According to an embodiment of the disclosure, a housing of an electronic device may include a first surface including a first portion having an irregularity formed thereon and a second portion spaced apart from the first portion and having an irregularity formed thereon. The irregularities formed on the first surface may be formed by etching. A maximum height of the irregularity formed on the first portion may be different from a maximum height of the irregularity formed on the second portion. The maximum height of irregularities formed on the first surface may gradually increase or decrease from the first portion to the second portion.

An inhibited hydrofluoric acid aqueous composition, said composition comprising: hydrofluoric acid in solution; and a weak base selected from the group consisting of: lysine, arginine, histidine, glutamine, asparagine, tryptophan, and tyrosine; wherein said weak base and hydrofluoric acid are present in a molar ratio of at least 1:1. Also disclosed is a mud acid using this inhibited acid composition.

An inhibited hydrofluoric acid aqueous composition, said composition comprising: hydrofluoric acid in solution; and a weak base selected from the group consisting of: lysine, arginine, histidine, glutamine, asparagine, tryptophan, and tyrosine; wherein said weak base and hydrofluoric acid are present in a molar ratio of at least 1:1. Also disclosed is a mud acid using this inhibited acid composition.

A metallic stamp and die for the craft industry comprises a predetermined acid-etched design on a surface of a metallic plate. A first layer of a metallic paint is applied over the front and back surfaces of the metallic stamp and die. A second layer of a rubber paint is applied over the metallic paint. The metallic paint facilitates bonding of the rubber paint to the metallic plate and increases the life of the coating of the rubber paint. The rubber paint is configured to absorb and store an ink and facilitate transfer of the ink to one or more substrates, thus enabling stamping of the design on the substrate. The metallic die can be configured for a plurality of uses, such as embossing, cutting, heat-foiling, stamping, scoring, and inserting patterns or designs in a plurality of substrates.

A capacitor and a method of processing an anode metal foil are presented. The method includes electrochemically etching the metal foil to form a plurality of tunnels. Next, the etched metal foil is disposed within a widening solution to widen the plurality of tunnels. Exposed surfaces of the etched metal foil are then oxidized. The method includes removing a section of the etched metal foil, where the section of the etched metal foil includes exposed metal along an edge. The section of the etched metal foil is placed into a bath comprising water to form a hydration layer over the exposed metal on the section of the etched metal foil. The method also includes assembling the section of the etched metal foil having the hydration layer as an anode within a capacitor.

A method of manufacturing a semiconductor package, the method including providing a first seed layer on an insulation layer such that the first seed layer includes a first metal material; providing a second seed layer on the first seed layer such that the second seed layer includes a second metal material different from the first metal material; forming photoresist patterns on the second seed layer; forming conductive patterns between the photoresist patterns, including the second metal material, and having line shapes that extend in a first direction; removing the photoresist patterns; etching the second seed layer to form second seed patterns having line shapes extending in the first direction; and etching the first seed layer to form first seed patterns having line shapes extending in the first direction, wherein an etchant includes deionized water, a fluorine compound, a competing compound, and a corrosion inhibitor.

A metallic stamp and die for the craft industry comprises a predetermined acid-etched design on a surface of a metallic plate. A first layer of a metallic paint is applied over the front and back surfaces of the metallic stamp and die. A second layer of a rubber paint is applied over the metallic paint. The metallic paint facilitates bonding of the rubber paint to the metallic plate and increases the life of the coating of the rubber paint. The rubber paint is configured to absorb and store an ink and facilitate transfer of the ink to one or more substrates, thus enabling stamping of the design on the substrate. The metallic die can be configured for a plurality of uses, such as embossing, cutting, heat-foiling, stamping, scoring, and inserting patterns or designs in a plurality of substrates.

A method includes machining a raw surface of a metal component to remove first native oxide from a metal base of the metal component to generate an as-machined surface of the metal component. A second native oxide is formed on the metal base of the as-machined surface of the metal component subsequent to the machining. The method further includes, subsequent to the machining, performing operations to generate a finished surface of the metal component. The operations include a surface machining of the as-machined surface of the metal component to remove the second native oxide.

A method includes machining a raw surface of a metal component to remove first native oxide from a metal base of the metal component to generate an as-machined surface of the metal component. A second native oxide is formed on the metal base of the as-machined surface of the metal component subsequent to the machining. The method further includes, subsequent to the machining, performing operations to generate a finished surface of the metal component. The operations include a surface machining of the as-machined surface of the metal component to remove the second native oxide.

A method for manufacturing structured press elements comprises at least the following steps: the step of providing an element of metal; the step of providing a mask on a surface of the element for shielding portions of the surface; the step of treating non-shielded portions of the surface of the element; the step of removing the mask; wherein the method comprises at least a step in which the surface of the element is subjected to an ultrasonic treatment and/or that the step of providing the mask comprises at least a treatment with infrared radiation and/or that the step of chemically treating is performed with the surface directed downward.