Conductive Pattern Printing via Controlled Thermal Nip
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Solution Overview
Problem
Existing methods for producing conductive patterns in printed electronics often result in unpredictable spreading and solidification of conductive materials, leading to defects such as short-circuiting and cracking, which compromises the electrical connections and aesthetic quality of the final product.
Innovation Solution
A method involving the use of electrically conductive solid particles heated above their melting point and pressed against a substrate in a controlled nip, where the temperature is lower than the melting point, ensuring equal thermal masses for contact areas and adjacent conductive structures to form a continuous, reliable conductive layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive particles are heated and pressed to bond them together through melting and solidification, then electrical conductivity is achieved, but uncontrolled spreading and deformation occur causing short-circuits and manufacturing defects
Solution Approach 1:
The patent applies parameter changes by carefully controlling the temperature profile during the bonding process. The temperature is raised above the melting point of the conductive particles to enable bonding, then rapidly reduced below the melting point to prevent spreading. This dynamic parameter control allows the material to be molten only briefly for bonding while maintaining pattern integrity throughout the process.
Solution Approach 2:
The patent implements periodic action through a multi-stage temperature process: heating phase (temperature increases above melting point), bonding phase (brief maintenance at elevated temperature), and cooling phase (rapid temperature reduction below melting point). This periodic temperature variation enables controlled melting and solidification that achieves electrical conductivity without uncontrolled spreading or deformation.
2Strength
If conductive particles are melted and pressed against substrate, then bonding strength is improved, but cracking occurs during solidification weakening electrical connections
Solution Approach 1:
The patent uses parameter changes by implementing a controlled temperature cycle that raises the temperature above the melting point to enable strong bonding, then rapidly reduces it below the melting point to prevent cracking during solidification. This dynamic temperature control allows the material to bond strongly while maintaining structural integrity and avoiding cracks that would compromise electrical connections.
Solution Approach 2:
The patent applies the skipping principle by rapidly transitioning through the critical temperature zone. The temperature is quickly raised above the melting point for bonding, then rapidly reduced below it to complete solidification before cracks can form. This rushed transition through the phase change region minimizes the time the material spends in a vulnerable state where cracking could occur.
3Reliability
If conductive material is spread to form continuous layers, then electrical conductivity is achieved, but resolution and detail of conductive structures are lost
Solution Approach 1:
The patent applies parameter changes by controlling the temperature profile to enable just enough spreading for electrical continuity while preventing excessive spreading that would blur pattern details. The rapid heating above melting point allows controlled flow for bonding, and the rapid cooling below melting point freezes the pattern in sharp detail. This parameter control achieves the dual goal of electrical conductivity and high resolution.
Solution Approach 2:
The patent implements periodic action through a controlled temperature cycle: heating phase enables material flow for bonding without excessive spreading, bonding phase maintains temperature for continuous layer formation, and cooling phase rapidly solidifies the material to preserve fine pattern details. This periodic temperature variation allows the material to flow only when necessary while maintaining pattern resolution throughout the process.
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 uncontrolled spreading and smearing, prevents short-circuits, and achieves improved resolution and accuracy in conductive patterns, enhancing the industrial yield and aesthetic design by maintaining the intended shape and size of the conductive elements.
Implementation Method 1
heating the conductive particles to a temperature higher than a characteristic melting point of the particles to establish a melt
Implementation Method 2
pressing the melt against the substrate in a nip, the temperature of the contact portion of which being lower than the aforesaid characteristic melting point so as to solidify the particles into essentially electrically continuous layer
Data Source
AI summary
A method (200, 300, 500) for producing an electrically conductive pattern on substrate (202, 402), comprising: providing electrically conductive solid particles onto an area of the substrate in a predefined pattern (508), where the pattern (403) comprises a contact area (404B) for connecting to an electronic component and a conductive structure (404A) having at least a portion (414) adjacent to the contact area, heating the conductive particles to a temperature higher than a characteristic melting point of the particles to establish a melt (510), and pressing the melt against the substrate in a nip, the temperature of the contact portion of which being lower than the aforesaid characteristic melting point so as to solidify the particles into essentially electrically continuous layer within the contact area and within the conductive structure in accordance with the pattern (512), wherein the thermal masses of the contact area and the at least adjacent portion of the conductive structure are configured substantially equal.