GB2139424A - Magnetic Actuator - Google Patents

Abstract

A mechanism for actuating a pusher bar (64) of an integrated circuit chip-carrier handler includes a rotor assembly (95) having a clutch portion (97) cooperating with a field portion (99) of the assembly (95). Leads (101) convey a signal from a microprocessor to the field portion (99) to induce a current through windings housed within the field portion (99). A magnetic field is, thereby, created about the assembly (95). The assembly (95) is disposed for rotation about an axis, and an armature (103), normally spaced closely proximate in an axial direction from the clutch portion (97), is disposed for revolution about the axis. The armature (103) is formed from a ferrous material so that, when the assembly (95) is energized to create the magnetic field, it will be drawn into, and held in tight engagement with, the clutch portion (97) of the assembly (95). A remote end of the armature (103) is pivotally connected to a corresponding pusher bar (64) so that, as the armature (103) is revolved about the axis, the pusher bar (64) will be moved in a direction along its longitudinal axis to urge chip carrier units (42) from the bottom end (62) of a magazine track into a conveyor station. <IMAGE>

Description

SPECIFICATION Singulation Mechanism Technical Field The present invention deals broadly with the field of article movement systems. More narrowly, the invention is related to the field of handlers of the type for maneuvering integrated circuit chip carriers into engagement with contacts at a test site so that the circuits can be evaluated for proper performance characteristics. The test site interfaces with a tester by which the circuits are analyzed. The invention specifically relates to apparatus for feeding individual chip carriers from the bottom of a magazine track into a station of a conveyor which transfers the carriers to the test site in such a manner so that the contacts of the carrier are correctly engaged with contacts at the test site.

Background of the Invention In the last few decades, the semi-conductor industry has burgeoned. The electronics revolution initiated by the semi-conductor has had a significant impact upon the consumer, industrial, defense, and other governmental markets.

Many applications to which various electronic components are put require that the components be completely accurate in their operation and that all subcomponents function properly. Other applications, however, do not require such close tolerances as are necessary in more sophisticated applications.

For various reasons, the manufacturing process for integrated circuits, as in the case of other manufacturing processes, will produce units of different quality. For this reason, it is necessary to test the units not only to answer the relatively unsophisticated question of whether they are operable or not, but also to classify the units by degree of operability and quality. The best units can be used in applications wherein closetolerances and accuracy are essential. Those of lesser quality and integrity still might, however, be able to be used in other less demanding applications.

To this end, various high speed testing devices have been developed in order to ascertain the quality of function and integrity of various IC chips. Typically, such testers can perform testing upon in excess of three units per second. It is, therefore, necessary to provide handling equipment capable of feeding units to the test site and conveying those units away from the test site at at least as rapid a rate.

Various types of high speed handlers have been developed to solve this problem. Because of the high speed of operation, however, difficulties exist in devising structures which minimize the potential for jamming of the chip carriers as they are moved along a path through the input section of the handler, through the test site, and through the output section of the handler. The possibility of jamming is particularly likely at locations where the direction of movement of the chip carriers is changed. It is, therefore, particularly important that any handler designed to handle chip carriers at a high speed rate include structures for inhibiting canting and skewing of the carriers as they are passed therethrough.

An essential characteristic of any handler must be that it feeds chip carriers to the test site in a proper orientation. Typically, chip carriers are relatively planar in construction and have contact pads extending to only one of two oppositely facing planar surfaces. It is, therefore, essential that the proper face of the carrier be placed into engagement with the contacts at the test site in electronic communication with the tester.

In order to facilitate the proper orientation of the carriers at the test site, they must be fed into a handler with a given orientation. The handler must, thereafter, assure that, as the carriers pass through the various conveying means to the test site, they will not become inverted so that the contact pads will not engage the contacts at the test site. Additionally, because certain pins at the test site are specifically designated for engagement with certain of the contact pads, it is necessary that the handler conveying structure assure that the chip carriers are not rotated any measure about an axis extending perpendicularly to planes defined by the generally oppositely facing surfaces of the carrier. The operator of the tester can, thereby, feel relatively certain that testing of the carriers will be properly conducted and achieve a high mesure of validity.

In a typical chip carrier handler, carriers are fed into a magazine along one or more inclined tracks.

The carriers are conveyed on the tracks to a bottom end thereof at which location their direction of movement is changed by approximately 90 degrees. When a chip carrier is sensed as being in a position at the bottom end of one of the tracks, a pusher bar can be actuated to engage and move the lowermost chip carrier to urge it in a direction generally transverse to the direction of movement of the carriers down the magazine track.

Because of the potential for jamming at this juncture, it is imperative that the pusher bar function both at the proper time and in a smooth manner. A microprocessor can be used to send a signal in order to initiate actuation of the pusher bar. Various mechanic structures have been devised to receive the microprocessor signal and convert that signal into movement of the pusher bar. The invention of the present application more efficiently effects the conversion of microprocessor signal to mechanical movement.

