Automated PCB Signal Integrity Testing via Scattering Parameters

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current printed wiring board testing methods inadequately assess signal integrity due to reliance on impedance measurements alone, leading to costly assembly of faulty components and potential system-level defects.

Innovation Solution

An automated system that measures transmission line responses to signal test patterns, simulates network performance using scattering parameters and virtual models, and includes robots and a network analyzer for precise characterization and calibration, ensuring accurate calibration and measurement integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If impedance measurements alone are used to test printed wiring boards, then testing simplicity is maintained, but signal integrity assessment becomes inadequate

Engineering Contradiction:

Improvetesting simplicityVSAvoidsignal integrity assessment

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent combines multiple testing methods (impedance measurement, time-domain reflectometry, and network analysis) into a single integrated test system. This merging allows the system to maintain operational simplicity while comprehensively assessing signal integrity through multiple measurement techniques simultaneously.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The test system is designed with multi-functionality, capable of performing impedance measurements, TDR analysis, and network analysis through a single automated platform. This universal approach enables comprehensive signal integrity assessment without requiring separate specialized equipment for each measurement type.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If manual measurements on coupons are performed for RF impedance defects, then measurement precision is improved, but productivity decreases

Engineering Contradiction:

ImproveRF impedance defect detectionVSAvoidtesting throughput

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The system incorporates automated calibration and verification procedures that perform self-checks and self-adjustments. The automated calibration using verification substrates and calculated compliance ranges enables the system to maintain high measurement precision without requiring manual intervention, thereby preserving productivity.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical measurement processes with automated robotic positioning and electronic measurement systems. This substitution maintains the precision of manual measurements while dramatically increasing throughput by eliminating manual operations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If flying head probe tester is used for impedance measurements, then measurement capability is enhanced, but device complexity increases

Engineering Contradiction:

Improveimpedance measurement capabilityVSAvoidtest system configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The test system is designed as a universal platform that integrates multiple measurement capabilities (impedance, TDR, network analysis) into a single system. This multi-functional design provides the adaptability of specialized equipment while avoiding the complexity of maintaining separate systems for each measurement type.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Reliability

If comprehensive signal integrity testing is implemented, then reliability is improved, but loss of time increases

Engineering Contradiction:

Improvedefect detection accuracyVSAvoidtesting duration

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs automated calibration using verification substrates before actual production testing. This preliminary calibration establishes compliance ranges that enable rapid defect detection during production testing, ensuring comprehensive reliability assessment without significantly increasing overall testing time.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The test system operates continuously with automated probe positioning, measurement, and data analysis. The robotic system maintains continuous contact with the PCB under test, performing multiple measurement types in sequence without interruption, thereby maximizing testing efficiency while maintaining comprehensive defect detection.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS8446165B2Link analysis compliance and calibration verification for automated printed wiring board test systems

Publication Date: 2013.05.21 MAYO FOUNDATION FOR MEDICAL EDUCATION & RESEARCH

AI summary

A transmission line on a printed wiring board is tested and printed wiring board manufacturing variability is assessed. A response of the transmission line to a signal test pattern is measured. A network including a plurality of components connected by the transmission line is then simulated. The simulated network is based on the measured scattering parameters and virtual models representative of each of the components in the network. A system-level output response of the simulated network to a simulated input signal is analyzed, and the printed wiring board is characterized based on a comparison of the system-level output response to a printed wiring board performance metric threshold.