A method provides a structure that includes a substrate having a metal layer disposed on a surface and a metal feature disposed on the metal layer. The method further includes immersing the structure in a plating bath contained in an electroplating cell, the plating bath containing a selected solder material; applying a voltage potential to the structure, where the structure functions as a working electrode in combination with a reference electrode and a counter electrode that are also immersed in the plating bath; and maintaining the voltage potential at a predetermined value to deposit the selected solder material selectively only on the metal feature and not on the metal layer. An apparatus configured to practice the method is also disclosed.

A method provides a structure that includes a substrate having a metal layer disposed on a surface and a metal feature disposed on the metal layer. The method further includes immersing the structure in a plating bath contained in an electroplating cell, the plating bath containing a selected solder material; applying a voltage potential to the structure, where the structure functions as a working electrode in combination with a reference electrode and a counter electrode that are also immersed in the plating bath; and maintaining the voltage potential at a predetermined value to deposit the selected solder material selectively only on the metal feature and not on the metal layer. An apparatus configured to practice the method is also disclosed.

The present disclosure relates to methods of monitoring the concentrations of silver ion and complexing agent in tin-silver (SnAg) electrodeposition solutions, and analysis and process control using such methods. Methods can include adding a precipitating agent to an electrodeposition solution including at least tin ions, silver ions, and complexing agent to cause a reaction between at least a portion of the precipitating agent and substantially all of the silver ions (to precipitate silver ions as a precipitant); adding a metallic salt to the electrodeposition solution to cause a reaction with substantially all of the remaining precipitating agent; measuring the endpoint of the silver ion back titration; further adding metallic salt to cause a further reaction with the complexing agent; and measuring the endpoint of the complexing agent titration.

The present disclosure relates to methods of monitoring the concentrations of silver ion and complexing agent in tin-silver (SnAg) electrodeposition solutions, and analysis and process control using such methods. Methods can include adding a precipitating agent to an electrodeposition solution including at least tin ions, silver ions, and complexing agent to cause a reaction between at least a portion of the precipitating agent and substantially all of the silver ions (to precipitate silver ions as a precipitant); adding a metallic salt to the electrodeposition solution to cause a reaction with substantially all of the remaining precipitating agent; measuring the endpoint of the silver ion back titration; further adding metallic salt to cause a further reaction with the complexing agent; and measuring the endpoint of the complexing agent titration.

Functionalized microscale 3D devices and methods of making the same. The 3D microdevice can be realized with the combination of top-down (lithographic) and bottom-up (origami-inspired self-assembly) processes. The origami-inspired self-assembly approach combined with a top-down process can realize 3D microscale polyhedral structures with metal/semiconductor materials patterned on dielectric materials. In some embodiments, the functionalized 3D microdevices include resonator-based passive sensors, i.e. split ring resonators (SRRs), on 3D, transparent, free-standing, dielectric media (Al.sub.2O.sub.3).

The copper pillars have improved integrity such that they can readily withstand the harsh reflow conditions of post solder bump application without readily failing. The method of making the copper pillars having the improved integrity involves a two-step electroplating process of varying current densities.

A metal particle having a particle diameter of 10 m or more and 1000 m or less and includes Cu and trace elements and a total mass content of P and S, among other trace elements, is 3 ppm or more and 30 ppm or less. A method for producing a metal particle including producing a molten metal material by melting a metal material in a crucible, wherein Cu as determined in GDMS analysis is over 99.995% and a total of P and S is 3 ppm or more and 30 ppm or less; applying a pressure of 0.05 MPa or more and 1.0 MPa or less to drip the molten metal material through an orifice, thereby producing a molten metal droplet; and rapidly solidifying the molten metal droplet using an inert gas whose oxygen concentration is 1000 ppm or less.

A metal particle having a particle diameter of 10 m or more and 1000 m or less and includes Cu and trace elements and a total mass content of P and S, among other trace elements, is 3 ppm or more and 30 ppm or less. A method for producing a metal particle including producing a molten metal material by melting a metal material in a crucible, wherein Cu as determined in GDMS analysis is over 99.995% and a total of P and S is 3 ppm or more and 30 ppm or less; applying a pressure of 0.05 MPa or more and 1.0 MPa or less to drip the molten metal material through an orifice, thereby producing a molten metal droplet; and rapidly solidifying the molten metal droplet using an inert gas whose oxygen concentration is 1000 ppm or less.

Provided is a surface-coated metal porous body having a three-dimensional network structure, the surface-coated metal porous body including: a framework forming the three-dimensional network structure; and a coating film provided on a surface of the framework, wherein the framework has a body including a metal element as a constituent element, the coating film includes a scale-like carbon material and a fine-grained conductive material, a distance D between two points that are farthest from each other on an outer perimeter of a main surface of the scale-like carbon material is 5% or more and 120% or less relative to a thickness of the framework, and the scale-like carbon material is deposited on the surface of the framework.

A core material including a core and a solder plating layer of a (SnBi)-based solder alloy made of Sn and Bi on a surface of the core. Bi in the solder plating layer is distributed in the solder plating layer at a concentration ratio in a predetermined range of, for example, 91.7% to 106.7%. Bi in the solder plating layer is homogeneous, and thus, a Bi concentration ratio is in a predetermined range over the entire solder plating layer including an inner circumference side and an outer circumference side in the solder plating layer.