US20020011863A1 - IC chip tester with heating element for preventing condensation - Google Patents

Abstract

An IC chip testing apparatus provided with an IC socket206to which an IC chip is brought into electrical contact, a printed circuit board205with one terminal which is electrically connected to a terminal of a test head and with another terminal which is electrically connected to a terminal of the IC socket206, and a heating element208provided at the printed circuit board205. The IC chip testing apparatus may be provided with a socket320to which an IC chip to be tested is detachably mounted; a socket guide382holding the socket320; a chamber306to the opening392of which the socket guide382is attached so that an IC chip mounting opening of the socket320faces inside the chamber and able to maintain the inside at a predetermined state less than ordinary temperature; a printed circuit board400which is electrically connected to a terminal of the socket320and which is arranged at the outside of the chamber opening392of the chamber6; and a heating board406which is provided around the chamber opening392of the chamber306and heats the printed circuit board400by heat conduction. It is possible to prevent condensation of the printed circuit board which tends to occur at the time of application of a low temperature and radiation of heat from the IC socket which tends to occur at the time of application of a high temperature or low temperature.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention[0001]
• The present invention relates to an electronic device testing apparatus for testing semiconductor integrated circuit devices (hereinafter abbreviated as “ICs”) and other electronic devices, more particularly relates to an electronic device testing apparatus able to prevent condensation on the printed circuit board easily occurring during the application of a low temperature and the radiation of heat from a socket easily occurring during the application of a high temperature or low temperature.[0002]
• 2. Description of the Related Art[0003]
• A handler of an IC chip testing apparatus or other electronic device testing apparatus conveys a large number of IC chips held on a tray into it, brings them into electrical contact with a test head in a state with a high temperature or low temperature thermal stress applied, and has them tested at the IC testing apparatus. When the tests are completed, the IC chips are conveyed out from the test head and reloaded on trays in accordance with the results of the test so as to sort them into categories such as good chips and defective chips.[0004]
• The handlers of the related art may be roughly classified by type of application of temperature into chamber type handlers which reload IC chips to be tested on a special tray called a “test tray”, convey it into a temperature application chamber to bring the IC chips to a predetermined temperature, then push the IC chips against the test head in the state loaded on the test tray and heat plate type handlers which load IC chips on a heat plate (also called a “hot plate”) to apply a high temperature thermal stress to them, then pick up a several number of the IC chips at a time by suction heads and convey them to the test head against which they are then pushed.[0005]
• In both types of handlers, the test head against which an IC chip is pushed is provided with an IC socket having contact pins and one or more printed circuit boards (mother board, daughter boards, sub-boards, etc.) electrically connected to the IC socket. The printed circuit boards are connected to input-output terminals of the test head. The IC chip is tested by the testing apparatus through the test head.[0006]
• When applying a high temperature or low temperature thermal stress in a chamber type handler, however, while the IC chip is given a high temperature or low temperature in the chamber, when the IC chip is brought into contact with the IC socket, the heat is dissipated from there and therefore the problem arises of a fluctuation in the applied temperature during the tests. In particular, in a test head of a type directly connected to the IC socket and mother board and other printed circuit boards, the heat conducted to the IC socket is easily radiated to the printed circuit boards. When applying a low temperature thermal stress, further, condensation occurs at the printed circuit boards and therefore there was a danger of a detrimental effect on the signal characteristics.[0007]
• Also in a heat plate type handler, while the IC chip is given a high temperature, when the IC chip is brought into contact with the IC socket, the heat is dissipated from there and therefore the problem arises of a fluctuation in the applied temperature during the tests in the same way.[0008]
• Also in a test head of a type where a spacing frame is arranged between the IC socket and thee print circuit board, when the IC chip is given an extremely low temperature stress of about −50° C., the low temperature conducts through the coaxial cable and the daughter board connecting the IC socket and the print circuit board and therefore there is a danger that condensation occurs at the printed circuit boards.[0009]
• Further, in a testing apparatus testing an IC chip inside a chamber in this way, since the chip mounting opening of the socket in which the IC chip is mounted faces inside the chamber and the terminals of the socket are connected to the test head through a printed circuit board outside the chamber (performance board), the structure is one susceptible to entry of outside air behind the socket. Therefore, there is the problem of a susceptibility to condensation at the printed circuit board behind the socket or the test head. If condensed moisture flows to electrical contact portions, there is the danger of causing short-circuits at the electrical wiring. Therefore, condensation must be prevented at all costs.[0010]
• Accordingly, in the testing apparatuss of the related art, a large distance was set between the socket and the printed circuit boards and a spacing frame or other heat insulating structure was arranged between them to prevent condensation at the printed circuit boards behind the socket and the test head.[0011]
• If a large distance is set between the socket and the printed circuit boards in this way, however, the electrical path from the socket to the printed circuit boards (electrical cables etc.) becomes longer and noise more easily occurs, so the reliability of the tests is liable to drop. Further, it is not possible to use general purpose printed circuit board holding rings and other parts and it is necessary to prepare special spacing frames and other heat insulating structures, so the manufacturing costs rise.[0012]
SUMMARY OF THE INVENTION
• A first object of the present invention is to provide an electronic device testing apparatus which can prevent the condensation at the printed circuit boards which easily occurs at the time of application of a low temperature and the radiation of heat from the socket which easily occurs at the time of application of a high temperature or low temperature.[0013]
• A second object of the present invention is to provide an electronic device testing apparatus which can, by a relatively inexpensive structure, effectively prevent the occurrence of condensation behind a socket where an electronic device is mounted for testing.[0014]
• To achieve the first object of the present invention, according to a first aspect of the present invention, there is provided an electronic device testing apparatus comprising a socket to which an electronic device is brought into electrical contact, a circuit board with one terminal which is electrically connected to a terminal of a test head and with another terminal which is electrically connected to a terminal of the socket, and a heating element provided at the circuit board.[0015]
