Composite Thin Copper Foil Carrier Release Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The bonding strength between the carrier layer and the thin copper foil in flexible printed circuit boards (FPCBs) is poor and non-uniform due to the carrier layer sticking to the hot pressing roller during the manufacturing process, leading to issues like wrinkles, blisters, and premature peeling, which increases production costs and reduces the number of circuits per unit volume.
Innovation Solution
The use of benzotriazole (BTA) as an anti-stick agent on the carrier layer and silane coupling agents near the thin copper foil, along with a release layer, to prevent the carrier layer from sticking to the hot pressing roller and ensure proper adhesion and easy removal of the thin copper foil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the carrier layer is pressed under high temperature and pressure during hot pressing, then the thin copper foil is consolidated to the insulating resin layer, but the carrier layer sticks to the hot pressing roller causing poor bonding strength and non-uniform consolidation
Solution Approach 1:
A release layer is introduced as an intermediary between the carrier layer and the hot pressing roller. This release layer prevents direct adhesion between the carrier layer and the roller surface during hot pressing, eliminating the sticking problem while allowing effective heat and pressure transmission for consolidation of the thin copper foil to the insulating resin layer.
Solution Approach 2:
The surface properties of the carrier layer are modified by depositing a release layer with controlled adhesion characteristics. This changes the interfacial parameters between the carrier layer and hot pressing roller, reducing the bonding strength at this interface to prevent sticking while maintaining adequate bonding at the copper foil-resin interface.
2Reliability
If the carrier layer bonding strength to thin copper foil is increased to prevent peeling, then peeling is reduced, but the carrier layer becomes difficult to separate for reuse
Solution Approach 1:
The interface between the carrier layer and thin copper foil is segmented into two distinct interfaces: one between the carrier layer and release layer, and another between the release layer and thin copper foil. This segmentation allows independent optimization of each interface's bonding characteristics - strong bonding where needed and weak bonding where separation is required.
Solution Approach 2:
The release layer serves as a mediator that creates an asymmetric bonding structure. It provides sufficient adhesion to prevent premature peeling during manufacturing while maintaining a controlled weak interface that allows easy separation when the carrier layer needs to be reused, solving both reliability and ease of manufacture requirements.
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 solution prevents the carrier layer from sticking to the hot pressing roller, maintaining evenness and preventing blisters, thereby enhancing the bonding strength and reducing defects in the FPCBs, while allowing for efficient separation and reuse of the carrier layer.
Implementation Method 1
wherein the structural carrier layer has a release layer on one side, the release layer providing a release mechanism
Implementation Method 2
The nodular layer has a roughened surface which increases the surface area and adhesion
Implementation Method 3
The anti-tarnish layer prevents oxidation and corrosion of the copper surface
Implementation Method 4
The use of benzotriazole (BTA) as an anti-stick agent on the carrier layer and silane coupling agents near the thin copper foil, along with a release layer, to prevent the carrier layer from sticking to the hot pressing roller and ensure proper adhesion
Data Source
AI summary
A method and production of composite foils and thin copper foils peeled from said composite copper foils is disclosed for use in forming printed circuit boards (PCB). Either the composite foil or only the thin copper foil can be laminated to a polymer layer to form the printed circuit board, with the step of separating the thin copper foil from the composite copper foil is performed subsequent to said laminating step.