PCB Inspection Machine Height Detection and Interference Avoidance
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Solution Overview
Problem
Existing inspection machines for printed circuit boards face challenges in preventing interference between the imaging device and electronic components during close-up imaging, particularly due to varying component heights and data management inaccuracies.
Innovation Solution
An inspection machine equipped with a detection unit that scans the printed circuit board to determine the heights of electronic components, using a control unit to set a limit distance for the imaging device to avoid interference, and includes sensors for detecting minimum, intermediate, and maximum approaching distances to adjust the imaging device's position accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the imaging device approaches the printed circuit board to minimize the irradiation distance for high resolution close-up imaging, then the resolution is improved, but the electronic components mounted on the printed circuit board and the imaging device interfere with each other
Solution Approach 1:
The system performs preliminary height detection of electronic components using a detection unit (such as a laser displacement sensor or vision sensor) before the imaging device approaches the printed circuit board. The control unit calculates the maximum component height and determines a safe approaching distance that maintains the minimum irradiation distance required for high resolution while preventing interference with electronic components.
Solution Approach 2:
The system dynamically adjusts the approaching distance of the imaging device based on the detected heights of electronic components. Rather than using a fixed distance, the control unit calculates an optimal approaching distance for each inspection task based on the maximum component height detected, allowing the imaging device to get as close as possible to achieve high resolution without causing interference.
2Object-affected harmful factors
If data management is used to restrict the approaching distance for each printed circuit board, then interference is prevented, but data input errors, communication errors, and mismatches between registered data and actual products may occur
Solution Approach 1:
The system uses the printed circuit board itself to provide the information needed for safe imaging. The detection unit directly measures the heights of electronic components on the actual board being inspected, eliminating the need to rely on pre-registered data. The control unit uses these self-measured values to calculate the appropriate approaching distance, ensuring both interference prevention and accuracy without data management errors.
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
Ensures effective prevention of interference between the imaging device and electronic components, allowing for high-resolution close-up imaging while minimizing unnecessary restrictions on the close-up function.
Implementation Method 1
detection unit that detects heights of electronic components on the printed circuit board to be subjected to inspections by irradiation light that is irradiated onto the printed circuit board
Data Source
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AI summary
Disclosed is an inspection machine provided with an imaging device that capture a close-up image of the imaging target portion of the printed circuit board (W) on which a plurality of electronic components (C) are mounted, by coming close to a printed circuit board (W). The inspection machine has a sensor unit (120) that detects the heights of the electronic components (C) on the printed circuit board (W) by irradiation light (Ll, L2) in a first direction that is along the surface of the printed circuit board (W). Control means (600) of the inspection machine sets a limit distance to a position above the highest electronic component (C) among heights detected from the electronic components. The control means (600) also restricts a facing distance by which the imaging device is accepted to approach the printed circuit board (W), to be the limit distance.