LED Package with Integrated ESD Protection and Reflective Substrate
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Solution Overview
Problem
Existing LED packages are larger than necessary due to multiple components, which hinders the development of compact portable display technologies like cell phones and handheld computers, where size reduction is crucial.
Innovation Solution
A package design featuring a semiconductor substrate with reflective metal-coated sidewalls, a hermetically sealed glass lid, and integrated ESD protection and electrical feed-through connections, which reduces component count and size by incorporating ESD protection circuitry and feed-through connections within the substrate, and uses a thin membrane for improved heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multiple components (thermally conductive sub-mount, heatsink slug, pre-molded thermoplastic lens, separate ESD protection circuitry) are used in the LED package, then the LED chip is protected and thermally managed, but the package size becomes much larger than the LED chip itself
Solution Approach 1:
The patent combines multiple separate components into a single integrated substrate. The ESD protection circuitry, thermal management functions, and mechanical support structures are merged into one substrate that directly bonds to the LED chip, eliminating the need for separate sub-mounts, heatsink slugs, and ESD protection circuitry components.
Solution Approach 2:
The substrate serves multiple functions simultaneously: it provides mechanical support for the LED chip, conducts heat away from the chip, offers ESD protection through integrated circuitry, and provides a mounting surface for optical elements. This multi-functionality reduces the overall component count and package size.
2Volume of moving object
If a thin membrane substrate is used to reduce package size, then the package becomes more compact, but heat transfer efficiency may be compromised
Solution Approach 1:
The substrate is constructed from composite materials that combine high thermal conductivity with mechanical strength. This allows the substrate to be thin for compact packaging while maintaining effective heat transfer from the LED chip through the substrate to the external environment.
3Volume of moving object
If ESD protection circuitry is integrated within the substrate, then the package size is reduced, but the substrate design becomes more complex
Solution Approach 1:
The substrate design segments different functional regions: areas dedicated to ESD protection circuitry, areas for thermal conduction, areas for LED chip mounting, and areas for optical element attachment. This segmentation allows each region to be optimized independently while maintaining overall compact integration.
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 design minimizes package size, enhances light efficiency by redirecting scattered light, improves reliability through hermetic sealing, and allows for closer packing of light elements, enabling smaller mobile devices and high-resolution displays.
Implementation Method 1
The sidewalls of the substrate recess can have a reflective coating wherein substantially all the sidewalls of the substrate recess are covered with the reflective coating. The metal coated sidewalls of the substrate recess can help to direct scattered light emitted by the light emitting element towards the transparent lid and out of the package.
Implementation Method 2
The transparent lid is hermetically sealed to the substrate, wherein the light emitting element is housed within the hermetically sealed region. By encapsulating the light emitting element within a hermetically sealed region, the reliability and lifetime of the encapsulated device can be improved.
Implementation Method 3
the substrate can include a thin membrane on which the light emitting element is supported to provide low thermal resistance for improved heat transfer
Data Source
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AI summary
A package (20) includes a substrate (26) with a recess (24) in which a light emitting element 028) is mounted. A surface of the substrate (26) forms an exterior surface of the package (20). A lid (22) may be attached to the substrate (26) to define a sealed region in which the light emitting element (28) is mounted. The lid (22) is transparent to a wavelength of light emitted by the light emitting element (28). Electrostatic discharge protection circuitry (40) in the substrate (26) is electrically coupled to the light emitting element (28).