Abstract:
A magazine for carrying a plurality of multi-chip modules (MCMs) in association with an automated MCM handler for automated module testing. The magazine includes a body defining a plurality of mutually parallel receptacles extending between two opposing body sides, each body side having a different height relative to the height of the receptacles. Each receptacle is separated from an adjacent receptacle by a baffle member. At least one notch ins formed in each baffle member so as to form at least one row of aligned notches extending across and contiguous with each receptacle. The aligned row of notches is configured to receive an elongated element for effectively altering the length of each receptacle. At least one recess is formed in an underside of the magazine and transversely intersects each receptacle. The magazine may also include structure to accommodate vertical stacking of the magazine with a plurality of like magazines.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of application Serial No. 09/065,799, filed Apr. 23, 1998, now U.S. Pat. No. 6,229,323, issued May 8, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to handling of multi-chip modules (MCMs) to facilitate automated testing and sorting thereof and, more specifically, to a magazine for carrying a plurality of MCMs in cooperative association with an automated module handler adaptable to handle different types and configurations of such modules. 
     2. State of the Art 
     Production and quality demands of the computer industry, and particularly the personal computer industry, have compelled automation of component testing with ever-higher throughputs. Individual semiconductor dice are at least subjected to a nominal level of testing and burn-in prior to being mounted on carrier substrates, such as printed circuit boards, and complete testing and characterization of dice to qualify what are termed “known good die” or “KGD” are becoming more prevalent, although by no means standard procedures. Over and above the testing of individual dice, however, is the requirement that a multi-chip module, comprising a carrier substrate, such as a circuit board bearing a plurality of dice thereon, be tested and characterized as an operational unit before being installed in a personal computer, either as original equipment or as part of an upgrade. 
     One particularly common type of multi-chip module is a multi-chip memory module, wherein a plurality of memory dice is mounted to one or both sides of a carrier substrate, which is then installed in a card slot in a personal computer chassis to provide or upgrade the memory capacity of the computer by connection of the module to the computer motherboard bearing the processor and logic circuits. The most common types of memory modules are currently Single In-line Memory Modules (SIMMs) and Dual In-line Memory Modules (DIMMs). Both SIMMs and DIMMs employ multiple pin edge connectors running along a single edge of the carrier substrate, the edge connectors providing electrical connections to the motherboard through the chassis of the computer. The edge connectors may include a single set of contacts extending about the edge, as in the case of a SIMM, or discrete contacts on each side of the carrier substrate adjacent the edge to provide more separate contact locations, as in the case of a DIMM. 
     As noted above, it is required that multi-chip modules, including without limitation memory modules, be tested prior to installation to ensure that they will be fully operational. Module handlers have been developed to automatically present modules to a testing device or “tester”, which conducts the test of a module, the results of which test, in comparison to criteria preprogrammed in the tester, dictate the sort category of the module. The sort categories are conventionally either “pass” or “fail”, although sorting into operational subcategories depending on variations in operational module performance is becoming more common. Handlers may include a hopper or tray into which a plurality of modules is preloaded before placement on the handler, which then feeds one module at a time to a test site for testing through the multiple pin edge connector of the carrier substrate and, subsequently, to a receptacle based upon the module&#39;s exhibited test characteristics. 
     Handlers, and specifically the module conveyance systems thereof, are ideally reconfigurable to accommodate different thicknesses of modules, the term “thickness” being used herein to denote the dimension of a module perpendicular to the plane of the carrier substrate, termed a “card” or “printed circuit board”. Module thickness depends in part on carrier substrate thickness, in part on the height of the dice (including packaging) carried by the carrier substrate, and in part on whether dice are mounted to one or both sides of the carrier substrate. Many prior art handlers are only reconfigurable to accommodate different module thicknesses through extensive and complex removal and replacement of a substantial number of parts, which takes time and often requires the use of various tools. 
