Infrared Sensor Testing via Frequency-Modulated Signal Isolation
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Solution Overview
Problem
Current automatic testing equipment (ATE) lacks the capability to efficiently test infrared sensors, requiring complex mechanical manipulations and separate testing setups, which are time-consuming and inefficient.
Innovation Solution
An infrared source that emits a frequency-modulated test signal, combined with a signal processor and heat mass, allows for direct testing of infrared sensors within ATE, using electronic modulation to isolate test signals from background radiation, enabling multiple temperature testing without mechanical manipulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional pin tester boards are used to test infrared sensors, then the testing capability is maintained with existing equipment, but the infrared sensors cannot be tested because the equipment lacks the necessary infrared testing capability
Solution Approach 1:
The pin tester board is enhanced to perform both traditional electrical pin testing and infrared sensor testing. The board includes a infrared source that can be selectively activated to emit infrared radiation for testing the infrared sensor, while maintaining all original pin testing capabilities. This multi-functional approach allows a single device to handle both testing requirements without needing separate equipment.
2Reliability
If separate infrared testers with blackbodies are used, then infrared sensors can be tested, but the testing process requires disconnecting chips from ATE and using complex mechanical manipulations
Solution Approach 1:
The patent replaces mechanical blackbody radiation sources with an electrically-driven infrared LED source. The infrared LED is controlled by a controller that modulates the LED output at a specific frequency, eliminating the need for mechanical blackbodies and their associated thermal mass and mechanical manipulation systems. This substitution simplifies the device while maintaining test accuracy.
Solution Approach 2:
The infrared LED is modulated at a specific frequency (e.g., 1 kHz) to create a periodic infrared signal. This frequency modulation allows the sensor to distinguish the test signal from background infrared radiation through frequency filtering. The periodic action enables precise measurement without requiring complex mechanical positioning or thermal equilibrium adjustments.
3Object-affected harmful factors
If mechanical shutters are used to isolate IR source, then background radiation interference is reduced, but the testing time increases due to mechanical manipulation
Solution Approach 1:
The patent replaces mechanical shutters with electronic frequency modulation of the infrared LED. Instead of physically blocking or unblocking the infrared source, the system modulates the LED output at a distinct frequency. The sensor and processing circuitry then filter for this specific frequency, effectively isolating the test signal from background radiation without any mechanical movement. This eliminates shutter operation time while maintaining interference rejection.
Solution Approach 2:
Frequency modulation acts as an intermediary between the infrared source and the sensor. By encoding the test signal at a specific frequency, the system creates a distinguishable signal that can be separated from background radiation through frequency filtering. This intermediary approach allows continuous operation without mechanical interruption, reducing testing time while maintaining signal isolation.
4Adaptability or versatility
If multiple blackbodies at different temperatures are used, then infrared sensors can be tested at multiple temperatures, but the system complexity and manipulation requirements increase
Solution Approach 1:
The patent uses a dynamically controllable infrared LED source that can be modulated at different frequencies to simulate different temperature conditions. Instead of using multiple static blackbodies at fixed temperatures, the system dynamically adjusts the LED drive characteristics to create equivalent thermal responses. This allows a single source to provide multiple temperature test conditions without requiring multiple physical sources or complex manipulation systems.
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 solution enables rapid, efficient, and stable testing of infrared sensors within ATE, reducing the need for mechanical shutters and multiple blackbodies, allowing for simultaneous testing of multiple sensors and improving test accuracy by isolating desired radiation.
Implementation Method 1
The infrared source is stimulated with a signal to produce a frequency-modulated infrared test signal
Implementation Method 2
an infrared source that emits a frequency-modulated test signal
Implementation Method 3
combined with a signal processor and heat mass
Data Source
AI summary
An apparatus for use with automatic testing equipment for testing infrared sensors on integrated circuits is provided. The apparatus includes an infrared source, a heat mass, and an electronic frequency modulator. The infrared source is modulated according to a predetermined test frequency such that the infrared source emits an infrared test signal representative of a test temperature and corresponding to the temperature of the heat mass and the predetermined test frequency. A signal processor, electrically coupled to an integrated circuit having an infrared sensor, receives a sensed signal from the infrared sensor in response to the infrared test signal and uses the sensed signal according to the predetermined test frequency to determine a measured temperature.