Direct-Written Bus Bars for Adhesive-Free Conductive Ink Circuits

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Traditional screen printed resin-based conductive ink circuits face challenges in achieving robust adhesion of bus bars due to the need for specialized adhesive curing and handling, which can be compromised by inexperienced workers.

Innovation Solution

Direct writing of metal or alloy bus bars, such as copper, onto screen printed conductive ink circuits using technologies like MesoPlasma ™< thermal spray or Aerosol Jet ®< , eliminating the need for adhesives and curing, thereby enhancing adhesion and manufacturing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conductive adhesive is used to bond bus bars to screen printed resin-based conductive ink, then electrical connection is achieved, but adhesion robustness deteriorates due to curing requirements and specialized handling

Engineering Contradiction:

Improveadhesion robustnessVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the conductive adhesive layer from the bonding process, eliminating the need for curing and specialized handling. Bus bars are directly bonded to the screen printed conductive ink traces through direct writing techniques, extracting the problematic adhesive component while maintaining electrical connection functionality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates an asymmetric bonding interface where the bus bar material composition is specifically tailored to bond directly with the conductive ink trace material. This asymmetric material pairing enables direct adhesion without requiring a separate adhesive layer, simplifying the overall structure while improving reliability.

Inventive Principle:

Principle #4Asymmetry

2Ease of manufacture

If conductive adhesive and curing process are used, then bus bar attachment is achieved, but manufacturing time and labor costs increase

Engineering Contradiction:

Improveattachment processabilityVSAvoidcuring time

Core Design Contradiction:

Ease of manufactureVSLoss of time

Solution Approach 1:

The bus bar material is prepared in advance with surface characteristics and composition optimized for direct bonding to conductive ink. This preliminary material preparation eliminates the need for post-deposition curing processes, allowing immediate attachment without time-consuming adhesive curing steps.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent skips the entire adhesive curing phase by using direct writing bonding technology. The process rushes through the attachment step in a single operation without the intermediate curing wait time, significantly reducing total manufacturing cycle time while maintaining attachment quality.

Inventive Principle:

Principle #21Skipping (Rushing through)

3Reliability

If traditional adhesive bonding method is used, then electrical connection is established, but adhesion quality deteriorates when workers lack experience

Engineering Contradiction:

Improveconnection robustnessVSAvoidoperator skill requirement

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The direct writing bonding process is self-regulating and does not require operator judgment or skill for adhesive application. The system automatically controls material deposition and bonding parameters, making the process self-service oriented and independent of worker experience levels, thereby ensuring consistent adhesion quality.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the manual mechanical adhesive application process with an automated direct writing system. This substitution eliminates the need for operator skill in adhesive handling and application, as the automated system precisely controls material placement and bonding, ensuring reliable connections regardless of worker experience.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 method provides superior bus bar attachment with improved adhesion and reduced labor time and costs, ensuring robust electrical connections without the need for specialized adhesive handling.

Implementation Method 1

direct writing alloy and/or metal bus bars, e.g. copper bus bars, onto areas of a desired electrical connection, e.g. desired electrical connection areas, of the conductive ink. The step of direct writing includes forming a conformal layer of the copper bus bars on the conductive ink

Methodology Applied

Scientific EffectDirect writing deposition: Deposition (physical)

Data Source

PatentEP2863720B1Direct writing bus bars for screen printed resin-based conductive inks

Publication Date: 2025.11.26 GOODRICH CORP

Figure 1~2
Figure 3~4
Figure 5

AI summary

A method for providing an electrical connection (107; 207; 307) for conductive ink (102; 202; 302) includes direct writing a bus bar (104; 204; 304) onto areas of a desired electrical connection of the conductive ink. The conductive ink is screen printed onto a dielectric film (106; 206; 306) to create a conductive circuit. An aircraft heated floor panel (200) includes at least one floor panel (203) of an aircraft. The one floor panel includes a conductive circuit (201) having a conductive ink (202) including a bus bar (204) directly written onto areas of a desired electrical connection (207) of the conductive ink. The conductive ink is screen printed onto a dielectric film (206) to create a conductive circuit.