Wafer-Level LED Packaging With Separators for Thermal Stability
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Solution Overview
Problem
Conventional LED packaging is time-consuming and costly due to the need for precise handling of converter materials and encapsulants on singulated die, and it faces issues with heat management and thermal expansion, leading to potential delamination.
Innovation Solution
Wafer-level packaging where a metal support substrate with a coefficient of thermal expansion similar to the LED structure is used, incorporating discrete converter and cover elements, and separators to facilitate precise packaging and testing before dicing, reducing handling requirements and enhancing thermal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional LED packaging processes are used with singulated die, then individual LED devices can be manufactured, but manufacturing time and costs increase due to precise handling requirements
Solution Approach 1:
The patent merges multiple packaging operations (converter material application, encapsulant formation, and device assembly) into a single wafer-level process. Multiple LED die are packaged simultaneously on the wafer before dicing, eliminating the need for sequential handling of individual die and reducing overall manufacturing time
Solution Approach 2:
The patent performs packaging operations at the wafer level before the LED die are singulated. Converter materials and encapsulants are applied to the entire wafer or multiple die simultaneously in advance, so that when the wafer is diced, each individual LED die is already packaged and requires no further handling
2Ease of operation
If LED die are mounted to separate support substrates, then individual devices can be assembled, but the process becomes time-consuming and requires precise handling
Solution Approach 1:
The patent combines the support substrate function with the LED wafer itself. The LED structure is formed on a support substrate that remains intact throughout the packaging process, serving as the final mounting substrate for all LED die simultaneously, thereby eliminating separate mounting operations
Solution Approach 2:
The support substrate serves multiple functions: it provides mechanical support during fabrication, acts as the mounting platform for all LED die, and serves as the final package substrate. This multi-functional approach eliminates the need for separate mounting substrates and reduces assembly steps
3Reliability
If conventional packaging is used, then LED devices can be manufactured, but heat management becomes difficult and thermal expansion causes delamination
Solution Approach 1:
The patent changes the material parameters of the support substrate, specifically selecting materials with coefficients of thermal expansion matched to the LED structure. This parameter matching prevents thermal stress and delamination during temperature cycling, improving device reliability
Solution Approach 2:
The patent employs composite material structures including the LED structure formed on the support substrate, with converter materials and encapsulants that provide both mechanical support and thermal management. The composite structure is designed to manage heat dissipation while maintaining thermal stability
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 approach reduces manufacturing time and costs by allowing precise packaging and testing at the wafer level, minimizing delamination risks, and improving thermal management through the use of a metal support substrate.
Implementation Method 1
a metal support substrate with a coefficient of thermal expansion similar to the LED structure
Data Source
AI summary
Wafer-level packaging of solid-state transducers (“SSTs”) is disclosed herein. A method in accordance with a particular embodiment includes forming a transducer structure having a first surface and a second surface opposite the first surface, and forming a plurality of separators that extend from at least the first surface of the transducer structure to beyond the second surface. The separators can demarcate lateral dimensions of individual SSTs. The method can further include forming a support substrate on the first surface of the transducer structure, and forming a plurality of discrete optical elements on the second surface of the transducer structure. The separators can form barriers between the discrete optical elements. The method can still further include dicing the SSTs along the separators. Associated SST devices and systems are also disclosed herein.