Abstract:
An apparatus which inserts electronic memory modules into test equipment via direct horizontal insertion eliminating the need for intermediary connectors or adapters. The apparatus incorporates guide rails that maintain precise alignment of the electronic memory modules through the testing apparatus, sensors and microprocessor controlled belt apparatus to clear the automated transport paths of electronic memory module handler apparatus and automatically stacks the tested electronic memory modules.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates in general to electronic test equipment, and in particular to an electronic memory module tester having an automatic feeder handler and alignment assembly. 
     BACKGROUND OF THE INVENTION 
     Prior art test equipment includes automatic testers for testing electronic memory modules. The electronic memory modules have typically comprised circuit boards that have random access memory (RAM) integrated circuits mounted thereto. The circuit boards have been provided with surface contact pads that are typically aligned along one edge of the circuit board. This type edge connector configuration has been utilized for connecting the RAM integrated circuit components mounted to the circuit board to data buses of the devices within which the memory modules are used. Such memory modules have included SIMM, DIMM, and SODMM types of memory. Additionally, memory cards may also be utilized having the appearance of a credit card, and also having surface connectors mounted thereto for connecting the internally disposed memory thereof to equipment in which the aforementioned memory module is used. 
     Prior art in the technical field of the invention has encountered several important problems that negatively affect the accuracy and reliability of the test equipment. The invention described herein addresses these problems. 
     Test Accuracy. Electronic memory modules are typically tested after manufacturing to assure that they will perform properly after installation into a data processing system. Usually, a test connector is removably secured to edge connectors of the electronic memory modules under test to make contact to the surface pads for connecting the electronic memory modules to testing circuitry. In the prior art, automatic memory module test equipment included automatic memory module handlers. These prior art handlers typically utilized a conveyer belt for automatically feeding components through the test equipment. A stop was often utilized which was selectively retractable. The stop was selectively extended to stop the electronic memory module under test in a second position for engaging a connector to electrically connect the electronic memory module under test to the test equipment circuitry. 
     As is well known in the art, memory modules and the edge connectors therefor have been greatly reduced in size in recent years. The size of the connecter contact members has often been expressed in terms of the distance between corresponding points on adjacent ones of the surface contact pads of the electronic memory modules. Prior art contact pad spacing have been sized from 0.050 to 0.070 inches apart (50 mil to 70 mil). More recently, component spacing of 0.030 inches (30 mil) down to 0.025 inches (25 mil) have been utilized in fabricating electronic memory modules. 
     These recent reductions in the size of spacing between contact pads have reduced the ability of prior art handlers to adequately position the electronic memory modules edge surface contact pads for aligning with the test leads of the test connectors mounted to the handler equipment. This often results in test failures caused by misalignment between the test leads and the surface contact pads. Improvements for more closely aligning electronic memory modules under test with tester equipment connectors are desirable, such that alignment therebetween will be improved and the failure rate of electronic memory modules caused by inadequate testing procedures and equipment will be reduced. 
     Additionally, the testing of memory modules has become extremely sensitive to electrical current and testing signal irregularities. Prior art required adapters that are the actual testing contact with the memory testers. These prior art adapters produce current and testing signal irregularities that produce false or inaccurate testing results. Physically, the “fingers” are 1.5 inch long. A transition board also has to be made to adapt the signal source connection to the “finger” connection. This complicates the electrical path by the addition of one connector transition and also the 1.5 inch length of the contactor. This addition works fine at a low frequency signal situation (under 50 Mhz) while it totally distorts the signal at high frequency. The term is call “impedance mis-mismatch”. It essentially means that a normal signal goes through a not-so-smooth path and part of the signal is bounced back (echo) instead of getting through. The bounced back signal causes the original signal to have a “double vision” at the end of the path and render the signal un-recognizable. 
     The recent increases in sensitivity of memory modules to current and signal irregularities make it highly desirable to develop testing mechanisms and methodologies that minimize irregularities in current and signal. 
     Additionally, prior art handler equipment uses a retractable platform on which the module rests during the testing process. When testing is completed, the platform is retracted, allowing the module to drop into a mechanism that moves the module away from the testing position. The retractable platform in prior art requires constant adjustment because memory modules do not have a uniform thickness. Some modules have memory chips attached to only one side of the module board. Some modules have memory chips attached to both sides of the module board. Memory chips are also uneven in thickness. This uneven thickness of memory modules requires adjustment of the retractable platform. Misalignment of the platform can cause jams because the modules are then not in position for the testing process. Misalignment of the platform also causes test failures due to simple misalignment of the module in the memory tester. Additionally, repeated insertions of electronic memory modules into the testing interfaces of electronic memory module testers causes wear in the plastic edges of the interfaces. The wear of these edges results in improper alignment of electronic memory modules. 
