Abstract:
A system for analyzing electronic devices is described. An input station receives a plurality of electronic devices. A pick-and-place transport apparatus having a pick up tip for engaging and transporting one of the electronic devices at a time from the input station to the electric machine interface station, disengaging from the electronic device, and moving away from the electronic device The pick up tip is movable for engaging the electronic device while at the electric machine interface station and transporting the electronic device away from the electric machine interface station to disengage the electronic devices from the electric machine interface. First and second thermal devices secured to the support structure on opposing sides of the electronic device when the electronic device is at the electric machine interface station to simultaneously transfer heat to or form the electronic device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation-in-part of prior U.S. patent application Ser. No. 13/628,594, filed on Sep. 27, 2012, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1). Field of the Invention 
         [0003]    This invention relates generally to a system and method for analyzing electronic devices, including determining a parameter of a measured electronic device. 
         [0004]    2). Discussion of Related Art 
         [0005]    Before electronic devices are packaged for shipping, it is often required to measure certain parameters of the electronic devices. The parameters may for example be used for programming the electronic devices or may be measured to determine correct functioning of the electronic devices. 
         [0006]    A system that is used for analyzing electronic devices often includes a handler and an electric machine. The handler may for example have a bin where electronic devices are loosely deposited, a feed mechanism that feeds the devices one at a time and an electric machine interface station where one electronic device at a time is located against terminals of an electric machine interface. The electric machine is connected to the electric machine interface and can be used for programming the electronic devices, or first measuring frequencies of the electronic devices and then programming the electronic devices based on the frequencies. 
         [0007]    It is often required that the electronic devices be analyzed at temperatures other than room temperature. These temperatures are usually achieved with a thermal device located at the electric machine interface station. Such a thermal device usually heats or cools only one side of the electronic devices thus resulting in a temperature profile from one side to an opposing side of the electronic device. Such a temperature profile makes it difficult to determine accurate measurements for the electronic device as it would perform under conditions where the temperature through the electronic device is uniform, for example under all steady state conditions. 
         [0008]    U.S. patent application Ser. No. 13/628,594 describes a system for analyzing electronic devices includes an input station, a transport apparatus, an electric machine interface station, an electric machine interface, a support structure and first and second thermal components. The input station receives a cab with a plurality of electronic devices and the transport apparatus transports the cab with the electronic devices from the input station to the electric machine interface station. The electric machine interface engages the electronic devices when the electronic devices are at the electric machine interface station, and is disengageable from the electronic devices for the cab to be transportable by the transport apparatus away from the electric machine interface station. The first and second thermal components are located on opposing sides of the electronic device when the electronic device is at the electric machine interface station to simultaneously transfer heat to or from the electronic devices. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention provides a system for analyzing electronic devices including an input station configured to receive a plurality of electronic devices, a pick-and-place transport apparatus, an electric machine interface station, the pick-and-place transport apparatus having at least one pick up tip for engaging each of the electronic devices, transporting at least one of the electronic devices at a time from the input station to the electric machine interface station, disengaging from the electronic device, and moving away from the electronic device, an electric machine interface positioned to engage the electronic device when the electronic device is at the electric machine interface station from the electronic device, the at least one pick up tip being movable for engaging the electronic device while at the electric machine interface station and transporting the electronic device away from the electric machine interface station to disengage the electronic devices from the electric machine interface and first and second thermal devices secured to the support structure on opposing sides of the electronic device when the electronic device is at the electric machine interface station to simultaneously transfer heat to or form the electronic device. 
         [0010]    The system may further include a tape feeder that feeds the electronic devices to an input station where the pick up tip engages with the electronic devices. 
         [0011]    The system may further include that the input station is an input and output station and the pick up tip disengages from the electronic device at the input and output station after the electronic device is tested. 
         [0012]    The system may further include that the first thermal device includes a thermal head that is movable between a disengaged position to allow for the pick up tip to transport the electronic device to the electric machine interface station and an engaged position wherein after the pick up tip is moved away from the electric machine interface station, engages with the electronic device. 
