Silicon Substrate LED Packaging with Integrated Circuits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing surface-mounted LED structures face issues with poor temperature tolerance, non-ideal heat dissipation, and difficulty in miniaturization due to metal brackets, and they require complex and costly processes with gold wire connections, which are prone to failure and limit integration of peripheral circuits.
Innovation Solution
A surface-mounted LED structure using a silicon substrate with a planar upper surface, oxide layers, metal electrode layers, and flip-chip mounting with metal bumps, integrating peripheral functional circuits and a colloidal lens for improved heat dissipation and reliability, eliminating the need for gold wires and deep grooves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a metal bracket is used as the packaging substrate, then the LED structure can be assembled, but the temperature tolerance is poor and heat dissipation is non-ideal
Solution Approach 1:
The patent changes the substrate material from metal bracket to silicon substrate, fundamentally altering the thermal parameters. Silicon provides superior temperature tolerance and heat dissipation capabilities compared to metal brackets, directly resolving the thermal management issues while maintaining manufacturing feasibility through established semiconductor fabrication processes
Solution Approach 2:
The patent employs a composite structure combining silicon substrate with oxide layers and metal electrode layers. This multi-material approach leverages the excellent thermal properties of silicon while adding functional layers for electrical connection and protection, achieving both thermal performance and manufacturing ease
2Reliability
If gold wires are used for connecting electrodes, then electrical connection can be achieved, but connection failure is the most common failure mode
Solution Approach 1:
The patent extracts and eliminates the gold wire connection component entirely. By using a silicon substrate with integrated metal electrode layers and vias, the design removes the separate gold wire bonding step, thereby eliminating the primary failure mode associated with wire connections while simplifying the overall structure
Solution Approach 2:
The patent merges the electrical connection function into the substrate itself. The silicon substrate integrates the mechanical support, thermal management, and electrical connection functions through built-in metal electrode layers and vias, eliminating the need for separate gold wire connectors and improving reliability
3Ease of manufacture
If a deep groove is dug on the upper surface of the silicon wafer, then the LED chip can be embedded, but the process becomes complex and costly with difficulty in internal wiring
Solution Approach 1:
The patent inverts the traditional approach by placing metal electrode layers on the upper surface of the silicon substrate before mounting the LED chip. This reversal eliminates the need for deep grooves and complex internal wiring, as connections are established through vias and surface-mounted electrodes, significantly simplifying the manufacturing process
Solution Approach 2:
The patent performs preliminary actions by pre-forming the metal electrode layers and vias on the silicon substrate before LED chip mounting. This advance preparation of electrical connection structures eliminates the need for complex post-mounting wiring and deep groove fabrication, reducing both process complexity and precision requirements
4Temperature
If the LED chip is face-up mounted, then the structure is simple, but heat dissipation is poor and gold wire connection is required
Solution Approach 1:
The patent inverts the traditional face-up mounting approach by using face-down mounting with the LED chip's light-emitting surface facing the silicon substrate. This inversion enables direct thermal contact between the chip and substrate for superior heat dissipation while allowing metal bumps to provide electrical connection, eliminating the need for gold wires
Solution Approach 2:
The patent replaces the mechanical gold wire bonding system with a direct mechanical and thermal contact system. The LED chip is mounted face-down with direct contact to the silicon substrate, providing both structural support and thermal management, while electrical connection is achieved through metal bumps rather than flexible wires
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
The solution provides enhanced thermal performance, reduced volume, lower costs, and increased stability by directly integrating functional circuits on the silicon substrate, enabling reliable multi-chip modules and large-scale production with improved heat management.
Implementation Method 1
an oxide layer covering the upper surface of the silicon substrate, with two metal electrode layers for connecting positive and negative electrodes respectively, arranged in the upper surface of the oxide layer and insulated from each other
Implementation Method 2
Two conductive metal pads are respectively arranged on the lower surface of said silicon substrate, and said conductive metal pads are electrically connected to the metal electrode layers on the upper surface of the silicon substrate by a metal lead arranged on the side wall of the silicon substrate
Implementation Method 3
A heat conduction metal pad is arranged on the corresponding lower surface of the silicon substrate just below the LED chip
Data Source
AI summary
The present invention relates to a surface mounted LED structure of integrating functional circuits on a silicon substrate, comprising the silicon substrate and an LED chip. Said silicon substrate has an upper surface of planar structure without grooves. An oxide layer covers the upper surface of the silicon substrate, and metal electrode layers are arranged in the upper surface of the oxide layer. The upper surfaces of said metal electrode layers are arranged with metal bumps, and the LED chip is flip-chip mounted to the silicon substrate. Two conductive metal pads are arranged on the lower surface of said silicon substrate, said conductive metal pads are electrically connected to the metal electrode layers on the upper surface of the silicon substrate by a metal lead arranged on the side wall of the silicon substrate. A heat conduction metal pad is arranged on the corresponding lower, surface of the silicon substrate just below the LED chip. Peripheral functional circuits required by LED are integrated on the upper surface of said silicon substrate. The structure of the present invention has advantages of good heat dissipation effect and small volume, and direct integration of functional circuits such as protection and drive circuits etc. in the silicon substrate achieves large-scale production package of wafer level, reducing the cost of packaging and lighting fixture.