It, thereby, minimizes problems of misoriented chip carriers, which might result during high speed operation of a handler, and consequent jamming.

Summary of the Invention The invention of the present application is a mechanism for actuating a pusher bar of the type used in integrated circuit chip carrier handler devices. Such bars are typicaily disposed for reciprocal movement along a path intersecting the bottom of a magazine track down which the carrier device is moved. The mechanism includes a rotor which is disposed for rotation about an axis. Typically, the rotor is mounted to a shaft for rotation about the longitudinal axis thereof along with the shaft. The mechanism further includes means.for magnetizing the rotor when desired. An armature is provided and is positioned proximate the rotor spaced slightly axially therefrom when the rotor is demagnetized. The armature is formed from a ferrous type material so that, when the rotor is magnetized, it will be drawn into and held in tight engagement therewith.Consequently, as the rotor is rotated, the armature will be dragged to revolve therewith. At a location on the armature remote from the axis, the armature is operatively connected to the pusher bar so that, when the armature is made to revolve, the pusher bar will be actuated in a direction to urge a chip carrier at the bottom end of one of the magazine tracks into a station in the conveyor.

In a preferred embodiment, means can be provided for revolving the armature in a direction opposite that in which it moves in actuating the pusher bar to urge a chip carrier into a conveyor station. Such means will, thereby, retract the pusher bar in order to allow another carrier unit to move down the magazine track to the bottom position thereof. The counter-revolving means can comprise a spring extending between a location on the armature and a location on a frame to which the pusher bar, the rotor, the rotor's mounting shaft, and the armature are mounted. As the armature moves in its first angular direction (that is, the direction to urge chip carriers into the conveyor station), tension will be taken on the spring. A stop can be provided to preclude revolution of the armature beyond a point it must attain in order to completely urge a carrier into the conveyor station.As a signal is received indicating that the carrier is in the conveyor station, the rotor will be demagnetized, and the spring tension will return the armature to a position retracting the pusher bar so that another chip carrier can enter the bottom of the magazine track.

Means can, further, be provided to manually revolve the armature about the' axis. This means can comprise a boss angularly spaced from the main portion of the armature which extends between the axis and the location of attachment to the pusher bar. In a preferred structure, the boss is positioned at 1 80 degrees from the main portion of the armature. With the rotor demagnetized, manual pressure on the boss can effect movement of the pusher bar to move a chip carrier unit from the magazine track into the conveyor station.

The invention of the present application is thus an improved mechanism for urging chip carrier units from a magazine track into a station of a conveyor unit capable of delivering the units to the test site of a handler device. More specific features and advantages obtained in view of those features will become apparent with reference to the detailed description of the invention, attached claims, and accompanying drawing figures.

Brief Description of the Drawings There is now described by way of example and with reference to the accompanying drawings, apparatus and a combination which are preferred embodiments of the several aspects of the invention.

In the drawings: Fig. 1 is a perspective view of a handler device in which the invention of the present application can be embodied; Fig. 2 is a side elevational view of the handler of Fig. 1; Fig. 3 is a view taken generally along the line 3-3 of Fig. 2; Fig. 4 is a view taken generally along the line 4 of Fig. 2; Fig. 5 is a view taken generally along the line 5-5 of Fig. 3; Fig. 6 is a view taken generally along the line 6-6 of Fig. 3; Fig. 7 is an enlarged view illustrating chip carrier unit impingement sleeves and an embodiment of means for sensing the presence of a carrier unit at the bottom end of a feed track; Fig. 8 is an enlarged view illustrating another embodiment of means for sensing the presence of a carrier unit at the bottom end of a feed track;; Fig. 9 is a view illustrating an alternative embodiment of a stack lifter structure; Fig. 10 is an elevational view of a pusher bar actuation assembly in accordance with the present invention; Fig. 11 is an enlarged view taken generally along the line 11-11 of Fig. 10; and Fig. 12 is an enlarged view of a portion of Fig.

10 illustrating a series of rotors and their corresponding armatures in greater detail.

Detailed Description of the Invention Referring now to the drawings wherein like reference numerals denote like elements throughout the several views, Fig. 1 illustrates a handler device 10 used in conjunction with a semi-conductor component tester. The handler device 10 includes a test site 12 (as best seen in Figs. 3 and 5) where each of a multiplicity of carriers mounting an IC chip are consecutively fed for testing. As seen in Fig. 5, the test site 12 has a multiplicity of leads 14, each lead extending from a pin (not shown) within the test site 12.

When a chip carrier is fed to the test site 12, contact pads positioned about the periphery of the chip carrier are brought into engagement with the pins at the test site 12. For this reason, therefore, orientation of the chip carrier is particularly important. Particular leads 14 extending from the test site 12 to the tester are specifically designated to communicate electronically with a particular one of the contact pads on the carrier.

