In a thermocompressive soldering process, a conductive overlay of a material such as gold is applied to a contact finger of a circuit board. In carrying out this process, the overlay is initially carried on an adhesively coated strip such as a polyimide tape. To transfer the overlay to the contact finger, it is aligned with the contact finger and temporarily attached to the circuit board. A heat conductive resilient sheet is then interposed between the circuit board and a thermode. The thermode is adjusted to engage the contact finger with a predetermined force. The force is resiliently distributed by the interposed sheet. Heat is then applied from the thermode through the resilient sheet to liquefy a solder coating on the overlay and to bond the overlay to the contact finger upon resolidification of the solder. The applied force is sustained during the application of head and during a subsequent cooling period during which the solder resolidifies. The resilient sheet minimizes seepage of solder to the top surface of the overlay and thereby prevents contamination of such surface by the solder.

Bonding contact members to circuit boards

A sealing cover for an hermetically sealed container comprises an environmentally resistant metal lid, an intermediate plated metallic "picture frame", and a solder deposit metallurgically bonded to that "frame". Such a cover is particularly adapted for the sealing of semiconductor packages, and is especially advantageous in that it need not employ precious metals.

Sealing cover for an hermetically sealed container

A process for the diffusion welding of copper and stainless steel, which comprises sandwiching a thin layer of at least one metal selected from the group consisting of Ni, Ni-base alloys, Cr, Ni-Cr, and Cr-Ni with little gas contents, as an insert metal, between the surfaces of copper and stainless steel to be bonded, and then diffusion welding the sandwich.

A process for the diffusion welding of copper and stainless steel

A metal wire cord which comprises a metal wire and a ternary alloy of Cu-Zn-Co coated on the surface of said metal wire. The wire cord has high drawability and such prominent adhesivity to rubber as is highly resistant to corrosion by saline water.

Metal wire cord

A method for making a joint between copper or copper alloys and austenitic steel alloys, in which method in between the junction surfaces of the objects to be joined together, there is arranged at least one intermediate layer, so that the junction surfaces in cluding their intermediate layers are pressed together, and at least the junction area is heated in order to create a diffusion joint. In the method, there is brought a first intermediate layer (3) on the junction surface of the steel object (2) or against said surface, mainly in order to prevent the nickel loss from the steel object (2), and at least a second intermediate layer (4) on the junction surface of the copper object (1) or against said surface in order to activate the creation of a diffusion joint.

Method for making a joint between copper and stainless steel

Means and method for rendering solderable a stainless steel body resistant to corrosive attack from common electrolytes. The method includes the steps of covering at least one surface of a stainless steel body with layers of metal including a first metal layer selected from the group consisting of nickel, cobalt and chromium which serves as a barrier layer to the diffusion of a subsequent metal layer or layers therethrough to the stainless steel body. The subsequent metal layer is resistant to corrosive attack from common electrolytes and is solderable. The subsequent metal layer consists of silver alloyed with a noble metal selected from the group consisting of gold, palladium, platinum, rhenium and osmium. The alloy layer may be formed by covering the barrier layer with a layer of silver and then a layer of gold or one of the other metals. The layered stainless steel body is heated to a temperature below the melting point temperature of the metal layer having the lowest melting point so that the layers, with the exception of the barrier layer, diffuse into one another, thereby forming the alloy layer overlaying the barrier layer which is resistant to corrosive attack from common electrolytes and is solderable. The stainless steel body is rendered solderable.

Edwin Russell Koons

Papers

Solderable stainless steel