LED Display Module Using Through-Hole Interconnects

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The high manufacturing cost and complexity of COB LED modules due to the need for metal core PCBs with multiple layers and intricate conductive patterns, which also pose challenges in thermal resistance and noise control, necessitate a cost-effective and flexible design without bonding wires.

Innovation Solution

The design incorporates a printed circuit board with conductive pads, layers of molding compound, and a network of conductive tracks on the molding compound, eliminating the need for bonding wires by using through-holes and trenches filled with conductive material to connect LED chips to the PCB, along with a black resin layer for enhanced contrast and a transparent layer for color mixing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If metal core PCBs with multiple layers and intricate conductive patterns are used, then heat dissipation efficiency is improved, but manufacturing cost and device complexity increase

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidPCB structure complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent divides the heat dissipation function into separate components: the PCB substrate provides structural support and basic conduction, while dedicated thermal vias and heat sinks handle thermal management. This segmentation allows each component to be optimized independently, reducing overall complexity while maintaining heat dissipation efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces thermal vias as intermediary elements between the LED chips and the PCB ground plane. These vias act as thermal conduits that efficiently transfer heat without requiring the entire PCB to be a metal core structure, thereby reducing manufacturing cost and complexity while maintaining effective heat dissipation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If metal core PCBs with multiple layers are used, then heat dissipation is improved, but manufacturing cost increases

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The patent employs standard FR-4 PCB substrates instead of expensive metal core PCBs. By using conventional, inexpensive materials and adding targeted thermal management features (thermal vias, heat sinks), the design achieves effective heat dissipation at lower manufacturing cost, embodying the principle of using cheaper alternatives when full-performance materials are unnecessary.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent applies thermal management features locally rather than globally. Instead of making the entire PCB a metal core structure, thermal vias and heat sinks are strategically placed only where heat dissipation is needed (near LED chips), reducing material costs while maintaining effective thermal management.

Inventive Principle:

Principle #3Local quality

3Use of energy by moving object

If COB LED technology is used to increase LED density, then lumen-per-watt ratio is improved, but manufacturing complexity increases due to bonding wires and processes

Engineering Contradiction:

Improvelumen-per-watt ratioVSAvoidbonding process complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the bonding wire component from the COB LED structure. By using direct solder bump connections between LED chips and PCB pads, the design removes the unnecessary bonding wire layer, simplifying the manufacturing process while maintaining the high LED density and efficiency benefits of COB technology.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical bonding wire connection system with a direct electrical and mechanical connection via solder bumps. This substitution eliminates the need for delicate wire bonding processes, reducing manufacturing complexity and improving reliability while maintaining electrical connectivity and mechanical support.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Quantity of substance

If multi-layered PCBs with complex metal patterns are used, then LED density is improved, but noise control becomes difficult

Engineering Contradiction:

ImproveLED densityVSAvoidelectrical noise

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent segments the conductive paths into dedicated signal traces and ground planes. By separating high-frequency signal routes from ground returns and using controlled impedance traces, the design reduces electromagnetic interference and noise while accommodating high LED density, avoiding the noise problems associated with complex multi-layer metal patterns.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS10923024B2LED display module and method of making thereof

Publication Date: 2021.02.16 SCT

AI summary

An LED display module contains a PCB, one or more layers of molding compound disposed on the surface of the PCB, a network of conductive tracks disposed on a surface of the one or more layer of molding compound away from the PCB, a plurality of through-holes extending through the one or more layers of molding compound, and an array of LED chips disposed in the one or more layers of molding compound. Each of electrodes on the LED chip is connected to one of the conductive pads via a conductive path. The conductive path comprises a conductive material inside one of the plurality of the through-holes and a portion of the network of conductive tracks.