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US 5,172,851 AGranted
Method of forming a bump electrode and manufacturing a resin-encapsulated semiconductor device
AssigneeMatsushita Electronics Corporation
InventorsAkira Matsushita, Hidekazu Konishi
Life of this patent
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Abstract
A bump electrode having a protrusion is formed. The protrusion is made of a folded wire whose tail is bonded to a cavity on the base of the bump electrode. A method of manufacturing a resin-sealed semiconductor device encapsulating a chip equipped with bump electrodes is also presented.
Claims14
A method of forming a bump electrode comprising the steps of:
- forming a swollen head at the tip of a metal wire drawn out from the tip of a capillary;
- pressing the swollen head to a pad electrode on a semiconductor chip by the tip of said capillary to crush said swollen head, thereby bonding said swollen head and said pad electrode, wherein the crushed swollen head part becomes a base part of said bump electrode, and a cavity is formed on the top surface of said base part;
- moving said capillary in a loop forming motion above said base part, and folding back the wire extending from said base part toward the base part;
- pressing and bonding the wire to said cavity by the tip of the capillary to form a loop of wire;
- and
- cutting off the wire further extending from said bonded part
- thereby leaving the loop of wire as a protrusion on said base part.
4 more elements
A method of forming a bump electrode comprising the steps of:
- forming a swollen head at the tip of a metal wire drawn out from the tip of a capillary, defining a wire root at a point where the swollen head and the wire connect;
- pressing said swollen head to a pad electrode of a semiconductor chip by the tip of said capillary to crush said swollen head, thereby bonding said crushed swollen head and said pad electrode, wherein said crushed swollen head becomes a base part of said bump electrode;
- moving said capillary in a loop forming motion above said base part, said loop forming motion comprising an upward movement and a downward movement and by the downward movement of the capillary cutting off the wire extending from said base part at the vicinity of the wire root, thereby forming a protrusion substantially at the center of the top surface of the base part.
Dependencies are inferred from the claim text.