Wire Connection Fault Analysis Using Slit and Diffuse Illumination

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for fault analysis of wire connections between substrates and semiconductor components are time-consuming and costly due to the need for multiple scans and complex image processing, especially when detecting errors in densely packed wire connections.

Innovation Solution

A method utilizing a line camera and dual projection devices, where a slit projection device projects a light gap onto the wire connections, allowing for reliable detection and analysis in a single pass, combined with diffuse illumination to avoid shading and enhance image processing, enabling accurate error analysis with improved resolution and reduced data volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple scans are performed to ensure reliable measurement, then measurement reliability is improved, but inspection time and cost increase

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidinspection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the illumination function into two distinct systems: a first projection device with slit projection for wire-specific illumination and a second projection device with diffuse illumination for general lighting. This segmentation allows each illumination mode to be optimized for its specific purpose, enabling reliable wire detection in a single scan without requiring multiple passes

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by directing the light slit specifically onto the wire connections while leaving other areas with different illumination characteristics. The slit projection illuminates only the relevant wire areas with high precision, while the diffuse illumination provides general lighting for the entire substrate, allowing reliable measurement in a single scan

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If oblique illumination is used to prevent shadows, then shadow artifacts are reduced, but wire detection accuracy may be compromised

Engineering Contradiction:
Improveshadow artifactsVSAvoidwire detection accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent merges two illumination approaches by combining the first projection device (slit projection) and second projection device (diffuse illumination) in a single inspection system. The slit projection provides oblique illumination to reduce shadows on wires, while the diffuse illumination from the second device compensates for any shadowing effects and provides uniform lighting, achieving both shadow reduction and high detection accuracy in one scan

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 allows for rapid and reliable fault analysis of wire connections by focusing on the wire alone with the light gap, reducing the need for multiple scans and improving detection accuracy, thus simplifying and speeding up the inspection process while minimizing costs.

Implementation Method 1

a first projection device with at least one slit projection device, with which a light gap is created

Methodology Applied
Scientific EffectLight projection: Light

Implementation Method 2

light reflected from the light gap on the wire being detected by the line camera

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

a second projection device, with which diffuse light is projected onto the product

Methodology Applied
Scientific EffectDiffuse illumination: Light

Data Source

PatentEP3104117B1Method of analyzing faults in wire connections
Publication Date: 2019.11.06 WITRINS S R O
  • EP3104117B1 patent drawingFigure 1
  • EP3104117B1 patent drawingFigure 2
  • EP3104117B1 patent drawingFigure 3

AI summary

The invention relates to an inspection system (10) for defect analysis of a wire connection (11) between a substrate (13) and a semiconductor device (15, 16) of a product (12), wherein the inspection system comprises a first projection device (24), a line scan camera (28) and a processing device, wherein the first projection device has at least one slit projection device (25), wherein a light slit (33) can be projected onto a wire (21, 22) of the wire connection by means of the slit projection device, wherein light from the light slit reflected from the wire can be detected by means of the line scan camera in a detection plane (39) of the line scan camera extending transversely, preferably orthogonally to a substrate surface (14), and wherein an analysis image information of the product can be derived from a plurality of line scan image information from the line scan camera by means of the processing device.wherein the slit projection device is arranged relative to the line camera such that the light slit can be projected onto the product running within the detection plane, wherein the inspection system comprises a second projection device, wherein the second projection device has at least one illumination device, wherein diffuse light can be projected onto the product by means of the illumination device, and wherein light of the diffuse light reflected from the product in the detection plane can be detected by means of the line camera.