Methods and apparatus for transferring electrical components

Abstract

A mechanism for handling semiconductor wafers includes a feed section which comprises a vertically movable elevator able to hold a number of vertically spaced carriers. Each carrier has a film frame mounted thereon for supporting a wafer. A pulling mechanism pulls a selected carrier out of the elevator along a first axis and into a pick and place section. A transfer mechanism removes individual dies from the wafer and moves them to a flip station along a second axis oriented perpendicularly to the first axis. The transfer mechanism can move different distances along the second axis to be able to remove dies arranged in a row along the second axis. The flip station is driven by a single motor to both lower and invert the dies.

What is claimed is:  
     
         1 . A wafer handling apparatus, comprising: 
 a frame structure forming: 
 a wafer feed section for storing a wafer holder adapted to support a wafer comprised of precut dies,  
 a wafer pick and place section spaced from the wafer feed section along a first axis, and  
 a wafer receiving section spaced from the wafer pick and place section along a second axis crossing the first axis;  
   a holder displacement mechanism arranged for movement between the feed section and the pick and place section for transferring a wafer holder from the feed section to the pick and place section linearly along the first axis; and    a transfer mechanism arranged for movement between the pick and place section and the receiving section for picking up and transferring wafer dies from the pick and place section to the receiving section linearly along the second axis,    the transfer mechanism being movable by different distances along the second axis for picking up dies arranged adjacent one another at different locations along the second axis.    
     
     
         2 . The wafer handling mechanism according to  claim 1 , wherein the wafer feed section comprises an elevator movable up and down and arranged to contain a plurality of wafer holders in vertically spaced relationship, and a drive mechanism for moving the elevator up and down to position selected wafer holders in position to be connected to the holder displacement mechanism.  
     
     
         3 . The wafer handling mechanism according to  claim 2 , wherein the wafer holder includes a carrier and a film frame mounted on the carrier.  
     
     
         4 . The wafer handling mechanism according to  claim 3 , wherein the carrier comprises: 
 a plate having a hole extending therethrough;    at least one clamp for holding the film frame onto the carrier so that a wafer on the film carrier is disposed over the hole in the plate.    
     
     
         5 . A wafer holder for use in a wafer feeding machine, the wafer holder comprising: 
 a film frame adapted to support a film in a stretched condition, which film supports a precut semiconductor wafer;    a carrier comprising a plate have a through-hole in a central portion thereof, the carrier further comprising at least one clamp for holding the film frame onto the carrier so that a wafer on the film frame is disposed over the hole in the plate;    a connector mounted at one edge of the carrier for enabling the wafer holder to be engaged by the wafer feeding machine.    
     
     
         6 . The wafer holder of  claim 5 , wherein said plate includes parallel edges adapted to be slidably received in an elevator rack.  
     
     
         7 . The wafer holder of  claim 5 , wherein the connector comprises a pair of pins in spaced configuration.  
     
     
         8 . The wafer holder of  claim 7 , wherein the at least one clamp comprises a spring clip.  
     
     
         10 . A wafer feed mechanism in an apparatus for handling semiconductor wafers, the wafer feed mechanism comprising: 
 an elevator movable up and down in a frame;    a plurality of wafer carriers mounted in the elevator in vertically spaced-apart relationship, the wafer carriers being slidable into and from the elevator in a horizontal direction;    a plate-like film frame mounted on each wafer carrier, the film frame forming an aperture, and including a film extending across the aperture; and    a precut semiconductor wafer mounted on the film of each film frame.    
     
     
         11 . The wafer feed mechanism of  claim 10 , wherein the carrier comprises: 
 a plate having a hole extending therethrough;    a recess formed adjacent one end of the plate, the recess disposed parallel to the plate and opening toward the hole, the recess receiving a first edge portion of the film frame;    a plurality of removable positioning pins extending into the recess and mating with respective positioning notches formed in the first edge portion of the film frame; and    a hold-down structure mounted on the plate to one side of the hole disposed opposite to the recess for holding a second portion of the film frame.    
     
     
         12 . The wafer feed mechanism according to  claim 11 , wherein some of the film frames have different size apertures formed therethrough, and at least some of the carriers having different sized holes formed therethrough to conform to the sizes of the apertures of the respective film frames.  
     
     
         13 . A method of feeding semiconductor wafers comprising the steps of: 
 A. seating the wafers on respective film frames, each film frame having an aperture and a film extending across the aperture for supporting the respective wafer, the apertures of at least some of the film frames being of different size from the apertures of others of the film frames;    B. mounting the film frames on respective carriers, each carrier having a hole sized in accordance with the size of the aperture of the respective film frame, the hole of each carrier being aligned with the aperture of the respective film frame;    C. positioning the carriers in vertically spaced relationship in respective support seats of a vertically movable elevator, each of the carriers configured to be received in any of the support seats; and    D. selectively raising and lowering the elevator to bring a selected carrier to an elevation suitable for being removed from the elevator.    
     
