Abstract: A lead frame for use in an optical semiconductor device has a die pad portion on which an optical semiconductor element is mounted and a lead portion electrically connectable with the optical semiconductor element. A surface on a lead frame substrate forming a part of or an entirety of the die pad portion and the lead portion is laminated with a glossy Ni plating layer having a gloss of 2.0-3.5 and a noble metal plating layer including an Ag plating layer, as an uppermost layer, having a gloss of 1.6 or more.

Abstract: A lead frame for use in an optical semiconductor device has a die pad portion on which an optical semiconductor element is mounted and a lead portion electrically connectable with the optical semiconductor element. A surface on a lead frame substrate forming a part of or an entirety of the die pad portion and the lead portion is laminated with a glossy Ni plating layer having a gloss of 2.0-3.5 and a noble metal plating layer including an Ag plating layer, as an uppermost layer, having a gloss of 1.6 or more.

Abstract: Methods for producing a substrate for semiconductor element mounts are provided. A base substrate can be prepared having on a first metal layer, a second metal layer through which a metal layer for instrumentation is hardly diffusible. A patterned resist mask layer on the second metal layer can be formed. A surface of the second metal layer under reprocessing treatment can form a reprocessed surface which can be provided with an organic film that controls adhesion between the metal layer for instrumentation and the reprocessed surface by a liquid agent containing a component that shows the nature of amphoteric surfactant. The metal layer for instrumentation can be formed on the reprocessed surface via the organic film. A semiconductor element mount portion and an electrode terminal portion can be electroformed on the metal layer for instrumentation. The resist mask from the second metal layer of the base substrate may be removed.

Abstract: [Object] To provide a substrate for semiconductor element mount that makes it possible to stably produce, in a highly mass-productive manner, surface-mount type semiconductor devices.