Referring then to Fig. 1 , the handler 10 illustrated includes a cabinet 1 6 in which are housed various electronic function components, a hot air blower (not shown), and other elements.

Various controls and function indicia 1 8 are mounted on a generally upwardly facing panel 20 of the cabinet 16. A magazine 22 from which chip carriers are fed to the test site 12 is held above the cabinet 1 6 by appropriate support means 24.

As best seen in Fig. 6, the magazine 22 can include a plurality of downwardly sloped tracks 26 down which carriers move in being fed to the test site 12. Depending upon the type of movement system, the angle of inclination can vary between 1 and in excess of 35 .

Referring again then to Fig. 1, a hot air conduit 28 exits a side wall 30 of the cabinet 16 and enters the magazine 22 through a hot air fitting therein. The air can be used to both float the carriers down the magazine tracks 26 by forming an air film thereon and heat the carriers to temperatures which the chips mounted thereon normally operate when installed in a device with which they are intended to be used. The chips can, thereby, be tested under conditions simulating normal operating conditions. A typical temperature to which the carriers in the magazine 22 are heated is in excess of 1 SOC Centigrade.

A hot air return duct 32 can be provided to recirculate the air which had passed through the magazine 22 back to the blower and heater unit disposed within the cabinet 1 6. A thermally sealed heating system can, thereby, be provided in order to minimize the demands placed upon the heater unit.

Also seen in Fig. 1 is a return duct 34 for heated air which has been channeled to the test site 12 and a conveyor area to maintain the temperature of the chip carriers being tested through the time at which they have been ejected from the test site 12 after completion of testing.

The air conducted to the test site 12 and conveyor area can flow through a conduit branching off a main hot air conduit. Similarly, the return duct 34 from the test site 12 and conveyor area can merge with the main return duct.

A magazine 22 having ten vertically spaced tracks 26 is illustrated. It will be understood, of course, that the particular number of tracks 26 provided can vary although spacing between tracks 26 will necessarily be the same as verticle spacing between stations on the conveyor 36 which are positionable laterally adjacent the bottoms of the tracks 26.

The particular handler 10 illustrated in the figures incorporates a modularity feature wherein chip carriers of different sizes can be accommodated. To this end, a magazine insert 38 capable of accommodating a particular size of carrier can be interchanged for another insert which accommodates carriers of a different size.

Means can be provided for securing the particular magazine insert 38, when it is in position, within the magazine 22. A knob 40 which impinges upon an upper surface of the insert 38 when it is in position can be provided for this purpose. By rotatably adjusting the knob 40 so that it screws downwardly, secure retention of the insert 38 within the magazine 22 can be effected.

A conveyor 36 by which chip carriers 42 are immediately transported to the test site 12 is best illustrated in Figs. 3 and 5. The conveyor 36 is endiess in nature and is shown as being disposed for running about three sprockets 44, 44', 46 in a generally vertically extending plane. Two of the sprockets 44, 44' are fixed for rotation about axels 48, 48' mounted to a lower tensioning member 50, and the third 46 of the sprockets is disposed for rotation about an axel 52 mounted to an upper tensioning member 54. By urging the tensioning members 50, 54 away from one another along a shaft 56, the correct amount of tension can be applied to the conveyor 36.

Each of a plurality of conveyor stations 58 includes a pair of finger-like elements 60 between which one chip carrier 42 is positioned as the conveyor 36 runs downwardly along the back side of the handler 10 in feeding the carriers 42 to the test site 12. With respect to a particular station 58 passing downwardly proximate the back side of the handler 10, a lower of the fingerlike projections serves as a floor on which the carrier can be seated, and the upper of the projections functions as a covering ceiling.

As best seen in Fig. 3, a vertical plane defined by the conveyor 36 is substantially parallel to a vertical plane defined by the tracks 26 within the magazine 22. The plane defined by the conveyor 36 is closely spaced laterally from the bottoms 62 of the magazine tracks 26, and the vertical distances between each of the stations 58 of the conveyor 36 is substantially the same as the vertical distances between the bottoms 62 of the tracks 26. Each of the stations 58 can, therefore, be positioned laterally adjacent one of the bottom ends 62 of the tracks 26.

Referring now to Fig. 4, the spatial relationship of a track 26, a conveyor station 58, and a pusher bar 64 actuable to urge a carrier unit 42 at the bottom of the particular track 26 into the station 58 of the conveyor 36 is illustrated. Fig. 4 further illustrates means known in the prior art for actuating the pusher bar 64. The actuation means includes a bell crank 66 which is formed by the rigid intersection of first and second arms 68, 70.

The bell crank 66 is shown as being mounted for pivoting about an axis 72 extending generally vertically proximate the intersection of the arms 68, 70.

