Laminated magnetic core and method of manufacturing same

Abstract

A laminated magnetic core is characterized in that core-forming thin sheets each having a surface roughness such that the maximum height Rmax is at least 1 .mu.m are laminated together with a sheet-to-sheet distance of 2 to 10 .mu.m, desirably 3 to 6 .mu.m and that at least a part of protruded portions of the opposite roughed surfaces is diffusion-bonded to each other at the interface between adjacent thin sheets. The laminated magnetic core may have innumberable voids present at the diffusion-bonded interface between the adjacent thin sheets. This invention further provides a method of manufacturing a laminated magnetic core comprising the steps of providing a plurality of core-forming thin sheets each having a surface roughness such that the maximum height Rmax is at least 1 .mu.m; laminating and bonding said core-forming thin sheets one upon another through an organic adhesive, desirably at a sheet-to-sheet distance of 2 to 10 .mu.m; punching out a block of a given shape from said laminated and bonded core-forming sheets by a press; and thereafter magnetically annealing the block while decomposing and vaporizing said organic adhesive to effect diffusion-bonding at the interface between adjacent thin sheets of the block lefting innumberable voids at the interface.

Dependencies are inferred from the claim text.