Abstract:
A temperature control apparatus includes a socket holder which is provided on a tester head and holds a socket to mount an IC chip. A socket cover has an opening to pass the end of a handler pusher for holding the IC chip on testing. The socket cover forms a closed space around the IC chip in a state that the IC chip is pressed to the socket by the pusher. A gas supplying unit externally supplies the closed space with gas of a predetermined temperature.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-134224, filed May 2, 2005, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a temperature control apparatus, and more particularly to a temperature control apparatus for holding a temperature of an IC chip to be tested by a handler at a predetermined temperature during the test. 
     2. Description of the Related Art 
     An IC chip has been used for the control of a consumer electric apparatus regardless of indoor and outdoor uses. A temperature condition for use of an IC chip extends over a wide range of −55° C. to +150° C. for example. An IC chip is checked for stable operation under such a temperature condition in the course of production and shipment. Therefore, a handler and a tester are used for testing an IC chip. For example, in a room temperature test, a socket is placed on a tester head at a room temperature, and an IC chip is placed on the socket. This test is performed by placing a room-temperature IC chip on a socket, and holding the IC chip to the socket by a pusher of a handler. However, the socket and pusher are influenced by the heat generated in the tester head and handler, and often heated to a temperature higher than a room temperature. Thus, the test is performed in a temperature condition higher than a room temperature. In a high-temperature test, IC chips are held at a predetermined high temperature by using a high-temperature bath provided in a handler, and a required number of IC chips is taken out, for example, one by one, and set on a socket. In this case, also, a socket is not set to a high temperature, and an IC chip is cooled by a socket immediately after being placed on the socket. As a result, an IC chip is tested at a temperature lower than a desired temperature. 
     Because of the above reason, an IC chip cannot be tested in a desired temperature condition. An IC chip not tested in a correct temperature condition is shipped, incorporated in an apparatus, and used. As a result, the quality of IC chip test is lowered, and the reliability of handler and tester is also lowered. 
     It is considerable to control a temperature in a tester head and handler to eliminate the influence to the temperature of an IC chip placed on a socket. However, it is necessary to modify largely a tester head or handler for this purpose. The modification cost is high, and increases the cost of IC chip test. 
     BRIEF SUMMARY OF THE INVENTION 
     According to an aspect of the present invention, there is provided a temperature control apparatus comprising a socket holder which is provided on a tester head and holds a socket to mount a test object IC chip, a socket cover which has an opening to pass the end of a handler pusher for holding the IC chip on testing, and forms a closed space around the IC chip in a state that the IC chip is pressed to the socket by the pusher, and a gas supplying unit which externally supplies the closed space with gas of a predetermined temperature. 
     According to the invention, there can be provided a temperature control apparatus, which can provide a test temperature environment suitable for an IC chip with ease and low cost while keeping test quality and reliability of the tester and/or handler by providing a correct test temperature environment. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  is a block diagram showing the configuration of a first embodiment of the present invention; 
         FIG. 2  is a plan view of a socket adapter plate for explaining the operations of the embodiment shown in  FIG. 1 ; 
         FIG. 3  is a plan view of a socket adapter plate for explaining the operations of the embodiment shown in  FIG. 1 ; 
         FIG. 4  is a chart for explaining the temperature control operations of  FIG. 1 ; 
         FIG. 5  is a chart for explaining the temperature control operations of  FIG. 1 ; 
         FIG. 6  is a block diagram showing the configuration of another embodiment of the invention; 
         FIG. 7  is a sectional view showing the essential part of still another embodiment of the invention; 
         FIG. 8  is a block diagram showing the configuration of a temperature gas generation unit including a microcomputer shown in  FIG. 1 ; 
         FIG. 9  is a block diagram showing the configuration of a still further embodiment of the invention; 
         FIG. 10A  is a plan view showing the internal configuration of a socket unit in a temperature setting space shown in  FIG. 9 ; and 
         FIG. 10B  is a sectional view showing a gas path in the socket unit shown in  FIG. 10A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of the invention will be explained in detail hereinafter with reference to the accompanying drawings. 
       FIG. 1  is a block diagram showing the configuration of a first embodiment of the invention. One IC chip is tested at one time in this embodiment, but the invention is applied also to a case that two or more IC chips are tested at the same time. In  FIG. 1 , a test object IC chip  11  having a contact  10   a  for connection is placed on a socket  12  and tested. The socket  12  is made of insulation material such as plastic, has a contact such as a solder ball connected in contacting with the contact  10   a , and held on a tester head  14  through a performance board  13 . The contact  10   a  of the IC chip  11  is electrically connected to the tester head  14  through the performance board  13  by a connector pin  10  connected to the contact of the socket  12 . The tester head  14  is connected to a tester body  15 , and controls its operation at the time of test. 