         [0013]    The system may further include a thermal distribution piece that is located around the electric machine interface station, a thermal plate located around the thermal head, a backing plate secured to the thermal plate with a body of the thermal head between portions of the thermal plate and the backing plate and at least one spring between the thermal head and the backing plate, the spring biasing the thermal head so that a surface of the body of the thermal head rests on a surface of the thermal plate, a tip of the thermal head extending from the body of the thermal head making contact with the electronic device before the thermal plate makes contact with the thermal distribution piece, the thermal head moving towards the backing plate against a force of the spring until the thermal plate makes contact with the thermal distribution piece. 
         [0014]    The system may further include a purge cover having an inlet and outlet located over the electric machine interface station. The purge cover may have a main piece and a door, the door being movable relative to the main piece between an open position and a closed position. 
         [0015]    The system may further include that the second thermal device includes a thermal housing defining chamber having an inlet and an outlet, a heat exchange device having an inlet and an outlet, an outlet of the heat exchange device being connected to the inlet of the chamber, heat transferring between a fluid in the chamber and the electronic device. 
         [0016]    The system may further include that a printed circuit board and a socket mounted to the printed circuit board, the socket defining the electric machine interface station. 
         [0017]    The system may further include an electric tester connected through the printed circuit board to contacts in the socket. 
         [0018]    The system may further include that the second thermal device includes a thermal housing, the thermal housing and a surface of the printed circuit board jointly defining the chamber. 
         [0019]    The system may further include that the first and second thermal device are heaters 
         [0020]    The system may further include that the first and second thermal device are coolers. 
         [0021]    The system may further include that the first and second thermal devices cool the electronic device to below 0° C. 
         [0022]    The invention also provides a method of analyzing electronic devices including engaging at least one pick up of a pick-and place transport apparatus with each of a plurality of electronic devices, transporting at least one of the electronic devices at a time with the pick up tip from an input station to an electric machine interface station, disengaging the pick up tip from the electronic device, moving the pick up tip away from the electronic device to allow for testing of the electronic device, simultaneously transferring heat to and from first and second thermal components located on opposing sides of the respective electronic device when the respective electronic device is at the electric machine interface station, communicating signals between an electric machine and a circuit in the respective electronic device through the electric machine interface, moving the pick up tip to the electronic device, engaging the electronic device with the pick up tip while at the electric machine interface station and transporting the electronic device away from the electric machine interface station and transporting the electronic device with the pick up tip away from the electric machine interface station. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    The invention is further described by way of example with reference to the accompanying drawings, wherein: 
           [0024]      FIG. 1  is a top plan view of a system for analyzing electronic devices according to one embodiment of the invention; 
           [0025]      FIG. 2  is a cross-sectional side view on  2 - 2  in  FIG. 1 ; 
           [0026]      FIG. 3  is a cross-sectional side view on  3 - 3  in  FIG. 1 ; 
           [0027]      FIGS. 4   a  to  4   g  are cross-sectional side views illustrating functioning of the system; and 
           [0028]      FIG. 5  is a cross-sectional side view of a system for analyzing electronic devices according to another embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]      FIG. 1  of the accompanying drawings illustrates a system  10  for analyzing electronic devices, according to an embodiment of the invention, in plan view.  FIG. 2  illustrates the system  10  in cross-sectional side view on  2 - 2  in  FIG. 1 .  FIG. 3  illustrates the system  10  in cross-sectional side view on  3 - 3  in  FIG. 1 . 
         [0030]    As shown in  FIG. 2 , the system  10  includes a printed circuit board  12 , a socket  14 , a first thermal device  16 , a movable mounting plate  18 , a second thermal device  20 , a plurality of internally threaded sleeves  22  and threaded screws  24 ,  26 ,  28  and  30 . 
         [0031]    The first thermal device  16  includes a thermally conductive gasket  32 , a thermal distribution piece  34 , a gasket  36 , a purge cover  38 , a thermal plate  40 , a thermal head  42  and a backing plate  44 . 
         [0032]    The second thermal device  20  includes a thermally insulative gasket  46  and a thermal housing  48  made of a thermally insulative material. 
         [0033]    The socket  14  has a recess forming an electric machine interface station  50  for placing an electronic device. An electric machine interface  52  is formed by contacts in a base of the electric machine interface station  50 . The socket  14  is located on the printed circuit board  12  and is electrically connected thereto. Electric signals can conduct through conductors in the printed circuit board  12  to and from the contacts at the electric machine interface  52 . 
