Multiline TDI Sensor Resampling for Faster Circuit Inspection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing automated inspection systems for electrical circuits face limitations in throughput due to the constraints of minimum line acquisition time and pixel size, which are influenced by the optics and sensor characteristics, leading to a trade-off between inspection speed and feature resolution.

Innovation Solution

The use of a multiline Time Delay Integration (TDI) sensor with multiple parallel lines and a linear displacer allows for adjustable spatial resolution without changing optical magnification, enabling enhanced throughput by constructing composite output pixels through mutual displacement and overlapping sensor pixel data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the pixel size is reduced to inspect smaller features, then manufacturing precision is improved, but productivity deteriorates due to slower inspection speed

Engineering Contradiction:

Improvefeature inspection precisionVSAvoidinspection throughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent combines multiple TDI sensor lines (e.g., 4 lines) to form a larger effective sensor area. By merging the output pixels from multiple lines into composite output pixels, the system achieves larger effective pixel size (e.g., 4x larger) without reducing optical magnification, thereby maintaining inspection precision while increasing throughput

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent employs dynamic displacement of the sensor relative to the circuit board during exposure. The TDI sensor lines are sequentially shifted by one pixel pitch between exposures, allowing each composite output pixel to accumulate photons from multiple sensor lines. This dynamic operation enables the sensor to effectively cover a larger area and inspect smaller features faster

Inventive Principle:

Principle #15Dynamics

2Manufacturing precision

If the optical magnification is increased to reduce pixel size for smaller features, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:

Improvefeature inspection precisionVSAvoidoptics complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the effective pixel size parameter through software processing rather than optical adjustment. By combining outputs from multiple TDI lines and creating composite pixels, the system achieves different effective pixel sizes (e.g., 1x, 2x, 4x larger) without changing the optical magnification, thereby avoiding the complexity of interchangeable lenses or magnification mechanisms

Inventive Principle:

Principle #35Parameter changes

3Productivity

If the line acquisition time is reduced to increase throughput, then productivity is improved, but measurement precision deteriorates due to insufficient photon collection

Engineering Contradiction:

Improveinspection throughputVSAvoidsignal quality

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements continuous photon accumulation across multiple TDI sensor lines during the exposure period. Instead of capturing photons in discrete short intervals, the system continuously integrates photon signals as the sensor displaces sequentially through multiple lines, effectively extending the photon collection period and maintaining signal quality while increasing throughput

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent merges photon collections from multiple TDI sensor lines into composite output pixels. By combining the signals from N lines, the system achieves N times more photons per effective pixel, thereby maintaining or improving measurement precision while enabling faster inspection through the parallel line structure

Inventive Principle:

Principle #5Merging (Combining)

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 optimizes inspection throughput by allowing flexible pixel sizes and resolutions, reducing blur and complexity while maintaining high inspection efficiency.

Implementation Method 1

at least one multiline Time Delay Integration (TDI) sensor having multiple parallel lines of sensor pixels

Methodology Applied

Scientific EffectTime Delay Integration (TDI):

Data Source

PatentUS12449475B2Resampling with TDI sensors

Publication Date: 2025.10.21 ORBOTECH LTD

AI summary

Apparatus for inspecting electrical circuits including a scanner including at least one multiline Time Delay Integration (TDI) sensor having multiple parallel lines of sensor pixels, the multiple lines being separated from each other by a separation distance along a scanning axis, each of the sensor pixels having a sensor pixel dimension along the scanning axis, a linear displacer providing mutual displacement of the TDI sensor and an electrical circuit to be inspected along the scanning axis and scanning optics directing light reflected from the electrical circuit to the sensor pixels, the scanning optics defining a projection of each sensor pixel onto the electrical circuit, which projection defines the area on the electrical circuit from which light reaches each sensor pixel, each projection having a sensor pixel projection dimension along the scanning axis and an image generator constructing an image from composite output pixels of the TDI sensor.