According to the method for producing chromium plated parts, a plurality of workpieces are immersed in a chromium plating bath, a plating treatment is performed by using a pulse current, and chromium plating layers that have compressive residual stress and suppressed cracking are deposited on surfaces of the plurality of workpieces. A direct current from plating separation lower limit current density up to a range in which the chromium plating layers have compressive residual stress is superimposed during downtime of application of the pulse current.

According to the method for producing chromium plated parts, a plurality of workpieces are immersed in a chromium plating bath, a plating treatment is performed by using a pulse current, and chromium plating layers that have compressive residual stress and suppressed cracking are deposited on surfaces of the plurality of workpieces. A direct current from plating separation lower limit current density up to a range in which the chromium plating layers have compressive residual stress is superimposed during downtime of application of the pulse current.

According to the method for producing chromium plated parts, a plurality of workpieces are immersed in a chromium plating bath, a plating treatment is performed by using a pulse current, and chromium plating layers that have compressive residual stress and suppressed cracking are deposited on surfaces of the plurality of workpieces. A direct current from plating separation lower limit current density up to a range in which the chromium plating layers have compressive residual stress is superimposed during downtime of application of the pulse current.

According to the method for producing chromium plated parts, a plurality of workpieces are immersed in a chromium plating bath, a plating treatment is performed by using a pulse current, and chromium plating layers that have compressive residual stress and suppressed cracking are deposited on surfaces of the plurality of workpieces. A direct current from plating separation lower limit current density up to a range in which the chromium plating layers have compressive residual stress is superimposed during downtime of application of the pulse current.

The present disclosure relates to coatings. For example, some embodiments may include methods for producing a coating comprising: depositing a metallic matrix on a substrate by electrochemical deposition using a deposition bath including carbon comprising particles and oxide particles dispersed therein; wherein the carbon comprising particles are embedded into the metallic matrix and pores are distributed in the coating; wherein at least 80% of the pores have a pore diameter in a range from 3 to 30 m; wherein oxide particles are incorporated into and fixed in the pores during deposition and the oxide particles remain partially uncoated by the material of the metallic matrix.

Provided is a solder material having oxidation resistance at the time of melting solder or after melting it, as well as managing a thickness of oxide film at a fixed value or less before melting the solder. A Cu core ball 1A is provided with a Cu ball 2A for keeping a space between a semiconductor package and a printed circuit board and a solder layer 3A that covers the Cu ball 2A. The solder layer 3A is composed of Sn or a solder alloy whose main component is Sn. For the Cu core ball 1A, lightness is equal to or more than 65 in the L*a*b* color space and yellowness is equal to or less than 7.0 in the L*a*b* color space, and more preferably, the lightness is equal to or more than 70 and the yellowness thereof is equal to or less than 5.1.

Provided is a solder material having oxidation resistance at the time of melting solder or after melting it, as well as managing a thickness of oxide film at a fixed value or less before melting the solder. A Cu core ball 1A is provided with a Cu ball 2A for keeping a space between a semiconductor package and a printed circuit board and a solder layer 3A that covers the Cu ball 2A. The solder layer 3A is composed of Sn or a solder alloy whose main component is Sn. For the Cu core ball 1A, lightness is equal to or more than 65 in the L*a*b* color space and yellowness is equal to or less than 7.0 in the L*a*b* color space, and more preferably, the lightness is equal to or more than 70 and the yellowness thereof is equal to or less than 5.1.

Disclosed herein are methods for electroplating which employ seed layer detection. Such methods may operate by selecting a wafer, illuminating one or more points within an interior region of the wafer surface, measuring a first set of one or more in-process color signals from the one or more points within the interior region, illuminating one or more points within an edge region of the wafer surface, measuring a second set of one or more in-process color signals from the one or more points within the edge region, each color signal having one or more color components, calculating a metric indicative of a difference between the color signals in the first and second sets of in-process color signals, determining whether an acceptable seed layer is present on the wafer based on whether the metric is within a predetermined range, and repeating the foregoing for one or more additional wafers.

Disclosed herein are methods for electroplating which employ seed layer detection. Such methods may operate by selecting a wafer, illuminating one or more points within an interior region of the wafer surface, measuring a first set of one or more in-process color signals from the one or more points within the interior region, illuminating one or more points within an edge region of the wafer surface, measuring a second set of one or more in-process color signals from the one or more points within the edge region, each color signal having one or more color components, calculating a metric indicative of a difference between the color signals in the first and second sets of in-process color signals, determining whether an acceptable seed layer is present on the wafer based on whether the metric is within a predetermined range, and repeating the foregoing for one or more additional wafers.

A hydroxyl graphene-modified plating sealant and a preparation method thereof are disclosed. The plating sealant comprises a film-forming material, a resist, a defoaming agent, a levelling agent, and deionized water; the resist is a nanoscale hydroxyl graphene aqueous solution comprising hydroxyl graphene having a mass fraction of 3.5% to 4% and a pH of 8.0 to 9.5. Nanoscale hydroxyl graphene is used as a resist in the plating sealant of the disclosure, then the hydroxyl groups on hydroxyl graphene can react with the hydroxyl groups of the film-forming material, i.e. silica sol and the silane polymer, by dehydration condensation, thereby significantly improving the performance of the sealing film. The sealing film has higher corrosion resistance and abrasion resistance compared with that prepared by graphene or reduced graphene oxide sealant.