A polyimide (PI) substrate, including a glass substrate is provided, wherein a first PI layer is disposed over the glass substrate, and a second PI layer is disposed over the first PI layer. The first PI layer is formed with a first PI material, and the second PI layer is formed with a second PI material. Disposal of the second PI layer over the first PI layer allows for manual and complete peeling of the second PI layer from the first PI layer.

The present invention relates to a polyamic acid composition for packaging electronic components and a method for packaging electronic components using the same, wherein the polyamic acid composition comprises a dianhydride main component having a benzophenone structure as a dianhydride-based monomer in a high proportion and a diamine component having a benzene ring as a diamine-based monomer, whereby it is possible to improve a coefficient of thermal expansion, a glass transition temperature, an elongation, and the like of a polyimide thin film formed therefrom, and when the polyimide thin film is used as a packaging material for an inorganic material such as a silicon water, it exhibits excellent adhesion to the inorganic material and can be easily removed upon O.sub.2 plasma removal, as well as has a remarkably low residual ratio of organic residues on the surface of the inorganic material after the removal, so that it can be easily used as a packaging material for electronic components and the like.

The present invention relates to a polyimide precursor composition, and a polyimide film manufactured using same. According to the present invention, since a polyimide film is manufactured from a mixture of a polyimide precursor having a structure that is advantageous to surface charge accumulation and a polyimide precursor having a structure capable of exhibiting high heat-resistant characteristics, a flexible device using the polyimide film as a substrate can have both improved charge accumulation characteristics caused by an electric field to be generated during the operation of a TFT device and heat high heat-resistant characteristics.

This disclosure relates to a photosensitive stacked structure that includes first and second layers, in which the first layer is a photosensitive, dielectric layer and the second layer is a photosensitive layer. The dissolution rate of the first layer in a developer is less than the dissolution rate of the second layer in the developer.

This disclosure relates to a photosensitive composition that includes at least one fully imidized polyimide polymer having a weight average molecular weight in the range of about 20,000 Daltons to about 70,000 Daltons; at least one solubility switching compound; at least one photoinitiator; and at least one solvent. The composition is capable of forming a film or a dry film having a dissolution rate of greater than about 0.15 micron/second using cyclopentanone as a developer.

In order to provide an imide oligomer or the like which can give a cured product exhibiting excellent thermal oxidative stability, an imide oligomer is obtained by reacting together an aromatic tetracarboxylic acid component, an aromatic diamine component, and a terminal capping agent. The imide oligomer contains, in a specified proportion: a compound containing a phenylethynyl group; and a compound containing no carbon-carbon unsaturated bond capable of an addition reaction. One or each of the aromatic tetracarboxylic acid component and the aromatic diamine component contains a component having an asymmetrical and non-planar structure.

A polyimide precursor composition according to an exemplary embodiment includes an imide precursor having an organic group derived from a cyclic ether group-containing compound. A polyimide film formed using the polyimide precursor composition has improved heat resistance and mechanical properties, and has high absorbance in a wavelength range in an ultraviolet region.

According to one embodiment, a varnish for a photo alignment film includes an imidization promotor and a first polyamic acid-based compound in an organic solvent. The first polyamic acid-based compound is a polyamic acid or a polyamic acid ester. The imidization promotor has skeleton containing no primary amino group and no secondary amino group. The first polyamic acid-based compound has terminal skeletons containing no primary amino group.

According to one embodiment, a varnish for a photo alignment film includes an imidization promotor and a first polyamic acid-based compound in an organic solvent. The first polyamic acid-based compound is a polyamic acid or a polyamic acid ester. The imidization promotor has skeleton containing no primary amino group and no secondary amino group. The first polyamic acid-based compound has terminal skeletons containing no primary amino group.

The present invention provides curable polyimides with low color that are resistant to long term thermo-oxidative degradation. These materials, which include polyimides that are fully aromatic, are synthesized in anisole and are contemplated for use in high temperature applications such as in the aerospace industry and for use as encapsulants for light emitting diodes that will be exposed to high temperatures.