         [0034]    The thermal distribution piece  34  is placed on the printed circuit board  12  with the gasket  32  between the thermal distribution piece  34  and an upper surface of the printed circuit board  12 . The thermal housing  48  is placed on a lower surface of the printed circuit board  12  with the gasket  46  between the thermal housing  48  and the printed circuit board  12 . The thermal housing  48  has a plurality of openings  54  therein and the gasket  46  has a plurality of openings  56  that are aligned with the openings  54 . Each sleeve  22  is located within a portion of an opening  54  and an opening  56 . Referring to only the left side of the drawing, openings  58  are formed in the printed circuit board  12 , socket  14  and thermal distribution piece  34 , respectively. The openings  54 ,  56 ,  58 ,  60  and  62  are aligned with one another. One screw  24  is inserted into a bottom of the opening  54  and turned into the thread within the sleeve  22 . One screw  26  is inserted into a top of the opening  62  and then through the openings  60 ,  58  and  56  and is turned into the thread within the sleeve  22 . The screws  22  and  24  thereby secure the gasket  32 , thermal distribution piece  34 , gasket  46  and thermal housing  48  to the printed circuit board  12 . 
         [0035]    The purge cover  38  is located over the thermal distribution piece  34  on the printed circuit board  12  with the gasket  36  between the purge cover  38  and the printed circuit board  12 . Openings  66 ,  68  and  70  are formed in the printed circuit board  12 , gasket  36  and purge cover  38  such that one of the openings  66  is aligned with one of the openings  68  and one of the openings  70 . The opening  70  is internally threaded. One screw  30  is inserted from below into the opening  66  and then through the opening  68 . The screw  30  is then turned so that its thread turns into the thread of the opening  70 . The purge cover  38  is thereby secured to the printed circuit board  12  with the gasket  36  between the purge cover  38  and the printed circuit board  12 . In another embodiment the purge cover may not be mounted to the printed circuit board and be mounted to a hander of a pick-and place transport apparatus instead. 
         [0036]    The thermal head  42  is inserted into the thermal plate  40  and the backing plate  44  is located above the thermal head  42 . The backing plate  44  is then secured to the thermal plate  40  with the thermal head  42  held between the backing plate  44  and the thermal plate  40 . Openings  74  and  76  are formed in the thermal plate  40  and the mounting plate  18 . Each opening  76  is aligned with a respective opening  74 . The openings  76  are internally threaded. One screw  28  is inserted from below into the opening  74 . The screw  28  is then turned so that its thread turns into the thread of the opening  76 . The thermal plate  40  is thereby secured to the mounting plate  18 . 
         [0037]    As shown in  FIG. 3 , the thermal plate  40  has a smaller opening  80  and a larger opening  82 . A surface  85  connects the smaller opening  80  to the larger opening  82 . The thermal head  84  has a base  86 , a body  88  and a tip  90 . The base  86  has a lower surface  92 . The base  86  is larger than the smaller opening  80  so that the surface  92  rests on the surface  85 . 
         [0038]    The first thermal device  16  further has a plurality of springs  96  located between the thermal head  84  and the backing plate  44 . The springs  96  are compressed when the backing plate  44  is pressed towards the thermal plate  40 . Screws  98  secure the backing plate  44  to the thermal plate  40 . The springs  96  then bias the body  88  so that the surface  92  remains on the surface  85 . 
         [0039]    The purge cover  38  has a main piece  100  and a door  102 . The main piece  100  has an opening  104 . The door  102  is movable between a position where the opening  104  is open and a position where the opening  104  is closed by the door  102 . It is preferred to have a door such as the door  102 , although for smaller parts a purge cover may be provided with only a small opening such as the opening  104  without a door. If the opening is small enough, sufficient positive pressure can still be created in the purge cover to prevent air from entering the purge cover. 
         [0040]    The thermal distribution piece  34  has a side wall  106  and a top portion  108 . An opening  110  is formed in the top portion  108 . The side wall  106  is located adjacent the socket  14  and the top portion  108  is located above a top surface of the socket  14 . Heat transfers through the thermal distribution piece  34  to or from the socket  14 . 
