Automated positioning

• US 3,988,535 A
• Filed: 11/04/1975
• Issued: 10/26/1976
• Est. Priority Date: 11/04/1975
• Status: Expired due to Term

• Current Assignee: AT&T Technologies Inc (Nokia Corporation)
• Original Assignee: Western Electric Co., Inc. (Nokia Corporation)
• Inventors: Myscofski, Ronald F., Lach, Walter, Hickman, Henry H., Kalke, Avinash R.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Coles, Edward L.
• Application Number:
  US05/628,729
• Time in Patent Office: 357 Days
• Field of Search: 178/DIG. 1, 178/DIG. 38, 178/6.8, 178/DIG. 36, 178/ DIG. 21
• US Class Current: 348/87
• CPC Class Codes: H01L 21/682 Mask-wafer alignment in general G03F7/70, G03F9/70
• CPC Class Codes: H05K 13/0813 Controlling of single components prior to mounting, e.g. orientation, component geometry H05K13/0812 takes precedence

Abstract

Beam-lead chips are held to a magnetic carrier and incident light reflected by the shiny beam leads is seen by a TV camera. The electronic image is normalized and insignificant reflections are ignored. An X-Y table moves the magnetic carrier to bring the next chip within the field of view of the camera. The table then moves the carrier in two dimensions while seeking the reflections of specific beam leads. The locations of the edges of the desired beam leads are noted, and the X-Y table quickly moves to its final position midway between the noted edges. A subtraction of the X and Y data results in a θ correction signal. The chip is then vacuum lifted from the magnetic carrier by a prior art bonding head. Meanwhile, a substrate has been similarly positioned using another TV camera. The bonding head moves the chip to the substrate and bonds the beam leads.

Claims

1. A method of positioning an article having at least one prominent feature including generating first video signals representing the article including all prominent features which comprises;

generating second video signals representing a first position marker;

generating a third video signal representing a second position marker;

moving the article in a direction to bring a prominent feature into a position wherein the first video signals of that prominent feature coincide with the second video signals of the first position marker;

moving the article in a direction to bring a prominent feature into a position wherein the first video signals of that prominent feature coincide with the third video signals of the second position marker; and

moving the article to a position midway between its positions at which coincidence was achieved with the first position marker and the second position marker.

2. A method of using a video camera having a video field scanned by a video raster, to position an integrated circuit having beam leads with edges, to locate precisely the integrated circuit for a manufacturing operation, comprising the steps of;

moving the integrated circuit to a location within the optical field of the video camera;

illuminating the integrated circuit from a plurality of directions to form reflections from its beam leads;

generating a video signal representing the integrated circuit;

defining a first area and a second area within the video raster;

relatively moving the video signal and at least the first area in a first dimension to bring the image of an edge of a beam lead into coincidence with an edge of the first area;

relatively moving the video signal and at least the second area in a first direction in the first dimension to bring the image of an edge of a beam lead into coincidence with an edge of the second area;

measuring a first distance relatively moved by the video signal and the first and second areas in the first dimension between the coincidence of the image of an edge of a beam lead and the edge of the first area and the coincidence of the image of an edge of a beam lead and the edge of the second area; and

moving the integrated circuit in the first dimension in a direction opposite to the first direction by a distance equal to one-half of the measured first distance.

3. A method according to claim 2 further comprising:

generating a third and a fourth area within the video raster;

relative moving the video signal and at least the third area in a second dimension orthogonal to the first dimension to bring the image of an edge of a beam lead into coincidence with an edge of the third area;

relatively moving the video signal and at least the fourth area in a second direction in the second dimension to bring the image of an edge of a beam lead into coincidence with an edge of the fourth area;

measuring a second distance relatively moved by the video signal and the third and fourth area in the second dimension between the coincidence of the image of an edge of a beam lead and an edge of the third area and the coincidence of the image of an edge of a beam lead and an edge of the fourth area; and

moving the integrated circuit in the second dimension in a direction opposite to the second direction by distance equal to one-half of the measured second distance.

4. A method according to claim 3 which further comprising:

generating a rotary correction signal in accordance with the difference between the first and second distances; and

rotating the integrated signal by an amount representative of that correction signal.

5. A method of positioning an article having at least one prominent feature comprising:

generating first video signals representing the article including all prominent features;

generating second video signals representing a first pair of position markers;

generating a third video signal representing a second pair of position markers;

moving the article in a direction to bring a prominent feature into position wherein the first video signals of a prominent feature coincides with the second video signals of the first position markers;

moving the article in a direction to bring a prominent feature into position wherein the first video signals of a prominent feature coincides with the third video signals of the second position markers;

generating a locating signal indicative of one-half the distance that the article is moved between the coincidence with the first position markers and the coincidence with the second position markers; and

moving the article in accordance with said locating signal to a position midway between the first position markers and the second position markers.

6. A system for positioning an article having at least one prominent feature including generating video signals representing the article including all prominent features which comprises:

a first pair of position markers superimposed on the video signals;

a second pair of position markers superimposed upon the video signals;

means for moving the article and a prominent feature thereon into a position wherein the video signals of that prominent feature coincide with the first position markers;

means for moving the article and a prominent feature thereon into a position wherein the video signals of that prominent feature coincide with the second position markers; and

means for moving the article to a position midway between its positions at which coincidence was achieved with the first position markers and the second position marker.

7. In a system for orienting a device having four opposed sides and at least one lead extending orthogonally in X and Y directions from each side:

means for movably supporting the device;

means for electronically beam scanning a zone of the support means to produce video signals and a video display of the zone;

means for impressing four reference marker signals into video signals to produce two pairs of reference marker images on the video display which are diametrically opposed with equal spacing between marker images in each pair;

means for moving the support means to position the device and the leads within said scanned zone and with the image of each lead laterally spaced from one of the images of the reference markers;

means for imparting reciprocating motion to the support in the X direction and in the Y direction;

means responsive to each concidence of a reference marker signal with the video signal generated by the reflection of the beam from the edge of a lead for generating a motion reversing signal and then a motion terminating signal;

means responsive to each motion reversing signal for reversing the movement of the support means in the X and Y directions;

means for monitoring the movements of the support means and generating correction signals indicative of one-half the movements in the X and Y directions; and

means responsive to the correction signals for reverse moving the support means a distance equal to one-half the distance travelled during each reverse reciprocation of the support means.

8. A method of using a video camera having a video field scanned by a video raster, to postion an article having prominent features with edges, to locate precisely the article for a manufacturing operation, comprising the steps of:

moving the article to a location within the optical field of the video cameras;

illuminating the article from a plurality of directions to form reflections from its prominent features;

generating a video signal representing the article;

defining a first area and a second area within the video raster;

relatively moving the video signal and at least the first area in a first dimension to bring the image of and edge of a prominent feature into coincidence with an edge of the first area;

relatively moving the video signal and at least the second area in a first direction in the first dimension to bring the image of an edge of a prominent feature into coincidence with an edge of the second area;

measuring a first distance relatively moved by the video signal and the first and second areas in the first dimension between the coincidence of the image of an edge of a prominent feature and the edge of the first area and the coincidence of the image of an edge of a prominent feature and the edge of the second area; and

moving the article in the first dimension in a direction opposite to the first direction by a distance equal to one-half of the measured first distance.