• The heating element is preferably printed on the circuit board.[0016]
• The printed circuit board is preferably provided in proximity to the socket.[0017]
• In the electronic device testing apparatus of the first aspect of the present invention, since the printed circuit board is provided with a heating element, it is possible to heat the printed circuit board in accordance with the temperature to be applied so as to reduce the temperature gradient between the electronic device and the printed circuit board and therefore suppress radiation of heat from the socket to the printed circuit board. Further, since the heating element also serves as an auxiliary means for application of a high temperature, it is possible to shorten the time for raising the temperature and possible to expect an improvement in the throughput of the electronic device testing apparatus. On the other hand, by heating the printed circuit board at the time of application of a low temperature, it is possible to prevent condensation from occurring at the printed circuit board.[0018]
• In the present invention, the heating element is not particularly limited in where it is provided, but should at least be provided around the socket when applying a high temperature. This is since it is sufficient to keep heat from being conducted to the printed circuit board through the socket. As opposed to this, when applying a low temperature, it is desirable to provide the heating element substantially across the entire area of the printed circuit board. This is because condensation occurs when the ambient temperature drops and such condensation must be prevented across the entire area of the printed circuit board.[0019]
• In the electronic device testing apparatus of the first aspect of the present invention, the method of provision of the heating element is not particularly limited. A heating unit may be mounted on the printed circuit board or the heating element may be printed on the printed circuit board. As the method of printing the heating element on the printed circuit board, the method of forming a pattern by etching, the method of printing planar nichrome wiring, etc. may be mentioned. By printing the heating element on the printed circuit board, interference etc. with other components connected on the printed circuit board is eliminated and the printed circuit board can be placed even in narrow spaces.[0020]
• In the electronic device testing apparatus of the first aspect of the present invention, the relative arrangement of the socket and the printed circuit board is not particularly limited. The invention may be applied to not only a test head of the type where the socket is substantially directly connected to the printed circuit board, but also a test head of the type where the socket is connected to the printed circuit board through a socket board, spacing frame, etc. In particular, as explained above, the effect of prevention of radiation of heat and prevention of condensation becomes greater when the printed circuit board is provided in proximity to the socket.[0021]
• To achieve the second object of the present invention, according to a second aspect of the present invention, there is provided an electronic device testing apparatus comprising a socket to which an electronic device to be tested is detachably mounted; a socket guide holding the socket; a chamber to the opening of which said socket guide is attached so that an electronic device mounting opening of the socket faces inside the chamber and able to maintain the inside at a predetermined state less than ordinary temperature; a circuit board which is electrically connected to a terminal of the socket and which is arranged at the outside of the chamber opening of the chamber; and a heating board which is provided around the chamber opening of the chamber and heats the printed circuit board by heat conduction.[0022]
• In the present invention, the heating board is not particularly limited, but preferably is a board containing a rubber heater or other planar heating element. Further, the electronic device tested by the testing apparatus of the present invention is not particularly limited, but an IC chip is shown as a preferable example.[0023]
• The heating board is preferably provided around the chamber opening of the chamber through a mounting base.[0024]
• The socket guide is preferably detachably mounted to the mounting base.[0025]
• The circuit board preferably contacts the heating board through a circuit board holding ring so as to form a first air-tight space at the circuit board side of the socket guide. Note that in the present invention, the “air-tight space” is not necessarily a completely air-tight space and may also communicate with the outside through some space. An air-tightness of an extent enabling a dry gas to be sealed in the space is sufficient.[0026]
• A first seal member is preferably interposed at the portion of contact of the circuit board holding ring and the heating board.[0027]
• A second seal member is preferably interposed at the portion of contact of the circuit board and the circuit board holding ring.[0028]
• At the anti-chamber side of the circuit board is preferably attached a reinforcing plate so as to form a second air-tight space with the circuit board and the reinforcing plate is preferably provided with a drying nozzle for feeding dry gas into the second air-tight space. Note that as the dry gas, dry air is preferable.[0029]
• Preferably, the circuit board is electrically connected through a plurality of movable pins on a movable pin holding ring projecting out in a ring-shape from a test head sending test drive signals to the electronic device mounted at the socket, the reinforcing plate is provided at the inside of the movable pin holding ring, and the second air-tight space formed between the circuit board and the reinforcing plate is made air-tight by a seal ring provided at the inside of the movable pin holding ring.[0030]
• The circuit board may be brought in contact with the heating board through a seal member so as to form a first air-tight space at the circuit board side of the socket guide.[0031]
• The heating board is preferably formed with a drying passage for feeding dry gas into the first air-tight space.[0032]
• In the electronic device testing apparatus according to the second aspect of the present invention, since a heating board is provided around the chamber opening of the chamber with an inside cooled to a temperature less than ordinary temperature and the printed circuit board is heated by heat conduction, the printed circuit board positioned behind the socket is heated to a temperature above the dew point of the ambient gas. Therefore, it is possible to effectively prevent the occurrence of condensation at the printed circuit board behind the socket and the test head.[0033]
• Further, in the electronic device testing apparatus according to the second aspect of the present invention, since no special spacing frame or other heat insulating structure is employed, it is possible to use general purpose printed circuit board holding rings and other parts and the manufacturing costs become lower. Further, since it is no longer necessary to separate the printed circuit board and the socket by more than the necessary amount of distance, the electrical path from the socket to the printed circuit board (electrical cables etc.) can be shortened, greater resistance to noise can be obtained, and the reliability of the tests can be improved.[0034]