The pusher bar 64 is disposed for reciprocating movement (from right to left and vice versa as viewed in Fig. 4). A right end of the pusher bar 64 is shown as being pivotally attached to an end of the first arm 68 of the bell crank 66 remote from the intersection of the two arms 68, 70. As the bell crank 66 is rotated about its axis 72 of pivoting, therefore, the pusher bar 64 will be reciprocated.

An end of the second arm 70 of the bell crank 66 remote from the intersection of the arms 68, 70 is shown as having pivotally attached thereto the end of a shaft 74 remote from a solenoid housing 76 relative to which the shaft 74 teiescopes. The shaft 74 is biased to a normally extended position by a pair of springs 78 hooked, at first ends thereof, into an eye 80 formed in the remote end of the second bell crank arm 70.

Opposite ends of the springs 78 are hooked about generally vertically extending pins 82 mounted in elements 84 of the handler frame structure.

When the handler 10 automatically determines, by means of electronic components, that a chip carrier 42 is in position at the bottom end 62 of the particular track 26 corresponding to a particular pusher 64 and its actuation structure, that a conveyor station 58 laterally adjacent the chip carrier 42 is empty, and that it is proper to urge the carrier 42 into the station because it has attained a threshold temperature required for testing, a current is induced in the solenoid windings. The solenoid, thereby, functions to retract the shaft 74 within the housing 76, overcoming the bias of the springs 78. The bell crank 66 is, thereby, rotated about its pivot axis 72 in a clockwise direction as viewed in Fig. 4.

The pusher bar 64 is, consequently, urged leftwardly as seen in that same figure.

Fig. 4 illustrates the track 26 down which chip carriers 42 pass as being perforated, the perforations 86 being spaced and aligned along a direction in which the carriers 42 move down the track 26. The perforations 86 allow heating air to encircle the carriers 42 and heat the chips to the test temperature. Further, when the angle of inclination of the tracks 26 is relatively small, the heating air can pass upwardly through the perforations 86 to create an air cushion thereon so that the carriers 42 can be floated gently down the surface of the track 26 to the bottom end 62 thereof.

A number of chip carriers 42 are illustrated in phantom in Fig. 4. When the solenoid shaft 74 of the pusher bar 64 actuation means is in its normally extended position, a leading edge 88 of the pusher bar 64 is closely proximate one edge of the carrier 42 in the bottommost position of the track 26. The pusher bar 64 has a side 90, generally perpendicular to the leading edge 88, which is aligned substantially along the intersection of the bottommost carrier and the second carrier immediately adjacent to the bottom most carrier. Since the pusher bar 64, in the embodiment illustrated, is not adjustable along the track 26 down which the chip carriers 42 pass, the side 90 of the pusher bar 64 defines where the line of engagement between the two lowermost carriers must be.When a magazine insert 38 for accommodating smaller chip carriers 42 is used, a first stop 92 must be adjusted so that the stack of carriers 42 does not move downwardly along the track 26 to a point at which the line of engagement between the two lowermost carriers 42 bypasses the side 90 of the pusher bar 64.

Similarly, the lateral dimension of the conveyor station 58 can be adjusted by a second stop 94 movable to the right as viewed in Fig. 4.

Figs.10,11, and 12 illustrate a magnetic clutch mechanism in accordance with the invention of the present application. Referring first to Fig. 12, a series of axially spaced rotor assemblies 95 are illustrated. Although Fig. 12 illustrates three of the assemblies 95, and Fig. 10 illustrates a system having ten of the assemblies 95, it will be understood that, in an application wherein the mechanism is used in an integrated circuit chip carrier handler device, as many rotor assemblies as there are tracks 26 in the magazine 22 will be provided. Each rotor assembly 95 includes a clutch portion 97 and a field portion 99.The field portion 99 houses a series of wire windings (not shown) therein, and, when a current is caused to flow through the windings by actuation of a circuit including leads 101 from a microprocessor (not shown), the clutch portion 47 of the rotor assembly 95 will become magnetized.

Each rotor assembly 95 has a corresponding armature 103 normally disposed axially a small distance from the rotor assembly clutch portion 97. Since, in a preferred embodiment, a shaft 105 to which the rotor assemblies can be mounted by use of cap screws 107 is oriented generally vertically, gravity will tend to effect the spacing of the armatures 103 from their corresponding rotor clutch portions 97.

When the microprocessor, by appropriate sensing means, senses a chip carrier 42 at the bottom of a track 26 and a conveyor station in position laterally adjacent that bottom end of the track 26, a current will be induced within the rotor field portion 99. The armature 103 is made of a ferrous material and the normal spacing of the armature 103 from the clutch portion 97 of the rotor assembly 95 is small enough so that the armature 103 will be drawn into, and maintained in frictional engagement with, the clutch portion 97.The magnetic attraction induced between the rotor assembly 95 and the armature 103 is such that, if the rotor assembly 95 is rotated about the longitudinal axis of the shaft 105, the armature 103 will be caused to be revolved about the axis with only minimal slipping at the interface between the armature 103 and the clutch portion 97 of the rotor assembly 95, even when the armature 103 resists the tendency to revolution because of drag as will become more apparent hereinafter.

