Wafer-Scale Hermetic Sealing for Semiconductor Light Emitting Devices

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Solution Overview

Problem

Current methods for mounting semiconductor light-emitting devices on substrates often lead to contamination during processing steps like dicing and application of wavelength converting materials, as they do not provide a hermetic seal at the wafer scale.

Innovation Solution

A wafer-scale method is developed where a semiconductor light emitting device wafer is attached to a support substrate wafer, with thick metal layers and an insulating material forming a seal around each device, preventing contamination during subsequent processing steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If semiconductor light-emitting devices are mounted on substrates using conventional methods, then the devices can be attached to substrates, but contamination occurs during processing steps like dicing and application of wavelength converting materials

Engineering Contradiction:
Improvedevice integrityVSAvoidcontamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the substrate into multiple separate recesses, each containing a semiconductor light-emitting device. This segmentation isolates each device within its own enclosed space, preventing contamination from affecting other devices during processing steps like dicing and wavelength converting material application.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The semiconductor light-emitting device is nested within a recess in the substrate, creating a hierarchical structure where the device is contained within the substrate cavity. This nesting provides hermetic sealing that protects the device from contamination while maintaining electrical and thermal connections.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If conventional mounting methods are used, then devices can be attached to substrates, but hermetic sealing is not achieved at wafer scale

Engineering Contradiction:
Improvehermetic sealVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The recesses are formed in the substrate before the semiconductor light-emitting devices are mounted. This preliminary action creates pre-prepared enclosed spaces that will provide hermetic sealing once the devices are attached, eliminating the need for post-attachment sealing operations and enabling wafer-scale manufacturing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The recess structure acts as an intermediary element between the semiconductor device and the external environment. It provides a hermetic barrier that seals the device while still allowing for electrical connections through conductive paths and thermal management, without requiring complex additional sealing components.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If devices are mounted without sealed structures, then manufacturing is simpler, but contamination occurs during dicing and processing

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcontamination during processing
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The substrate is segmented into multiple recesses that naturally provide containment for each device. This segmentation approach provides hermetic sealing through the substrate structure itself, avoiding the need for additional complex sealing components while protecting devices from contamination during processing.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2831930B1Sealed semiconductor light emitting device and method of forming thereof
Publication Date: 2018.09.19 LUMILEDS HLDG BV
  • EP2831930B1 patent drawingFigure 1~4
  • EP2831930B1 patent drawingFigure 5~9
  • EP2831930B1 patent drawingFigure 10~14

AI summary

A method according embodiments of the invention includes providing a wafer of semiconductor devices. The wafer of semiconductor devices includes a semiconductor structure comprising a light emitting layer sandwiched between an n-type region and a p-type region. The wafer of semiconductor devices further includes first and second metal contacts for each semiconductor device. Each first metal contact is in direct contact with the n-type region and each second metal contact is in direct contact with the p-type region. The method further includes forming a structure that seals the semiconductor structure of each semiconductor device. The wafer of semiconductor devices is attached to a wafer of support substrates.