Lead frame

Abstract

Abstract PURPOSE:To lower a cost and to enhance a corrosion-resistant property by a method wherein, in a lead frame which uses a palladium-plated film as an outer-package plated film, a tin-cobalt alloy-plated film is formed on the substratum of the palladium-plated film. CONSTITUTION:A tin-nickel alloy-plated film or a tin-cobalt alloy-plated film 12 is first formed on the whole surface of a lead frame 10; a palladium-plated film 14 as an outer-package plated film is formed on the tin-nickel plated film or the tin-cobalt alloy-plated film 12. As a blank for the lead frame 10, copper, a copper alloy, a 42 alloy (iron-nickel alloy) or the like is used. The thickness of the palladium-plated film 14 as the outer-package plated film is not limit specially; it is decided by taking into consideration the wire bonding property at inner leads and the solderability at outer leads; the thickness of 0.03 to 0.5mum, normally about 0.1mum, is sufficient. The thickness of the tin-nickel alloy-plated film or the tin-cobalt alloy-plated film 12 is set to 0.1 to 1.5mum.

Inventors

• 👤 Akihiko Murata
• 👤 明彦 村田
• 👤 Norio Wakabayashi
• 👤 若林　則男

Bibliographic Details