John Wilson

AUTOMATIC THERMAL CALIBRATION OF DETAILED IC PACKAGE MODELS

Electronics Product Specialist

Mechanical Analysis Division

June 2016

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Topics

Motivation

Calibration Process Comparison

Automated Calibration Example

JRW, Automatic Thermal Calibration, June 2016

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Model Calibration - Motivation

Calibrating thermal models to match transient measurements is critically important for modern electronics thermal design.

Maximize Model Accuracy— Calibrating all model aspects for all package time constants ensures the

package will respond accurately for any steady state or transient application. Relying on single metric type data is not enough.

— Vital to demonstrate this accuracy to ensure informed design decisions are made

Certified Supply Chain Models— Provide simulation models that will respond correctly to any driving power

profile.— Provide empirical evidence that this is the case.

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Model Calibration Process Comparison

JRW, Automatic Thermal Calibration, June 2016

Historical Process

FloTHERM and T3Ster Automated Process

Good Enough?

Steady state at discrete points

Transient thermal response

Initial model with best known values

Initial model with range of somewhat known values

Fully Calibrated

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T3Ster: Experimental Measurement

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T3Ster Measurement Output

JRW, Automatic Thermal Calibration, June 2016

P1

P2

t

P

ΔP

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T3Ster Structure Function

T3Ster Master software converts the measured thermal response into a Structure Function. One way to interpret this is the RC path that the heat takes from the junction, through the device, and to the ambient.

Die

Die Attach

Copper

Solder/Insulation

CopperFrame

TIM

ColdPlate

Ambient

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Calibration Example

A detailed FloTHERM model of the package was simulated in a virtual test environment with best known input values

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Quantifying Uncertainties

JRW, Automatic Thermal Calibration, June 2016

…And the range of somewhat known values

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Calibration Interface

Important factors— Import measurement data,

define temperature to calibrate

— Specify/adjust design limits— Verify measurement and

analysis consistency— Design Experiments— Calibration extent

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Design Of Experiments

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Calibration Results

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Response Surface Optimization Output

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Result Comparison: Peak Temperature

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Result Comparison: Temperature Distribution

JRW, Automatic Thermal Calibration, June 2016

Uncalibrated

Calibrated

80ms Pulse, t: 20ms

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Summary

Correlating a model against transient measurements provides the most accuracy

Structure functions help identify areas of inconsistency between the assigned model values and measurement results

Automating calibration provides for a repeatable and scalable process

Thanks!

JRW, Automatic Thermal Calibration, June 2016

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w w w . m e n t o r . c o m

JRW, Automatic Thermal Calibration, June 2016