Wirebond Workmanship: Ball (Thermosonic) Bonding

Bond Wire Placement:

Ball bonds must be a minimum of two wire diameters "D" to a maximum of five wire diameters at its widest "W" diameter.

All die ball bonds shall be at least 50 percent within the unglassivated bonding pad area

The center of a wire bond shall be within the boundaries of the unglassivated bonding pad area.

The center of the wire must be within the boundaries of the periphery of the ball.

All ball bonds shall be completely within the boundary of the package post.

Note: If the package post is smaller than 1.5 times the minimum bond size at least 50 percent of the bond shall be on the post .

For glass sealed packages, bonds shall not be within 20 mils of the end of the post.

Ball bonds shall have a minimum spacing of 0.25 mils between the bond and:

-glassivated noncommon metallization

- end of die

- another bonding wire, or

- another bond

Multiple bonds on a common bonding pad or post shall not overlap more than 25 percent.

Bonds shall be placed on the bonding pad so that less than 2.0 mils of bond periphery extends onto any connecting paths.

Bonding should not damage bond pads.

Crescent (tailless bond) shall:

The width "W" shall not be less than 1.2 times or more than 5.0 times of the wire diameter in width.

The length "L" shall not less than 0.5 times or more than 3.0 times the wire diameter in length The presence of Tool Marks is acceptable.


Crescent bond impression shall cover the entire width of the wire .

Courtesy Rockwell Collins