Light-Emitting-Element Package Sealing via Stepped Metal Frame
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Solution Overview
Problem
Existing light-emitting-element mounting packages face challenges in achieving airtight sealing due to insufficient solder application at joining surfaces, leading to potential leaks.
Innovation Solution
The package design incorporates a metal substrate and frame with inclined or stepped portions that allow for increased application of joining material, ensuring a larger area is sealed, including the use of metal alloys like Kovar and silver solder for enhanced joining performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the frame is formed by brazing the metal member and the insulating member together, and is brazed to the top surface of the metal substrate, then the joining is completed, but the areas of joining surfaces are limited and the amount of solder supplied to each joining surface is insufficient
Solution Approach 1:
The patent introduces a stepped structure that extends the joining surface in the vertical dimension. The first end surface is positioned at a first height from the bottom surface, while the second end surface is positioned at a second height greater than the first height. This dimensional change creates multiple joining surfaces at different levels, increasing the total joining surface area available for solder application and improving airtight sealing.
2Reliability
If the amount of solder is very small, then the joining is completed, but a leak will occur between the inside and outside of the package
Solution Approach 1:
The stepped structure with multiple end surfaces at different heights creates additional space and surface area for solder application. The first end surface at the first height and the second end surface at the second height provide multiple joining interfaces, allowing a larger total amount of solder to be supplied and distributed across multiple surfaces, thereby preventing leaks while maintaining reliable joining.
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 effectively seals the package by applying a larger amount of joining material over a greater area, ensuring reliable airtightness and improved joining performance, which enhances the package's sealing capabilities.
Implementation Method 1
A joining material joins the substrate and the frame together. The joining material is disposed between the front surface of the substrate and a part of the substrate-side end portion of the frame that opposes the front surface of the substrate.
Data Source
AI summary
A light-emitting-element mounting package includes a substrate and a frame that are each made of a metal. The substrate includes a front surface and a back surface that oppose each other, and is provided with a mounting portion for a light emitting element at the front surface. The frame stands on the front surface of the substrate and includes an inner side surface that surrounds the mounting portion and an outer side surface. A substrate-side end portion of the frame includes a curved inclined surface (inclined portion) in a region near the outer side surface. The curved inclined surface is inclined toward a center of the frame in a thickness direction. A silver solder (joining material) is provided between the front surface of the substrate and the frame.