PRESENTATION

WIRE BONDINGGroup 2: Tống Văn Khoa

Cao Văn Phước Trần Phúc Thành

Why Wire Bonding? Enable an IC to be electrically

interconnected to the package, and to allow that IC to be handled, tested and “burnt-in”

Such “qualified” IC used in electronic product.

Interconnected to other ICs, passives, flat panel displays, keyboards, sensors, connectors, antennas, switches, etc.

PRIMARY purpose – enable ICs to be interconnected with rest of the system.

Primary functions of IC assembly:(1) To provide signal and power distribution of

the packaged IC to the system.(2) To provide mechanical support to fragile IC(3) To provide environmental protection of the

IC

Another way to bonding: Tape automated bonding (TAB)Flip chip

IntroductionUsed in interconnecting the Die to various substrates… The most popular interconnection methodWire bonding is a SOLID phase welding process

where the two metallic materials, a thin wire and the metallization on Pad surface are brought into intimate contact under a combination of heat, pressure, and/or ultrasonic energy…..

Types of Wire BondingWire bonding is made using two types of

tools:A Wedge- Called Wedge bondingB: Capillary- Called ball bondingVery inexpensive- A penny per pin

Bonding Tools

Ball BondingProcess Steps

Capillary loaded with Au wireEFO wand generates a spark to melt the Au

wire at the tipApply pressure and ultrasonic energy, heat to

form ball bond at bond pad on chip sideBonding on substrate padLoop formationPackage bond pad formation by stitch bondingWire break-off to finish process

Wedge Bonding

Al Is More Suitable For Wedge Bonding

Process StepsWedge tool loaded

with wireApply pressure

and ultrasonic energy to form wedge

Bonding on substrate pad

Loop formationPackage bond pad

formationWire break-off to

finish process

Features of Wire Bonding MethodHigh speed( Bonding time 40ms: 2-4 wires/

sec)EconomicalStrong bondLarger Bonding pad (0,2mm gold wire:

0,5*0,5 mm pad)Ultrasonic can be used

(Dis)advantagesThe advantages of wirebonding:

Highly flexible chip-to-package interconnection process

Low defect rates or high yield interconnection processing

Easily programmed High reliability interconnection structure Very large industry infrastructure supporting the

technologyRapid advances in equipment, tools, and material

technologyThe disadvantages of wirebonding:

Slower interconnection rates due to point-to-point processing of each wirebond

Long chip-to-package interconnection lengths, degrading electrical performance

Larger footprint required for chip to package interconnection

SummaryFunction of Wire BondingTypes of Wire Bonding

Ball BondingWedge Bonding

Advantages and Disadvantages

ReferencesWikipedia

http://en.wikipedia.org/wiki/Wire_bondinghttp://en.wikipedia.org/wiki/Ball_bonding

Youtubehttp://r1---sn-o097zuel.c.youtube.com/videoplay

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Nano- Electronic Materials Group-HUST