Wire bonder tail length monitor
AssigneeKulicke & Soffa Investments, Inc.
InventorsJames M. Weaver, Ehud Efrat, Daniel J. Muldoon
Life of this patent
Estimating the term…
Abstract
Apparatus for monitoring the length of a fine wire tail made after the second bond of a fine wire interconnection includes a continuity circuit and a wire bond monitoring system (WBMS) in an automatic wire bonder. The Z axis position of the bonding tool is sensed to determined the height of the bonding tool on second bond and at the time the fine wire breaks from second bond. The monitoring circuit determines if the wire clamps are initiated and when and if the electronic flame-off control is fired. Logic circuit in the WBMS determine if wire tail after second bond is of a proper length to make a ball on the wire tail and if not, what remedial measures must be made to avoid damage to the semiconductor device being bonded.
Claims19
Apparatus for monitoring the length of a fine wire tail made after a second bond, comprising:
- means for sensing the initial Z.sub.O vertical axis height of a bonding tool at second bond,
- means for sensing the height Z.sub.B of said bonding tool while moving upward when said fine wire is electrically disconnected from said second bond,
- logic control means for determining if a proper length fine wire tail has been made, and
- EFO monitor means for monitoring and controlling an electronic flame off electrode coupled to said logic control means for making a ball on a wire determined to be a proper length fine wire tail.
A method of monitoring the making of fine wire tails after making a second wire bond of a fine wire interconnection, comprising the steps of:
- making a second wire bond with a fine wire in a bonding tool,
- raising the bonding tool to a predetermined tail length height while the fine wire is still attached to said second bond,
- clamping the fine wire at said tail length height,
- raising said bonding tool to a flame off height after clamping said fine wire to break said fine wire at said second bond,
- sensing the Z-axis height of said bonding tool at said second bond and at the Z axis height when said fine wire breaks,
- determining the length of fine wire tail extending from said bonding tool, and
- determining if the length of fine wire tail is of a length that is proper for making a ball on said fine wire tail before making a ball.
Dependencies are inferred from the claim text.