     One relatively simple approach to handler conveyance system reconfiguration is disclosed in U.S. Pat. No. 5,667,077, wherein an existing module handler conveyance channel is made reconfigurable to accommodate thicker or thinner modules through the insertion within the channel of one of a plurality of different-thickness, removable, justifying plates, the channel being sized to accommodate the thickest module contemplated for testing by the absence of any justifying plate whatsoever. The handler type to which the modifications are suggested, exemplified by the MC Systems, Inc. Model 828-MCM and Model 838-SIMM/DIMM Module Handlers, includes a vertical magazine or hopper which feeds modules to a belt-driven conveyance system employing the aforementioned variable-width channel to transport the modules in series to a test site and then to receptacles in a plurality of sort categories. Disadvantages of such an apparatus include the need for a large number of justifying plates if modules of a wide variety of thicknesses are to be tested, the practice of physical stacking of modules on top of one another (which may lead to damage), inability to ensure precise module alignment entering the conveyance system, lack of a positive grip on each module as it is conveyed to the test site (which may present alignment and jamming problems), lack of positive engagement and alignment of each module with the test contacts at the test site, and the lack of a positive and certain displacement of each tested module from the test site when it is to be moved toward the sort receptacles. 
     Another approach to module handlers is exhibited by the Exatron, Inc. Model 3000B SIMM/DIMM Handler, which employs gravity feed of singulated modules from a magazine along an inclined track to a test site, after which a tested module either slides directly into a bin of the appropriate sort category or into an output arm over a movable tray, the arm opening to release the module into a slot of the tray when aligned therewith. This handler is very operator time-intensive as it fails to provide a mechanism for receiving a large number of modules for test as it is limited to a single hand-loadable magazine of a set configuration fixed to a carriage on the handler, fails to provide positive retrieval of modules from the magazine and placement at the test site, fails to provide positive alignment of the modules at the test site, fails to provide positive displacement of a tested module from the test site, and does not appear to be quickly or easily adaptable to modules of varying thicknesses. 
     In short, conventional multi-chip module handlers suffer from insufficient automated input capacity, as well as a lack of positive module retrieval and placement at the test site, positive module alignment for test, and positive displacement of a tested module from the test site for sorting. Finally, the adaptability of conventional handlers to various types of modules is limited and cumbersome. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with one aspect of the invention, a magazine is provided for carrying a plurality of multi-chip modules (MCMs) in cooperative association with an automated MCM handler. The magazine and automated handler may be cooperatively used in conjunction with any of a variety of testers. 
     The magazine includes a body having a row of mutually parallel receptacles formed therein. Each receptacle extends from a first body side to a second opposing body side. The first body side is defined to have a height relative to the plurality of receptacles, and the second body side is defined to have a height which is lesser than the height of the first body side relative to the plurality of receptacles. A plurality of baffle elements longitudinally extend between the first and second body sides and are positioned such that each of the baffle elements is located between two adjacent receptacles. A plurality of notches are formed in the baffles with at least one notch in each baffle element and contiguous with the two receptacles adjacent the baffle elements. The plurality of notches define an aligned row of notches positioned inwardly of the first and second body sides which extends across all of the receptacles. 
