Wire bonding equipment
The machines that stitch fine metal wires between the die's pads and the package, forming the electrical connections in the most widely used interconnect method.
In short
Wire bonding equipment connects the die to its package by welding very fine metal wires from the chip's pads to the package leads. It is the most common way to make a packaged chip's electrical connections.
Why it matters
Every signal and power line into and out of the chip runs through these connections. Wire bonding is mature, flexible, and low-cost, which is why it still dominates a huge share of packaged devices.
Beginner intuition
After a die is mounted, its tiny pads must be wired to the outside world. Wire bonding welds a hair-thin wire from each pad to a matching point on the package.
Each bond is a tiny weld made with heat, pressure, and ultrasonic vibration — repeated hundreds of times per chip, very fast.
Where it fits in manufacturing
In the interconnect step, after die attach, for wire-bonded package types.
How it works
What goes in
- A die-attached substrate or leadframe
- Fine bonding wire (a metal such as gold, copper, or aluminium)
What happens inside
- First bond: the tool forms a bond on the die pad.
- Loop: it feeds and shapes a wire loop across to the package.
- Second bond & cut: it bonds to the package lead and cuts the wire, then repeats for the next pad.
What comes out
- A die whose pads are electrically connected to the package, ready for encapsulation.
Major subsystems
Bond head & capillary
Guides the wire and forms each bond.
Ultrasonic + heat system
Supplies the energy that welds the wire.
Wire feed
Feeds and tensions the bonding wire.
Vision / alignment
Locates pads and leads precisely.
Process parameters that matter
- Bond pitch
- How closely spaced the pads and bonds are — finer pitch is harder.
- Loop height / shape
- The wire arc, which must avoid shorts and fit the package.
- Bond strength
- How well each weld holds — checked by pull and shear tests.
- Throughput
- Bonds (wires) per second.
A note on numbers
Common issues
What can go wrong:
- Weak or lifted bonds → opens
- Wire sweep or sagging loops → shorts
- Cratering or pad damage under the bond
- Wrong wire material or settings → reliability loss
Yield implications
A single bad bond can fail a whole package; bond reliability is a major back-end quality metric.
Advanced & research
Emerging and research directions, beyond today’s established practice.
- Copper and silver wire for cost and performance
- Fine-pitch and high-count bonding
- Wire bonding for power and high-reliability parts
How this connects
Related process
Related concepts
Related materials
Related equipment
Packaging connection
Wire bonding is one of the two main ways a package makes its electrical connections (the other is flip-chip).
Packaging →Supply-chain connection
It depends on fine bonding wire and substrates from the packaging-materials supply chain.
Supply chain →