Solder Joint Life Prediction Using Thermal Cycle Acceleration Factors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods cannot predict the life of solder joints in electronic circuits, leading to functional loss due to cracks before the semiconductor elements reach the end of their life, as solder joint life is typically shorter than the power cycle lifetime of semiconductor elements.
Innovation Solution
A solder joint life predictor that includes a temperature sensor, storage for a reference acceleration factor, and a calculator to determine an actual acceleration factor based on temperature variations, integrating ratios to predict the life of solder joints by comparing the integrated value with a threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing life prediction methods are used, then the power cycle lifetime of semiconductor elements can be predicted, but the life of solder joints cannot be predicted
Solution Approach 1:
The patent changes the prediction parameters from semiconductor junction temperature to solder joint temperature, and from power cycle lifetime to acceleration factor based on thermal shock test conditions. This parameter transformation enables the prediction method to be adapted from semiconductor elements to solder joints.
Solution Approach 2:
The patent creates a universal prediction method that can assess the life of both semiconductor elements and solder joints within the same electronic circuit system. By measuring solder joint temperature and calculating acceleration factors, the system achieves multi-functional prediction capability covering different component types with varying lifespans.
2Duration of action of moving object
If the electronic circuit is used beyond solder joint life, then the semiconductor element may still be functional, but a crack is generated in the solder joint causing functional loss
Solution Approach 1:
The patent performs preliminary life prediction of solder joints before actual failure occurs. By continuously monitoring temperature and calculating accumulated acceleration factors, the system predicts remaining life and prompts replacement before cracks develop, preventing functional loss while maximizing operational duration.
Solution Approach 2:
The patent implements a feedback mechanism where the calculated acceleration factor and predicted life are continuously monitored and compared against thresholds. When the predicted life approaches zero or the acceleration factor exceeds a threshold, the system provides feedback to prompt replacement, creating a closed-loop reliability management system.
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
Enables accurate prediction of solder joint life, allowing for proactive maintenance to prevent functional loss and improving appliance safety by identifying potential failures earlier.
Implementation Method 1
a temperature sensor to measure temperature of a solder joint on an electronic circuit board
Implementation Method 2
a temperature sensor to measure temperature of a solder joint on an electronic circuit board
Data Source
AI summary
A control device including a solder joint life predictor includes: a temperature sensor that measures temperature of a solder joint on an electronic circuit board that drives a heater and a motor; a storage that stores a reference acceleration factor that is an acceleration factor based on a test condition of a thermal shock test and a reference condition in an environment in which the electrical appliance is used; a calculator that calculates an actual acceleration factor from a temperature variation range and a maximum reached temperature of the solder joint during one cycle from start to end of driving of the heater or the motor; and a determiner that predicts the life of the solder joint by comparing the integrated value of the acceleration factor ratios with a threshold.