Optical LED Wafer Inspection Probe for Non-Contact Electro-Optical Measurement
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Solution Overview
Problem
The challenge lies in efficiently inspecting small light-emitting diodes (LEDs) with reduced electrode sizes, where traditional inspection methods face difficulties in alignment, probe damage, and prolonged inspection times due to the need for precise contact and sequential probing.
Innovation Solution
An inspection apparatus and method utilizing a sensing probe integrated with a Z-axis translation stage, height measurement module, and illumination light source, which adjusts distance based on relative height information to irradiate LEDs with an illumination beam, generating charge, electric field, or voltage distributions for non-contact measurement of electro-optical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the probe size is reduced to match the small electrode size of micrometer-scale LEDs, then alignment precision and measurement accuracy are improved, but the probe becomes more fragile and prone to damage
Solution Approach 1:
The patent replaces the mechanical contact-based probe system with an optical measurement system. The optical probe uses light interaction to measure electrode characteristics without physical contact, eliminating the fragility and damage issues associated with mechanical probes while maintaining high measurement precision for micrometer-scale electrodes
2Measurement precision
If the probe sequentially contacts each electrode for inspection, then measurement accuracy is maintained, but the inspection process becomes time-consuming and labor-intensive
Solution Approach 1:
The patent merges multiple sequential measurement operations into a single parallel operation. By enabling the optical probe to simultaneously measure multiple electrodes across different scan regions, the system achieves high-speed inspection without sacrificing measurement accuracy, thereby resolving the contradiction between precision and productivity
3Measurement precision
If the probe is required to precisely align and contact small electrodes, then measurement accuracy is improved, but the complexity of the inspection process increases
Solution Approach 1:
The patent replaces complex mechanical alignment and contact procedures with simplified optical measurement procedures. The optical system naturally achieves precise alignment through light propagation characteristics and eliminates the need for delicate mechanical contact, thereby reducing process complexity while maintaining high measurement accuracy
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 rapid and accurate inspection of multiple LEDs without physical contact, reducing damage risks and inspection time, while maintaining precision in determining functional and non-functional LEDs and their electro-optical characteristics.
Implementation Method 1
An illumination beam is allowed to simultaneously irradiate the light-emitting diodes of the to-be-inspected region to generate a charge distribution, an electric field distribution, or a voltage distribution on the light-emitting diodes of the to-be-inspected region due to a photovoltaic effect caused by the illumination beam
Data Source
AI summary
An inspection apparatus for inspecting a light-emitting diode wafer is provided. The inspection apparatus includes a Z-axis translation stage, a sensing probe, a height measurement module, a carrier, an illumination light source, and a processing device. The sensing probe is integrated with the Z-axis translation stage. The Z-axis translation stage is adapted to drive the sensing probe to move in a Z axis. The sensing probe includes a photoelectric sensor, a beam splitter, and a photoelectric sensing structure. One of the photoelectric sensor of the sensing probe and the height measurement module is adapted to receive a light beam penetrating the beam splitter, and the other one of the photoelectric sensor of the sensing probe and the height measurement module is adapted to receive a light beam reflected by the beam splitter. The carrier is configured to carry the light-emitting diode wafer. The illumination light source is configured to emit an illumination beam to irradiate the light-emitting diode wafer. An inspection method for inspecting light-emitting diodes is also provided.