A polyimide and a method for manufacturing the polyimide are provided. The method for manufacturing the polyimide includes: mixing a diamine compound with a substance and an organic solvent, wherein the diamine compound includes an amide bond, and a molecular structure of the substance includes an ether dianhydride; and forming the polyimide by a cross-linking and curing process. A regular molecular chain arrangement, wherein the regular molecular chain arrangement has highly oriented in-plane crystallization and low free volume; a simple rigid planar structure; and intramolecular hydrogen bonds are introduced to prepare the polyimide that has high barrier performance, excellent heat resistance, and a low thermal expansion coefficient.

The present invention relates to a liquid crystal alignment agent composition including a copolymer for liquid crystal alignment agent containing two types of repeating units classified according to the types of diamine-derived functional groups, and a crosslinker compound in which the protecting group having a specific structure was introduced, a method for preparing a liquid crystal alignment film using the same, and a liquid crystal alignment film and a liquid crystal display device using the same.

A liquid crystal alignment agent and a preparation method thereof, a liquid crystal alignment film and a preparation method thereof, and a liquid crystal cell are provided. A piperazine monomer is added to a liquid crystal alignment agent, a bulk resistance value and a surface resistance value of a liquid crystal alignment agent material can be reduced, and the ability of the liquid crystal alignment agent material to release residual charges can be effectively improved, thereby increasing the reliability and stability of an electronic product. The liquid crystal cell using the liquid crystal alignment agent has advantages such as high voltage holding ratio (VHR) and low residual voltage.

The present disclosure provides a polyimide polymer, which includes a repeating unit represented by formula (I). Formula (I) is defined as in the specification. The present disclosure further provides a polyimide mixture and a polyimide film, wherein the polyimide mixture is prepared by the polyimide polymer, and the polyimide film is prepared by the polyimide mixture.

Disclosed therein are a photoalignment polyimide copolymer making it easier to form a liquid crystal alignment layer with excellences in alignment properties, thermal and structural stabilities, and adhesiveness to a substrate, and a liquid crystal alignment layer using the same. The photoalignment polyimide copolymer includes all the three types of repeating units each having a defined structure.

A polyimide precursor comprising at least one repeating unit represented by the following chemical formula (5): ##STR00001##
in which A.sub.3 is a divalent group of an aromatic diamine or an aliphatic diamine, from which amino groups have been removed; and X.sub.3 and Y.sub.3 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms, and/or at least one repeating unit represented by the following chemical formula (6): ##STR00002##
in which A.sub.3 is a divalent group of an aromatic diamine or an aliphatic diamine, from which amino groups have been removed; and X.sub.4 and Y.sub.4 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.

A polymer, a composition, and a polysiloxane-polyimide material thereof are provided. The polymer includes a first repeat unit and a second repeat unit. The first repeat unit has a structure represented by Formula (I) and the second repeat unit has a structure represented by Formula (II) ##STR00001##
wherein A.sup.1 and A.sup.3 are independently tetravalent moiety; A.sup.2 is a divalent moiety; n≥1; m≥1; R.sup.1 is independently hydrogen, C.sub.1-8 alkyl, C.sub.1-8 fluoroalkyl, C.sub.1-8 alkoxy, or C.sub.6-12 aryl; and R.sup.2 is independently hydrogen, C.sub.1-8 alkyl, C.sub.1-8 fluoroalkyl, C.sub.1-8 alkoxy, C.sub.6-12 aryl, or a reactive functional group.

Objects of the present invention are: to obtain a polyimide that is excellent in heat resistance, transparency, and optical isotropy and is soluble in an organic solvent; to provide, by using either a polyimide or a polyamic acid which is a precursor or the polyimide, a product or a member that is highly required to have heat resistance and transparency; and particularly to provide a product and a member both of which are obtained by applying a polyamic acid solution and a polyimide solution of the present invention to the surface of an inorganic substance such as glass, metal, metal oxide, or a single crystal silicon. These objects can be attained by a polyimide acid and a polyimide which are each prepared from an alicyclic tetracarboxylic dianhydride and a monomer having a fluorene structure.

The present application relates to a polyamic acid composition, a method for preparing the polyamic acid composition, a polyimide comprising the same, and a coating material comprising the same, which provides a polyamic acid composition capable of implementing a low permittivity and heat resistance, and insulation properties, adhesion and mechanical properties in a harsh condition such as a high temperature simultaneously, a method for preparing the polyamic acid composition, a polyimide comprising the same and a coating material comprising the same.

A method of manufacturing a bump structure includes forming a passivation layer over a substrate. A metal pad structure is formed over the substrate, wherein the passivation layer surrounds the metal pad structure. A polyimide layer including a polyimide is formed over the passivation layer and the metal pad structure. A metal bump is formed over the metal pad structure and the polyimide layer. The polyimide is a reaction product of a dianhydride and a diamine, wherein at least one of the dianhydride and the diamine comprises one selected from the group consisting of a cycloalkane, a fused ring, a bicycloalkane, a tricycloalkane, a bicycloalkene, a tricycloalkene, a spiroalkane, and a heterocyclic ring.