External electrical connectors and methods of forming such external electrical connectors are discussed. A method includes forming an external electrical connector structure on a substrate. The forming the external electrical connector structure includes plating a pillar on the substrate at a first agitation level affected at the substrate in a first solution. The method further includes plating solder on the external electrical connector structure at a second agitation level affected at the substrate in a second solution. The second agitation level affected at the substrate is greater than the first agitation level affected at the substrate. The plating the solder further forms a shell on a sidewall of the external electrical connector structure.

External electrical connectors and methods of forming such external electrical connectors are discussed. A method includes forming an external electrical connector structure on a substrate. The forming the external electrical connector structure includes plating a pillar on the substrate at a first agitation level affected at the substrate in a first solution. The method further includes plating solder on the external electrical connector structure at a second agitation level affected at the substrate in a second solution. The second agitation level affected at the substrate is greater than the first agitation level affected at the substrate. The plating the solder further forms a shell on a sidewall of the external electrical connector structure.

Method for reducing concentration of iron ions in a trivalent chromium electroplating bath, including: (i) providing the trivalent chromium electroplating bath including trivalent chromium ions, and iron ions, (ii) subjecting at least a portion of the bath to air agitation, to obtain an air-agitated portion of the bath, (iii) contacting the air-agitated portion with an ion exchange resin, to obtain a resin-treated portion of the bath, and (iv) returning the resin-treated portion of the bath to the trivalent chromium electroplating bath,
provided that the bath provided in step (i) was or is utilized for electrodepositing chromium on a substrate applying a cathodic current density of 18 A/dm.sup.2 or more, after step (iii), iron ions in the resin-treated portion have a lower concentration than in the air-agitated portion, and after step (iv), iron ions in the bath have a concentration below 50 mg/L.

Method for reducing concentration of iron ions in a trivalent chromium electroplating bath, including: (i) providing the trivalent chromium electroplating bath including trivalent chromium ions, and iron ions, (ii) subjecting at least a portion of the bath to air agitation, to obtain an air-agitated portion of the bath, (iii) contacting the air-agitated portion with an ion exchange resin, to obtain a resin-treated portion of the bath, and (iv) returning the resin-treated portion of the bath to the trivalent chromium electroplating bath,
provided that the bath provided in step (i) was or is utilized for electrodepositing chromium on a substrate applying a cathodic current density of 18 A/dm.sup.2 or more, after step (iii), iron ions in the resin-treated portion have a lower concentration than in the air-agitated portion, and after step (iv), iron ions in the bath have a concentration below 50 mg/L.

A method for compact and flat bismuth metal preparation by electrolysis is provided. In the method, one or more of β-naphthol, acacia, sulfonated and vulcanized alkylphenol ethoxylate and naphthol ethoxylate oxides are added to the acidic solution of bismuth methanesulfonate as additives, and the cathodic bismuth is obtained by electrolysis at 20-80° C. The method for bismuth metal preparation is simple and easy to promote, environment-friendly, and the obtained bismuth metal has a flat and compact surface and good plate formation effect.

The embodiments herein relate to apparatuses and methods for electroplating one or more materials onto a substrate. Embodiments herein utilize a cross flow conduit in the electroplating cell to divert flow of fluid from a region between a substrate and a channeled ionically resistive plate positioned near the substrate down to a level lower than level of fluid in a fluid containment unit for collecting overflow fluid from the plating system for recirculation. The cross flow conduit can include channels cut into components of the plating cell to allow diverted flow, or can include an attachable diversion device mountable to an existing plating cell to divert flow downwards to the fluid containment unit. Embodiments also include a flow restrictor which may be a plate or a pressure relief valve for modulating flow of fluid in the cross flow conduit during plating.

Systems and methods for electroplating are described. The electroplating system may include a vessel configured to hold a first portion of a liquid electrolyte. The system may also include a substrate holder configured for holding a substrate in the vessel. The system may further include a first reservoir in fluid communication with the vessel. In addition, the system may include a second reservoir in fluid communication with the vessel. Furthermore, the system may include a first mechanism configured to expel a second portion of the liquid electrolyte from the first reservoir into the vessel. The system may also include a second mechanism configured to take in a third potion of the liquid electrolyte from the vessel into the second reservoir when the second portion of the liquid electrolyte is expelled from the first reservoir. Methods may include oscillating flow of the electrolyte within the vessel.

Systems and methods for electroplating are described. The electroplating system may include a vessel configured to hold a first portion of a liquid electrolyte. The system may also include a substrate holder configured for holding a substrate in the vessel. The system may further include a first reservoir in fluid communication with the vessel. In addition, the system may include a second reservoir in fluid communication with the vessel. Furthermore, the system may include a first mechanism configured to expel a second portion of the liquid electrolyte from the first reservoir into the vessel. The system may also include a second mechanism configured to take in a third potion of the liquid electrolyte from the vessel into the second reservoir when the second portion of the liquid electrolyte is expelled from the first reservoir. Methods may include oscillating flow of the electrolyte within the vessel.

A plating apparatus includes a workpiece holder, a plating bath, and a clamp ring. The plating bath is underneath the workpiece holder. The clamp ring is connected to the workpiece holder. The clamp ring includes channels communicating an inner surface of the clamp ring and an outer surface of the clamp ring.

A plating apparatus includes a workpiece holder, a plating bath, and a clamp ring. The plating bath is underneath the workpiece holder. The clamp ring is connected to the workpiece holder. The clamp ring includes channels communicating an inner surface of the clamp ring and an outer surface of the clamp ring.