Referring now to Fig. 10, an integrated circuit chip carrier handler 10 can utilize a single shaft 105 to which are mounted a plurality of rotor assemblies 95. The shaft 105 and the rotor assemblies 95 mounted thereto are held in place by opposite bearing block mounts 109, 109'. A support member 111 of the handler 10 can have, mounted thereto, a motor mount 113. The mount 113, in turn, supports a stepping motor 11 5 which can be substantially coaxial with the shaft 105. As seen in Fig. 10, the stepping motor 11 5 need not be limited to a single size. A larger motor is shown in solid line, while a smaller motor is shown in phantom.

A stub shaft 117 of the motor 11 5 can be connected to the shaft 105 in order to drive the shaft 105. This can be accomplished by means of a flexible coupling 119 attached intermediate the stub shaft 11 7 and the upper end of the rotor assembly mounting shaft 105.

When an integrated circuit chip carrier 42 is sensed as being at the bottom end of a magazine track 26, the microprocessor responds by sending a signal to the rotor assembly 95. The field portion 99 of the rotor assembly 95 is energized to create a magnetic field about the assembly 95.

The field, in turn, pulls the armature 103 into contact with the clutch portion 97 of the assembly 95. With the rotor assembly 95 so energized, the stepping motor 1 15 rotates the shaft 105 and, in turn, the various rotor assemblies 95 mounted thereto. If a particular assembly is energized, the corresponding armature 103 will be caused to be revolved about the longitudinal axis of the shaft 105.

An end of the armature 103 remote from the shaft 105 its operatively connected to a corresponding pusher bar 64. As the armature 103 is made to revolve in a first direction (clockwise as viewed in Fig. 11), the pusher bar 64 to which it is attached will be urged in a direction upwardly as seen in that figure. A chip carrier 42 at the bottom of the magazine track 26 will, thereby, be urged into an immediately laterally adjacent conveyor station 58.

The armature 103 will be rotated by the stepping motor 11 5 a multiplicity of increments in this first direction. First stop means 121 can be provided to preclude revolution of the armature 103 beyond a position at which the pusher bar 64 has moved a sufficient distance in order to completely urge the carrier unit 42 into the conveyor station 58. When the armature 103 has been revolved this measure, the microprocessor will cause flow of current through the leads 101 and to the field portion 99 of the rotor assembly 95 to be terminated. A consequent termination of the magnetic field induced at the clutch portion 97 of the rotor assembly will result. The armature 103 will, therefore, disengage from the rotor clutch 97 at this point.

Means can be provided for revolving the armature 103 in a second direction opposite the first revolutional direction. In a preferred embodiment, this means can take the form of a tensioning spring 123 extending from a point on the armature 103 spaced radially from the axis about which the armature 103 revolves, and a location on a frame 111 to which the pusher bar 64, the rotor assembly 95, and the armature 103 are mounted. Such a spring 123 will, normally, bias the armature 103 in the second direction of revolution.

A second stop member 125 can be provided to preclude revolution of the armature 103, and consequent withdrawal of the pusher bar 64, beyond a necessary position. When the armature 103 is in engagement with this second stop 125, a subsequent chip carrier unit 42 can move down the magazine track 26 to the bottom end thereof without being obstructed by the pusher bar 64.

As can be seen, oppositely facing surfaces of the pusher bar 64 are disposed in planes generally parallel to that of the magazine track 26. Since the armature 103 extends generally horizontally, the remote end thereof which is operatively connected to the pusher bar 64 can be angled at a measure sufficient so that that end is substantially parallel to the planes of the pusher bar surfaces.

Means can be provided for manually revolving the armatures 1 03 in their first directions. Such manual means can comprise, in the case of each armature 103, a boss 127 formed integrally with its respective armature 1 03. In a preferred structure, the boss 127 can project in a direction away from the pusher bar 64 so that, when manual actuation is desired, the main portion of the armature 103 will not obstruct such activity.

Fig. 4 illustrates, in phantom, a shaft 96 which is maintained, as can be seen in Figs. 7 and 8, generally horizontal. Figs. 7 and 8 illustrate a plurality of the shafts 96, one corresponding to each of the tracks 26 proceeding downwardly within the magazine 22. A shaft is disposed relative to each track 26 above a plane along which a carrier unit 42 is urged by the pusher bar 64 and on a side of the bottom 62 of a track 26 opposite the side on which the pusher bar 64 is disposed.

