Abstract: A method for forming a copper-Invar-copper (CIC) laminate having an intermetallic layer of negligible thickness, and a structure associated with the CIC laminate. Starting with a block of Invar, the method includes a cleaning step followed by an electroplating step. The cleaning step electrochemically cleans the block of Invar with an acid solution while applying a negative voltage bias to the block of Invar. The electroplating step electroplates copper on the block of Invar, resulting in the block of Invar being sandwiched between two layers of copper, such that an intermetallic layer of zero or negligible thickness is disposed between the block of Invar and each layer of copper. Each layer of copper has a uniform thickness. If the starting block of Invar contains a through hole, then the electroplating step will plate a ring of copper on the through hole wall.

Abstract: A method for forming a copper-Invar-copper (CIC) laminate having an intermetallic layer of negligible thickness, and a structure associated with the CIC laminate. Starting with a block of Invar, the method includes a cleaning step followed by an electroplating step. The cleaning step electrochemically cleans the block of Invar with an acid solution while applying a negative voltage bias to the block of Invar. The electroplating step electroplates copper on the block of Invar, resulting in the block of Invar being sandwiched between two layers of copper, such that an intermetallic layer of zero or negligible thickness is disposed between the block of Invar and each layer of copper. Each layer of copper has a uniform thickness. If the starting block of Invar contains a through hole, then the electroplating step will plate a ring of copper on the through hole wall.

Abstract: An electronic structure that includes a copper-Invar-copper (CIC) laminate of negligible thickness, such as a thickness not exceeding about 0.5 microns. The electronic structure may have a via passes through the CIC laminate such that the via is plated with a ring of copper. The ring of copper and the copper in the CIC laminate may have about the same grain structure.

Abstract: Processes for preparing copper-INVAR-copper (CIC) for use in making chip packaging and the CIC created. One process comprises annealing a CIC section at a temperature in a range of 1475° F. to 1625° F. for a time in a range of 40 to 120 seconds. Another process includes heat treating a CIC section at a temperature in a range of 1275° F. to 1425° F. for a time in a range of 40 to 120 seconds. The above processes can be combined. The CIC section created exhibits unique electrical, physical, and mechanical properties.

Abstract: A printed circuit board having a diffusion barrier layer between layers of copper-invar-copper material to prevent the migration of nickel, originating from the invar, into the surrounding copper layers is disclosed. A printed circuit board having a diffusion barrier layer between a conductive core and a conductive layer, and a method of forming the printed circuit board are also disclosed.