Mitsui Mining & Smelting Co. Ltd. has developed new ultra-thin, 1.5-micron and 3-micron, copper foils for the next generation of High Density Interconnects (HDI).  Micro Thin-Ex™ consists of a special minute nodular treatment that has very low and uniform profile, making it suitable for ultra fine line formation, high frequency boards, and applications where impedance control is critical. The product consists of three layers: the ultra-thin copper foil, an 18-micron copper foil carrier to support the ultra-thin copper foil, and the releasing layer between the two copper foils. After lamination of the product to a base material, the carrier foil is removed from the laminate.

MicroThin-Ex™ provides a thin, uniform layer of copper with excellent peel strength. Once the plating of the features and vias is completed, the extraneous thin copper can be easily removed in a flash etch process.  A tin coating to protect the features and vias is not required as the flash etching removes minimal material.  

MicroThin-Ex™ is available in North America through Oak-Mitsui, Inc..  Please contact Abbas Moosavi at (518) 686-8037 for further information.