Conductive Film Patterning for Transparency and Low Wire Resistance
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Solution Overview
Problem
Existing conductive films used in optoelectronic devices face challenges in maintaining low wire resistance while ensuring adequate light transparency, as thicker electrodes to reduce resistance impair light transmission, and materials like organic semiconductor materials and PTFE are unstable during deposition, affecting device performance.
Innovation Solution
A conductive film with two regions of differing light transmittance, using a first film of conductive material and a second film of fluorinated polymer, where the fluorinated polymer has specific thermal stability and molecular weight properties to ensure stable deposition and high light transparency, and a method involving dry coating and masking to pattern the films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of the electrode is increased to reduce sheet resistance, then wire resistance is reduced, but light transparency decreases
Solution Approach 1:
The conductive film is designed with different thicknesses in different regions: a first region with relatively low light transmittance (thicker) and a second region with relatively high light transmittance (thinner). This local variation in thickness allows the film to provide adequate conductivity where needed while maintaining light transparency in other areas, thus resolving the contradiction between reducing wire resistance and maintaining light transparency.
2Ease of manufacture
If organic semiconductor materials or PTFE are used to suppress metal film formation, then patterned conductive films can be formed, but the materials are easily depolymerized or thermally decomposed during deposition
Solution Approach 1:
The patent specifies precise thermogravimetric parameters for the fluorinated polymer: (1) the temperature at which the thermogravimetric loss rate substantially reaches 100% is 400°C or lower, and (2) the temperature width from 10% to 90% loss rate is within 200°C. These parameter constraints ensure the material decomposes at controlled temperatures during deposition, preventing depolymerization while enabling effective pattern formation through selective metal film suppression.
3Stability of the object's composition
If fluorinated polymer with narrow decomposition temperature range is used, then stable pattern formation is achieved, but deposition process control becomes more difficult
Solution Approach 1:
The patent performs preliminary characterization of the fluorinated polymer's thermogravimetric properties before the deposition process. By pre-determining that the temperature width from 10% to 90% loss rate is within 200°C and the 100% loss temperature is 400°C or lower, the deposition process can be optimized in advance with appropriate temperature profiles and heating rates, simplifying real-time process control while ensuring stable pattern formation.
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 a conductive film with balanced conductivity and transparency, enabling stable production and improved device performance by avoiding material degradation and ensuring uniform film thickness.
Implementation Method 1
when the temperature is increased at a temperature-increasing rate of 2° C./min under a pressure of 1×10−3 Pa, the temperature at which the thermogravimetric loss rate substantially reaches 100% is 400° C. or lower
Implementation Method 2
a method of preliminary forming a patterned film by a material which suppresses formation of a metal film, and then forming a metal film to overlap with the patterned film e.g. by deposition or sputtering
Data Source
AI summary
To provide a novel conductive film having two regions differing in the light transmittance, an optoelectronic device having such a conductive film, and a method for producing a conductive film by which such a conductive film can readily be produced.A conductive film, which has a first region and a second region having a light transmittance higher than the first region,the conductive film having a first film formed of a conductive material as a material and a resin film formed of a fluorinated polymer as a material,the first film being disposed to overlap with at least the first region among the first region and the second region,the resin film being disposed to overlap with the second region, andthe fluorinated polymer satisfying the following (1) and (2):(1) when the temperature is increased at a temperature-increasing rate of 2° C./min under a pressure of 1×10−3 Pa, the temperature at which the thermogravimetric loss rate substantially reaches 100% is 400° C. or lower;(2) when the temperature is increased at a temperature-increasing rate of 2° C./min under a pressure of 1×10−3 Pa, the temperature width from a temperature at which the thermogravimetric loss rate is 10% to a temperature at which it is 90%, is within 200° C.