• Further, in the present invention, by bringing the printed circuit board into contact with the heating board through a printed circuit board holding ring so as to form a first air-tight space at the printed circuit board side of the socket guide and forming in the heating board a drying passage for feeding dry gas in the first air-tight space, the first air-tight space can be filled with a dry gas. This enables condensation behind the socket guide to be further effectively prevented.[0035]
• Further, in the present invention, by attaching a reinforcing plate at the anti-chamber side of the printed circuit board so as to form a second air-tight space with the printed circuit board and attaching to the reinforcing plate a drying nozzle for feeding dry gas into the second air-tight space, the second air-tight space can also be filled with a dry gas. This enables condensation behind the printed circuit board as well to be further effectively prevented.[0036]
BRIEF DESCRIPTION OF THE DRAWINGS
• These and other objects and features of the present invention will become more apparent from the following description of the preferred embodiments given with reference to the attached drawings, in which:[0037]
• FIG. 1 is a plan view of an IC chip testing apparatus according to a first embodiment of the present invention;[0038]
• FIG. 2 is a sectional view along the line II-II of FIG. 1;[0039]
• FIG. 3 is a sectional view showing details of a contact section of a test head of FIG. 2;[0040]
• FIG. 4 is a plan view of a socket guide of FIG.[0041]3;
• FIG. 5 is plan view of a performance board of FIG. 3;[0042]
• FIG. 6 is a sectional view along the line VI-VI of FIG. 5;[0043]
• FIG. 7 is a plan view of a performance board of an IC chip testing apparatus according to another embodiment of the present invention;[0044]
• FIG. 8 is a sectional view of a test head of an IC chip testing apparatus according to another embodiment of the present invention;[0045]
• FIG. 9 is a sectional view of a test head of an IC chip testing apparatus according to still another embodiment of the present invention;[0046]
• FIG. 10 is a schematic overall view of an IC chip testing apparatus according to a first embodiment of the present invention;[0047]
• FIG. 11 is a sectional view of key parts of the IC chip testing apparatus;[0048]
• FIG. 12 is a sectional view of key parts showing the state before attachment of the socket guide shown in FIG. 11 to the chamber side; and[0049]
• FIG. 13 is a sectional view of key parts of the IC chip testing apparatus according to another embodiment of the present invention.[0050]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Preferred embodiments of the present invention will be discussed in detail below:[0051]
• First Embodiment[0052]
• As shown in FIG. 1, the IC[0053]chip tester apparatus1 corresponding to the electronic device tester apparatus of the present embodiment is comprised of ahandler10,test head20, andtester30. Thetest head20 and thetester30 are connected via acable40. The pre-test IC chips carried on afeed tray102 of thehandler10 are pushed against the contact sections of thetest head20 byX-Y conveyors104,105, the IC chips are tested through thetest head20 and thecable40, and then the IC chips finished being tested are placed onto sortingtrays103 in accordance with the results of the tests.
• The[0054]handler10 is provided with aboard109. On theboard109 are providedconveyors104,105 for the IC chips to be tested, explained later. Theboard109 further is formed with anopening110. As shown in FIG. 2, IC chips are pushed againstcontact sections201 of thetest head20 arranged behind thehandler10 through thisopening110.
• The[0055]board109 of thehandler10 is provided with twoX-Y conveyors104,105. Among these, theX-Y conveyor104 is configured to be able to move amovable head104cfrom a region of the sortingtrays103 to feedtrays102, empty trays101, theheat plate106, and twobuffer sections108,108 byrails104a,104bprovided along its X-direction and Y-direction. Further, themovable head104cis designed to be able to be moved in the Z-direction (that is, the vertical direction) by a not shown Z-axial actuator. Two IC chips to be tested can be picked up, conveyed, and released at one time by two suction heads104dprovided at themovable head104c.
• As opposed to this, the[0056]X-Y conveyor105 is configured to be able to move amovable head105cbetween the twobuffer sections108,108 and thetest head20 byrails105a,105bprovided along its X-direction and Y-direction. Further, themovable head105cis designed to be able to be moved in the Z-direction (that is, the vertical direction) by a not shown Z-axial actuator. Two IC chips can be picked up, conveyed, and released at one time by two suction heads105dprovided at themovable head105c.
• The two[0057]buffer sections108,108 move back and forth between the operating regions of the two X-Yconveyors104,105 by therails108aand not shown actuators. Thebuffer section108 at the top in the figure works to convey IC chips conveyed from theheat plate106 to thetest head20, while thebuffer section108 at the bottom works to eject the IC chips finished being tested at thetest head20. The provision of these twobuffer sections108,108 enables the two X-Yconveyors104,105 to operate simultaneously without interfering with each other.
• In the operating region of the[0058]X-Y conveyor104 are provided afeed tray102 on which IC chips to be tested are loaded, four sortingtrays103 on which tested ICs are stored sorted into categories according to the test results, and an empty tray101. Further, aheat plate106 is provided at a position in proximity to thebuffer section108.
• The[0059]heat plate106 is for example a metal plate and is formed with a plurality of indentations into which IC chips are dropped. Pre-test IC chips from thefeed tray102 are transferred to theindentations106aby theX-Y conveyor104. Theheat plate106 is a heat source for applying a predetermined thermal stress to the IC chips. The IC chips are heated to a predetermined temperature by theheat plate106, then pushed against the contact sections of thetest head20 through one of thebuffer sections108.
• The top (contact sections[0060]201) of thetest head20 according to the present embodiment, as shown in FIG. 3, is provided with frog rings202 electrically connected to thetest head20 throughcables203. Each of the frog rings202 has a plurality of pogo pins204 (contact pins having movable pins supported to be able to advance and retract in the axial direction by springs and biased in a direction where the movable pins project out by the springs) provided facing upward in a ring. Aperformance board205 is provided with terminals contacting the pogo pins204. Further, twoIC sockets206,206 are mounted to the top of the performance board205 (corresponding to the printed circuit board according to the present invention) in an electrically connected state. Due to this, the contact pins (not shown) of theIC sockets206 are electrically connected to thetest head20 body through theperformance board205, pogo pins204, frog rings202, andcables203.
• Note that each of the two[0061]IC sockets206 has fitted into it asocket guide207 having an opening207aand guide pins207bas shown in FIG. 4 and that an IC chip held by asuction head105dis pushed against anIC socket206 through the opening of thesocket guide207. At this time, the guide pins207bprovided at thesocket guide207 are inserted into the guide holes105d1 formed in thesuction head105d, whereby the IC chip andIC socket206 are positioned with respect to each other.
