Methods of modifying the composition of material layers

Abstract

Methods of modifying the composition of layers using selectively absorbing films are described. The composition of a layer can be modified by applying a selectively absorbing film in proximity to the applied coating and components of the layer can be selectively removed to provide a modified layers. The methods can be used to increase the concentration of particles in the layer.

Description

FIELD[0001]The disclosure relates to methods of modifying the composition of layers and to modified layers using selectively absorbing films. The composition of a layer can be modified by applying a selectively absorbing film onto the layer and components of the layer can be removed to modify the composition of the layer. The methods can be used to increase the concentration of particles in the layer.BACKGROUND[0002]Viscous pastes are widely used to manufacture electronic devices. Pastes are used, for example, to deposit electrical conductors and optoelectronic elements. The viscous pastes can be applied using methods such as screen printing or roller coating. To facilitate the application process, the viscosity of the paste can be tailored to accommodate, for example, the dimensions of surface features, feature pitch, feature aspect ratio, and application speed. The viscosity can be adjusted, for example, using lower molecular weight constituents, by adding solvents, rheological co...

AI Technical Summary

Benefits of technology

The present invention provides methods for modifying the composition of a layer by applying a selectively absorbing film and causing one or more components of the layer to absorb into the film. This results in a modified layer with a different composition. The modified layer can be cured to create a stable modification. The invention also provides methods for fabricating pixels using the modified layer, and electronic systems including the modified layer. The selectively absorbing film can absorb components without affecting the overall shape or activity of the layer, making it easier to modify the composition without causing damage. The technical effects include improved precision and control in modifying the composition of a layer, and improved performance of electronic devices comprising the modified layer.

Problems solved by technology

Furthermore, because these unbound constituents, which are useful in the application process, can take up a substantial volume percent of the paste, and can compromise device performance.

As a result, these constituents can limit the density of particles that can be incorporated into a thin film.

Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements.

For example, increasing amounts of particles increase the viscosity of the layer composition, which can make it difficult to apply the composition into small substrate features.

As a result, the vol % loading of filler in an initial layer composition can be less than is desired for the final cured film.

However, due to constraints associated with the application method and / or the surface topography, it may not be possible to obtain the desired particle loading for the final product in the initially deposited layer.

For certain applications, a bottom layer can be non-uniform within the plane.

A bottom layer can have non-uniform physical and / or material properties within the plane of the film.

For example, when a layer is disposed within small-dimensioned wells, a solid film may not be able to sufficiently conform to enable contact with material disposed within a well.

However, compressing the absorbing film can also reduce the free volume.

However, not all components are volatile, and the high viscosity of the coating can prevent or reduce diffusion of the volatile component to the layer surface.

Repeated use of a selectively absorbing film to remove the carrier can result in a substantial increase in the vol % loading of the particles in the layer.

Depending on the method of application a composition can include components that facilitate the deposition process but that are either not useful or not desired in a cured product.

Such additives may not bind to a cured network and may leach from the matrix with time.

This can result in tailoring the properties of the matrix in a sequential fashion such that a hydrophobic surface becomes hydrophilic during the absorption process.

However, in certain displays, having a thin dimensions can be desirable and therefore the intensity of a pixel cannot be increased by increasing the volume underlying the pixel.

High particle content increases the viscosity of a composition, and it is difficult to fill cavities using viscous materials.

Although low viscosity materials and rheology modifiers can be used in the composition to mitigate the effects of high particle content, the content of the particles can be less than desirable.

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