Light-Emitting Device Package Gastightness and Power Supply
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Solution Overview
Problem
Conventional light-emitting device mounting packages face challenges in supplying sufficient electrical power due to high electrical resistance in conductor portions and maintaining gastightness, especially when ceramic substrates are inserted into through holes with improper dimensional control.
Innovation Solution
A package design featuring a substrate, frame, lead terminal, and insulating member with a metalized layer, where the lead terminal penetrates through holes in both the substrate and insulating member, and is fixed via a collar portion, allowing for increased power supply and reliable gastightness without strict dimensional tolerance control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conductor portions formed of tungsten or molybdenum are used to supply electrical power to the light-emitting device, then the package structure is simple and easy to manufacture, but the electrical resistance is high which prevents sufficient electrical power supply
Solution Approach 1:
The patent changes the material parameter of the conductor portions from high-resistance materials (tungsten, molybdenum) to low-resistance materials (copper, aluminum, or their alloys). This parameter change directly reduces electrical resistance and enables sufficient electrical power supply to the light-emitting device while maintaining ease of manufacture through standard bonding wire or tab connection techniques.
2Ease of manufacture
If ceramic substrates are inserted into quadrangular through holes with loose dimensional tolerances, then the manufacturing process is simpler and more tolerant, but insertion becomes difficult or excessively large gaps are formed which fail to maintain gastightness
Solution Approach 1:
The patent segments the sealing function from the structural support function by introducing a separate sealing ring member that fits into the through hole. The ceramic substrate can be inserted with loose tolerances for structural support, while the sealing ring provides the gastight seal. This segmentation allows independent optimization of each component's dimensional requirements.
Solution Approach 2:
The sealing ring acts as an intermediary component between the through hole and the ceramic substrate. It compensates for dimensional variations and ensures gastightness even when the ceramic substrate dimensions vary within tolerance ranges. The sealing ring mediates the interface between these components to maintain reliable sealing.
3Reliability
If strict dimensional tolerance control is applied to through holes and ceramic substrates, then gastightness is maintained, but manufacturing complexity and difficulty increase
Solution Approach 1:
The patent divides the sealing function into a separate sealing ring component rather than relying on precise dimensional control of the ceramic substrate and through hole interface. This segmentation reduces the dimensional tolerance requirements for the main structural components while maintaining gastightness through the dedicated sealing element.
Solution Approach 2:
The sealing ring is a simple, inexpensive component that can be easily manufactured and replaced if necessary. By using this simple sealing element instead of requiring high-precision manufacturing of critical components, the overall device complexity is reduced while maintaining reliability.
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
Enables sufficient electrical power supply to the light-emitting device and maintains the package's gastightness effectively, reducing the risk of short circuits and thermal stress while allowing for easier assembly and reduced thermal conductivity requirements.
Implementation Method 1
a metalized layer is formed on the facing front surface to surround an opening of the second through hole on the facing front surface side
Implementation Method 2
the lead terminal penetrates the first through hole and the second through hole... enabling sufficient electrical power supply to the light-emitting device
Implementation Method 3
the lead terminal is fixed, via a collar portion radially extending from the lead terminal, to a region of the facing back surface around an opening of the second through hole
Implementation Method 4
an insulating member which has a facing front surface and a facing back surface... the insulating member is fixed to a region of the substrate or the frame around the first through hole
Implementation Method 5
maintain the gastightness of the space inside the package... the insulating member is fixed to a region of the substrate or the frame around the first through hole
Data Source
AI summary
A light-emitting device mounting package includes a substrate, a frame extending upward from the substrate and surrounding a mounting portion, a lead plate supported on the frame, and a ceramic plate having a facing front surface and a facing back surface on the opposite side. The frame has a first through hole through which the lead terminal extends. The ceramic plate has a second through hole, and a metalized layer formed on the facing front surface such that the metalized layer is spaced from an opening of the second through hole. The lead plate penetrates the first and second through holes and is fixed, via a collar portion, to a region of the facing back surface around an opening of the second through hole on the facing back surface side. The insulating member is fixed to a region around the first through hole via the metalized layer.