 Reliability Services in the Design Phase
Thermal Analysis
DEFINITION
Thermal analysis is used to estimate the temperature distribution throughout a product based on the thermal boundary conditions and specified heat sources.
SITUATION
Engineering teams typically do not understand thermal risks until after the first prototype is built and the product is tested. Being able to understand thermal issues prior to the completion of the design will save a lot of time and money.
OBJECTIVES
To understand thermal issues prior to the completion of the design.
VALUE TO YOUR ORGANIZATION
Some of the benefits of Thermal Analysis are that they:
1) allow engineers the ability to understand thermal issues before the design is complete;
2) allow engineers to model the thermal mass of the object adequately;
3) allow engineers to review distribution of temperature, thermal gradient and thermal flux.
RELIABILITY INTEGRATION
An example of Reliability Integration during Thermal Analysis is as follows:
Thermal Analysis Can Help Prepare for HALT
Proper thermal analysis during the Design Phase can pinpoint thermal issues which can then be verified in HALT. However, without knowing exactly where to look, HALT may miss the issues unless the device is monitored thermal or electrically.
METHODOLOGY
Temperature distribution can be used to estimate thermally induced stresses in a component. These stresses may be due to the temperature gradients or to thermal mismatch between dissimilar materials. The general analysis procedure may be repeated with different thermal loads and boundary conditions such as temperatures, heat flow, heat flux, convections, heat generation, adiabatic surfaces and radiation to compare with analytical or experimental results.
CASE STUDIES/OPTIONS
The following case studies and options provide example approaches. We shall tailor our approach to meet your specific situation.
1) Thermal Analysis Used to Help Plan a HALT
For a Medical Device company, we performed a thermal analysis during the design phase. As a result of this analysis, we discovered a few heat-generating areas of the design that were affecting some of the sensitive fiber-optics. We decided to run this configuration through HALT and to monitor this area of the board using thermocouples while carefully measuring the bit error rate for any degradation in performance of the fiber-optics. We found that under ambient conditions, the fiber-optics were safe, but if the environment reached its specified maximum, the life of the fiber-optics would degrade rapidly. Therefore, instead of redesigning and re-laying out the board, we just changed the fans to variable speed fans that increased in speed as the ambient temperature rose. top of page | 
Many New Reliability Services & Reliability Seminars added! 