A generally cylindrical sleeve 98 having an axially extending bore 100 formed therethrough is shown as being mounted on each of said shafts 96. The diameter of the bore 100 is somewhat larger than the diameter of the shaft 96 so that, when the sleeve 98 is suspended from the shaft 96, it will be free to move eccentrically thereabout. The total diameter of the sleeve 98, however, is sufficiently large so that the sleeve 98 will extend downwardly wherein an outer surface 102 thereof can engage a chip carrier 42 as it passes therebeneath. Because of the positioning of the shaft 96, the outer surface 102 of the sleeve 98 can form a wall to engage an edge of a carrier unit 42 as it comes down to the bottom 62 of the track 26. The sleeve 98 will impringe both laterally and downwardly upon the carrier 42.

A chip carrier 42, when it is at the bottom 62 of a track 26 will, therefore, be essentially contained on all four sides by the leading edge 88 of the pusher bar 64, the first stop 92, the corresponding sleeve 98, and the upwardly adjacent chip carrier on the particular track 26. It will be understood, of course, that the position of the shaft 96 can be adjusted laterally depending upon the size of the particular chip carrier 42 being tested. When a magazine insert 38 containing smaller chip carriers 42 is inserted into the magazine 22, the shafts 96 suspending the sleeves 98 would be moved to the right as viewed in Figs. 7 and 8. When a magazine insert 38 accommodating larger chip carriers 42 is in the magazine 22, the shafts 96 would be moved to the left as viewed in those figures.

The size of the conveyor stations 58 can be adjusted in a similar manner. The first stop 92 can further include a portion 104 movable toward the back of the conveyor station 58 to restrict the distance that smaller chip carriers 42 can move toward the back of the handler 10. Further, a Jbar 106 can be provided to adjustably limit the lateral movement of smaller carriers within the conveyor stations 58.

As previously discussed, the handler 10 can include means for sensing whether a chip carrier 42 is in position at a bottom end 62 of a particular track 26. Typically, an optical array is used for sensing whether a particular object is in a particular location. Such an array might include a light emission device and a photosensor normally illuminated by the device. When an object is in the particular location with respect to which information is sought, the photosensor will be eclipsed by the object and the absence of illumination of the photosensor will initiate an electrical signal indicating the presence of the object.

With structures as those discussed in this application, however, existing temperatures cause damage to LEDs and photosensors such that information provided by such arrays is, at best, unreliable.

The structure illustrated, therefore, provides means by which the presence of a chip carrier 42 at the bottom end 62 of a track 26 can be sensed by use of an LED and photosensor array (not shown) remote from the bottom 62 of the track 26. Fig. 7 illustrates a first representative embodiment for accomplishing this sensing. An LED emits a beam of light through a first tubular structure 108 in a direction of, and aligned with, the direction of movement of the pusher bar 64 in urging the carrier 42 into a conveyor station 58. A first mirror 110 is positioned proximate an end of the tubular structure 108 remote from the LED and in the beam of light emitted thereby. The mirror 110 is angled at 450 relative to the direction of the beam of light and reflects the beam upwardly 900 from the direction along which it passed through the first tubular structure 108.

A second mirror 112 is disposed above the first mirror 110 and in the beam of light as reflected by the first mirror 110. It is als6 angled 450 relative to the beam as reflected by the first mirror 110 in order to divert the light beam 900 to the right and in a direction opposite that along which it is emitted by the LED. The beam, thereafter, enters a second tubular structure 114 and illuminates the photosensor at a right end thereof.

As can be seen, the mirrors 110, 112 can be positioned laterally so that they sandwich a station at the bottom end 62 of a track 26 therebetween. Since apertures 11 6 are formed in both upper and lower walls of the station at the bottom end 62 of the track 26 in order to normally afford illumination of the photosensor, a chip carrier unit 42 in the station will cause eclipsing of the second mirror 112 and, consequently, of the photosensor.

It will be understood that the particular mirror arrangement illustrated is not exclusive, and other mirror arrangements can function equally as weli.

One might include a single mirror reflecting a beam of light from an LED to a photosensor wherein presence of a chip carrier at the bottom end of a track would break the beam to cause the photosensor to not be illuminated. Other multiple mirror arrangements can also be envisioned.

A second sensing arrangement in which the LED and photosensor can be maintained remote from a high temperature location is illustrated in Fig. 8. A first light transmitting medium rod 118 having one end at a light source such as an LED transmits light to an end 120 of the rod 118 remote from the LED. That end can include a beveled, silvered surface 122 to act as a reflecting mirror. A second rod 124 having a beveled, silvered surface 126 opposite that of the first rod 11 8 can be provided to transmit light therealong to a photosensor. The beveled, silvered surfaces 122, 126 of the rods 118, 124 can be positioned relative to one another so that they sandwich the station at which the presence of a chip carrier 42 is desired to be known therebetween.The surfaces 122, 126, as in the case of the angled mirrors 110, 112 of the first embodiment, can be beveled at angles so that light will be angled from the surface of the first rod to that of the second rod. If a chip carrier 42 is present between the remote ends of the rods 11 8, 124, an electrical signal indicating the presence of a carrier will be generated in response to the clipsing of the beveled surface of the second rod 124.

