Wire bonds having pressure-absorbing balls
AssigneeTexas Instruments Incorporated
InventorsSohichi Kadoguchi, Norihiro Kawakami
Life of this patent
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Abstract
A semiconductor device with a chip having at least one metallic bond pad (101) over weak insulating material (102). In contact with this bond pad is a flattened metal ball (104) made of at least 99.999% pure metal such as gold, copper, or silver. The diameter (104a) of the flattened ball is less than or equal to the diameter (103a) of the bond pad. A wire (110) is connected to the bond pad so that the wire has a thickened portion (111) conductively attached to the flattened metal ball. The wire is preferably made of composed metal such as gold alloy. The composition of the flattened ball is softer than the wire. This softness of the flattened ball protects the underlying insulator against damage caused by pressure or stress, when the composed ball is attached.
Claims13
A method for fabricating a semiconductor device, comprising the steps of:
- providing a semiconductor chip having at least one metallic bond pad over insulator material;
- forming a first free air ball of a first metal wire having a first composition at the tip of a first capillary;
- attaching said first free air ball to said bond pad, and separating said first ball from said first metal wire;
- providing a second metal wire having a second composition harder than the first composition;
- forming a second free air ball of the second metal wire at the tip of a capillary;
- and
- attaching said second free air ball to said first ball.
A method for fabricating a semiconductor device, comprising the steps of:
- providing a semiconductor chip having at least one metallic bond pad over an insulator material;
- forming a metal ball in contact with said bond pad from a first metal wire with a first composition;
- and
- connecting a second wire having a second composition harder than the first composition to said bond pad by forming a thickened portion of said wire on said metal ball.
Dependencies are inferred from the claim text.