Flexible Substrate Metal Wire Embedding via Debonding Layer
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Solution Overview
Problem
Existing methods for producing flexible substrates with metal wire embeddings face challenges such as high material consumption, thermal damage, and defects due to complex processing steps and sacrificial layer removal, which complicates the fabrication of flexible electronic devices like displays and solar cells.
Innovation Solution
A laminate structure comprising a carrier substrate, a debonding layer with a polyimide resin, and a flexible substrate layer with metal wiring, where the adhesion strength between the metal wiring and flexible substrate is greater than between the metal wiring and the debonding layer, allowing for easy separation using a physical stimulus without chemical changes, thereby simplifying the production process and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching techniques are used to form metal wire patterns, then metal wires can be formed on substrate, but large amounts of materials are consumed and processing steps become complicated
Solution Approach 1:
The invention extracts the metal wire formation process from the substrate and forms it on a separate carrier substrate first. The metal wires are deposited and patterned on the carrier substrate, then the carrier substrate with embedded metal wires is transferred to the final flexible substrate. This separation eliminates the need for repeated deposition and etching steps on the flexible substrate, reducing both material consumption and processing complexity.
Solution Approach 2:
The metal wire formation is performed in advance on the carrier substrate before transferring to the flexible substrate. By preliminarily forming the metal wire pattern on the carrier substrate, the invention avoids the need for subsequent deposition and etching steps on the flexible substrate, thereby simplifying the overall manufacturing process and reducing material consumption.
2Manufacturing precision
If thermal treatment is applied to metal layer in plastic substrate, then metal wires can be formed, but thermal damage occurs to the plastic substrate
Solution Approach 1:
The invention segments the manufacturing process into two independent stages: (1) forming metal wires on a carrier substrate that can withstand thermal treatment, and (2) transferring the metal wire-embedded carrier substrate to the flexible plastic substrate. This segmentation allows thermal treatment to be applied to the carrier substrate without damaging the plastic substrate, as the plastic substrate is not present during the thermal processing step.
Solution Approach 2:
The carrier substrate acts as an intermediary that temporarily holds the metal wires during formation and patternning. This intermediary carrier substrate enables thermal treatment of the metal layer without exposing the final plastic flexible substrate to damaging temperatures. The carrier substrate is removed after transferring the metal wire pattern to the flexible substrate.
3Ease of manufacture
If hard substrate is forcibly peeled from metal wire embedded polymer substrate, then substrate can be separated, but damage occurs to metal wires and polymer substrate
Solution Approach 1:
A debonding layer is preliminarily formed between the carrier substrate and the metal wire embedded flexible substrate. This debonding layer is specifically designed to have controlled adhesion properties that allow easy separation. The presence of this pre-formed debonding layer enables gentle peeling without forcing the separation, thereby preventing damage to the metal wires and polymer substrate while still achieving easy substrate separation.
4Ease of manufacture
If sacrificial layer is removed by dissolution in water or organic solvent, then flexible substrate can be separated from carrier substrate, but treatment costs increase
Solution Approach 1:
The invention extracts the separation mechanism from chemical dissolution and replaces it with mechanical peeling facilitated by a specially designed debonding layer. The debonding layer is engineered to have low adhesion strength to the carrier substrate, allowing the flexible substrate to be peeled off mechanically without requiring water or organic solvent treatment. This extraction of the chemical treatment step eliminates the associated costs and environmental concerns.
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 enables the easy separation of flexible substrates from the carrier substrate without laser or light irradiation, reducing fabrication costs and preventing defects, while maintaining the integrity of metal wires and reducing sheet resistance, making the substrate suitable for flexible devices.
Implementation Method 1
a debonding layer which is disposed on at least one surface of the carrier substrate and comprises a polyimide resin
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The present invention relates to a method for producing a metal wire embedded flexible substrate from a laminate structure. The laminate structure includes a carrier substrate, a debonding layer disposed on at least one surface of the carrier substrate and including a polyimide resin, a metal wiring layer disposed in contact with the debonding layer, and a flexible substrate layer disposed in contact with the metal wiring layer. The adhesion strength between the metal wiring layer and the flexible substrate layer is greater than that between the metal wiring layer and the debonding layer. According to the method of the present invention, the flexible substrate with the metal wiring layer can be easily separated from the carrier substrate even without the need for other processes, such as laser and light irradiation. The embedding of the metal wires in the flexible substrate layer decreases the sheet resistance of an electrode and can protect the metal wires from damage or disconnection even when the flexible substrate is deformed in shape.