     The magazine may include additional features, such as, for example, a second row of aligned notches which extends across the plurality of receptacles; one or more recesses in the underside of the magazine which transversely intersect the plurality of receptacles; structure for engaging a drive for moving the magazine; or elements formed on the magazine for accommodating the stacking of a plurality of like magazines. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 comprises a schematic top elevation of an embodiment of the module handler of the present invention, the perspective being perpendicular to the incline of the front of the handler; 
     FIG. 2 comprises a schematic side elevation of the module handler embodiment of FIG. 1; 
     FIG. 3 comprises a schematic rear elevation of the module handler embodiment of FIG. 1; 
     FIG. 4 comprises a top perspective view of a module magazine for the module handler of the present invention; 
     FIG. 5 comprises a bottom perspective view of the magazine of FIG. 4; 
     FIG. 6 is a top elevation of an exemplary multi-chip module in the form of a DIMM which may be handled by the magazine and module handler of the present invention; 
     FIG. 7 is a perspective view of a shipping tray usable with the handler of the present invention; and 
     FIGS. 8 through 10 comprise detailed perspective views of some of the component assemblies of the handler of the present invention, illustrating the manner in which certain components may be relocated to accommodate modules of differing thicknesses. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIGS. 1 and 2 of the invention, an embodiment  10  of the module handler of the present invention is schematically illustrated. As depicted in FIG. 2, the front face  12  of handler  10  is inclined at about a 35° angle to the horizontal to provide gravity assist to module movement. A tester  14  for testing the modules being processed by handler  10 , which may comprise any one of a number of commercially offered testers, resides within the housing  16  of handler  10 . One preferred tester usable with handler  10  is the Sigma 2 Tester offered by Darkhorse Systems, Inc. of Austin, Tex. The operation of handler  10  as to activation and sequencing of the various movable components and assemblies thereof, as well as initiation of the test sequence of tester  14 , is controlled by a programmed controller  18 , which may comprise any suitable commercially offered controller. One preferred controller is the Model 101-0092 Controller offered by Z World Engineering of Davis, Calif. As noted below, various sensors may also be employed to provide signals to controller  18  for initiation or cessation of activity of a particular component or assembly. 
     Commencing at the top of handler  10 , magazine input station  20  includes a magazine input zone  22  where a plurality of magazines  100  may be stacked. As can best be seen in FIG. 2, the magazine input stack (and also the output stack, as described later herein) is actually vertical or perpendicular with respect to the inclined front face  12  of handler  10  and not in the absolute sense, but will be described herein as being a “vertical” stack for the sake of convenience. Each magazine  100  of the input stack contains a plurality of multi-chip modules  200  such as, by way of example only, DIMMs or SIMMs, which are located in slots  102  in the magazines  100  and which are oriented in a mutually parallel relationship (see FIGS.  4  and  5 ). As seen in FIG. 3, input station  20  also includes an elevator  24  having upwardly projecting rams  26  located between drive belts  30  and  32  (FIG. 2) to lower the magazine stack as required when the former lowermost magazine  100   a  has moved horizontally out from under the stack so as to provide another full magazine  100   b  in the lowermost position. Input station  20  also includes a plurality (preferably four, spaced near each of the four corners of the input zone  22 ) of selectively extendable and retractable dogs  28  carried by a structure (not shown) extending above the front face  12  of handler  10  and located at an elevation to suspend a second-lowest magazine  100   c  in the input stack above the lowermost magazine  100   b  so that when elevator  24  has lowered magazine  100   b  completely, it may move horizontally from under the suspended magazine  100   c.    
     Magazines  100  are positively driven horizontally away from input station  20  and toward an indexing station  40  by two parallel, continuous, toothed drive belts  30  and  32 , each sliding on underlying rails  34  extending between input station  20  and output station  90  for vertical support, belt  32  engaging cooperating teeth  104  of like pitch at each end of each magazine  100  (see FIGS.  4  and  5 ). It is also contemplated that smooth-surfaced drive belts may be employed, engagement with and movement of the magazines  100  being effected by friction alone, but such alternative is less preferred due to the potential for reduced precision in positioning the magazine  100 . 
