Meaning
Thermal measurement methodologies for semiconductor devices must be standardized to ensure comparable test results across different manufacturers. The implementation of jesd92 establishes a uniform procedure for measuring the thermal resistance of single-chip semiconductor packages on high thermal conductivity test boards. This standard defines the dimensions, layer stack-up, and routing of the test board used during evaluation.
By defining these test conditions, the standard enables system designers to make direct comparisons of thermal performance between competing devices.
Test Configuration
The test board geometry and copper distribution are strictly controlled to minimize measurement variation. Under the jesd92 standard, the board must feature specific trace patterns and thermal vias that distribute heat predictably. This layout ensures that the primary heat flow path is representative of high-performance system designs.
Utilizing a standard board eliminates board-level design as a variable in the device thermal resistance calculation.
Thermal Evaluation
Environmental parameters during the test require precise control to guarantee repeatability. The device under test resides in a specified enclosure that prevents stray air currents from altering convective cooling rates. During the test, a known power is applied to the device, and the junction temperature is monitored using a temperature-sensitive parameter like a forward-biased diode voltage.
The ratio of the temperature change to the applied power determines the thermal resistance.
Design Integration
System engineers use these standard values to model thermal management solutions. This data establishes the cooling boundaries for the final product.