     The recent developments in memory module design, as described previously, make it extremely important to develop a mechanism for the insertion of memory modules in the memory testers that prevent jams and misalignment. 
     The invention as described herein corrects the aforementioned technical problems in the field of electronic memory module testing. The invention aligns and positions electronic memory modules more precisely than prior art. The use of guides and rails in the invention prevent misalignment. The implementation of protective interface guides prevents misalignment resulting from repeated inserts of electronic memory modules. 
     Automation. Industries that utilize memory modules usually utilize memory modules in high quantities. Therefore, the testing of memory modules is a process that must test high quantities of memory modules. The automation of the memory module testing is essential to the profitable and efficient operation of businesses that use memory modules. The industry uses handler equipment to bring untested memory modules to the memory tester, insert the memory modules into the tester, and sort the tested memory modules. 
     Prior art handlers use stacking columns that hold vertically stacked memory modules. Prior art stacking columns were susceptible to uneven stacking by operators. Unevenly stacked modules would enter the testing process unevenly and in positions that would cause jams in the testing pathway. The possibility of these jams renders prior art unsuitable to be used in the absence of an operator. The invention described herein produces uniform and even stacks of electronic memory modules. 
     Prior art handlers sort memory modules by depositing the modules into bins or receptacles. This method of sorting causes the memory modules to fall into bins. The falling modules can be damaged. As a result of this damage, even modules that pass testing can be subsequently damaged in the sorting process. The invention described herein automatically stacks tested electronic memory modules and eliminates the problem described above. 
     Prior art handler equipment uses conveyor belts to move modules along the testing path. The modules can become misaligned on the conveyor belt and jam the handler. When this happens, prior art requires an operator to manually clear the conveyor path, reset the equipment and restart the testing process. The possibility of these jams renders prior art unsuitable to be used in the absence of an operator. The invention described herein automatically detects jams and clears object from conveyor belt transport systems without the need of human attention. 
     Prior art handler equipment uses conveyor belts with stops that protrude up from the surface of the conveyor belt. These stops are used to position the memory modules into testing position and to move the memory module along the testing path. In prior art, these stops frequently caused jams in the testing pathway poor positioning. If a memory module is placed on a stop, the module will become jammed along the testing pathway. This malfunction occurs because the handler does not have a means of positioning the stops in places that will avoid jamming the test pathway. The invention described herein detects the positions of stops to prevent positions that would cause jams. 
     SUMMARY OF THE INVENTION 
     The present invention disclosed and claimed herein horizontally inserts memory modules directly into the testing sockets of memory testers. This horizontal and direct insertion virtually eliminates problems of current irregularity, signal fluctuations, and memory module misalignment encountered by prior art. 
     The present invention disclosed and claimed herein utilizes retractable rails on which memory modules rest as they are inserted into the memory module tester. The retractable rails hold the memory module by the edges of the memory module. Holding the memory modules in such a way eliminates the problems encountered by prior art caused by the irregular thickness of memory chips. The retractable rails position all memory modules in proper alignment regardless of the thickness of the memory chips used on the memory module. 
     The present invention disclosed and claimed herein uses a carriage that holds a memory module in the proper alignment by using guide rods that fit into standard notches in memory module boards. The guide rods hold the memory module during insertion into the memory module tester and provides the hold necessary to remove the memory module from the tester apparatus. 
     The present invention disclosed and claimed herein comprises an apparatus that stacks memory modules evenly and in proper alignment for the testing process. This apparatus consists of a stacking tray similar in construction and design to prior art stacking trays. However, the present invention incorporates guide rods positioned in the stacking column that match standard notches found on all memory module boards. The rods, when properly fitted into these notches, produce an evenly stacked column of untested modules. The guide rods hold the memory modules in the proper alignment for insertion into the testing socket of memory module testers. 
     The present invention disclosed and claimed herein comprises a conveyor belt that has protruding stops, an infrared sensor, a microprocessor and a step motor. The protruding stops have a shape that obscures the infrared sensor when moved over the sensor. The sensor, when blocked by the stop, causes the microprocessor to calibrate the position of the stop. The microprocessor then causes the step motor to move the stop to the proper position so that the stop will not cause jams in the testing pathway. 