     On the performance board  13 , a socket adapter plate  16  fixed by a not-shown fixing bolt is provided. A socket holder  16   h  is formed at the center of the socket adapter plate  16 . Gas paths  17  and  18  are formed inside of the socket holder. The gas path  17  is connected to a gate of a high-temperature gas generation unit  19 . The gas path  18  is connected to a gate of a low-temperature gas generation unit  20 . The high-temperature gas generation unit  19  is electrically driven by a driver  21 . The low-temperature gas generation unit  20  is electrically driven by a driver  22 . The drivers  21  and  22  are connected to a gas controller  23  or a socket temperature control unit through cables  29  and  30 , respectively. The operation of the whole gas controller  23  is controlled by a microcomputer  24  provided inside. 
     A socket chamber or space  27  for temperature setting described later is formed at the center of the socket holder  16   h  formed at the center of the socket adapter plate  16 , and the bottom opening of the socket chamber is closed by the socket  12 . The upper opening is closed by a socket cover  25  having an opening  25 A having the diameter a little larger than that of the distal end of a pusher  26  of the handler. The space  27  for temperature setting is formed between the bottom opening and upper opening. Under the surface of the socket cover  25 , a gas groove  25 D is formed to flow gas in a space to the socket holder  16   h . The socket cover  25  is positioned on the socket holder  16   h , so that one end of the gas groove  25 D is connected to the space  27  for temperature setting, and the other end is connected to the gas paths  17  and  18  formed in the socket holder  16   h . The pusher  26  is fixed to the lower end of a pusher holder  31  thicker than the pusher  26 , and moved up/down along the axis at the time of test. On the test, the IC chip  11  is pushed against the socket  11  by the pusher  26 , and a clearance is made between the lower side of the pusher holder  31  and the upper side of the socket cover  25 . Temperature gas discharged to the space  27  for temperature setting through the gas groove  25 D, for example, air set to a prescribed temperature is discharged to the outside of the handler through this clearance, and exhausted through the gas path  17  or  18 . Instead of the air, inert gas including no humidity may be used. As explained later in detail, for example, when the high-temperature gas generation unit  19  is driven by the driver  21 , the low-temperature gas generation unit  20  is not driven. Therefore, high-temperature gas, for example, hot air is pressed from the gas path  17  into the temperature setting space  27  through the gas groove  25 D, and exhausted from the other gas groove  25 D through the gas path  18  and low-temperature gas generation unit  20 . Contrarily, when the low-temperature gas generation unit  20  is driven, the high-temperature gas generation unit  19  acts as an exhausting path. 
     The high-temperature gas generation unit  19  and low-temperature gas generation unit  20  shown in  FIG. 1  are provided as a pair in the socket adapter plate  16  as shown in  FIG. 2 . Namely, in  FIG. 2 , a substantially square space  27  for temperature setting is formed at the center of the socket holder  16   h  formed at the center of the socket adapter plate  16 . At two opposed corners along the diagonal line of the square space, the gas groove  25 D connected to a pair of high-temperature gas generation units  19 A and  19 B is formed. On the other diagonal line rotated 90° against the diagonal line, another gas groove  25 D connected to a pair of low-temperature gas generation units  20 A and  20 B is formed. On the other diagonal line rotated 90° against the diagonal line, another gas groove  25 D connected to a pair of low-temperature gas generation unit  20 A and  20 B is formed. 
     The socket cover  25  having the opening  25 A is placed on the socket adapter plate  16  just like covering the upper part of the four gas grooves  25 D and temperature setting space  27 . The opening  25 A has the dimension larger than the outside dimensions of the IC chip  11  and pusher  26  plated on the socket  12 . The pusher  26  is inserted into the opening  25 A, as shown in  FIG. 1 . 
     Explanation will be given on the operation of the embodiment of  FIG. 1  hereinafter with reference to  FIG. 2 ,  FIG. 3  and  FIG. 8 . 
     When testing the IC chip  11  at a temperature of 150° C., for example, first place the socket cover  25  on the socket adapter plate  16  and form the temperature setting space  27 . Then, operate the handler, and place the IC chip  11  on the socket  12  through the opening  25 A. Lower the pusher  26  and push the IC chip  11  to the socket  12 . Otherwise, press the IC chip  11  to the socket  12  in the state that the IC chip is held or vacuum-sucked at the distal end of the pusher  26 . 
