Sony Corporation

Mutsumi Nagano

Kenji Ohsawa

Makoto Ito

Akira Kojima

Hideyuki Takahashi

Hiroyuki Shigeta

A method of manufacturing a lead frame comprises the steps of preparing a three-layered material comprising a metal base, an etching stopper layer made of a metal material different from that of the metal layer formed on a first surface of the metal base and a chromium layer formed on the etching stopper layer, forming a resist layer having a negative pattern relative to an inner lead to be formed on the chromium layer of the three-layered material, forming an inner lead by plating copper by using the resist layer as a mask, forming an outer lead on the metal base, removing a back of a region in which an inner lead of the metal base is formed by etching, removing the etching stopper layer, and removing the chromium layer.

Method of manufacturing lead frame having inner lead connected to outer

A lead frame includes a base member having a device hole for accommodating a semiconductor chip therein, a plurality of inner lead portions extended outward from respective sides of the device hole, outer lead portions electrically connected to the inner lead portions, respectively, an adhesion area to which the inner lead portions formed on the base member are adhered, and a plurality of dummy leads disposed on a portion of the adhesion area where a density of the inner lead portions is low.

Lead frame and integrated circuit package using the lead frame

A lead frame capable of easily connecting an inner lead to an electrode of a semiconductor element by way of a bump of the inner lead, and a method of manufacturing the lead frame capable of significantly easily forming the bump. A bump forming metal layer is formed on a metal base sheet on an area where each inner lead is to be formed. The inner lead is formed on the bump forming metal layer, and the bump forming metal layer is etched using the inner lead as a mask, thus forming a bump. After that, each outer lead is formed by selective etching of the metal base sheet from the rear surface side.

Etching method for forming a lead frame

An inner lead of a lead frame has an outer end portion extending so as to be connected with a side surface of an etching stop layer and with an upper surface of an outer lead. The outer lead is formed by etching both surfaces of a metal base, and the inner lead is formed by plating metal on the metal base with a resist layer used as a mask. The pitch of the outer lead can be made fine, and a bonding strength of the inner lead to the outer lead can be increased.

Lead frame and manufacturing method therefor

Disclosed is a semiconductor device comprising a lead frame which includes a metal layer forming an outer lead, a thin metal layer forming an inner lead, an intermediate layer held between the thick metal layer and the thin metal layer for forming a connection portion between the outer lead and the inner lead and a bump positioned at the extreme end of the lead frame, whereby making the lead frame as an electrode leading means by directly connecting the bump to each electrode of a semiconductor element, wherein the lead formed of the thick metal layer has a thickness of 30 to 300 .mu.m, the lead formed of the thin metal layer has a thickness of 10 to 50 .mu.m, and the bump has thickness of 5 to 50 .mu.m.

Growing community of inventors

Kanagawa, Japan

Mutsumi Nagano