IC Test Thermal Control Using Coupled Multi-Zone Heating
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Solution Overview
Problem
Existing temperature control systems for electronic devices under test face challenges in maintaining uniform temperature across multiple chips due to temperature gradients, which can compromise test results.
Innovation Solution
A system with multiple thermally-coupled zones, each equipped with independently controllable heaters and fans, uses a control circuit to manage temperature gradients by transforming temperature measurements into a normal coordinate system to generate power vectors that control heaters and fans, thereby minimizing temperature differences across zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single temperature control system is used for multiple chips, then device complexity is reduced, but temperature uniformity across chips deteriorates due to temperature gradients
Solution Approach 1:
The patent divides the temperature control system into multiple independent zones, each with its own heater and temperature sensor. This segmentation allows each zone to be controlled independently, eliminating temperature gradients across the chip while maintaining manageable system complexity through modular design.
Solution Approach 2:
The patent implements local temperature control by assigning dedicated heating and sensing elements to specific zones on the chip. This enables localized temperature adjustment to compensate for heat generation variations in different circuit regions, achieving uniform temperature distribution across the entire chip.
2Temperature
If multiple independent temperature control devices are used for each zone, then temperature uniformity is improved, but device complexity increases
Solution Approach 1:
The patent employs a universal control approach where multiple zones share common control circuitry and processing logic. The temperature control algorithm operates on aggregated temperature data from all zones, allowing the system to manage multiple temperature control devices through a unified control mechanism rather than requiring separate control systems for each zone.
Solution Approach 2:
The patent combines multiple temperature control functions into a single integrated control system. By merging the control logic and processing for all zones into one unified controller, the system achieves precise temperature uniformity across multiple zones while avoiding the complexity of having separate independent control systems for each zone.
3Measurement precision
If temperature control is maintained during testing, then test accuracy is improved, but energy consumption increases
Solution Approach 1:
The patent maintains continuous temperature control throughout the testing process rather than allowing temperature to fluctuate. This continuous action ensures test accuracy is preserved while the system efficiently manages energy by maintaining stable thermal conditions rather than repeatedly heating and cooling the chip during testing.
Solution Approach 2:
The patent dynamically adjusts temperature control parameters based on real-time testing requirements and thermal conditions. By changing control parameters such as heater power levels and sampling rates according to actual needs, the system maintains test accuracy while optimizing energy consumption to match the actual thermal management requirements during different phases of testing.
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
This approach effectively maintains uniform temperature across multiple zones, reducing temperature gradients and ensuring accurate test results by dynamically adjusting heat distribution based on real-time measurements.
Implementation Method 1
control the plurality of heaters in accordance with the power vector
Implementation Method 2
Each of the plurality of temperature sensors configured to measure temperature of one of the plurality of thermally-coupled zones
Implementation Method 3
a plurality of thermally-coupled zones... minimize a temperature gradient across the one or more chips being tested
Data Source
AI summary
A system includes a plurality of thermally-coupled zones and a plurality of thermal control devices, each controllable to thermally control one of the plurality of zones, and a plurality of temperature sensors, each configured to measure temperature of one of the plurality of zones. The system includes a control circuit configured to receive a temperature measurement for each of the plurality of zones, collect the temperature measurements in a temperature vector in a real coordinate system, and transform the temperature vector to a normal coordinate system that provides a plurality of uncoupled equations. The control circuit is configured to determine, based on the plurality of uncoupled equations and a desired temperature gradient, a desired power vector in the normal coordinate system, transform the desired power vector to the real coordinate system to generate a power vector, and control the plurality of heaters in accordance with the power vector.