Bump Void Detection via 3D Imaging and ED-XRF Analysis
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Solution Overview
Problem
Existing methods fail to accurately detect and quantify voids within bumps on microelectronic chips, which can affect product quality if void volume exceeds a threshold, particularly with the transition to lead-free solders like SnAg.
Innovation Solution
A system combining 3D imaging for calculating the outside contour volume of bumps and Energy-Dispersive-X-ray-Fluorescence (ED-XRF) analysis to determine the volume of solid materials, using polycapillary focusing optics for enhanced spatial resolution, to identify and quantify voids by comparing calculated volumes and material ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional inspection methods are used, then inspection speed is maintained, but void detection accuracy and volume calculation precision deteriorate
Solution Approach 1:
The patent combines three different inspection technologies (3D imaging, ED-XRF spectroscopy, and visual inspection) into a unified inspection system. This merging allows the system to achieve high void detection accuracy through complementary measurements while maintaining inspection speed by processing multiple parameters simultaneously in an integrated workflow.
Solution Approach 2:
The patent replaces conventional single-method mechanical inspection systems with a multi-technology system that uses 3D imaging and ED-XRF spectroscopy. This substitution enables more precise void detection and volume calculation while maintaining efficient inspection throughput through automated data processing and comparison algorithms.
2Measurement precision
If 3D imaging is used to calculate outside contour volume, then spatial resolution is improved, but measurement complexity increases
Solution Approach 1:
The patent makes the 3D imaging system multi-functional by using it not only for void detection but also for calculating the outside contour volume and providing spatial reference data. This universal approach reduces overall system complexity by consolidating multiple measurement functions into a single integrated system rather than requiring separate dedicated instruments for each function.
Solution Approach 2:
The patent introduces computational algorithms and data processing systems as intermediaries that bridge the 3D imaging hardware and the final void analysis. These intermediaries simplify the measurement process by automatically extracting volumetric data, comparing it with reference values, and providing diagnostic results, thereby reducing the operational complexity for users.
3Measurement precision
If ED-XRF analysis is applied to determine solid material volume, then material composition accuracy is improved, but inspection time increases
Solution Approach 1:
The patent performs preliminary actions by pre-calculating reference values for solid material volume and composition based on known bump specifications. These reference data are stored and ready for rapid comparison during actual inspection, allowing the ED-XRF measurements to be evaluated quickly without time-consuming real-time calculations, thus reducing overall inspection time while maintaining high material composition accuracy.
Solution Approach 2:
The patent implements feedback mechanisms where the ED-XRF material composition results are immediately compared with reference values and process specifications. This real-time feedback allows for rapid identification of out-of-spec conditions and enables dynamic adjustment of inspection parameters, reducing the time required for thorough material analysis while maintaining high accuracy.
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
Effectively detects and calculates void volumes in bumps, ensuring product quality by disqualifying bumps with voids exceeding a predetermined threshold, enhancing detection sensitivity and accuracy with improved spatial resolution.
Implementation Method 1
the solid material volume is calculated by ED-XRF (Energy-Dispersive-X-ray-Fluorescence analysis) analyze
Implementation Method 2
While an atom is hit by X-ray a characteristic energy is emitted from the atom and this energy is analyzed into the materials spectra of qualification and quantification
Implementation Method 3
Polycapillary focusing optics collects X-rays from the divergent X-ray source and direct them to a small focused beam at the sample surface with diameters as small as tens of micrometers
Implementation Method 4
X-ray optics can be used to enhance ED=XRF instrumentation
Implementation Method 5
The outside contour volume is calculated by using three dimensional image processing
Data Source
AI summary
A method and a system for bump's inspection are disclosed. The inspection done by comparing the volume of the bump's outside contour and the volume the solid materials from which the bump is made and/or analyzing the bump's solid materials ratio. Principally, the inspection id done by preparing an empiric reference table of the emitted energy received from the solid materials, from which a reference proper bump with a given volume is comprised, using ED-XRF (Energy-Dispersive-X-ray-Fluorescence analysis) analyze; obtaining a first calculated volume of the bump, using a 3D image-processing method; adapting the reference table according to the difference between the given volume and the first calculated volume of the bump; performing a second volume calculation of the bump by applying ED-XRF technology. The difference between the first and second volume calculations and the solid material combination are used to inspect the bump.