     Before proceeding further with a description of handler  10 , it will be helpful to further describe magazine  100 , which itself comprises part of the present invention, with reference to FIGS. 4 and 5. Each magazine  100  includes, as noted previously, a plurality of mutually parallel slots  102  oriented transversely to the length of the magazine  100  and its direction of travel through handler  10 . One side  106  of magazine  100  is of a height substantially the same as the baffles  108  which define slots  102  therebetween, while the other, “open” side  110  is of a substantially lower height, providing only a small lip against which modules  200  rest when magazine  100  is tilted at a 35° angle to the horizontal on the front face  12  of handler  10  (see FIG.  2 ). Teeth  104  are located on the bottom of side  110  at each end of magazine  100 . Baffles  108  are each notched at the same two locations  112  and  114  toward side  106  to provide, in combination, two longitudinally extending slots into which a metal, slat, bar or rod  115  may be inserted to shorten, if necessary, the effective length of each slot  102  to snugly accommodate modules  200  shorter than the total slot length and prevent shifting and possible damage to the modules  200  during handling of the magazine  100 . Upwardly extending post-like elements  116  with protrusions  118  are located at each corner of magazine  100 , and receptacles  120  are formed on the underside of each magazine  100  at locations to receive the protrusions  118  of another magazine  100  placed there underneath. The underside of each magazine  100  also includes two longitudinally-extending, mutually parallel recesses  122  and  124  which extend upwardly from the bottom of the magazine  100  a distance slightly larger than the height of side  110 . Recesses  122  and  124  intersect slots  102 , so that the carrier substrates of modules  200  loaded into slots  102  will extend into and across the recesses  122  and  124 . Finally, the underside of magazine  100  may include a shallow, longitudinally extending recess  126  running along and under side  106  to assist magazine  100  in tracking on drive belt  30 . Any suitable number of slots  102  may be employed in magazine  100  as sized and configured for use with input station  20  and output station  90 , at appropriate spacing to accommodate adjacent modules  200  received therein without interference. As shown in FIG. 4, magazine  100  comprises a thirty-five slot magazine adapted to receive modules with dice on only one side of the carrier substrate, although twenty-five slot magazines of the same length are also preferred for relatively thicker modules such as those having dice on both sides of the carrier substrate. 
     Returning to FIGS. 1-3, as magazine  100   a  moves through indexing station  40 , each module  200  is removed by indexing head  42  in cooperation with elevating ramps  44  (see FIGS. 1 and 3) as that module  200  is in vertical alignment with indexing head  42 . Indexing head  42  is movable in the X- and Y- directions as shown in FIG. 2, and indexing fingers  46  and  48  are spaced to closely bracket the leading and trailing edges of a module  200  when indexing head  42  is moved downwardly thereover. As magazine  100   a  approaches indexing station  40 , the bottom of each module  200  is contacted by inclined leading surfaces  44   a  of ramps  44  (see FIG.  3 ), the ramps  44  being aligned with recesses  122  and  124  of magazine  100   a  traveling thereover, each module  200  being gradually raised as it rides on ramps  44  as the magazine  100   a  travels toward indexing station  40  until that module  200  is resting on a horizontal upper surface  44   b  of the ramp  44  when aligned with the indexing head  42  at an elevation slightly above the height of a retaining lip provided by side  110  of the magazine  100   a . At this point, indexing head  42  moves in the X-direction to test site  50 , sliding and guiding module  200  therewith. It is also contemplated that elevating rams aligned with indexing station  40  might be employed in lieu of ramps  44  to raise each module for engagement and movement by the indexing head  42 , but this alternative structure would add some cost and complexity to the handler  10 , as well as requiring additional programming for controller  18 . 
     At test site  50 , between test site guide rails  52  (see FIGS. 1 and 2) and while still constrained by indexing head  42 , module  200 , still in a vertical orientation as removed from magazine  100 , is precisely aligned with respect to the test contacts which will engage the module&#39;s edge connectors  202  at the edge of carrier substrate  204  (see FIG. 6, wherein semiconductor memory dice  208  borne by carrier substrate  204  are also depicted) by insertion of locating pins  54  extendable transversely on carriage  56  (also termed a module locator bar) through tooling holes  206  in substrate  204 . In FIGS. 1 and 9, right-hand guide rail  52  has been cut away for a better view of locating pins  54  and carriage  56  therebelow. Carriage  56  is replaceable by the operator to accommodate multiple module configurations having tooling holes  206  at different locations on the variously sized substrates. For example only, and not by way of limitation, carriage  56  may be changed out to accommodate a change from a 72-pin to 168-pin module handling. The unused or “spare” carriage or locator bar or bars  56  to accommodate different module configurations may be carried on the handler  10  at the test site. 
