The disclosure discloses a circuit board, as well as a backlight module and a display device including the circuit board. The circuit board includes a copper exposure region which is covered with a conductive ink. By means of the copper exposure region and the conductive ink thereon, the function of conducting electrostatic charges for the circuit board can be realized at low cost in high efficiency, thereby reducing the risk of subjecting the electrical elements on the circuit board to electrostatic breakdown.

A resin film according to one aspect of the present invention is a resin film having polyimide as a main component, the resin film including a modified layer formed in a depth direction from at least one side of the resin film; and a non-modified layer other than the modified layer, wherein a ring-opening rate of an imide ring of the polyimide in the modified layer is higher than a ring-opening rate of an imide ring of the polyimide in the non-modified layer, and an average thickness of the modified layer from the one side of the resin film is greater than or equal to 10 nm and less than or equal to 500 nm.

According to one aspect of the present invention, a substrate for a printed circuit board includes: an insulating base film; and a metal layer that covers an entirety or a part of one or both surfaces of the base film, wherein the metal layer includes a sintered body layer of copper nanoparticles, and wherein the sintered body layer includes nitrogen atoms by greater than or equal to 0.5 atomic % and less than or equal to 5.0 atomic %.

An occupant or object sensing system in a vehicle includes electrical circuits for capacitive sensing and corresponding circuits shielding the sensing system from interference. A sensing circuit and a shielding circuit may be printed by screen printing with conductive ink on opposite sides of a non-conductive substrate. The substrate is a plastic film or other fabric that has an elastic memory structure that is resilient to stretching. The conductive inks used to print circuits onto the substrate have a similar resilience to stretching such that the substrate and the circuits thereon can be subject to deforming forces without breaking the printed circuits. The substrate may be covered with a carbon polymer layer to provide alternative conductive paths that enable fast recovery for conduction in the presence of any break in the printed conductive traces on the substrate.

A resin film according to one aspect of the present invention is a resin film having polyimide as a main component, the resin film including a modified layer formed in a depth direction from at least one side of the resin film; and a non-modified layer other than the modified layer, wherein a ring-opening rate of an imide ring of the polyimide in the modified layer is higher than a ring-opening rate of an imide ring of the polyimide in the non-modified layer, and an average thickness of the modified layer from the one side of the resin film is greater than or equal to 10 nm and less than or equal to 500 nm.

A printed circuit board includes a first insulating layer having a through hole, and a via disposed to fill the through hole and to be extended to at least one surface of the first insulating layer, wherein the via includes a plating layer having an inner wall part disposed on an inner wall of the through hole and a land part extended from the inner wall part and disposed on the at least one surface of the first insulating layer, and a metal paste layer including metal particles, and filled in the rest of the through hole and disposed on the plating layer.

A coating liquid for forming a conductive layer according to the present invention is a coating liquid for forming a conductive layer, the coating liquid containing fine metal particles, a dispersant, and a dispersion medium. In the coating liquid for forming a conductive layer, the fine metal particles contain copper or a copper alloy as a main component, the dispersant is a polyethyleneimine-polyethylene oxide graft copolymer, a polyethyleneimine moiety in the graft copolymer has a weight-average molecular weight of 300 or more and 1,000 or less, a molar ratio of polyethylene oxide chains to nitrogen atoms in the polyethyleneimine moiety is 10 or more and 50 or less, and the graft copolymer has a weight-average molecular weight of 3,000 or more and 54,000 or less.

A method for manufacturing circuit board, including: providing a substrate; printing a first conductive layer on a surface of the substrate, the first conductive layer includes a plurality of electrode units arranged in an M*N array, each of the electrode units includes a first electrode, and a plurality of second electrodes distributed around the first electrode; printing a first insulating layer on a side of the first conductive layer away from the substrate; printing a second conductive layer on a side of the first insulating layer away from the substrate; printing an anti-oxidation layer to cover surfaces of the first conductive layer and the second conductive layer away from the substrate; and printing a second insulating layer to cover regions of the substrate not covered by the first electrode and the second electrode. A circuit board is also provided.

Coating inkjet-printed traces of silver nanoparticles (AgNP) ink with a thin layer of eutectic gallium indium (EGaIn) increases the electrical conductivity and significantly improves tolerance to tensile strain. This enhancement is achieved through a room temperature sintering process in which the liquid-phase EGaIn alloy binds the AgNP particles to form a continuous conductive trace. These mechanically robust thin-film circuits are well suited for transfer to highly curved and non-developable 3D surfaces as well as skin and other soft deformable substrates.

The present invention is to solve the problem of residues in nanoimprint lithography without losing the merits thereof, i.e., low cost and high productivity, and provides a metal film formation technique advantageous in pattern accuracy and product reliability over time. A metal film formation method according to the present invention comprises a first step where a nanoimprint lithography material is deposited on an insulating substrate to form an underlayer, a second step where the underlayer is pressed with a mold having protrusions to pattern by nanoimprint lithography, a third step where residues of the underlayer at regions pressed with the protrusions of the mold are evaporated by heating to be removed, and forming a metal film at least on the patterned underlayer. A nanoimprint lithography material according to the present invention contains a catalyst for a metal plating.