End user´s method for estimating junction temperatures due to interactions of other dominant heat sources in close proximity to the device in question

There are many cases in which the end user of an electronic package needs to know the actual junction temperature for reliability analysis. Supplied values of θ_ja, θ_jc are not generally sufficient to estimate the junction temperature unless the supplier tested the component in exactly the same environment as the customer is using it. Issues such as the type of system board, ground plane density, and other components on the system board have a dramatic influence on the junction temperature of the device. Neglecting them can result in severe errors in junction temperature estimates. This paper describes yet another method which can provide an end user the capability to estimate junction temperature of a component in its application environment. With relatively inexpensive equipment, simple characterization experiments can be made which will allow reasonable estimates of the junction temperature over a wide range of package mounting and application environments