     After alignment, test contact clamps  58  (see FIG. 2) clamp test contacts to their target edge connectors  202 , as known in the art, and indexing head  42  is withdrawn upwardly in the Y-direction and moved back over magazine  100   a  at indexing station  40  in the X-direction for retrieval of the next module  200 , which is advanced for retrieval by movement of magazine  100   a  by drive belts  30  and  32 . Tester  14  conducts a test of module  200  at the test site through test contact clamps  58  in accordance with the tester&#39;s programming and as known in the art. 
     When the next module  200  is advanced to test site  50  by indexing head  42 , the tested module  200   a  at test site  50  has already been released and will normally slide downwardly along output track  60  between guide rails  62 . However, if the tested module  200   a  has not moved from test site  50 , indexing head  42  guiding the next module  200  from magazine  100  at indexing station  40  will positively eject the tested module  200   a  from test site  50 , pushing it onto output track  60 . 
     If tested module  200   a  has passed the testing, it will be stopped at either upper stop  70  or lower stop  72 , both of which are located above slide gate  74  which covers an aperture  76  in the bottom of output track  60 . Upper stop  70  is located on output track  60  to stop a module  200  above a slot  302  of an upper row of slots  302  in a shipping tray  300  (see FIG. 7 for shipping tray details), while lower stop  72  is located to stop a module above a slot  302  of a lower row of slots  302  in the shipping tray  300 , which is secured to a motor-driven carriage  80  movable on linear bearings transversely under output track  60  from left to right (as looking at FIG.  1 ). In operation, carriage  80  with an empty shipping tray  300  (see FIG. 7 for a detailed view of an exemplary shipping tray) is initially moved from a start position to the left of the output track  60  toward the right a distance so that the right-hand uppermost row tray slot  302  and lower row tray slot  302  are respectively aligned with upper and lower stops  70  and  72 . When a tested, passed module  200  slides down output track  60 , lower stop  72  is actuated to stop it above lower slot  302 , whereupon slide gate  74  is retracted and module  200  drops a short distance into aligned lower tray slot  302 . The next passed module  200  is stopped by upper stop  70  and dropped by retracted slide gate  74  into upper tray slot  302 . Carriage  80  then advances to the right a distance equal to that between adjacent, parallel slot centers in the same slot row of shipping tray  300  to align the next set of empty upper and lower tray slots  302  with output track  60 , and the sequence is repeated during module testing until shipping tray  300  is full. If a failed module  200  is released from the test site  50 , neither stop  70  or  72  is actuated and the module  200  slides the length of output track  60  into discard bin  82  at the bottom thereof. As the shipping tray  300  is filled with passed modules  200 , it moves progressively toward the right until it has passed completely under output track  60 . When completely full, the shipping tray  300  is cycled back to the left on carriage  80  and removed therefrom, and an empty shipping tray  300  secured thereto. If different shipping trays are to be employed with carriage  80 , changeable adapters  84  (see FIG. 2) boltable to carriage  80  may be employed to accommodate different trays. 
     Returning to the top of handler  10 , when a magazine  100  such as magazine  100   a  has passed completely through indexing station  40 , it continues its movement on drive belts  30  and  32  to output stack zone  92  of output station  90 , wherein an elevator  94  having rams  96  and a set of four spring-loaded, extendable dogs  98  respectively operate to lift and then suspend an empty magazine  100  from drive belts  30  and  32  at a level higher than that of a magazine  100 . Specifically, and with reference to FIG. 3, the previous empty magazine  100   d , as shown, has been raised to a level immediately above spring-loaded dogs  98 , which are located at an elevation higher than the height of magazines  100 , so that magazine  100   a  may travel under magazine  100   d  to a position in vertical alignment therewith. Magazine  100   a  is then raised by rams  96  of elevator  94  extending between drive belts  30  and  32  to contact the underside of magazine  100   d , which retracts spring-loaded dogs  98  by contact therewith as it moves upwardly, and the stack of magazines  100  is further raised by movement of magazine  100   d  until the output station dog locations are cleared by the underside of magazine  100   a , at which point dogs  98  are again extended by their biasing springs in a “ratchet” effect and elevator rams  96  are lowered by elevator  94  so as not to interfere with the next magazine  100  arriving at output station  90  on drive belts  30  and  32 . It will also be understood that powered, selectively extendable dogs as employed at the input station  20  might optionally be employed at output station  90 . However, such an arrangement would, of necessity, add complexity and cost to handler  10  as well as require additional programming for controller  18 . 