     The present invention disclosed and claimed herein uses the stop blocks to clear the conveyor belt pathway by moving the stop blocks along the conveyor belt pathway in both directions. 
     The present invention disclosed and claimed herein comprises an output stacker that receives tested modules and automatically stacks the modules for delivery. The tested module is moved to the stacker and slides onto a platform. The module is moved into the proper stacking position by a vertical rod. The platform is moved up to the bottom of a module stacker column. The bottom of the module stacker column has a mechanism that secures the memory module to the bottom of the stack 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates the memory module handler and stacker assembly. 
     FIG. 2 illustrates a memory module. 
     FIG. 3 illustrates a memory module input tray. 
     FIG. 4 illustrates a memory module pusher assembly—front view. 
     FIG. 5 illustrates memory module pusher assembly with memory module tester—cross section. 
     FIG. 6 illustrates a detailed view of guide rails and support rails. 
     FIG. 7 illustrates an electronic memory module tester with interface guides. 
     FIG. 8 illustrates interface guides. 
     FIG. 9 illustrates the belt transport mechanism. 
     FIG. 10 illustrates the sensor mechanism. 
     FIG. 11 illustrates the belt transport mechanism—top view. 
     FIG. 12 illustrates the stacker assembly with belt mechanism. 
     FIG. 13 illustrates the stacker assembly. 
     FIG. 14 illustrates the stacker with DIMM in position. 
     FIG. 15 illustrates the stacker assembly—up position. 
     FIG. 16 illustrates the stacker assembly—down position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, there is illustrated a memory module handler  1  and a stacker assembly  2  attached. FIG. 1 illustrates the manner in which the various components of this invention are interrelated. The input tray  3  is attached to a singulator  4  that regulates the rate at which memory modules are inserted into the invention. Memory modules  5  are placed into the input tray. The memory modules  5  are input into the invention by a singulator  4 . A singulator drops memory modules into the memory module pusher assembly  6 . Retractable holders  7  prevent the memory module  5  from falling through the pusher assembly  6 . The memory module pusher assembly  6  inserts memory modules  5  into an attached memory module tester. After a memory module  5  has been tested, the pusher assembly  6  removes the memory module from the attached memory module tester. After a memory module  5  has been removed, it is released from the pusher assembly  4  by putting the retractable holders  7  into a position that drops the memory module  5  from the memory module pusher assembly  4  onto the belt mechanism  8 . The belt mechanism  8  moves the tested memory module  5  to the stacker assembly  2 . The stacker assembly  2  receives the memory module  5  and the stacker platform  9  raises the memory module  5  to the bottom of the output tray  10 . The output tray  10  contains a stack of tested memory modules  5 . 
     Referring to FIG. 2, there is illustrated a typical electronic memory module. A typical electronic memory module consists of a board  20  that has notches  21 . On the board  20  are attached various memory chips  22 . 
     Referring to FIG. 3, there is illustrated a memory module input tray. The input tray incorporates two guide rods  30 . The guide rods are attached to the input tray in a position to fit into the notches  21  of a typical memory module  31 . A singulator  32  allows a single memory module  31  to pass at a time. The singulator  32  incorporates guide rods  33  that fit into the notches  21  of a typical memory module  31 . The guide rods of the input tray  30  and the guide rods of the singulator  33  position a memory module  31  for proper insertion into the pusher assembly (FIG.  4 ). 
     Referring to FIG. 4, there is illustrated a pusher assembly, front view. An input tray  3  is held in place by input tray holders  40 . FIG. 4 illustrates a memory module  41  placed into the pusher assembly by a singulator  32 . Retractable holders  43  hold the memory module in the proper vertical position. A memory module  41  is held in the proper horizontal position by guide rails  44 . An air cylinder  45  pushes an pulls the pusher frame  42  toward and from the socket gap  46 . A memory module tester is positioned such that its testing socket aligns with the socket gap  46 . When fully extended by the air cylinder  45 , the memory module  41  is inserted into the testing socket of a memory module tester. 
     Referring to FIG. 5, there is illustrated a cross section of a pusher assembly with a electronic memory module tester attached. An electronic memory module  50  is depicted in position to be inserted into the testing interface of the electronic memory module tester  51 . The electronic memory module is fixed in position by guide rails  52  and support rails  53 . The guide rails  52  hold the electronic memory module  50  in horizontal position and the support rails  53  hold the electronic memory module  50  in vertical position. The pusher assembly  54  inserts the electronic memory module  50  into the testing interface  55  of the electronic memory module tester  51 . The electronic memory module tester interface  55  is depicted with an interface guide  56 . The interface guide  56  guides the electronic memory module  50  into the electronic memory module tester interface  55 . The guide prevents the electronic memory module  50  from improper abrasion against the soft plastic edges of the electronic memory module tester interface  55 . 