         [0041]    The thermal housing  48  has side walls  112  and a lower wall  114 . A chamber  116  is defined jointly by the side walls  112 , the lower wall  114 , inner surfaces  118  of the gasket  46  and a lower surface of the printed circuit board  12 . Threaded openings  120  and  122  are formed through the side walls  112 . Pipe connectors  124  and  126  are screwed into the openings  120 . A hot or cold fluid (liquid or gas) enters through the pipe connector  124  into the chamber  116  and leaves the chamber  116  through the pipe connector  126 . 
         [0042]      FIG. 4   a  illustrates further components of the system  10  including an electric tester  128 , a tape feeder  130 , a heat exchange device  132  and a pick-and-place transport apparatus  134 . The electric tester  128  is connected through leads in the printed circuit board  12  and socket  14  to the contacts at the electric machine interface  52 . Electric signals can be transmitted between the electric tester  128  and the electric machine interface  52 . 
         [0043]    The tape feeder  130  holds a plurality of electronic devices  138 . The tape feeder  130  is movable so that the electronic devices  138  are moved one at a time to an input and output station  140 . 
         [0044]    The pick-and-place transport apparatus  134  includes a pick up tip  142 . As will be further understood by of ordinary skill in the art, the pick-and-place transport apparatus  134  further includes a mechanism and actuators to move the pick up tip  142  in x, y and z directions. The pick up tip  142  has a suction cup  144  at a lower end. A vacuum can be applied to the suction cup  144 . 
         [0045]    The heat exchange device  132  is located in a closed loop path that includes the chamber  116 . The heat exchange device  132  may for example be a heater or a cooler that supplies a liquid or a gas to the chamber  116  at between −20° C. and 50° C. In the case of cooled liquid or gas, it is important to note that the chamber  116  may exist at a temperature below 0° C. Unlike air, the liquid or gas in the chamber  116  is selected so as not to cause any condensation or frost within the chamber  116  and, in particular, on a lower surface of the printed circuit board  12 . In the case of a cooled liquid or gas, heat transfers from the electric machine interface  52  to the chamber  116 . In the case of a heated liquid or gas, heat transfers from the chamber  116  to the electric machine interface  52 . A pump  148  is located in line with the heat exchange device  132  and the chamber  116  to continuously circulate the liquid or gas through the heat exchange device  132  and the chamber  116 . It may also be possible to exhaust air or water without the air or water being recirculated in a closed path. 
         [0046]    The thermal head  84  is maintained at approximately the same temperature as the chamber  116 . The thermal head  84  may for example have a passage therethrough through which a hot or cold liquid or gas can flow. Alternatively, the mounting plate  18  may be held at a cold or hot temperature and the mounting plate  18  may keep the thermal head  84  at such a hot or cold temperature. The mounting plate  18  may for example have a passage therethrough through which hot or cold liquid or gas flows. One of ordinary skill in the art will appreciate that other mechanisms for heating and cooling may be provided within the mounting plate  18  and/or the thermal head  84 , such as a resistive heater or a Peltier device for cooling. 
         [0047]    The door  102  closes the opening  104 . A purge gas flows through an opening  150  into a cavity  152  over the electric machine interface  52 . The purge gas leaves the cavity  152  through an opening  154 . The purge gas may for example be nitrogen or another gas that does not cause condensation or frosting by any low temperatures that are created by the chamber  116  at the electric machine interface  52 . The door  102  can be opened and closed for a short amount of time without causing unnecessary condensation or frosting at the electric machine interface  52 . 
         [0048]    Movement of various components, measuring parameters of the electronic devices and testing of the electronic devices  138  is now described with reference to  FIGS. 4   b  to  4   g . It should be understood in the description of  FIGS. 4   b  through  4   g  that the chamber  116  and thermal head  84  remain at their respective low or high temperatures during such movement of the components and testing of the electronic devices  138 . 
