Kulicke & Soffa Capillary Nomenclature

Capillary Nomenclature: Explanation of common features and selection criteria for ball bond capillaries from Kulicke & Soffa, along with the key selection criteria to consider when choosing capillaries (IKB-011).

Capillary selection is key to a successful and stable ball bonding process. Capillaries are high precision manufactured, with attributes specific to the wire diameter in use and bonding process parameters.

Capillaries are manufactured from two main materials:

  • Toughened Alumina
  • ATLAS (very high mechanical strength Alumina)

The figure below describes the K&S capillary nomenclature:

K&S Wire Bonding Capillary Nomenclature

There are many factors to consider when selecting the correct capillary. The figure below will show you some of the other considerations that need to be taken into account:

• Hole Diameter (H):
This contributes to bond placement accuracy and wire clearance during looping.

• Length (L)
This contributes to the need for deeper access in products.

• Outer Radius & Face Angle (OR & FA)
This contributes to the formation and finish of the 2nd bond (stitch).

• Inner Chamfer Angle (ICA)
This contributes to the housing and formation of the F.A.B (Free Air Ball).

For further information on our range of wire bonding capillaries, please click HERE.

For further information on our range of MPP Manual Wire Bonders, please click HERE.

For further information on our range of Kulicke and Soffa Automatic Ball Bonders, please click HERE.

To visit the Kulicke & Soffa website, please click HERE





Alex Forster


11 December 2019


IKB011 Rev. 2