Circuit Board Inspection via Near-Infrared Imaging and Machine Learning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current inspection methods for circuit board assemblies are inadequate for quickly and efficiently detecting anomalies, especially in internal metal interconnects, and often require time-consuming x-ray tomography or are limited to surface-level visible light inspections.

Innovation Solution

The use of near-infrared (NIR) imaging combined with machine learning models to analyze NIR images of circuit boards, enabling the detection of anomalous features and reducing the need for x-ray imaging by capturing internal metal interconnects and chip components not visible in visible light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If visible light inspection is used, then inspection speed is fast and large number of boards can be inspected, but internal metal interconnects and chip components cannot be detected

Engineering Contradiction:
Improveinspection speedVSAvoiddetection of internal features
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces near-infrared radiation as an intermediary medium to penetrate the circuit board and reveal internal metal interconnects. The NIR imaging system acts as a mediator between the inspector and the hidden internal features, allowing detection without physical contact or disassembly of the board.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/x-ray based inspection methods with optical near-infrared imaging. Instead of using heavy x-ray equipment or physical sectioning of boards, the system uses NIR light to achieve internal feature detection, substituting a simpler optical system for complex mechanical or radiological systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If x-ray tomography is used, then all layers and solder joints can be imaged, but inspection is time-consuming and limited to few samples

Engineering Contradiction:
Improveimaging of internal layersVSAvoidinspection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent substitutes x-ray tomography with near-infrared imaging to achieve internal feature detection. The NIR system captures images in real-time or near real-time, eliminating the time-consuming nature of x-ray tomography while maintaining the capability to image internal layers and solder joints.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates optical copies (NIR images) of the internal circuit board structure without requiring physical sectioning or complex tomographic reconstruction. The NIR imaging system produces direct visual copies of internal features, replacing the need for time-intensive x-ray tomographic processing.

Inventive Principle:
Principle #26Copying

3Measurement precision

If x-ray imaging is used, then internal features can be detected, but cost and acquisition time are high

Engineering Contradiction:
Improvedetection of internal featuresVSAvoidinspection cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent employs inexpensive near-infrared imaging equipment instead of costly x-ray imaging systems. The NIR cameras and light sources are significantly cheaper than x-ray equipment, making the inspection process more cost-effective while maintaining the ability to detect internal features.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent replaces expensive x-ray imaging infrastructure with affordable near-infrared optical systems. This substitution dramatically reduces both equipment costs and operational expenses while achieving the same functional goal of internal feature detection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 allows for faster and more cost-effective inspection of circuit boards, enhancing the detection of assembly errors, malicious components, and intellectual property infringement by visualizing internal features with high contrast and accuracy.

Implementation Method 1

shining a near-infrared (NIR) light on the board and capturing an image of the board with a camera

Methodology Applied
Scientific EffectNear-infrared radiation penetration: Infrared Radiation

Data Source

PatentUS11715195B2Machine learning-based circuit board inspection
Publication Date: 2023.08.01 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US11715195B2 patent drawing
  • US11715195B2 patent drawing
  • US11715195B2 patent drawing

AI summary

Circuit board inspection by receiving a near infrared (NIR) image of at least a portion of a circuit board, analyzing the NIR image using a machine learning model, and detecting anomalous circuit board portions according to the analysis.