• In particular, the[0062]performance board205 according to the present embodiment, as shown in FIG. 5 and FIG. 6, is provided with aheating element208 in the area around where anIC socket206 orsocket guide207 is attached. Theheating element208, as shown in FIG. 6, may be formed as any layer in the multiple layer structure of the printed circuit board comprising theperformance board205. In the figure, aheating element layer208 is formed at the top surface of theperformance board205 and ground layers208a,208aare formed above and below it. By providing the ground layers208a, it is possible to suppress noise from occurring from theheating element layer208. The ground layers208a, however, are not essential to the present invention.
• The[0063]heating element layer208 may be provided at theperformance board205 comprised of a printed circuit board by forming a pattern of the heating element by etching and also by forming nichrome wiring planarly or other methods of mounting heating elements. Whatever the case, wiring for carrying a current becomes necessary, so in the example shown in FIG. 5, apower supply wiring208bis formed to the edge of theperformance board205 and aconnector208cis formed there. The specific technique is not limited in any way. Other means may also be employed.
• Further, in the present embodiment, a[0064]temperature sensor209 is provided at any location in the area where theheating element208 is provided so as to manage the temperature of theheating element208. By incorporating the temperature information from thetemperature sensor209, problems such as overheating or underheating are prevented. The control of the temperature of theheating element208, however, does not have to be precise. Rough control to the extent of controlling the supply of the power to theheating element208 is sufficient. At this time, the power may be supplied by the inverter method so as to prevent noise from theheating element208.
• Next, the operation will be explained.[0065]
• A pre-test IC chip carried on the[0066]feed tray102 of thehandler10 is picked up and held by theX-Y conveyor104 and transferred to anindentation106aof theheat plate106. By leaving it there for exactly a predetermined time, the IC chip rises to a predetermined temperature. Therefore, theX-Y conveyor104 transferring the not yet heated IC chip from thefeed tray102 to theheat plate106 releases the IC, then picks up and holds an IC chip which had been left at theheat plate106 and had been raised to the predetermined temperature and transfers it to abuffer section108.
• The[0067]buffer section108 to which the IC chip has been transferred moves to the right end of therail108a, is picked up and held by theX-Y conveyor105, and, as shown in FIG. 3, is pushed against anIC socket206 of thetest head20 through theopening110 of theboard109.
• At this time, the heat of the now high temperature IC chip is conducted to the ordinary[0068]temperature IC socket206 and starts to be radiated to theperformance board205 as well, but since theperformance board205 of the present embodiment is provided with theheating element208 and the area around the IC socket is heated to a suitable temperature, the temperature gradient between the IC chip and theperformance board205 becomes smaller and the amount of heat radiated to theIC socket205 is suppressed. Therefore, it is possible to test the IC chip at the initially desired temperature and improve the reliability of the test results.
• Further, since a drop in the temperature of the IC chip is suppressed by the[0069]heating element208 provided at theperformance board205, it is possible to set the heating temperature at theheat plate106 low and it is thereby possible to expect a shortening of the time for raising the temperature, that is, improve the throughput of the ICchip testing apparatus1.
• Second Embodiment[0070]
• In the above embodiment, the explanation was given using as an example an IC[0071]chip testing apparatus1 applying a high temperature thermal stress to the IC chip, but the electronic device testing apparatus of the present invention may also be applied to one applying a low temperature thermal stress. FIG. 7 is a plan view (plan view corresponding to FIG. 5) of a performance board according to another embodiment of the IC chip testing apparatus of the present invention.
• In this embodiment, the IC chip testing apparatus is one which applies a low temperature thermal stress to the IC chip, then pushes it against an IC socket of the test head and executes the tests. Liquid nitrogen or another low temperature gas is supplied to a region normally near the[0072]contact section201 of thetest head20. In particular, as shown in FIG. 7, theperformance board205 of this embodiment is provided with aheating element208 over substantially its entire area. The invention is not limited to this, but theheating element208 of the present embodiment is designed to prevent condensation on theperformance board205, so it is preferable to provide theheating element208 in the region where the electronic device is provided and not only the area around theIC socket206.
• The structure of the[0073]contact section201 of thetest head20 of the present embodiment is basically the same as that of the embodiment shown in FIG. 3, so will be explained with reference to that figure, but since the IC chip is allowed to stand in this low temperature atmosphere so that the IC chip will fall to the predetermined temperature, this is pushed against anIC socket206 of thetest head20 for the test.
• At this time, the heat of the now low temperature IC chip is conducted to the[0074]performance board205 through theIC socket206, whereby the air near the surface of theperformance board205 is cooled and condensation starts, but since theperformance board205 of the present embodiment is provided with theheating element208 and substantially theentire performance board205 is heated to a suitable temperature, it is possible to prevent the occurrence of condensation.
• Further, the IC chip testing apparatus of the present invention is particularly effective for a[0075]test head20 provided with theIC sockets206 andperformance board205 in close proximity as in the embodiment shown in FIG. 3, but does not exclude atest head20 of a type such as shown for example in FIG. 8 or FIG. 9.
• In the[0076]test head20 shown in FIG. 8, the performance board205 (corresponding to printed circuit board of the present invention) is mounted above thetest head body20a. Aspacing frame211 is provided above theperformance board205 viaspacer columns210 able to move vertically somewhat in the Z-direction.
• A[0077]socket board213 is provided above thespacing frame211 throughsocket board spacers212.IC sockets214 are provided on thissocket board213. Theperformance board205 and thesocket board213 are connected by a plurality ofcoaxial cables215.
• As opposed to this, in the[0078]test head20 shown in FIG. 9, aperformance board205 is attached above thetest head body20a. A device specific adapter (DSA) performance board216 (corresponding to the printed circuit board of the present invention) is provided above theperformance board205 throughspacer columns210 able to move vertically somewhat in the Z-direction. Aspacing frame211 is provided further above this, while asocket board213 is provided throughsocket board spacers212. Further, theDSA performance board216 andsocket board213 are connected byconnector boards217, while theDSA performance board216 andbase board209 are connected by aconnector218 andcoaxial cables215.
• Even in IC chip testing apparatuss provided with such test heads[0079]20, by provision of theheating elements208 shown in FIG. 5 to FIG. 7 at theperformance board205 shown in FIG. 8 and theDSA performance board216 shown in FIG. 9 (even plus the performance board205), a similar action and effect as in the above embodiment can be exhibited.