     
         14 . The method according to  claim 13  wherein step B includes sliding a first edge portion of each film frame into a recess disposed on the carrier while causing notches formed in the first edge portion to mate with positioning pins extending into the recess, and applying hold-down elements to a second side of the film frame disposed.  
     
     
         15 . A wafer feeder, comprising: 
 a main frame;    a wafer holder adapted to support a wafer including a plurality of precut dies;    a die flip station that includes a track and a pivotable platform slidably mounted on the track, the die flip station being mounted adjacent the wafer holder;    a pick-up head located so as to pick up a die from the wafer and drop the die onto the pivotable platform of the die flip station; and    a controller for controlling the die flip station so as to pivot the pivotable platform whereby the die can be dropped from the pivotable platform onto an adjacent surface;    wherein the die flip station includes a single drive for both pivoting the pivotable platform and for moving the pivotable platform linearly along the track.    
     
     
         16 . The wafer feeder of  claim 15 , wherein the single drive is a belt drive.  
     
     
         17 . The wafer feeder of  claim 15 , wherein when the pivotable platform is in a first receiving orientation and at a first receiving position on the track, movement of the drive in a first direction causes the pivotable platform to pivot to a dropping orientation.  
     
     
         18 . The wafer feeder of  claim 17 , wherein when the pivotable platform is in the dropping orientation at the first receiving position on the track, movement of the drive in the first direction causes the pivotable platform to move linearly along the track.  
     
     
         19 . The wafer feeder of  claim 18 , wherein the die flip station includes a slide frame that is slidably mounted on the track, and the pivotable platform is pivotably mounted to the slide frame.  
     
     
         20 . The wafer feeder of  claim 19 , further comprising a shuttle below the die flip station, wherein the adjacent surface is on the shuttle.  
     
     
         21 . A wafer handling apparatus, comprising: 
 a frame structure forming: 
 a wafer feed section for storing a wafer holder adapted to support a wafer comprised of precut dies,  
 a wafer pick and place section spaced from the wafer feed section along a first axis, and  
 a wafer receiving section spaced from the wafer pick and place section along a second axis crossing the first axis;  
   a holder displacement mechanism arranged for movement between the wafer feed section and the wafer pick and place section for transferring a wafer holder from the feed section to the pick and place section linearly along the first axis; and    a transfer mechanism arranged for movement between the wafer pick and place section and the wafer receiving section for picking up and transferring wafer dies from the wafer pick and place section to the wafer receiving section linearly along the second axis;    the transfer mechanism including a pick up head and a plurality of anvils arranged on a frame along the second axis, the frame being selectively movable along the second axis so that a selected one of the plurality of anvils can be coordinated with the pick up head to pick up dies from the wafer.    
     
     
         22 . A wafer handling apparatus, comprising: 
 a wafer feed section for storing a wafer holder adapted to support a wafer comprised of precut dies,    a wafer pick and place section spaced from the wafer feed section along a first axis, and    a wafer receiving section spaced from the wafer pick and place section along a second axis crossing the first axis;    a displacement mechanism arranged for movement between the wafer feed section and the wafer pick and place section for transferring a wafer holder from the wafer feed section to the wafer pick and place section linearly along the first axis;    a pick up head movable along the second axis for picking up dies from the wafer at an adjustable pick up location and delivering the dies to the wafer receiving section; and    a die eject chuck movable along the second axis in concert with the pick up head for cooperating with the pick up head in picking up dies from the wafer;    wherein the pick up location can be adjusted along the second axis by moving the pick up head and the die eject chuck along the second axis.    
     
     
         23 . The wafer handling apparatus of  claim 22 , wherein a plurality of dies arranged adjacent one another along the second axis can be picked up without moving the wafer by moving the pick up head and the die eject chuck along the second axis.  
     
     
         24 . A wafer handling apparatus, comprising: 
 a wafer feed section for storing a wafer holder adapted to support a wafer comprised of precut dies,    a wafer pick and place section spaced from the wafer feed section along a first axis, and    a wafer receiving section spaced from the wafer pick and place section along a second axis crossing the first axis;    a displacement mechanism arranged for movement between the wafer feed section and the wafer pick and place section for transferring a wafer holder from the wafer feed section to the wafer pick and place section linearly along the first axis;    a pick up head for picking up dies from the wafer and delivering the dies to the wafer receiving section; and    a plurality of die eject chucks extending along the second axis, wherein a selected one of the plurality of die eject chucks can be aligned with the pick up head so as to pick up a die from the wafer.    
     
     
         25 . The wafer handling apparatus of  claim 24 , wherein the pick up head is movable along the second axis and the plurality of die eject chucks are movable along the second axis in concert with the pick up head for cooperating with the pick up head in picking up the die from the wafer.