     In this state, input a test setting of a high temperature 150° C., for example, by using an input unit such as a keyboard connected to a CPU  80  of a microcomputer  24  provided in the gas controller  23  (corresponding to the input unit  81  in  FIG. 8 ). A temperature sensor  82  is provided inside the space  27  of the socket  12  in  FIG. 1 . A temperature signal in the socket  12  is detected by the temperature sensor, and sent to the CPU  80  of  FIG. 8  through a line  33 , and detected. The CPU  80  compares the temperature data of the sensor  82  with the set temperature of 150° C. inputted into the input unit  81 , and when the temperature data of the sensor  82  is lower than 150° C., sends a drive signal to the driver  21 , makes the high-temperature gas generation units  19 A and  19 B of  FIG. 2  generate a high-temperature gas of 150° C., presses to send a high-temperature gas of 150° C. into the temperature setting space  27  through the gas groove  25 D, and heats the IC chip  11 . In this case, the high-temperature gas is extremely stirred in the space  27 , and the space  27  is substantially uniformly heated. The gas lowered in temperature by this heating is exhausted from the other gas groove  25 D to the outside through the unused low-temperature gas generation units  20 A and  20 B. The heat of the IC chip is partially escaped through the socket  12  and pusher  26 , but as the IC chip is heated by the high-temperature gas, the IC chip is heated to 150° C. in short time, and a 150° C. detection signal is sent from the sensor  82  to the CPU  80 . As a result, as shown in  FIG. 4 , the IC chip  11  is held constant in a range of ±3° C. of an allowable range, for example, a set high temperature A° C. Therefore, a sudden temperature drop immediately after placing on a socket, as shown by a prior art temperature curve B, does not occur. When detecting the high temperature state, the CPU  80  sends the tester  15  a high temperature setting complete state signal through a not-shown communication path through an interface  83 , for example, and starts the high temperature test. The CPU  80  is set by program stored in a ROM  84  to execute preset operations, and the data obtained by the operations is stored in a RAM  85  as necessary. 
     Now, explanation will be given on the case that the IC chip  11  is set to a room temperature A and the temperature is kept within an allowable range as shown in  FIG. 5 , with reference to  FIG. 3 . In this case, temperature data designating a temperature lower than the room temperature of 25° C. for example 0° C. is input from the input unit  81  shown in  FIG. 8 . In this state, the socket cover  25  is placed on the socket adapter plate  16 , and then the IC chip  11  is pushed to the socket  12  by the pusher  26 . The sensor  82  is influenced by a temperature higher than the room temperature transmitted from the tester head  14  and pusher  26 , and detects this temperature higher than the room temperature. Thus, the CPU  80  detects the difference between the set temperature 25° C. and the temperature detected by the sensor  82 , drives the low temperature gas generation driver  22 , generates gas of 0° C. from the low-temperature gas generation units  20 A and  20 B, and sends the gas to the temperature setting space  27 . The temperature in the space  27  is lowered by this, and when the sensor  82  detects a temperature a little lower than the room temperature, the CPU  80  sends the tester  15  a start OK signal through the interface  83 . In this case, the IC chip  11  always receives heat from the socket  12  or pusher  26 , and when the sensor  82  detects the room temperature 25° C. the temperature of the IC chip  11  may be a little higher than the detected temperature. Therefore, when the sensor  82  indicates a value a little lower than 25° C., it is judged that the IC chip  11  is near the room temperature. The difference between the temperature detected by the sensor  82  and the actual temperature of the IC chip  11  is previously examined statistically and stored in the ROM  84  as data, and the data may be read by the CPU  80 . In this way, as shown in  FIG. 5 , the IC chip  11  is held near the room temperature or the temperature A within an allowable range, and not heated as indicated by the prior art curve B by receiving the heat from the socket or pusher. 
     Even for the low temperature test of the IC chip  11  at −5° C., for example, a gas of a temperature a little lower than −5° C. is generated by the temperature gas generation units  20 A and  20 B as shown in  FIG. 3 , and the gas may be supplied to the temperature setting space  27 . The sensor  82  detects the temperature of the space  27 . When the difference between the detected temperature and the actual temperature of the IC chip  11  is examined and stored in a memory table previously, the actual temperature of the IC chip  11  can be easily known from the memory table using the output data from the sensor  82 . 
     In the embodiment shown in  FIG. 1 , the gas controller  23  is provided independently of a handler or a tester  15 . In another aspect of the present invention, the gas controller  23  may be incorporated in a handler.  FIG. 6  is a block diagram showing the configuration of another embodiment of the invention based on this idea. In this case, in addition to a controller  51  and a microcomputer  54 , a handler  50  contains a high-temperature gas generation unit  55  and a low-temperature gas generation unit  56  for the temperature test of the IC chip  11 . The high-temperature gas generation unit  55  and the low-temperature gas generation unit  56  correspond to the high-temperature gas generation unit  19  and driver  21  and the low-temperature gas generation unit  20  and driver  22  shown in  FIG. 1 , respectively. The gas generated from the high-temperature gas generation unit  55  and low-temperature gas generation unit  56  is urged to send to the gas paths  17  and  18  formed in the socket holder  16   h  of the socket adapter plate  16  through gas pipes  52  and  53 , respectively. The other components of the embodiment of  FIG. 6  are the same as the embodiment of  FIG. 1 . The components are given with the same reference numerals, and explanation will be omitted. The microcomputer  54  provided in the controller  51  of  FIG. 6  has the similar configuration as that shown in  FIG. 8 , and performs the similar function as the embodiment of  FIG. 1  in the temperature test of the IC chip  11 . However, if the controller  51  has a not-shown computer for controlling whole operations of the handler  50 , the computer may of course be configured to perform the function of the microcomputer  54  instead of the microcomputer  54 . In this case, the temperature control of the IC chip  11  on the temperature test by high-temperature gas and low-temperature gas may be the same as in the embodiment of  FIG. 1 , and detailed explanation will be omitted. 
