Optoelectronic Component With Detached Sapphire Substrate
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Solution Overview
Problem
Existing optoelectronic components face challenges in achieving efficient white light emission due to the Stokes shift, which results in reduced efficiency and increased thickness, and lack effective thermal and mechanical stability.
Innovation Solution
A method involving a light-emitting semiconductor chip with a sapphire substrate detached using laser lift-off, allowing for a converter element to be applied for improved thermal connection and mechanical stability, reducing the component's thickness and enhancing efficiency by eliminating the Stokes shift, and using a converter element with an adhesive layer for secure attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a sapphire substrate is used to support the semiconductor chip, then mechanical stability is improved, but component thickness increases and thermal connection deteriorates
Solution Approach 1:
The sapphire substrate is completely removed from the semiconductor chip using laser lift-off technology. This extraction eliminates the thick substrate that increased component thickness while poor thermal connection, allowing the chip to be mounted directly on the carrier with improved thermal and mechanical contact.
Solution Approach 2:
The component is segmented into distinct functional layers: the semiconductor chip is separated from its original sapphire substrate and mounted on a new carrier substrate. This segmentation allows optimization of each layer's function - the carrier provides mechanical stability while enabling direct thermal contact with the chip.
2Strength
If a sapphire substrate is retained on the semiconductor chip, then mechanical support is maintained, but thermal connection to the converter element deteriorates
Solution Approach 1:
The sapphire substrate is extracted from the chip structure using laser lift-off, removing the thermal barrier that prevented efficient heat transfer from the chip to the converter element. This enables direct thermal coupling while the carrier provides the necessary mechanical support.
Solution Approach 2:
The carrier substrate acts as an intermediary that provides both mechanical support and thermal conduction pathways. It replaces the sapphire substrate's mechanical support function while simultaneously improving thermal connection to the converter element, as it is positioned in direct contact with the chip's active side.
3Loss of energy
If the semiconductor chip is mounted with the emission side facing the carrier, then thermal connection is improved, but contact point arrangement becomes complex
Solution Approach 1:
The chip is mounted in a flip-chip configuration with the emission side facing the carrier, inverting the conventional mounting orientation. This inversion enables direct thermal contact between the chip's active region and the carrier, improving heat dissipation. The contact points are arranged on the bottom surface to align with carrier contact pads, simplifying the overall connection architecture.
4Loss of energy
If the converter element is applied after sapphire substrate detachment, then thermal connection is improved, but manufacturing process complexity increases
Solution Approach 1:
The sapphire substrate detachment is performed as a preliminary action before converter element application. This sequence enables direct thermal coupling between the chip and converter element from the outset, maximizing thermal efficiency. The laser lift-off process is integrated into the manufacturing flow, allowing subsequent converter element bonding without additional complex steps.
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 method results in a flat, efficient white light-emitting optoelectronic component with improved thermal and mechanical stability, reducing the Stokes shift and increasing efficiency, while maintaining mechanical stability without the need for a substrate.
Implementation Method 1
detaching the sapphire substrate from the semiconductor chip
Data Source
AI summary
An optoelectronic component and a method for producing an optoelectronic component are disclosed. In an embodiment a method includes providing at least one light-emitting semiconductor chip comprising a sapphire substrate and an epitaxially grown layer sequence, arranging the light-emitting semiconductor chip with a side facing away from the sapphire substrate on a carrier, detaching the sapphire substrate from the semiconductor chip, applying a converter element on a region of the semiconductor chip in which the sapphire substrate was detached, arranging the semiconductor chip on an auxiliary carrier so that the converter element faces the auxiliary carrier and detaching the carrier from the semiconductor chip.