In order to minimize abrasion between the abutted edges of the carriers 42, a corner of the bar at an intersection of the edge and the side thereof can be beveled to form a ramp 128 up which the carrier adjacent the bottommost one and any carriers above the adjacent one will ride as the bar 64 continues to move leftwardly. The abutting surfaces will, thereby, be moved out of engagement to preclude abrasion damage.

Another type of chip carrier which can be processed by the handler has a main body portion 130 and a multiplicity of electrical contact pads 132 extending peripherally outwardly from the main body portion 130. The edges of such carriers have a castled configuration. Such a carrier can be seen in Fig. 8. When such chip carriers move down a magazine track 26, only the electrical contacts 1 32 of adjacent carriers 42 will be in engagement. The main body portions 130 of adjacent carriers will be slightly spaced.

When these carriers are being tested, the operation of the pusher bar 64 can, in the worst case, cause damage to a number of the chip carriers 42. Even if the carriers are not damaged, they can become jammed if contacts of adjacent carriers engage alternately such as gear teeth do.

An alternative embodiment of a "stack lifter" can be provided and used with such carrier units.

A ramp member 134 extending forwardly from the engagement edge 88 of the pusher bar 64 at the intersection of the edge 88 with the side 90 can be provided. As the pusher bar 64 moves toward engagement with the bottom most carrier, the ramp member 134 will engage the main body portions 130 of the bottommost unit and the unit adjacent thereto. The second lowermost chip carrier will, thereby, be urged away from the bottommost unit. The contacts 1 34 of the second lowermost unit will, consequently, be urged out of engagement with those of the bottom most unit prior to the point at which the bottom most unit is engaged by the leading edge 88 of the pusher bar 64.

The portion 104 of the first stop 92 which precludes movement of carriers 42 centrifugally outwardly from their positions in the stations 48 of the conveyor 36 follows the conveyor 36 as it passes around one of the lower sprockets 44' by which it is tensioned. Chip carriers are, thereby, held within their stations 58 within the conveyor 36 until the pocket 1 36 between the finger-like projections 60 of a station 58 is in registration with a chute 1 38 extending downwardly through the test site 12. When the pocket 1 36 becomes in registration with the chute 138, the carrier 42 will fall downwardly into the chute 138 at an acute angle with respect to the horizontal. The chute 138, thereafter, changes directions to a generally vertical orientation.The platen-like carriers, thereby, become oriented generally vertically.

The test site 12 includes a pair of pins 140, actuated by a solenoid 142, which are normally in an extended position to obstruct passage of carriers downwardly through the chute passage 138. A carrier, as it drops downwardly through the passage 138, will be stopped by these pins 140. With the carrier in such a position, its contact pads are positioned opposite electrical connector pins conversing with contacts leading to the tester.

Means (not shown) such as an optic system previously described herein can be used to ascertain when a carrier is in position with its contact pads opposite the pins of the test site.

When the presence of a carrier is sensed, an electronic signal can be sent to a solenoid 144 to actuate a plunger 146 which moves generally transversely to the direction in which the carriers pass down through the chute 1 38. The plunger 1 46 moves the chip carrier into engagement with the pins of the test site 1 2 so that testing can be conducted.

After completion of testing, a signal will be sent to the solenoid 142 operating the obstruction pins 140, directing those pins to retract to allow the carrier to continue its downward movement through the chute 138.

It will be understood that the running of the conveyor 36 is synchronized with testing time so that the pocket 1 36 of the next subsequent station of the conveyor 36 will become in registration with the chute 1 38 at substantially the same time as the previous carrier being tested is being released to pass away from the test site 1 2. Rapid and continuous operation of the handler 10 is, thereby, not impeded.

As best seen in Fig. 5, a cylindrical shuttle member 148 is disposed beneath the chute 138.

It is structured for uni-directional rotation about a generally horizontal axis which lies in a plane substantially parallel to a plane defined by a chip carrier as it drops down the chute 1 38. The cylindrical shuttle member 148 has a plurality of angularly spaced, longitudinally extending slots 1 50 formed in its outer surface 1 52. They extend sufficiently deeply into the cylindrical member 148 so that, when one of the slots 150 is in registration with the bottom of the chute 1 38 and a chip carrier 42 is deposited therein, the carrier will completely enter the slot 1 50 so that rotation of the shuttle 148 will not be precluded.

The cylindrical shuttle 148 illustrated in the figures has three slots 1 50 formed therein, and the slots 1 50 are formed at locations about the periphery of the shuttle 148 spaced at equal angles. The entrances to the slots 1 50 are, therefore, spaced at 1 20C from adjacent slots 150.

The shuttle 148 illustrated has slots 1 50 formed therein which do not extend directly radially outwardly from the center thereof. Rather, they extend at acute angles with respect to tangents to the surface 1 52 of the shuttle 148 at the points at which the slots 150 exit. It will be understood, however, that this configuration is not exclusive.

