Systems and methods for depositing thin film onto flexible substrate

Abstract

Systems and methods for depositing a thin film layer onto a flexible ferromagnetic substrate include a porous block in a deposition zone and a plurality of magnets embedded within the porous block. The magnets provide a downward force on a flexible ferromagnetic substrate being transported over the porous block, e.g., in a reel-to-reel system. Pressurized gas is forced upward through the porous block, providing an upward force that balances the downward force and supports the substrate at a desired height above the porous block. The substrate is thus held flat during transport through the deposition zone, enabling uniform deposition of a thin film layer.

Description

technical field [0001] The present disclosure relates to systems and methods for depositing thin film layers onto flexible substrates. More specifically, the disclosed embodiments relate to magnetic air bearings for transporting flexible substrates through a deposition zone. Background technique [0002] Thin film coatings (eg, semiconducting layers) can be applied to flexible substrates by chemical deposition. The deposition process may include conveying the substrate through a temperature-controlled chemical bath deposition zone. Chemical bath deposition is generally very sensitive to changes in substrate planarity. Variations in the height of the substrate relative to the heat source below and the bath level above can affect factors such as depth in solution, mixing and heat transfer, leading to inhomogeneities in the deposited layer. Therefore, it is desirable to keep the substrate flat during deposition; however, known solutions for conveying the substrate flat throu...

AI Technical Summary

Problems solved by technology

Variations in the height of the substrate relative to the heat source below and the bath level above can affect factors such as depth in solution, mixing and heat transfer, resulting in inhomogeneities in the deposited layer

Therefore, it is desirable to keep the substrate flat during deposition; however, known solutions for conveying the substrate flat through the deposition zone have disadvantages

For example, mechanically holding the substrate across the underlying backplane at high tension is difficult and does not completely eliminate variations in substrate height

Magnets or a vacuum can be used to pull the substrate flat against the backing plate, but the friction in this configuration often causes the substrate to tear, especially if the bath seeps from underneath

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