• Third Embodiment[0080]
• As shown in FIG. 10, the IC[0081]chip testing apparatus302 according to this embodiment is one which tests, as devices to be tested, IC chips in the state of ordinary temperature, low temperature, or high temperature and is provided with ahandler304 and a not shown test use main unit. Thehandler304 successively conveys IC chips to be tested to IC sockets provided on the test head and stores the IC chips finished being tested on predetermined trays sorted in accordance with the test results.
• In this embodiment, the[0082]handler304 is provided with achamber306. The top of thetest head310 is exposed at atest stage308 in thechamber306. The top of thetest head310 is shown in FIG. 11.Sockets320 are mounted at the top of thetest head310. The chip mounting openings of thesockets320 face the inside of thechamber306 so that IC chips322 conveyed by the suction heads324 can be successively detachably mounted.
• The[0083]IC sockets320 provided at thetest head310 are connected to the test use main unit (not shown) through cables. The IC chips322 detachably mounted at theIC sockets320 are connected to the test use main unit through cables and the IC chips322 are tested by test signals from the test main unit. The relation among theIC sockets320 andchamber306 and thetest head310 will be explained later in detail.
• As shown in FIG. 10, the[0084]handler304 has anIC magazine330 for storing IC chips to be tested and storing tested IC chips sorted into classes. TheIC magazine330 holdsloader use trays332A on which IC chips to be tested are carried, sortingtrays332B to332E on which tested IC chips are carried sorted into classes,empty trays332F, andoption trays332G. Thesetrays332A to332G are arranged at predetermined intervals along the X-direction and are stacked in the Z-direction (height direction).
• IC chips carried on a[0085]loader tray332A are conveyed to a soakstage336 inside thechamber306 using the first XY-conveyor334 attached to thehandler304. Further, IC chips finished being tested at thetest head310 are finally loaded and sorted on the sortingtrays332B to332E of theIC magazine330 using the second XY-conveyor335. Among the sortingtrays332B to332E, for example, thetray332C is the tray for good devices, while the other trays are the trays for the defective devices or devices for retesting.
• The[0086]empty trays332F are conveyed to and stacked over the sortingtrays332B to332E which have become filled with the tested IC chips and are used as sorting trays. Theoption trays332G are used for other applications.
• The inside of the[0087]chamber306 is of an air-tight structure except for the portion for the transfer of IC chips which is designed to be able to open and close by a shutter etc. For example, it can maintain a high temperature state of room temperature to about 160° C. or a low temperature state of room temperature to about −60° C. The inside of thechamber306 is divided into a soakstage336, atest stage308, and anexit stage340.
• The soak[0088]stage336 has aturntable338 arranged in it. The surface of theturntable338 hasindentations342 for temporarily holding IC chips arranged at a predetermined pitch along the circumferential direction. In the present embodiment, there are two indentations343 formed in the radial direction of theturntable338. The twoindentations342 are arranged at a predetermined pitch in the radial direction. Theturntable338 turns clockwise. The IC chips dropped into theindentations342 of theturntable338 at theloading position344 by the first XY-conveyor334 are given a thermal stress until the temperature conditions to be tested are reached while theturntable338 is being indexed in the direction of rotation.
• At a[0089]takeout position346 about 240 degrees in the direction of rotation from theloading position344 based on the center of rotation of theturntable338, the suction heads attached to one of the threecontact arms348 are positioned above theturntable338. At that position, IC chips can be taken out from theindentations342 by the suction heads. The threecontact arms348 are attached at angles of substantially equal amount in the circumferential direction with respect to theshaft350 and can be indexed 120 degrees at a time in the clockwise direction of rotation about theshaft350. Note that this “index” means to repeatedly turn by a predetermined angle, then stop, then again turn by a predetermined angle. At the time of this indexing of acontact arm348, the time when thearm348 is stopped corresponds to the time during which IC chips are mounted in sockets of thetest head310 and tested plus the time for attachment or detachment of the IC chips to or from the sockets. The stopping time of this indexing is the same as the stopping time of the indexing at theturntable338. Theturntable338 and thecontact arms348 are indexed synchronously.
• In the embodiment, the suction heads of one of the three[0090]contact arms348 are positioned above thetakeout position346 of the soakstage336, the suction heads of another of thecontact arms348 are positioned above the contact heads310 of thetest stage308, and the suction heads of the other of thecontact arms348 are positioned above theinlet352 of theexit stage340.
• The IC chips loaded in the[0091]indentations342 of theturntable338 at theloading position344 of theturntable338 are given a predetermined thermal stress while being indexed from theloading position344 to thetakeout position346 and are picked up by the suction heads of acontact arm348 at thetakeout position346. The IC chips picked up by the suction heads are positioned above thetest head310 by the indexing of thecontact arm348 in the clockwise direction. At that position, as shown in FIG. 11, the IC chips322 picked up and held by the suction heads324 are attached to thesockets320 and tested.
• The IC chips[0092]322 attached to thesockets320 above thetest head310 and finished being tested are picked up again by the suction heads324 and positioned above theinlet352 of theexit stage340 by the indexing of thecontact arm348 shown in FIG. 10 in the clockwise direction. At this position, the tested IC chips are slid to the exit position354 by an exit shifter in the direction of the arrow A. At the exit position of theexit stage340, the IC chips arranged above the exit shifter are returned from the temperature of the test, that is, the low temperature or the high temperature, to ordinary temperature. In the case of a low temperature test, the IC chips are returned to ordinary temperature at theexit stage340 so it is possible to effectively prevent condensation from occurring on the IC chips directly after being taken out from thechamber306.
• The IC chips arranged above the exit shifter at the exit position[0093]354 of theexit stage340 are returned to ordinary temperature, then shifted in the direction of the arrow B by a not shown exit arm and moved to an exit turn arranged at the receivingposition356. The exit turn is designed to be able to move back and forth between the receivingposition356 and theeject position358 by turning in the direction of the arrow C. The suction heads of the second XY-conveyor335 are designed to be able to move to theeject position358 of the exit turn. The tested IC chips arranged at the eject position by the exit turn are conveyed by theconveyor335 to one of the sortingtrays332B to332E based on the test results.
