Internal Voltage Level Shifting for IC Temperature Defect Screening

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Solution Overview

Problem

Current IC testing methods are time-consuming and costly, especially for simulating cold or hot temperature operations, as they require expensive and time-consuming non-room temperature test fixtures, and sampling cannot assure quality for all IC products.

Innovation Solution

Characterizing the internal voltage supply level of ICs to create a temperature-equivalent environment at room temperature, allowing for the detection of defects that would otherwise manifest at extreme temperatures during electrical testing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If non-room temperature testing is used to detect temperature-related defects, then detection accuracy is improved, but testing cost and time increase significantly

Engineering Contradiction:

Improvedetection accuracyVSAvoidtesting time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the electrical test parameters (voltage levels, current conditions) to simulate temperature effects. By applying specific voltage stress patterns that replicate the electrical characteristics of cold or hot operation, the system detects temperature-related defects without physically changing the test environment temperature, thus reducing testing time while maintaining detection accuracy.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If non-room temperature testing is used to detect temperature-related defects, then detection accuracy is improved, but testing cost increases significantly

Engineering Contradiction:

Improvedetection accuracyVSAvoidtesting cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent substitutes the mechanical/physical temperature control system with an electrical simulation approach. Instead of using thermal chambers and temperature-controlled fixtures to create cold or hot test environments, the system uses electrical parameter modulation (voltage stress patterns) to replicate the electrical effects of temperature, thereby eliminating expensive thermal testing equipment and reducing manufacturing costs while maintaining detection capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If 100% cold temperature testing is performed to ensure quality, then product quality is improved, but manufacturing time and cost increase

Engineering Contradiction:

Improveproduct qualityVSAvoidmanufacturing throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent performs preliminary electrical characterization and stress testing at room temperature using accelerated voltage stress patterns that simulate cold operation. This preliminary screening identifies temperature-sensitive defects before final packaging, allowing 100% testing of quality-critical items using cost-effective electrical methods rather than expensive cold temperature fixtures, thus maintaining high product quality while improving manufacturing throughput.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8030954B1Internal voltage level shifting for screening cold or hot temperature defects using room temperature testing

Publication Date: 2011.10.04 XILINX INC

AI summary

Operation of an internal voltage supply level (Vgg) of an IC is characterized over operating temperature or at a selected temperature to determine a temperature-equivalent internal voltage level. The internal voltage supply of the IC is set to the temperature-equivalent level, and the IC is tested at room temperature to screen for low-temperature defects or high-temperature defects.