     Referring to FIG. 6, there is illustrated a detailed view of the guide rails and support rails. The electronic memory module  60  is depicted held in position by the guide rails  61  and the support rails  62 . After the electronic memory module  60  is tested and removed from the electronic memory module tester interface  55 , the support rails are moved so that they no longer support the electronic memory module  60  permitting it to fall from the pusher assembly  54 . 
     Referring to FIG. 7, there is illustrated an electronic memory module tester with an interface guide. The electronic memory module  70  is positioned in the electronic memory module tester interface  71  by the interface guide  72  and a center guide  73 . The center guide  73  fits into a standard notch  74  on a electronic memory module  70 . The interface guide  72  prevents improper abrasion against the soft plastic edges of the electronic memory module tester interface  71 , and positions the electronic memory module  70  in the proper horizontal position for testing. 
     Referring to FIG. 8, there is illustrated the interface guide. The electronic memory module  80  is inserted into the electronic memory module tester interface  81 . The edges of the electronic memory module tester interface  82  are usually made of plastic. The interface guide  73  is positioned so that the electronic memory module  80  does not directly contact the edges of the electronic memory module tester interface  82 . The interface guide  83  prevents improper abrasion against the soft plastic edges of the electronic memory module tester interface  82 , and positions the electronic memory module  80  in the proper horizontal position for testing. 
     Referring to FIG. 9, there is illustrated a belt transport mechanism. A stepping motor  90  is attached to a belt  91 . The stepping motor  90  moves the belt around a wheel  92 . Stop blocks  93  are attached to the belt  91  for alignment purposes. Memory modules  5  are deposited after testing onto the bottom rail  94 . The stop blocks  93  are moved by the belt  91  in a manner that causes the stop blocks to come into contact with memory modules  5  that are deposited on the bottom rail  94 . The memory modules  5  are moved by the stop blocks  93  toward the exit trays  95 . 
     Referring to FIG. 10, there is illustrated the lateral view of a belt transport mechanism. An infrared sensor  100  is positioned just below the level of the belt  101  and where the stop blocks  102  on the belt  101  pass over the infrared sensor  100 . 
     Referring to FIG. 11, there is illustrated the top view of a belt transport mechanism. Stop blocks  110  attached to the belt  111  are constructed in a shape that, when viewed from the top, protrudes wider than the belt width. The shape of the stop block  110  allows the protruding part of the stop block  110  to cross in front of the infrared sensor  112 . Referring to FIG. 12, there is illustrated a stacker assembly with belt transport mechanism. A stop block  120  is illustrated moving a memory module  121  toward an exit tray  122 . Memory modules  123  are illustrated stacked in an output tray  124 . Memory modules  121  slide onto a stacking platform  125 . The stacking platform  125  raises the memory module  121  to the bottom of the stack of memory modules  123 . 
     Referring to FIG. 13, there is illustrated a stacker assembly. The stacker assembly consists of a stacking platform  130 , an alignment rod  131 , and an output tray  132 . Memory modules  121  are moved by the belt transport mechanism (FIGS. 10 and 11) onto the stacking platform  130 . The stacking platform  130  adds the memory module  121  to the output stack  133  held in the output tray  132 . 
     Referring to FIG. 14, there is illustrated a stacking mechanism. The electronic memory module  140  is held in alignment by a positioning rod  141 . The stacking platform  142  moves the electronic memory module  140  toward the output stack  143 . When the stacking platform  142  reaches its highest position, the stacker clips  144  slide under the electronic memory module  140  and remove it from the stacking platform  142 . The stacker clips  144  support the bottom of the output stack  143 . 
     Referring to FIG. 15, there is illustrated the stacker assembly in a raised position. There is illustrated a memory module  150  on the stacking platform  151 . The alignment rod  152  is depicted in a position that illustrates how it moves a memory module to the proper position for addition to the output stack of memory modules  153 . The alignment rod  152  moves the memory module to a position that is evenly aligned with the output stack of memory modules  153 . 
     Referring to FIG. 16, there is illustrated the stacker assembly in a lowered position. FIG. 16 depicts the stacking platform  160  and alignment rod  161  returning to a position to receive another memory module. 
     Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.