         [0049]    As shown in  FIG. 4   b , the mounting plate  18  and thermal head  84  are moved into an upper position. In the upper position, the pick-and-place transport apparatus  134  can move the pick up tip  142  into a space between the thermal head  84  and the socket  14 . As shown in  FIG. 4   a , the pick up tip  142  first moves in a downward direction until the suction cup  144  makes contact with one of the electronic devices  138  at the input and output station  140 . A vacuum is then applied to the suction cup  144  so that the electronic device  138  engages with the suction cup  144 . As shown in  FIG. 4   b , the pick up tip  142  moves upward away from the input and output station  140 , laterally and then down until the electronic device  138  is located on top of the electric machine interface  52 . The vacuum is then released from the suction cup  144  and the pick up tip  142  then moves away from the socket  14  to leave the electronic device  138  on the electric machine interface  52 . The pick up tip  142  then returns to its position shown in  FIG. 4   a.    
         [0050]    As shown in  FIG. 4   c , the mounting plate  18  is moved down so that the thermal head  84  blocks the space where the pick up tip  142  travels between the input and output station  140  and the electric machine interface  52 . As shown in  FIG. 4   d , the mounting plate  18  continues to move down until the tip  90  contacts a top surface of the electronic device  138 . The thermal plate  40  does not at this stage contact the thermal distribution piece  34 . 
         [0051]    As shown in  FIG. 4   e , a force is created that moves the mounting plate  18  further down until the thermal plate  40  contacts the thermal distribution piece  34 . The thermal head  84  simultaneously moves upwardly relatively into the thermal plate  40  against a spring force of the springs  96 . The surface  92  lifts off and separates from the surface  85 . The force that is created by the springs  96  ensures proper contact between the electronic device  138  and the contacts in the electric machine interface  52 . 
         [0052]    Heat can now transfer between the thermal head  84  and the electronic device  138 . In the case of heating of the electronic device  138 , the thermal head  84  heats the electronic device  138 . Heat may also conduct through the thermal plate  40  to the thermal distribution piece  34  and from the thermal distribution piece  34  to the socket  14 . A heated environment is thereby created for the socket  14 . Alternatively, a cooled environment can be created for the socket  14  by heat conducting from the socket  14  through the thermal distribution piece  34  and thermal plate  40  to the thermal head  84  and/or mounting plate  18 . 
         [0053]    Because the chamber  116  and the thermal head  84  are both heated (or both cooled), a more even temperature profile is created over the electronic device  138  and the socket  14 . A more even temperature profile allows for more accurate temperature of the electronic device  138  to be achieved and more predictability of the temperature of the electronic device  138 . 
         [0054]    When the electronic device  138  reaches its desired testing temperature, the electric tester  128  is used to test the electronic device  138  and/or measuring parameters of the electronic device  138  and/or programming the electronic device  138 . Such testing and/or measuring parameters of the electronic device  138  and/or programming the electronic device  138  may only be conducted for a fraction of a second or for a couple of seconds. 
         [0055]    As shown in  FIG. 4   f , the mounting plate  18  and the thermal head  84  are moved into the upper position shown in  FIG. 4   a . The pick up tip  142  moves to the electronic device  138  on the electric machine interface  52  and the suction cup  144  makes contact with the electronic device  138 . A vacuum is then applied to the suction cup  144  so that the electronic device  138  engages with the suction cup  144 . The pick up tip  142  is then moved upward, sideways and downward until the electronic device  138  is again located at the input and output station  140 . The suction cup  144  is then released from the electronic device  138  and the pick up tip  142  is slightly elevated. 
         [0056]    As shown in  FIG. 4   g , the door  102  closes the opening  104 . Purge gas is used to clear any unwanted condensation or frost within the electric machine interface  52  that may have occurred due to the door  102  being open in  FIGS. 4   b  to  4   f . The tape feeder  130  moves laterally so that another electronic device  138  moves into the input and output station  140 . The process described with reference to  FIGS. 4   a  to  4   f  is then repeated with the new electronic device  138  located at the input and output station  140 . 
         [0057]      FIG. 5  illustrates an embodiment that includes thermally conductive and electrically insulative gasket  170 , a metal plate  170  and a Peltier device  172 . The gasket  170  spaces the metal plate  170  from the printed circuit board  12  so that the metal plate  170  does not create short circuits in the printed circuit board  12 . A cold side of the Peltier device is located against the thermal plate  172  so as to cool the thermal plate  172 . The fluid in the chamber  116  cools a lower, hot side of the Peltier device  174 . 
         [0058]    While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive of the current invention, and that this invention is not restricted to the specific constructions and arrangements shown and described since modifications may occur to those ordinarily skilled in the art.