In designing an integrated circuit or another type of semiconductor, there will be a need to be able to make connections between components. These interconnections can be between elements on one printed circuit board. Less often, they can also be used to connect different elements or components of different printed circuit boards within a device or system.
An Overview
In its simplest form, the wire bonding process is really just a connection. The wire used can be one of several different alloys or metals with the most common being gold, silver, copper or aluminum.
The typical sizes of a wire used for the wire bonding process will depend on the power that will be required for the application. Low power requirements will use wires that may be as small as 15 micrometers with higher powered requirements increasing the diameter of the wire. Copper wire can be as large in diameter as 500 micrometers and still be effectively bonded with the two components in the design.
Attachment Options
In addition to the type and size of wire needed, it will also be essential to consider the attachment technique to connect the wire to the components. For gold and copper wire the most common technique is ball bonding, which uses a pre-formed ball on the end of the wire and heat, pressure or ultrasonic methods are used to create a weld that flattens the ball shape and secures the wire.
Wedge bonding positions the wire in the correct direction before the weld is completed. This is most often done with gold wire. Compliant bonding uses aluminum tape to cover the weld location and then provides the addition of heat and pressure.
Choosing the correct wire bonding process and attachment option for the specific application will be important. Designed to be highly effective and secure, this is an essential part of the dependability and performance of any circuit or semiconductor.