Inspection Unit Fault Verification with Fiducial Reference Bodies
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate inspection systems fail to detect deteriorating inspection performance until a user checks the inspection result, leading to improperly inspected PCBs being manufactured as products.
Innovation Solution
A method for verifying the accuracy and functionality of inspection units using fiducial markers, verification targets, and a reflector to ensure precise positioning and lighting, with a controller for automatic fault detection and calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual inspection result checking is used, then user can detect inspection issues, but inspection performance deteriorates before detection and PCBs are manufactured as products
Solution Approach 1:
The system performs preliminary verification actions by placing fiducial markers on the PCB before main inspection, and uses these markers to verify inspection unit accuracy and detect faults early in the inspection process, preventing deterioration of inspection performance
Solution Approach 2:
The system implements continuous feedback by verifying inspection unit accuracy using fiducial markers during inspection, automatically detecting when inspection performance deteriorates, and triggering recalibration to maintain reliable inspection
2Measurement precision
If automatic verification using fiducial markers is implemented, then inspection unit accuracy can be continuously monitored, but device complexity increases
Solution Approach 1:
Fiducial markers serve as intermediary objects between the inspection unit and the PCB, enabling verification of inspection unit accuracy without requiring complex verification equipment. The markers are simple reference features that the inspection unit can detect to determine its own positioning accuracy
Solution Approach 2:
The verification reference body contains copies of fiducial markers that match the inspection targets on PCBs. These marker copies allow the inspection unit to test its accuracy on known reference patterns without needing complex verification apparatus
3Reliability
If calibration target mounting is required for verification, then inspection unit can be calibrated, but productivity decreases due to manual intervention
Solution Approach 1:
The inspection unit performs self-verification by detecting fiducial markers on the PCB and comparing their positions with expected locations. The system automatically determines whether verification passes or fails and triggers recalibration only when needed, eliminating manual intervention and maintaining high productivity
Solution Approach 2:
The system performs verification periodically during the inspection process using fiducial markers already present on PCBs, rather than requiring separate manual calibration steps. This periodic verification maintains inspection reliability without significantly reducing production throughput
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
Enables continuous monitoring and automatic calibration of inspection units, preventing the production of defective PCBs by identifying and correcting faults in real-time.
Implementation Method 1
a reflector disposed on the frame to verify whether a light source, configured to generate light, in the inspection unit has a fault
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of verifying a fault of an inspection unit, an inspection apparatus, and an inspection system are disclosed. The method according to the present disclosure includes: providing a verification reference body which is formed on a frame attached to an inspection system; placing the inspection unit on the verification reference body; obtaining image data of the verification reference body through the inspection unit; verifying a fault of the inspection unit by extracting a movement error and height error of the inspection unit from the image data; and generating a verification result indicating the fault of the inspection unit.