optimizing the detection threshold based on the calculated anomaly results, the calculated explainability values and the final test results provided.