Wafer Prober Illuminator with Actuated Reflector for Rapid Source Switching
Solution Overview
Problem
Conventional wafer probers are unable to rapidly switch between different illumination sources, limiting their ability to perform reliable, high-speed, high-throughput testing of imaging sensor devices on wafers.
Innovation Solution
An illuminator system for wafer probers that includes multiple radiation sources, a reflector, and an actuator to rapidly switch between different positions, allowing for uniform and stable illumination with varying intensities and wavelengths, using a light pipe for efficient radiation transmission and a shutter for ambient light testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional wafer probers use a single illumination source, then the device complexity is low, but the productivity is limited due to inability to rapidly switch between different illumination sources
Solution Approach 1:
The illumination system is segmented into multiple independent radiation sources (first radiation source, second radiation source, etc.), each capable of emitting radiation at different wavelengths or intensities. This segmentation allows the system to selectively activate specific sources based on testing requirements, enabling rapid switching without complex mechanical movement while maintaining high productivity.
Solution Approach 2:
The illuminator is designed with multi-functionality by incorporating multiple radiation sources that can serve different testing purposes (e.g., visible light for color imaging, infrared for thermal imaging). This universal design allows a single illuminator to perform multiple testing functions, improving productivity without proportionally increasing device complexity.
2Illumination intensity
If complex relay optics are used to improve illumination quality, then the illumination uniformity is improved, but the cost and space requirements increase
Solution Approach 1:
The patent applies local quality by positioning radiation sources at specific locations relative to the wafer and using targeted illumination paths. Each radiation source is strategically placed to illuminate specific regions or angles, providing locally optimized illumination quality without requiring complex relay optics across the entire system. This reduces both cost and space requirements while maintaining adequate illumination uniformity.
3Productivity
If multiple radiation sources are used to enable rapid switching, then the productivity is improved, but the power consumption increases
Solution Approach 1:
The illuminator employs periodic action by activating radiation sources only when needed for specific testing operations. Instead of keeping all sources continuously powered, the system selectively activates the required radiation source based on the current testing task, reducing overall power consumption while maintaining the ability to rapidly switch between different illumination types for high-speed 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
Enables high-throughput testing and calibration of imaging sensor devices by rapidly switching between radiation sources, reducing power requirements and ensuring uniform illumination across multiple devices on a wafer, thereby improving testing efficiency and accuracy.
Implementation Method 1
a reflector adapted to receive IR radiation from the IR radiation sources
Implementation Method 2
using a light pipe for efficient radiation transmission
Data Source
AI summary
Various techniques are disclosed for an illuminator and related methods to be used with a wafer prober to provide illumination (e.g., visible and/or non-visible electromagnetic radiation) to perform testing, calibration, and/or inspection of devices on a wafer. For example, an illuminator may include a plurality of radiation sources, a reflector, an actuator for the reflector, a shutter, an actuator for the shutter, and/or a light pipe. Various components of the illuminator may interface with a wafer prober to provide sufficiently uniform and stable illumination with fast-switching intensities, wavelengths, and/or other properties. Such illumination provided by various embodiments of the illuminator may permit the wafer prober to perform high-throughput testing, calibration, and/or inspection of devices that may be fabricated and/or packaged on a wafer.