• In the[0094]device testing apparatus302 according to the present embodiment, a soakstage heat exchanger360 is arranged at the ceiling of the soakstage336 inside thechamber306 of thehandler304 and a teststage heat exchanger362 is arranged at the side wall of thetest stage308. Theseheat exchangers360 and362 are provided with cooling units using liquid nitrogen etc. as a coolant and blowers for circulating the cold air inside the chamber when thetesting apparatus302 is able to perform low temperature tests. When thetesting apparatus302 is able to perform high temperature tests, theheat exchangers360 and362 are provided with heating units and blowers. When the testing apparatus is able to perform low temperature tests and high temperature tests, theheat exchangers360 and362 are provided with cooling units, heating units, and blowers and are used switching between the cooling units and heating units. Theseheat exchangers360 and362 are controlled by atemperature controller370. Thetemperature controller370 receives as input output signals from atemperature sensor372 arranged at thetest stage308,temperature sensor374 arranged at the soakstage336, and other sensors and can control the amount of heat exchange (output) of theheat exchangers360 and362 in accordance with the output signals from these sensors.
• In the following explanation, the explanation will be given of the case where the[0095]testing apparatus302 is one able to perform both high temperature tests and low temperature tests and the testing apparatus is used mostly for performing low temperature tests. As shown in FIG. 11 and FIG. 12, at thetest stage308, the bottom of thechamber306 comprised of a heat insulating material etc. and themain base380 holding thechamber306 are partially cut away andsockets320 held on thetest head310 fit there.
• The[0096]sockets320 are held by socket guides382. Each of the socket guides382, as shown in FIG. 12, has a plurality of guide holes384. The guide holes384 are designed to have inserted into them guiderods386 affixed to thechamber306 side for positioning with thechamber306.
• The[0097]guide rods386 are attached to abase ring388. Thebase ring388 is affixed to a mountingbase390 and constitutes thechamber opening392. The mountingbase390 has a heat insulating property similar to that of thechamber306 and is affixed detachably to the bottom opening of thechamber306 and themain base380.
• As shown in FIG. 11, the[0098]socket guide382 has a plurality of guide pins394 attached to it projecting out toward the inside of thechamber306. The guide pins394 are inserted into the guide holes396 of theguide plate395 attached to asuction head324 for positioning of the IC chip322 picked up and held by asuction head324 and thesocket320.
• Behind the socket[0099]320 (outside of chamber) is connected a low temperatureuse socket adapter398 which is electrically connected to the terminals of thesocket320. Theadapter398 is affixed to the surface of the substantial center of the printedcircuit board400 and facilitates the electrical connection of the terminals of thesocket320 and the printedcircuit board400. At the bottom surface of the printedcircuit board400 are electrically connected a plurality ofmovable pins404 on a movablepin holding ring402 projecting out in a ring shape from thetest head310. Themovable pins404 are attached to the movablepin holding ring402 facing upward and are also called pogo pins (contact pins having movable pins supported to be able to advance and retract in the axial direction by springs and biased in a direction where the movable pins project out by the springs). They are pushed against the bottom terminals of the printedcircuit board400 for electrical connection with the printedcircuit board400. Note that the printedcircuit board400 is also called a performance board.
• The[0100]test head310 receives drive signals from the test use main unit, not shown, and sends test drive signals to the IC chip322 attached to thesocket320 through the movablepin holding ring402,movable pins404, printedcircuit board400, andadapter398.
• In the present embodiment, as shown in FIG. 11 and FIG. 12, a[0101]heating board406 having an opening at its center is bolted etc. to the bottom surface of the mountingbase390. Theheating board406 is also called an HIFIX heater and comprised of a rubber heater or otherplanar heating element408 sandwiched between aluminum sheets etc. At the bottom surface of theheating board406 is affixed in advance afirst seal member412. Thefirst seal member412 is configured for example as a silicone sponge rubber sheet or other sheet having elasticity. The top surface of the printed circuitboard holding ring414 detachably contacts the bottom surface of the inner circumference side of theheating board406 through thefirst seal member412 which seals the space between them. Further, thesecond seal member416 is attached between the printed circuitboard holding ring414 and the printedcircuit board400 and seals the space between them. Thesecond seal member416 is comprised of a synthetic resin sheet the same as or different from that of thefirst seal member412.
• As a result of the sealing by the[0102]first seal member412 and thesecond seal member416, a first air-tight space418 is formed at the printed circuit board side of thesocket guide382. This first air-tight space418 has communicated with it aradial drying passage410 formed in theheating board406. Dry gas can be filled into the first air-tight space418 from there. As the dry gas for being filled inside the first air-tight space418, for example dry air having a condensation temperature lower than the temperature inside thechamber306 may be used. For example, when the inside of thechamber306 is about −55° C., the condensation temperature of the dry air sealed inside the first air-tight space418 through thedrying passage410 is preferably about −60° C. The temperature of the dry air is for example about room temperature.
• As shown in FIG. 11 and FIG. 12, the printed circuit[0103]board holding ring414 is arranged at a position corresponding to the position of themovable pins404 contacting the bottom terminals of the printedcircuit board400. The top surface of the holdingring414 contacts the bottom surface of theheating board406 to push the printedcircuit board400 downward and secure the electrical contact with themovable pins404 and printedcircuit board400.
• A reinforcing[0104]plate420 is attached to the bottom surface of the center portion of the printed circuit board400 (anti-chamber side) through a plurality ofspacers422. The reinforcingplate420 is for preventing the printedcircuit board400 from bending and is positioned inside of the movablepin holding ring402. A second air-tight space424 is formed between the reinforcingplate420 and the printedcircuit board400 by attaching a ring-shapedthird seal member426 between the outer circumference of the reinforcingplate420 and the inner circumference of the movablepin holding ring402. Thisthird seal member426 is comprised of a ring of a synthetic resin the same as or different from the first seal member and seals the space between the reinforcingplate420 and the printedcircuit board400.
• The reinforcing[0105]plate420 has a dryingnozzle460 attached to it for feeding dry gas into the second air-tight space424. As the dry gas to be introduced inside the second air-tight space424, use may be made of dry air with a condensation temperature somewhat higher than the dry air introduced inside the first air-tight space418, for example, about −40° C. The temperature of the dry air is about the room temperature. The condensation temperature of the dry air introduced inside the second air-tight space424 may somewhat higher than the condensation temperature of the dry air introduced inside the first air-tight space418 because the second air-tight space424 is further away from the inside of thechamber306 than the first air-tight space418 and has a lower possibility of condensation.