     In the embodiment of  FIG. 1 , the gas set to a predetermined temperature is blown from outlets of the gas paths  17  and  18  to the side of the pusher  26  through the gas groove  25 D, and supplied to the temperature setting space  27  in this state. Further, if the temperature test gas is blown directly to the IC chip  11 , the temperature of the IC chip  11  can be more quickly set close to the gas temperature.  FIG. 7  is a sectional view of the essential part of an embodiment showing an example, with a downward nozzle  25 N formed at the distal end of the gas groove  25 D formed under the socket cover  25 . With this structure, by blowing hot air or cold air directly to the IC chip  11 , the temperature of the IC chip can be set efficiently in a short time. 
       FIG. 9  is a block diagram showing the configuration of a still further embodiment of the invention. In the embodiment of  FIG. 1 , high-temperature air and low-temperature air are fed to the temperature setting space  27  formed in relation to the socket  12  from the high-temperature gas generation unit  19  and the low-temperature gas generator unit  20 , respectively, and the high-temperature air and the low-temperature air are mixed inside the space  27  to form air of a desired temperature. In the embodiment of  FIG. 9 , it is configured in such a manner that high-temperature air and low-temperature air are sent to a mixer  91  and mixed therein, and the mixed air is then fed to the space  27 . By pre-mixing air before feeding into the space  27  in this way, it is possible to form air still more free of temperature irregularities than that in the embodiment of  FIG. 1  can be formed in the space  27 , and temperature setting of IC chips can be carried out more accurately. 
     In the embodiment of  FIG. 9 , a configuration is made in such a manner that a solenoid valve mechanism  92  is provided in a gas controller  23 A, room-temperature air fed from an external compressor  93  to the solenoid valve mechanism  92  is fed to an air heater  94  which is a high-temperature gas generation unit and a vortex tube  95  which is a low-temperature gas generation unit at a predetermined ratio under the control of the microcomputer  24 , and hot air and cold air generated, respectively, are sent to the mixer  91 . The microcomputer  24  receives output data from the temperature sensor  82  and carries out temperature control of air in the space  27  in accordance with a predetermined programming in the same manner as in the embodiment of  FIG. 1 . In this case, air delivered from the mixer  91  and set to a desired temperature may be supplied to inlets of the gas paths  17  and  18  formed in the socket adapter plate  16  of  FIG. 1 . 
     Now, the temperature setting space  27  in the embodiment shown in  FIG. 9  is configured around the pusher  26  shown in  FIG. 1  or  FIG. 6 . Furthermore, the temperature setting space  27  can be used in combination with a pusher end portion  26 A configured as shown in  FIGS. 10A and 10B . The pusher end portion  26 A has a housing  96  which is fixed to, for example, the end of the pusher  26  shown in  FIG. 1  by a screw S, and an air groove  97  and a suction hole  98  are formed inside the housing  96 . The air groove  97  communicates with an air outlet of the mixer  91  shown in  FIG. 9  via a pipe P connected to either one of two apertures  97 A and  97 B. The other aperture communicates with the atmosphere and is used for an exhaust port. The suction hole  98  is used to hold the IC chip  11  at its opening and is allowed to communicate with a not-shown vacuum device via a suction path  26 S formed through the pusher  26  inside. The housing  96  is formed with metal with good heat conductivity such as, for example, aluminum, and easily assimilates with the temperature of air introduced inside the air grove  97 , so that the IC chip  11  held at the opening of the suction hole  98  is quickly set to the temperature equal to that of the air introduced. 
     Now, in the case where the pusher end portion  26 A shown in  FIG. 10A  is mounted to the end of the pusher  26  and used for testing IC chips, the pusher end portion  26 A is vertically moved integrally with the pusher  26 . For this reason, the pipe P is made of a flexible material such as, for example, rubber in order to flexibly link the interval with the fixed mixer  91 . The configuration other than this is the same as that of the embodiment shown in  FIG. 1 , and further description will be omitted. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.