Lead frame and its manufacturing method
AssigneeSumitomo Metal Mining Co., Ltd.
InventorsIchinori Iitani, Youichirou Hamada
Life of this patent
Estimating the term…
Abstract
A leadframe is plated with palladium only to a surface of a metal plate on which semiconductors elements are to be mounted and a surface of the metal plate to be placed on a substrate, and is not plated with palladium to lead portions, pad portions, other portions except for the surfaces to be plated and the side surface, of the leadframe, thereby, the amount of use of palladium is reduced to minimum and a cheap leadframe can be provided.
Claims6
A leadframe formed from a metal plate comprising:
- a portion for mounting thereon a semiconductor element, portions to be bonded with gold wires, and portions to be soldered of the surface to be placed on a printed circuit board, wherein palladium is plated only to necessary and minimum part of said portions of said leadframe.
A leadframe formed from a metal plate comprising:
- a first surface for mounting thereon a semiconductor element, a second surface to be placed on a printed circuit board, and shaped lead portions, wherein palladium is plated only to said first and second surfaces, while palladium is not plated to other portions except for said first and second surfaces and the side surface of said leadframe.
A leadframe formed from a metal plate comprising:
- a first surface for mounting thereon a semiconductor element, a second surface to be placed on a printed circuit board, and shaped lead portions, wherein palladium is plated only to necessary and minimum part of said first and second portions, while palladium is not plated to other portions except for said necessary and minimum part and the side surface of said leadframe.
A method of manufacturing a leadframe, comprising the steps of:
- preparing a leadframe material by forming a metal plate,
- plating palladium to necessary and minimum portions of said leadframe material on which semiconductor elements are to be mounted, and
- plating palladium to portions to bond gold wires and necessary and minimum portions to be soldered of a surface to be placed on a printed circuit board, of said leadrame material.
A method of manufacturing a leadframe, comprising the steps of:
- preparing of a leadframe material by forming a metal plate,
- plating palladium only to a surface of said leadframe material on which semiconductor elements are to be mounted, and
- plating palladium only to a surface of said leadframe material to be placed on a printed circuit board, excepting lead portions, pad portions, other portions except for said surfaces to be plated and the side surface, of said leadframe material.
A method of manufacturing a leadframe, comprising the steps of:
- preparing a leadframe material by forming a metal plate,
- plating palladium only to necessary and minimum portions of a surface of said leadframe material on which semiconductor elements are to be mounted, and
- plating palladium only to necessary and minimum portions of a surface of said leadframe material to be placed on a printed circuit board, excepting lead portions, pad portions, other portions except for said surfaces to be plated and the side surface, of said leadframe material.
Dependencies are inferred from the claim text.