Continuous Lamination of Multi-Layer Flexible PCBs
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Solution Overview
Problem
Existing methods for manufacturing multi-layer flexible printed circuit boards (PCBs) are inadequate for handling patterned conducting layers with varying thickness and topology, leading to misalignment and creasing issues during lamination, particularly when trying to produce PCBs of arbitrary length.
Innovation Solution
A method utilizing a double belt press with continuous lamination and alignment features like through holes, along with a process of patterning and fixing substrates before lamination, to ensure precise alignment and bonding of substrates with patterned conducting layers, allowing for the production of multi-layer flexible PCBs of arbitrary length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If nip roller press is used for lamination, then continuous processing is achieved, but misalignment and layer creasing occur due to varying line force on patterned layers
Solution Approach 1:
The patent changes the fundamental lamination parameter from line force (nip roller) to distributed areal pressure (flat press), enabling uniform pressure application across patterned layers of varying thickness without causing misalignment or creasing
Solution Approach 2:
The patent introduces alignment features (through-holes with alignment pins or fiducial markers) as intermediary elements that maintain precise layer registration during the lamination process, eliminating misalignment issues
2Manufacturing precision
If static press is used for multi-layer lamination, then alignment precision is improved, but processing duration exceeds one hour limiting maximum PCB size
Solution Approach 1:
The patent performs preliminary alignment of layers using alignment features (through-holes and alignment pins) before applying pressure, allowing the lamination process to proceed quickly without requiring extended pressing time for alignment adjustment
Solution Approach 2:
The patent divides the lamination process into distinct stages: preliminary alignment using alignment features, then rapid bonding under controlled pressure and temperature, enabling efficient processing of large multi-layer PCBs
3Productivity
If continuous lamination is used for arbitrary length PCBs, then productivity is improved, but uniform pressure and temperature application becomes difficult
Solution Approach 1:
The patent employs a flat press system that provides universal areal pressure distribution across the entire PCB surface regardless of length, maintaining uniform pressure and temperature application for continuous production of arbitrary length PCBs
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 successful lamination of substrates with non-uniform thickness and topology, overcoming the limitations of traditional methods by allowing for long-duration, uniform pressure and temperature application, resulting in accurately aligned and bonded multi-layer flexible PCBs of extended lengths.
Implementation Method 1
a bondfilm comprising an adhesive layer
Implementation Method 2
laminating them together using a double belt press through which the substrates move in a continuous process
Implementation Method 3
allowing for long-duration, uniform pressure and temperature application
Data Source
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AI summary
A method of manufacturing a multilayer flexible circuit comprises providing first and1 second flexible substrates, each comprising a conductor layer and an insulator Iayer. The conductor layer of the first substrate is a patterned conductor Iayer. The first and second substrates are laminated together using a double belt press through which the substrates move in a continuous process. The method may include patterning the conductor layer of the first substrate and/or the conductor layer of the second substrate using an etching method that includes exposing a dry film resist on the conductor layer to a pattern by carrying out a plurality of exposures of adjacent and/or overlapping areas.