Electronics assembly apparatus with height sensing sensor

A method for providing a height of a feature n a reflective object, the object situated along an optical axis, the method comprising:

• a) energizing a first optical path directing light into a first line focus, the first line focus perpendicular to the optical axis and collecting a first partial image of the object from a detector;
• b) turning the first optical path off;
• c) energizing a second optical path directing light into a second line focus, the second line focus perpendicular to the optical axis and collecting a second partial image of the object from the detector;
• d) moving the object and the detector relative to each other, and repeating the steps of a) through c) until a desired number of first and second partial images has been acquired, and
• e) assembling the plurality of partial images into a pair of assembled images of the object, one assembled image comprised of first partial images and the other assembled image comprised of second partial images;
• and
• f) computing the height of at least one feature as a function of the two assembled images.

A pick and place machine adapted to place a component, the machine comprising:

• a host processor providing a desired location to place the component;
• a component placement head for releasably holding the component;
• a lens system for viewing the component, the system having an optical axis passing therethrough;
• a detector adapted to view the component and to provide a partial image thereof;
• a first optical path for projecting light into a first line focus;
• a second optical path for projecting light into a second line focus;
• a sensor motion control system adapted to cause a relative movement between the detector and the component;
• video processing electronics coupled to the detector, so that after the relative movement is finished, a plurality of first partial images from the detector is representative of a first assembled image of the component and a plurality of second partial images from the detector is representative of a second assembled image of the component, where the video processing circuitry provides feature height information as a function of the first and the second assembled images;
• where the host processor instructs the component placement head to move based at least in part upon the feature height information;
• and
• where the video processing electronics collects a plurality of first partial images until the relative movement between the component and the detector is finished, then the sensor motion control system resets and the video processing electronics collects a plurality of second partial images until the relative movement is finished, at which time the video processing electronics provides feature height information as a function of the two assembled images.

A wire bonder adapted to bond wire between a die pad and a lead frame, the bonder comprising:

• a host processor providing a desired location to bond wire;
• a wire bonder head adapted to dispense and electrically connect wire;
• a lens system for viewing at least a portion of one of the wire, the die pad, and the lead frame, the system having an optical axis passing therethrough;
• a detector adapted to view the portion, and to provide a partial image thereof;
• a first optical path for projecting light into a first line focus;
• a second optical path for projecting light into a second line focus;
• a sensor motion control system adapted to cause a relative movement between the detector and the portion;
• video processing electronics coupled to the detector, so that after the relative movement is finished, a plurality of first partial images from the detector is representative of a first assembled image of the portion and a plurality of second partial images from the detector is representative of a second assembled image of the portion, where the video processing circuitry provides at least feature height information of the portion as a function of the first and the second assembled images;
• where the host processor instructs the bonder head to move based at least in part upon the feature height information;
• and
• wherein the portion is representative of the wire, and the feature height information is representative of wire loop height.

An optical system for computing a height of a feature in a vertical direction, the system comprising:

• a sensor housing;
• a first and second optical path for providing a first and a second line foci spaced in the vertical direction, the first and second paths adapted to be energized sequentially;.
• a linear detector adapted to view the feature and provide a plurality of partial images of the feature;
• electronics for processing two sets of the plurality of partial images to form two respective assembled images, the electronics providing the height of the feature as a function of a ratio of an intensity corresponding to the feature between both assembled images;
• and
• wherein the machine is selected from the group of machines called pick and place machines, screen printers and wire bonders.

A method for providing a height of a feature on a reflective object, the object situated along an optical axis, the method comprising:

• projecting light into a line focus, the line focus perpendicular to the optical axis;
• causing the line focus and the object to relatively move with respect to each other along the optical axis;
• collecting a first assembled image of the object before the relative movement and substantially simultaneously collecting a second assembled image of the object after the relative movement of the line focus and the object, each step of collecting comprising the steps of:
• 1) capturing a plurality of partial images of the object from a linear detector, as the linear detector and the object move relative to each other in a scan direction;
• and
• 2) assembling the plurality of partial images into an assembled image of the object;
• and
• computing the height of at least one feature as a function of the two assembled images.