A bulk substrate for stretchable electronics. The bulk substrate is manufactured with a process that forms a soft-elastic region of the bulk substrate. The soft-elastic region includes a strain capacity of greater than or equal to 25% and a first Young's modulus below 10% of a maximum local modulus of the bulk substrate. The process also forms a stiff-elastic region of the bulk substrate. The stiff-elastic region includes a strain capacity of less than or equal to 5% and a second Young's modulus greater than 10% of the maximum local modulus of the bulk substrate.

The present invention relates to a method for forming a circuit using a seed layer. The method for forming a circuit using a seed layer according to the present invention, may realize a fine pitch, increase the adhesion of the circuit, and prevent the migration phenomenon.

The disclosure relates to a microcircuit forming method. The microcircuit forming method according to the disclosure comprises: a seed-layer forming step for forming a high-reflectivity seed layer on a substrate material by using a conductive material; a pattern-layer forming step for forming a pattern layer on the seed layer, the pattern layer having a pattern hole arranged thereon to allow the seed layer to be selectively exposed therethrough; a plating step for filling the pattern hole with a conductive material; a pattern-layer removing step for removing the pattern layer; and a seed-layer patterning step for removing a part of the seed layer which does not overlap the conductive material in the plating step, wherein the high-reflectivity seed layer has a specular reflection property.

An etching solution for copper and copper alloy surfaces comprising at least one acid, at least one oxidising agent suitable to oxidise copper, at least one source of halide ions and further at least one polyamide containing at least one polymeric moiety according to formula (I) ##STR00001##
wherein each a is independently from each other selected from 1, 2 and 3; each b is an integer independently from each other ranging from 5 to 10000; each R.sup.1 is a monovalent residue independently from each other selected from the group consisting of substituted or unsubstituted C1-C8-alkyl groups and a method for its use are provided. Such etching solution is particularly useful for retaining the shape of treated copper and copper alloy lines.

An etch chemistry solution for treating metallic surfaces in which the etch chemistry solution includes an oxidizing agent and gluconic acid. The etch chemistry solution may also include an oxidizing agent and a short-chained polyethylene polymer glycol or a short-chained polyethylene copolymer glycol. The metallic surfaces are usually used in circuits such as flexible circuits.

The disclosure relates to a method for manufacturing a transfer film including an electrode layer, the method comprising: an electrode layer formation step of forming an electrode layer on a carrier member by using a conductive material; a placement step of placing the carrier member on at least one side of an insulating resin layer respectively; a bonding step of bonding the carrier member and the insulating resin layer together by applying pressure thereto; and a transfer step of removing the carrier member to transfer the electrode layer on the insulating resin layer.

An etch chemistry solution for treating metallic surfaces in which the etch chemistry solution includes an oxidizing agent and gluconic acid. The etch chemistry solution may also include an oxidizing agent and a short-chained polyethylene polymer glycol or a short-chained polyethylene copolymer glycol. The metallic surfaces are usually used in circuits such as flexible circuits.

Provided is a chemical mechanical polishing composition to be used for forming a circuit board including a resin substrate on which a wiring layer containing copper or a copper alloy is provided, the chemical mechanical polishing composition including: (A) at least one selected from a group consisting of carboxyl group-containing organic acids and salts thereof; (B) a basic compound having a first acid dissociation constant (pKa) of 9 or more; and (C) abrasive grains, wherein the component (A) has a complex stability constant with copper of 5 or less, and wherein the chemical mechanical polishing composition has a pH value of from 1 to 3.

Provided is a chemical mechanical polishing composition to be used for forming a circuit board including a resin substrate on which a wiring layer containing copper or a copper alloy is provided, the chemical mechanical polishing composition including: (A) at least one selected from a group consisting of organic acids and salts thereof; (B) a phosphorus-containing compound; and (C) abrasive grains each having an absolute value of a zeta potential in the composition of 5 mV or more, wherein, when a content of the component (A) in the composition is represented by M.sub.A mass % and a content of the component (B) therein is represented by M.sub.B mass %, a ratio M.sub.A/M.sub.B of the content of the component (A) to the content of the component (B) ranges from 1 to 10, and wherein the chemical mechanical polishing composition has a pH value of from 1 to 3.

An etching solution for copper and copper alloy surfaces comprising at least one acid, at least one oxidising agent suitable to oxidise copper, at least one source of halide ions and further at least one polyamide containing at least one polymeric moiety according to formula (I)

##STR00001##

wherein each a is independently from each other selected from 1, 2 and 3; each b is an integer independently from each other ranging from 5 to 10000; each R.sup.1 is a monovalent residue independently from each other selected from the group consisting of substituted or unsubstituted C1-C8-alkyl groups and a method for its use are provided. Such etching solution is particularly useful for retaining the shape of treated copper and copper alloy lines.