The shuttle 148 illustrated in Fig. 5 rotates in a counter-clockwise direction as viewed in that figure. As it rotates, a chip carrier 42 deposited in one of its slots 1 50 will, by gravity and centrifugal force created by rotation of the shuttle, exit into a sort shuttle 1 54 which moves rapidly across a plurality of classification bins 1 56 in the output section 158 of the handler 10. As seen in Fig. 1, an embodiment of the handler includes sixteen classification bins 1 56. In operation, however, all of the bins 1 56 need not be used. Functional controls 18 on the panel of the cabinet 16 can select the number of bins 1 56 and the testing results which justify a particular chip carrier being placed into a particular bin 156.

In order to insure validity of testing, it is necessary that the orientation of a carrier 42 be establishabie from the time that it is inserted into the magazine 22 along a track 26 thereof, through the'test site 12, and into the output section 1 58 of the handler 10. Normally, chip carriers 42 are maintained in a stick in which the orientation is known. The stick can be abutted to a track 26 within the magazine 22, and the carriers can be allowed to slide downwardly onto the track 26. The assumption is, of course, that the orientation with the stick is such that, as the various chip carriers pass down the track 26, onto the conveyor 36, and down the conveyor 36, to the test site 12, they will be brought into engagement with the pins at the test site in a proper orientation.

The operation of the cylindrical shuttle member 148 and its spatial relationship to the test site chute 138 and the sort shuttle 1 54 are such that chip carriers will be conveyed to the various classification bins 1 56 of the output section 1 58 of the handler 10 in the same orientation in which they were fed into the magazine track 26.

Consequently, if retesting of carriers distributed into a particular bin 1 56 is necessary, the carriers in the bin 1 56 can be drawn into a storage stick which can, thereafter, be engaged with one of the magazine tracks 26 in order to feed the carriers onto that track 26.

Claims (12)

1. Apparatus for moving a bar for pushing objects, in a direction in which the objects are to be pushed, along a path on which the bar is disposed for reciprocation, comprising: (a) a rotor disposed for rotation about an axis: (b) means for magnetizing the rotor; and (c) armature means formed from a material capable of being magnetically attracted, said armature means being positioned closely proximate said rotor along said axis and disposed for revolution thereabout, and having a portion, remote from said axis, operatively connected to the bar so that as said armature means revolves about said axis in a first direction, the bar will be moved in the direction in which objects are to be pushed.

2. Apparatus in accordance with claim 1 further comprising means for revolving said armature means in a second direction, opposite to said first direction, about said axis to retract the bar when said rotor is demagnetized.

3. Apparatus in accordance with claim 2 further comprising a frame mounting the bar, said rotor, and said armature, and wherein said second direction revolving means comprises a spring extending between a location on said frame and a location on said armature spaced radially from said axis to bias said armature in said second direction.

4. Apparatus in accordance with claim 3 further comprising first and second stop means to limit revolution of said armature in said first and second directions, respectively.

5. In combination with a device for consecutively feeding semi-conductor component carrier units into a carrier unit test site interfacing with a semi-conductor tester, wherein the feeding apparatus includes a track having a surface along which carrier units move to a bottom end thereof, and a conveyor, having a station positionable laterally adjacent the bottom end of the track, for transferring carrier units from the bottom end of the track to the test site; apparatus for urging a carrier unit from the bottom end of the track into the conveyor station when the station is adjacent the bottom end of the track, comprising: (a) pusher means disposed for reciprocal movement along a path intersecting the bottom end of the track and the station; (b) a magnetizable rotor disposed for rotation about an axis; and (c) a ferrous armature normally spaced axially proximate said rotor and disposed for revolution about said axis, said armature having a remote end operatively connected to said pusher means; (d) wherein, as said rotor is magnetized, said armature is drawn into and held in tight engagement therewith so that, as said rotor is rotated about said axis, said armature will be revolved about said axis, moving said pusher means along said path to urge a carrier unit at the bottom end of said track into the conveyor station.

6. Apparatus in accordance with claim 5 further comprising means for manually revolving said armature in a direction to urge a carrier unit at the bottom end of said track into the conveyor station.

7. Apparatus in accordance with claim 6 wherein said manual means comprises a boss, carried by said armature, projecting in a direction away from said pusher means.

8. Apparatus in accordance with claim 5 wherein said rotor is mounted to a shaft for rotation, and wherein said shaft extends generally perpendicularly to said path of said pusher means.

9. Apparatus according to claim 1, substantially as described herein with reference to the accompanying drawings.

10. Apparatus for moving a bar for pushing objects, in a direction in which the objects are to be pushed, along a path on which the bar is disposed for reciprocation, substantially as described herein and substantially as shown in the accompanying drawings.

11. A combination according to claim 5, substantially as described herein with reference to the accompanying drawings.

12. A combination according to claim 5, substantially as described herein and substantially as shown in the accompanying drawings.