Wire Bonding

Wire Bonding is considered the most flexible and cost effective method of making interconnects on an integrated circuits. The wire bond forms a fine pitch interconnects between microelectronic and optoelectronic components. The history of wire bonding traces back to the late 1950's when the first thermocompression wedge bonder was developed.

Wire Bond Interconnects

Palomar is able to precisely and accurately peform the following five types of wire bonding, both via system ownership and contract assembly:

fine pitch gold wire
gold wire in place of ribbon
gold wire bonding
reverse wire bond to die application
reverse wire bond

Wire Bonders

Wire Bonding	Fine Pitch Au Wire Bonding Application: Fine pitch wire bonding for bonding high density die is measured in pitch. This is a pitch that every year gets a little smaller. The limiting factor on the Palomar Model 8000 is generally the capillary. The model 8000 can bond with as little as 4 grams of force! This high resolution control of bond parameters is what makes fine pitch wire bonding smaller each year. The SEM photo shows wires bonded at 50 um pitch and the ball is only 30 um.

Requirements	Specifications
Model 8000 Wire Bonder	Wire = .6 mil (15 um) 99.99 Au
	Capillary = GAISER 1800 UFAB series
	Temperature = 150 C
	Picture Magnification = x600
	Ball Diameter = 30 um
	Ball height = not measured
	Shear strength = not tested
	Pitch = 50 um

	Au Wire Bonding in place of Ribbon Application: Wire bonding RF devices with all ball bonds saves a machine transfer and setup time and possibly the purchase of another machine. Some active tuning is also possible by removing wires after completion. This picture shows 3 rows of transverse pitch gold wire bonds to replace a large ribbon bonding process.

Requirements	Specifications
Model 8000 Wire Bonder	Wire = 1 mil (25.4 um) 99.99 Au
	Capillary = GAISER 1500 series
	Temperature = 150 C
	Picture Magnification = x100
	Ball Diameter = 75 um
	Ball height = not measured
	Shear strength = not tested
	Pitch = NA

	Au Wire Bonding Application: Gold wire bonding describes what the Palomar Model 8000 was designed to do. Deep Access in a package, long wires and varying part heights are just fine for bonding. The picture shows a long wire 100 + mil bonding an output pin in a package.

Requirements	Specifications
Model 8000 Wire Bonder	Wire = 1 mil (25.4 um) 99.99 Au
	Capillary = GAISER 1500 series
	Temperature = 150 C
	Picture Magnification = x50
	Ball Diameter = 75 um
	Ball height = not measured
	Shear strength = not tested
	Pitch = NA

	Reverse Bond to Die Application: Low profile reverse bond to a die. Stand-off-stitch is used to place a ball bump on the die pad and then stitching onto t he ball bump. A second ball bump is used on the pad as a fulcrum to keep the wire from sagging onto the die edge. Loop Height 4 mil above die

Requirements	Specifications
Model 8000 Wire Bonder	Wire = 1 mil (25.4 um) 99.99 Au
Tailless Bump mode	Substrate = Al pad
Standard Wire Loop Mode	Temperature = 150 C

	Reverse Bond to Die Application: Low profile reverse bond to a die. Stand-off-stitch is used to place a ball bump on the die pad and then stitching onto the ball bump. Loop Height 10 mil above die

Requirements	Specifications
Model 8000 Wire Bonder	Wire = 1 mil (25.4 um) 99.99 Au
Tailless Bump mode	Substrate = Al pad
ELM2 Wire Loop Mode	Temperature = 150 C