• Note that a[0106]space430 is also formed between theseal ring428 attached to the outer circumference of thesocket adaptor398 and the printedcircuit board400, but since the dry air inside the second air-tight space424 is introduced into thisspace430 through through holes formed in the printedcircuit board400, it is also possible to effectively prevent condensation at that portion.
• In the electronic[0107]device testing apparatus302 of the present embodiment, aheating board406 is attached around the chamber opening392 of thechamber306 with an inside cooled to a temperature below ordinary temperature and the printedcircuit board400 is heated by heat conduction through the printed circuitboard holding ring414. Therefore, it is possible to effectively prevent condensation from occurring at the printedcircuit board400 behind the socket and thetest head310.
• Further, in the IC[0108]chip testing apparatus302 according to the present embodiment, since a special spacing frame or other heat insulating structure is not employed, it is possible to use general purpose printed circuit board holding rings414 and other parts and the manufacturing costs become lower. Further, since it is no longer necessary to separate the printedcircuit board400 and thesocket320 by more than the necessary amount of distance, the electrical path from thesockets320 to the printed circuit board400 (electrical cables etc.) can be shortened, greater resistance to noise can be obtained, and the reliability of the tests can be improved.
• Further, in the IC[0109]chip testing apparatus302 according to this embodiment, by bringing the printedcircuit board400 into contact with theheating board406 through a printed circuitboard holding ring414 so as to form a first air-tight space418 at the printed circuit board side of thesocket guide382 and forming in the heating board406 adrying passage410 for feeding dry gas in the first air-tight space418, the first air-tight space418 can be filled with a dry gas. This enables condensation behind thesocket guide382 to be further effectively prevented.
• Further, in the IC[0110]chip testing apparatus302 of the present embodiment, by attaching a reinforcingplate420 at the anti-chamber side of the printedcircuit board400 so as to form a second air-tight space424 with the printedcircuit board400 and attaching to the reinforcing plate420 a dryingnozzle460 for feeding dry gas into the second air-tight space424, the second air-tight space424 can also be filled with a dry gas. This enables condensation behind the printedcircuit board400 as well to be further effectively prevented.
• Fourth Embodiment[0111]
• As shown in FIG. 13, the[0112]test stage308aof the testing apparatus according to this embodiment is configured so that the printedcircuit board400aconstituting the test board is directly heated by theheating board406. Below, only the points of difference from the testing apparatus according to the first embodiment will be explained. The explanation of common portions will be partially omitted.
• The center of the mounting[0113]base390aaffixed to the bottom opening of thechamber306 has attached to it abase ring388aand forms the chamber opening392a. Asocket guide382ais bolted etc. to thebase ring388aso that thesocket320 is positioned at the center of the chamber opening392a.
• Behind the mounting[0114]base390a(outside of chamber) is bolted etc. aheating board406 having an opening at its center through a mountingplate450 serving also as a heating insulating member and a sealing member. Theheating board406 is also called an HIFIX heater and is comprised of a rubber heater or otherplanar heating element408 sandwiched between aluminum sheets. The bottom surface of theheating board406 has afirst seal member412 attached to it in advance. Thefirst seal member412 is comprised for example of a silicone sponge rubber sheet or other sheet having elasticity.
• In the present embodiment, when connecting and affixing to the[0115]socket320 thesocket adapter398aattached to the substantial center of the printedcircuit board400aserving as the test board, the surface of the outer circumference of the printedcircuit board400acomes into direct contact with the bottom of theheating board406 through thefirst seal member412 and the printedcircuit board400ais directly heated by theheating board406.
• The[0116]heating board406 is formed with aradial drying passage410. Dry gas can be filled into the first air-tight space418aformed between thesocket guide382aand the printedcircuit board400a. As the dry gas for being filled inside the first air-tight space418a, for example dry air having a condensation temperature lower than the temperature inside thechamber306 may be used. For example, when the inside of thechamber306 is about −55° C., the condensation temperature of the dry air sealed inside the first air-tight space418athrough thedrying passage410 is preferably about −60° C. The temperature of the dry air is for example about room temperature.
• In the electronic device testing apparatus according to this embodiment, a[0117]heating board406 is attached around the chamber opening392aof thechamber306 with an inside cooled to a temperature below ordinary temperature and the printedcircuit board400ais heated directly by heat conduction. Therefore, the printedcircuit board400apositioned behind thesocket320 is heated to a temperature above the dew point of the ambient gas. Therefore, it is possible to effectively prevent condensation from occurring at the printedcircuit board400abehind the socket.
• Further, in the IC chip testing apparatus according to the present embodiment, since a special spacing frame or other heat insulating structure is not employed, the manufacturing costs become lower. Further, since the distance between the printed[0118]circuit board400aand thesockets320 becomes remarkably short, the electrical path from thesockets320 to the printedcircuit board400a(electrical cables etc.) can be shortened, greater resistance to noise can be obtained, and the reliability of the tests can be improved.
• Further, in the IC chip testing apparatus according to this embodiment, by bringing the printed[0119]circuit board400ainto contact with theheating board406 so as to form a first air-tight space418aat the printed circuit board side of thesocket guide382 and forming in the heating board406 adrying passage410 for feeding dry gas in the first air-tight space418a, the first air-tight space418acan be filled with a dry gas. This enables condensation behind thesocket guide382 to be further effectively prevented.
• Other Embodiments[0120]
• Note that the present invention is not limited to the above embodiments and can be changed in various ways within the scope of the invention.[0121]
• For example, in the third and fourth embodiments, the explanation was mainly given of the case of conducting low temperature tests inside the[0122]chamber306 shown in FIG. 10, but the present invention can also be applied even when conducting ordinary temperature tests inside the chamber6. Further, the testing apparatus2 shown in FIG. 10 is of a type enabling both ordinary temperature tests and high temperature tests as well in the chamber6, but the testing apparatus according to the present invention can also be applied to a testing apparatus conducting only low temperature tests or a testing apparatus conducting only ordinary temperature tests. Further, in the testing apparatus according to the present invention, the method of handling the IC chips in the handler4 is not limited to the illustrated embodiments.

