LED Module with Integrated FET for Compact Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED modules face challenges in reducing size and thickness while ensuring stable operation under supply voltage fluctuations, and they often require increased fabrication steps when mounting LED dies and bare-chip semiconductor devices on the same side of the circuit substrate.
Innovation Solution
The LED module incorporates a circuit substrate with LED dies, an FET die for current limiting, and a constant current circuit, all mounted on the same side, along with a dam for separation and coverage with fluorescent resin, to reduce size and thickness while maintaining stable operation and minimizing fabrication steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LED dies and driver circuit are mounted on opposite sides of the circuit substrate, then stable operation is ensured, but the module thickness increases
Solution Approach 1:
The patent merges the driver circuit and LED dies into the same mounting surface (circuit substrate) by implementing a current limiting circuit that integrates FET die, resistors, and capacitors alongside the LED dies. This consolidation eliminates the need for separate mounting surfaces, thereby reducing module thickness while maintaining functional stability through proper circuit design.
Solution Approach 2:
The patent transitions from a three-dimensional stacked arrangement (driver circuit on one side, LED dies on the other) to a two-dimensional planar integration on the same circuit substrate surface. This dimensional change allows all components to coexist on the same plane, reducing the thickness dimension while preserving electrical functionality through careful layout and connection design.
2Area of stationary object
If driver circuit size is reduced to fit on the same side as LED dies, then module size is reduced, but operation stability deteriorates under voltage fluctuations
Solution Approach 1:
The patent employs parameter changes by selecting specific component values and characteristics - using depletion-mode FETs with appropriate threshold voltages, selecting resistor values that provide proper current limiting, and choosing capacitor values for adequate decoupling. These parameter optimizations enable a compact circuit design that maintains stability under voltage fluctuations despite the reduced size constraint.
Solution Approach 2:
The current limiting circuit incorporates feedback mechanisms where the FET die regulates current based on voltage conditions, and capacitors provide voltage stabilization feedback. This feedback control ensures that even in a compact configuration, the circuit maintains stable operation under supply voltage fluctuations by automatically adjusting component operation based on real-time electrical conditions.
3Area of stationary object
If LED dies and integrated circuit are mounted on the same side, then module size is reduced, but the number of fabrication steps increases
Solution Approach 1:
The patent segments the circuit into distinct functional blocks (LED die mounting regions, FET die mounting regions, resistor mounting regions, capacitor mounting regions) that are spatially separated on the same substrate. This segmentation allows each component type to be mounted and processed independently using standardized procedures, avoiding the need for complex integrated fabrication processes while achieving compact overall size.
Solution Approach 2:
The circuit substrate serves multiple functions simultaneously: it provides mechanical support for all components, electrical interconnection between components, thermal management pathways, and structural integration for the entire module. This multi-functionality consolidates what would otherwise require separate fabrication and assembly steps into a single unified platform, reducing overall fabrication complexity.
Data Source
AI summary
The purpose of the present invention is to reduce the size and thickness of an LED module in which a plurality of LED dies along with other electronic components are mounted on a circuit board, and at the same time to stabilize the operation of the module with respect to source voltage fluctuation. The LED module includes: a circuit board; a plurality of LED dies that are mounted on one surface of a circuit board as bare chips and constitute a series circuit; an FET die that is mounted on the one surface of a circuit board as bare chips and controls a current flowing through the plurality of LED dies; and a constant current circuit that is mounted on the one surface of a circuit board and is series-connected to the series circuit. The constant current circuit includes the FET die.