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US 4,792,079 AGranted
Apparatus for ultrasonic wire bonding
AssigneeVEB Elektromat Dresden
InventorManfred Bansemir
Life of this patent
Estimating the term…
Abstract
The invention relates to an apparaus for ultrasonic wire bondings whereby the contact loci can be connected by wire straps, by means of ultrasonic welding, e.g. for connecting terminals on component mounts or the like to bonding islands on semiconductor chips. The inventive apparatus has means for combined axial and radial guiding of the rotatable bonding head, with low overall mass of the vertically movable parts and low moment of inertia around the rotational axis. As a result of the inventive disposition of the microscope objective, the object distance to the component can be set directly via the controllable vertical drive of the bonding head.
Claims9
An apparatus for ultrasonic wire bonding comprising:
- (a) a bonding head including
- (i) an ultrasonic generator,
- (ii) a sonotrode having an axis and a foot which defines a weld surface, and
- (iii) gripping means for advancing a bonding wire to said sonotrode and for severing the bonding wire,
- said bonding head being movable vertically in the direction of said sonotrode axis and rotatably about an axis parallel to the sonotrode axis and passing approximately through the weld surface at the foot of the sonotrode;
- (b) a cylindrical piece concentric with the axis of rotation of said bonding head and having a lower end face to which the bonding head is attached, said cylindrical piece have an eccentrically disposed bore running parallel to the axis of rotation of said bonding head, said bore having an axis;
- (c) bushing means for firmly holding said cylindrical piece;
- (d) flange means at an upper end of said cylindrical piece for engaging first drive means so as to vertically move said bonding head, said flange means having an eccentrically disposed bore running parallel to the axis of rotation of said bonding head;
- (e) radial bearing means for receiving said bushing means, said radial bearing means being adjustable without play, said radial bearing means including a ball-bearing cage, bearing balls and an inner race member with an upper end face and a lower end face, to permit longitudinal movement of said bushing means without play and such that said bearing means operates as a two-row angular-contact ball bearing;
- (f) drum means for accommodating electrical leads for the bonding head, said drum means being attached to the lower end face of the inner race member;
- (g) a toothed-belt pulley affixed to the upper end face of said inner race member;
- (h) a first rod eccentrically mounted on the drum means;
- (i) two rollers mounted on the bonding head and resting against said first rod;
- (j) a second rod mounted on the toothed-belt pulley;
- (k) a lever pivotally mounted with respect to said pulley;
- (l) spring means for holding a radial orientation of said lever with respect to the rotational axis of the bonding head;
- (m) transverse lug means on said lever for limiting the range of movement of said second rod;
- (n) fixed detent means for limiting rotational movement of the lever in one direction;
- and
- (o) a microscope objective screwed into a lower region of said bore in said cylindrical piece.
17 more elements
An apparatus for ultrasonic wire bonding comprising:
- (a) a bonding head including
- (i) an ultrasound generator,
- (ii) a sonotrode having an axis and a foot which defines a weld surface, and
- (iii) gripping means for advancing a bonding wire to said sonotrode and for severing the bonding wire, said bonding head being movable vertically in the direction of said sonotrode axis and rotatably about an axis parallel to the sonotrode axis and passing approximately through the weld surface at the foot of the sonotrode;
- (b) a cylindrical piece concentric with the axis of rotation of said bonding head and having a lower end face to which the bonding head is attached;
- (c) bushing means for firmly holding said cylindrical piece;
- (d) flange means at an upper end of said cylindrical piece for engaging first drive means so as to vertically move said bonding head;
- (e) radial bearing means for receiving said bushing means and for permitting longitudinal movement of said bushing means without play and such that said bearing means operates as a two-row angular-contact ball bearing;
- (f) drum means for accommodating electrical leads for the bonding head, said drum means being attached to a lower end face of the radial bearing means;
- (g) a pulley affixed to an upper end face of said radial bearing means;
- (h) second drive means for rotating said bonding head;
- and
- (i) limiting means for limiting rotation of said pulley in one direction.
10 more elements
Dependencies are inferred from the claim text.