Claims (13)

1. An electronic device testing apparatus comprising:

a socket to which an electronic device is brought into electrical contact,

a circuit board with one terminal which is electrically connected to a terminal of a test head and with another terminal which is electrically connected to a terminal of the socket, and

a heating element provided at the circuit board.

2. The electronic device testing apparatus as set forth inclaim 1, wherein the heating element is on the circuit board.

3. The electronic device testing apparatus as set forth inclaim 1, wherein the printed circuit board is provided in proximity to the socket.

4. An electronic device testing apparatus comprising:

a socket to which an electronic device to be tested is detachably mounted;

a socket guide holding the socket;

a chamber to the opening of which said socket guide is attached so that an electronic device mounting opening of the socket faces inside the chamber and able to maintain the inside at a predetermined state less than ordinary temperature;

a circuit board which is electrically connected to a terminal of the socket and which is arranged at the outside of the chamber opening of the chamber; and

a heating board which is provided around the chamber opening of the chamber and heats the circuit board by heat conduction.

5. The electronic device testing apparatus as set forth inclaim 4, wherein the heating board is attached around the chamber opening of the chamber through a mounting base.

6. The electronic device testing apparatus as set forth inclaim 5, wherein the socket guide is detachably attached to the mounting base.

7. The electronic device testing apparatus as set forth inclaim 4, wherein the circuit board contacts the heating board through a circuit board holding ring so as to form a first air-tight space at the circuit board side of the socket guide.

8. The electronic device testing apparatus as set forth inclaim 7, wherein a first seal member is interposed at the portion of contact of the circuit board holding ring and the heating board.

9. The electronic device testing apparatus as set forth inclaim 7, wherein a second seal member is interposed at the portion of contact of the circuit board and the circuit board holding ring.

10. The electronic device testing apparatus as set forth inclaim 4, wherein at the anti-chamber side of the circuit board is attached a reinforcing plate so as to form a second air-tight space with the circuit board and the reinforcing plate is provided with a drying nozzle for feeding dry gas into the second air-tight space.

11. The electronic device testing apparatus as set forth inclaim 10, wherein the circuit board is electrically connected through a plurality of movable pins on a movable pin holding ring projecting out in a ring-shape from a test head sending test drive signals to the electronic device mounted at the socket, the reinforcing plate is provided at the inside of the movable pin holding ring, and the second air-tight space formed between the circuit board and the reinforcing plate is made air-tight by a seal ring provided at the inside of the movable pin holding ring.

12. The electronic device testing apparatus as set forth inclaim 4, wherein the circuit board is brought in contact with the heating board through a seal member so as to form a first air-tight space at the circuit board side of the socket guide.

13. The electronic device testing apparatus as set forth inclaim 7, wherein the heating board is formed with a drying passage for feeding dry gas into the first air-tight space.

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