     It should be noted at this time that the various components of handler  10  may be easily adjusted to accommodate different lengths, heights and thicknesses of modules  200  as required. For example, and with reference to FIGS. 8 through 10, wherein detailed views of various components and assemblies of handler  10  are depicted, quick release pins P are employed at various locations in conjunction with appropriately located receiving apertures A to position the components connected by the quick release pins P to underlying stationary components to accommodate various widths and heights of modules. In a similar manner, Allen head bolts B are employed with different threaded bores T to relocate other components, such as changing the height of test site guide rails  52 . In a similar manner, the longitudinal location of upper and lower stops  70  and  72  along output track  60  to accommodate different shipping trays may be changed by loosening bolts B, sliding the associated stop up or down the track, and retightening the bolts B. Stop elements  70   a  and  72   a  of each respective stop  70  and  72  (see FIG. 10) include thicker and thinner ends to alternately project into output track  60 , and are rotatably reversible (see arrows) to accommodate double or single-sided modules  200  (i.e., in terms of dice on both or only one side of the carrier substrate) in combination with output track guide rail  62  locational changes. Different sets of stop elements (each stop element being reversible as described) may be also used, for example, to precisely accommodate different dice heights, such as thin small outline package (TSOP) dice versus small outline j-lead (SOJ) dice. If used, the different sets of elements may be carried on handler  10  next to output track  60 . While not illustrated in detail, indexing fingers  46  and  48  may be adjusted in height, and indexing finger  48  adjusted in longitudinal location on indexing head  42  using bolts B and in combination with different threaded bores T on indexing head  42 , while stop block  49  is rotationally reversible to provide a different stop point when retrieving DIMMs versus SIMMs from a magazine  100  (see FIG.  2 ). For simplicity, components previously identified in conjunction with FIGS. 1-7 bear the same reference numerals in FIGS. 8-10. 
     It should also be noted that the drive systems of the various mechanisms described herein are conventional, and that electric, hydraulic and pneumatic drives may be interchanged as appropriate and dictated by suitability of each for a particular purpose. For example, indexing head  42  is preferably driven by two double-acting air (pneumatic) cylinders, one each for the X-and Y-directions. Similarly, carriage  56  bearing locating pins  54  is driven by a similar air cylinder, as are test contact clamps  58 , as well as upper and lower stops  70  and  72 , slide gate  74 , elevators  24  and  94  and dogs  28  and  98 . However, hydraulic or electric drives for these components, or any of them, may be substituted. Belts  30  and  32  are preferably driven by an electric rotary stepper motor or precise control of magazine advance through indexing station  40 . 
     Finally, in order to confirm proper operational positioning of the various movable components of the handler  10  and of the modules  200  being handled for test and sort and avoid unnecessary cycling and jamming of handler  10 , it is preferred that a number of sensors be placed at suitable locations. Depending on the parameter to be detected by a sensor, or control to be effected in response to the position of a component or module, proximity or through-beam sensors, or autoswitch sensors, all as know in the art, may be employed and signals therefrom communicated to controller  18  to trigger or halt a particular operational sequence of the handler  10 . Such sensors and their use being well known in the art, and their placement being a matter of discretion by the designer as a function of the need to confirm various component and module positions, no further description thereof will be offered herein. 
     While the present invention has been described in the context of a certain preferred embodiment, those of ordinary skill in the art will understand and appreciate that it is not so limited. Specifically, additions, deletions and modifications to the invention as disclosed herein may be made without departing from the scope of the invention as defined by the claims hereinafter set forth.