LED Interposer Structure for In-Process Inspection and Yield Screening
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Solution Overview
Problem
Existing display devices face challenges in efficiently manufacturing and inspecting light emitting diodes (LEDs) for next-generation display applications, leading to high process costs and complexity.
Innovation Solution
An interposer structure is developed, comprising a temporary substrate with common pads and LEDs, allowing for simultaneous manufacturing and inspection of LEDs with a method that includes attaching a temporary substrate to common pads, removing the wafer, and using probes to inspect luminous properties, thereby simplifying the process and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional separate manufacturing and inspection processes are used for LEDs, then manufacturing precision and inspection accuracy can be maintained, but process complexity and cost increase significantly
Solution Approach 1:
The patent merges the LED manufacturing process and inspection process into a single integrated system. The LED is manufactured on a temporary substrate with built-in test structures, allowing both fabrication and electrical/optical characterization to occur without transferring the device to different tooling or substrates. This eliminates multiple process steps and reduces overall complexity while maintaining manufacturing precision.
Solution Approach 2:
The patent introduces a temporary substrate as an intermediary platform that supports both manufacturing and inspection functions. This substrate includes integrated test structures and connection interfaces that enable electrical and optical measurements during the manufacturing process itself, acting as a mediator between the manufacturing equipment and inspection equipment without requiring separate processing stages.
2Productivity
If multiple separate processes are used for LED manufacturing and inspection, then quality control can be maintained, but process time and cost increase
Solution Approach 1:
The patent incorporates test structures and measurement interfaces into the LED device during the initial manufacturing process on the temporary substrate. By preparing the inspection-capable structure in advance alongside the LED fabrication, the inspection can be performed immediately after manufacturing without requiring additional preparation steps, device transfers, or separate setup procedures, thereby eliminating time losses.
3Measurement precision
If LEDs are inspected after complete manufacturing, then final product quality can be verified, but defective LEDs cannot be identified early in the process
Solution Approach 1:
The patent implements in-process inspection capabilities that provide immediate feedback on LED quality during the manufacturing process. The temporary substrate includes integrated test structures that allow electrical and optical measurements to be performed on LEDs while they are still on the substrate, enabling real-time quality assessment and early identification of defective devices before final packaging or assembly.
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
The interposer structure enables cost-effective and efficient manufacturing and inspection of LEDs, improving process yield and convenience by ensuring only normal LEDs are separated for display panel integration.
Implementation Method 1
a light emitting diode (LED) is attracting attention as a next generation display device
Implementation Method 2
the light emitting diode has a fast lighting speed, excellent luminous efficiency
Data Source
AI summary
An interposer may include a temporary substrate, a common pad disposed on the temporary substrate and light emitting diodes (LEDs) disposed on the common pad. Each of the light emitting diodes may include a first electrode, a first semiconductor layer, an emission layer, a second semiconductor layer, a second electrode, and a passivation layer. The second electrode, the second semiconductor layer, the emission layer, the first semiconductor layer and the first electrode may have a structure formed from sequential lamination. The passivation layer may enclose the second semiconductor layer, the emission layer and the first semiconductor layer. The common pad may be electrically connected to the second electrode at a lower side of the light emitting diodes. The first electrode in each of the light emitting diodes may extend to an upper portion of the passivation layer. A method for inspecting light emitting diodes disposed on a temporary substrate is also disclosed.