Gold and Aluminum Bond Wire Properties
Ultrasonic & Wedge Bonding

Gold wire bonding is a popular technique in the integrated circuit (IC) industry due to its reliability, durability, and low resistance. The technique is commonly used to create interconnects between components such as transistors, capacitors, and resistors, as well as to connect ICs to their packaging. See table of bonding wire properties below.

Thermosonic Wire Bonding is a process used in the manufacturing of integrated circuits (ICs) to create interconnections between the different components of the IC. This technique involves the use of heat and ultrasonic vibrations to bond a thin wire made of gold or aluminum to the components of the IC.

The process of thermosonic wire bonding typically involves several steps. First, a thin wire is fed through a machine that guides it to the correct location on the IC. The wire is then heated using a combination of high-frequency ultrasonic vibrations and thermal energy, which softens the wire and causes it to bond to the components of the IC.

One of the advantages of thermosonic wire bonding is that it can create very strong and reliable bonds between the wire and the components of the IC. This is because the ultrasonic vibrations used in the bonding process help to break down any oxides or contaminants on the surface of the components, allowing the wire to form a strong bond.

In addition, thermosonic wire bonding can be used with a wide range of materials, making it a versatile bonding technique for IC manufacturers. The technique can also be used to create interconnects between components with very small feature sizes, which is important for high-density ICs.

However, like all bonding techniques, thermosonic wire bonding does have some limitations. For example, the process can be time-consuming, as each wire must be bonded individually. In addition, the heat and ultrasonic energy used in the bonding process can potentially damage the components of the IC if not carefully controlled.

Wedge Wire Bonding is a process used in the manufacturing of integrated circuits (ICs) to create interconnections between the different components of the IC. This technique involves the use of a wedge-shaped tool to bond a thin wire made of gold or aluminum to the components of the IC.

The process of wedge wire bonding typically involves several steps. First, a thin wire is fed through a machine that creates a wedge-shaped tool. The tool is then brought into contact with the components of the IC, and pressure is applied to bond the wire to the components.

One of the advantages of wedge wire bonding is that it can create strong and reliable bonds between the wire and the components of the IC. This is because the wedge-shaped tool allows for precise control of the bonding force and placement of the wire.

In addition, wedge wire bonding can be used with a wide range of materials, making it a versatile bonding technique for IC manufacturers. The technique can also be used to create interconnects between components with very small feature sizes, which is important for high-density ICs.

However, like all bonding techniques, wedge wire bonding does have some limitations. For example, it can be more difficult to control the quality of the bonds with this technique compared to other bonding techniques such as thermosonic bonding. In addition, the size and shape of the wedge tool can limit the accessibility to certain components, especially in complex IC designs.

Here is an article which gives equations for calculating fusing current when the duty cycle is very small, "Bond Wire Fusing in ICs with Pulsed Current." Note that much larger currents can be handled with very short pulses. Here is the whitepaper for the formula.

This paper by Sandia National Laboratories is titled, "1 Mil Gold Bond Wire Study."

These values (for a constant current) are typical for standard industry bond wire, and could vary from one product to another.
Wire Type	Diameter (mils)	Wire Area (mils²)	Resistivity (Ω/inch)	Typical DC Fusing Current (amps)	Recommended Bond Pad Size (mils)
Gold	1.00	0.79	1.16	0.6-0.7	4 x 4
	1.30	1.33	0.693	0.9-1.0	5 x 5
	1.50	1.77	0.521	1.2-1.4	6 x 6
	2.00	3.14	0.294	1.6-2.0	8 x 8
Aluminum	1.00	0.79	1.33	0.27-0.30	3.5 x 3.5
	1.25	1.23	0.856	0.4-0.5	4 x 4
	1.50	1.77	0.595	0.6-0.7	6 x 6
	2.00	3.14	0.335	1.0-1.2	6 x 8
	3.00	7.07	0.149	2-2.5	9 x 12
	4.00	12.57	0.0838	3.5-4.0	12 x 20
	5.00	19.63	0.0537	5-6	15 x 25
	8.00	50.27	0.0210	11-12	20 x 32
	10.00	78.54	0.0134	16-18	25 x 40
	12.00	113.10	0.0093	21-23	30 x 48
	15.00	176.71	0.0059	20-35	40 x 60
	20.00	314.16	0.0033	50-60	50 x 80

99.99% purity @ 20°C

Posted March 15, 2023
(updated from original post on 2/13/2009)

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