A method for forming an electrical interconnect on an integrated lead suspension or suspension component of the type formed from a laminated sheet of material having a stainless steel layer, a conductive lead layer and an insulating layer separating the stainless steel and conductive lead layers. An aperture is formed through at least the insulating layer to expose the stainless steel layer at an interconnect site. An interconnect mask is applied around the interconnect site. Conductive material is electroplated onto the stainless steel layer at the interconnect site to form a plated interconnect. The mask is then removed. The method is used to form an interconnect bond pad on the same side of the stainless steel layer as the conductive lead layer in one embodiment. In another embodiment the aperture is formed through the insulator layer and the stainless steel layer, and conductive material is built up on the stainless steel layer during the electroplating step until it meets and plates onto the conductive lead layer to form a stainless steel side interconnect. In yet another embodiment the aperture is formed through the insulator layer and the conductive lead layer, and conductive material is built up on the stainless steel layer during the electroplating step until it meets and plates onto the conductive lead layer to form a conductive lead side interconnect.

Plated ground features for integrated lead suspensions

A method for forming an electrical interconnect on an integrated lead suspension or suspension component of the type having a stainless steel layer, a conductive lead layer and an insulator layer separating the stainless steel and conductive lead layers. An aperture is formed through only the insulator layer to expose the stainless steel layer at an interconnect site. An interconnect mask is applied around the interconnect site. A first conductive material is electroplated onto the stainless steel layer at the interconnect site to form a plated interconnect between the spring metal layer and the conductive lead layer. The mask is then removed. An electrical interconnect between the stainless steel and conductive lead layers including an aperture only through the insulator layer and an electroplated conductive material interconnect extending between both the spring metal layer and the conductive lead layer.

Internal stress in plated deposits has been a common problem that may affect the functionality of coatings. Electrodeposition parameters and insoluble particles modify the characteristics and the level of internal stress of coatings. The influence of the electrocodeposition parameters and their interaction effects on the internal stress during the electrodeposition of Ni and Ni–MoS2 composite coatings were studied by fractional factorial design. The parameters studied and their ranges were: MoS2 particle concentration (0–10 g L−1), temperature (30–50°C), pH (2–4), current density (1·2–4·8 A dm−2), and coating thickness (25–50 μm). MoS2 addition into Watts bath resulted in the decrease in the tensile internal stress values or even changed the stress character from tensile to compressive. Moreover, low stress values were obtained when pH was 2 and coating thickness was 50 μm.

Effects of current density, coating thickness, temperature, pH and particle concentration on internal stress during Ni–MoS2 electrocodeposition

This sheet metal comprises a substrate (12) made of stainless steel containing more than 16% of chromium in its weight composition, coated with a metal layer (16) containing chiefly tin. Between the metal layer (16) and the substrate (12) the sheet metal comprises a layer (14) of an intermetallic compound containing at least iron, chromium and tin. To manufacture this sheet metal, a layer (16) of metallic coating containing chiefly tin is deposited by an electrolytic route on a sheet (12) made of stainless steel. The coated sheet metal is heated to a temperature above the melting temperature of the coating layer (16) to permit the formation of the intermetallic compound. The heating is maintained for a sufficient period for the surface of the coating layer (16) to have a matt appearance.

Process for the manufacture of a coated stainless steel sheet

A method is disclosed for the chrome plating of a stainless steel automotive bumper having a plastic structural backing. The backing is submersible within the acid treating baths used to chrome plate the outer surface of the stainless steel portion of the bumper.

Automotive bumper and its manufacturing process

In a process for plating nickel upon a surface of a workpiece made of stainless steel, the workpiece is immersed in an electrolytic sulfuric acid bath, with the workpiece anodically connected. Thus, DC current flows from the workpiece, through the bath, to a separate cathode in the bath. Thereafter, the sulfuric acid is rinsed from the workpiece and the workpiece surface is electroplated with nickel which will strongly adhere to the surface. Finally, the nickel-plated part may be conventionally electroplated with chrome.

Wayne K. Raymond

Papers

Process for electroplating nickel over stainless steel