Multi-Junction LED Package Layout for Matched Forward Voltage
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Solution Overview
Problem
Conventional LED packages face challenges in producing high-quality light with desired emission characteristics while maintaining high light emission efficiency due to varying forward voltages of LED chips with different material systems, leading to complex electrical connections and non-uniform light emissions.
Innovation Solution
The arrangement of multiple-junction LED chips in LED packages with single-junction chips, where the multiple-junction chips have forward voltages similar to the single-junction chips, allowing for a common anode or cathode connection, thereby simplifying electrical connections and enabling uniform light emission across different colors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LED chips with different material systems and emission colors are arranged in close proximity on a common submount, then the device can provide multiple color emissions, but the electrical connection complexity increases due to varying forward voltages
Solution Approach 1:
The patent applies parameter changes by configuring multiple-junction LED chips to have forward voltages within 25% (preferably within 15%) of single-junction LED chips. This voltage parameter matching enables simplified common anode or common cathode electrical connections across different LED chip types and emission colors, resolving the contradiction between multi-color capability and electrical connection complexity
Solution Approach 2:
The patent implements universality by designing LED packages where multiple-junction and single-junction LED chips with different emission colors can all be connected to common anode or common cathode structures. This universal connection approach allows a single driver circuit to control multiple LED chips with varying forward voltages, reducing electrical complexity while maintaining multi-color emission capability
2Adaptability or versatility
If multiple LED chips with different forward voltages are used to achieve diverse emission characteristics, then the color gamut is improved, but non-uniform light emissions occur due to voltage mismatches
Solution Approach 1:
The patent resolves the uniformity issue by changing the forward voltage parameter of multiple-junction LED chips to match single-junction chips. By ensuring forward voltages are within 25% of each other, the patent achieves uniform light emission across different LED chips while maintaining diverse emission characteristics through different junction configurations and material systems
3Reliability
If separate driver circuits are used for LED chips with different forward voltages, then each chip can be optimally driven, but the device complexity and power losses increase
Solution Approach 1:
The patent applies universality by enabling a single driver circuit to optimally drive multiple LED chips with different emission colors and junction configurations. By matching forward voltages within 25%, the single driver can control multiple chips without requiring separate driver circuits, reducing complexity while maintaining optimal driving performance through unified current control
4Use of energy by moving object
If multiple LED chips are arranged in close proximity to maximize light output, then the luminous efficacy is improved, but heat generation and power losses increase due to electrical complexity
Solution Approach 1:
The patent reduces power losses by changing the electrical configuration to use common anode or common cathode connections with matched forward voltages. This parameter matching minimizes electrical complexity and associated power losses, allowing multiple LED chips to be arranged in close proximity for high luminous efficacy without excessive heat generation from inefficient electrical connections
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 configuration reduces electrical complexity, allows for uniform light emission, and enables the use of a single driver for all LED chips, minimizing heat generation and power losses.
Implementation Method 1
LEDs convert electrical energy to light and generally include one or more active layers of semiconductor material (or an active region) arranged between oppositely doped n-type and p-type layers. When a bias is applied across the doped layers, holes and electrons are injected into the one or more active layers where they recombine to generate emissions such as visible light or ultraviolet emissions.
Data Source
AI summary
Solid state light-emitting devices and more particularly arrangements of multiple-junction light-emitting diode (LED) chips in LED packages and corresponding LED displays are disclosed. Multiple-junction LED chips are arranged in LED packages with single-junction LED chips. Multiple-junction LED chips are configured to have forward voltages the same or similar to single-junction LED chips in the same LED package. Common anode or common cathode arrangements for multiple-junction and single-junction LED packages are disclosed. Multiple-junction LED chips configured to provide different emission wavelengths than single-junction LED chips while also having same or similar forward voltages are disclosed.