Printable Diode Suspension for Low-Cost LED Manufacturing

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Solution Overview

Problem

Current methods for manufacturing light emitting and photovoltaic devices are costly and labor-intensive, making them unsuitable for widespread consumer and business adoption due to the complexity and expense of traditional semiconductor wafer-based processes.

Innovation Solution

A composition of fully formed semiconductor diodes suspended in a liquid or gel medium, enabling them to be printed using screen printing or flexographic techniques, with a solvent and viscosity modifier mixture that maintains diodes in a functional state for extended periods, allowing for the creation of LED-based devices and photovoltaic panels with reduced manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional semiconductor wafer-based processes are used to manufacture LEDs and photovoltaic devices, then device functionality and reliability are ensured, but manufacturing cost and labor intensity increase significantly

Engineering Contradiction:
Improvedevice functionalityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the diode structure from the traditional semiconductor wafer fabrication process and places it into a printable ink formulation. Individual diodes are removed from the wafer context and suspended in a liquid medium, allowing them to be deposited independently through printing processes rather than requiring complex wafer-level integration

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a liquid or gel medium as an intermediary carrier that suspends and transports diodes during the printing process. This medium acts as a bridge between the diode fabrication process and the final device assembly, enabling low-cost deposition while maintaining diode functionality

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If traditional semiconductor wafer-based processes are used to manufacture LEDs and photovoltaic devices, then device performance is maintained, but production time and labor intensity increase

Engineering Contradiction:
Improvedevice performanceVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent combines multiple discrete manufacturing steps (diode fabrication, packaging, wire bonding, assembly) into a single printing operation. By formulating diodes as printable ink, the process merges material deposition with device assembly, eliminating sequential manual operations and significantly reducing production time

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces complex mechanical assembly processes (sawing wafers, bonding wires, assembling packages) with a printing process. The printing mechanism deposits diodes directly onto substrates in their functional configuration, substituting multi-step mechanical operations with a single deposition step

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If diodes are suspended in a liquid solvent for printing, then ease of deposition is achieved, but diodes settle out and clump together requiring active sonication

Engineering Contradiction:
Improveease of depositionVSAvoidsuspension stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent introduces a binder as an intermediary substance that mediates between the diodes and the solvent. The binder adsorbs to diode surfaces and provides steric or electrostatic stabilization, preventing aggregation while maintaining suspension流动性, thus eliminating the need for active sonication

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite ink formulation combining solvent, binder, and diodes into a stable suspension system. The binder component forms a protective interface around diodes, creating a composite structure that prevents direct diode-diode contact and aggregation, ensuring long-term suspension stability

Inventive Principle:
Principle #40Composite materials

4Ease of operation

If trapezoidal-shaped diodes are placed in solvent with matching holes in substrate, then self-assembly is achieved, but diodes settle rapidly and cannot be stored or printed

Engineering Contradiction:
Improveself-assembly capabilityVSAvoidsuspension stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent extracts the shape-dependent self-assembly mechanism and replaces it with a chemistry-based stabilization approach. Instead of relying on geometric matching for both assembly and suspension, the invention separates these functions: suspension stability is achieved through binder chemistry, while assembly is achieved through printed placement

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical parameters of the suspension medium by adding binder molecules that interact with diode surfaces. This chemical modification transforms the suspension from unstable (rapid settling) to stable (long-term storage capability), enabling printing applications

Inventive Principle:
Principle #35Parameter changes

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 approach reduces production costs and simplifies the manufacturing process, making LED-based lighting and photovoltaic devices more affordable and accessible for widespread use by enabling the production of functional diodes in a non-inert atmosphere using a printing process.

Implementation Method 1

a liquid or gel containing two-terminal integrated circuits or other semiconductor devices which are actually dispersed and suspended in the liquid or gel medium

Methodology Applied
Scientific EffectSuspension: Suspension

Implementation Method 2

quantum dots, which are functionalized or capped with organic molecules to be miscible in an organic resin and solvent

Methodology Applied
Scientific EffectSolvation: Solvation

Data Source

PatentEP2617781B1Printable composition of a liquid or gel suspension of diodes and method of using the same
Publication Date: 2020.11.25 NTHDEGREE TECHNOLOGIES WORLDWIDE INC
  • EP2617781B1 patent drawingFigure 1
  • EP2617781B1 patent drawingFigure 2
  • EP2617781B1 patent drawingFigure 3

AI summary

An exemplary printable composition of a liquid or gel suspension of diodes comprises a plurality of diodes, a first solvent and/or a viscosity modifier. In other exemplary embodiments a second solvent is also included, and the composition has a viscosity substantially between about 1,000 cps and about 25,000 cps at about 25° C. In an exemplary embodiment, a composition comprises: a plurality of diodes or other two-terminal integrated circuits; one or more solvents comprising about 15% to 99.9% of any ofN-propanol, isopropanol, dipropylene glycol, diethylene glycol, propylene glycol, 1-methoxy-2-propanol, N-octanol, ethanol, tetrahydrofurfuryl alcohol, cyclohexanol, and mixtures thereof; a viscosity modifier comprising about 0.10% to 2.5% methoxy propyl methylcellulose resin or hydroxy propyl methylcellulose resin or mixtures thereof; and about 0.01% to 2.5% of a plurality of substantially optically transparent and chemically inert particles having a range of sizes between about 10 to about 30 microns.