Abstract:
A mounting pedestal is designed to hold a DUT in position for both electrical testing and vibration testing. The design is such that the pedestal can remain thermally sealed from an environment created within a confined area so as to impart vibration to a DUT positioned within the environmentally protected area, the vibration coming from a vibrator outside the environmentally sealed area. The pedestal, in one embodiment, extends through the base of a DUT holding tray while still preserving the environment within the sealed area. In one embodiment, the pedestal can position the DUT in any of several selected orientations.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Application No. 60/962,677 filed Jul. 31, 2007, which application is hereby incorporated by reference herein; and this present application is related to concurrently filed, co-pending, and commonly-assigned: U.S. patent application Ser. No. XX/XXX,XXX, Attorney Docket 10070331-1, entitled “TRAY FOR HANDLING DEVICES TO BE TESTED”; and U.S. patent application Ser. No. XX/XXX,XXX, Attorney Docket No. 10070330-1, entitled “SYSTEMS AND METHODS FOR FACILITATING USE OF A UNIVERSAL TEST CONNECTION FOR A PLURALITY OF DIFFERENT DEVICES.” 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates to electronic circuit testing systems and more particularly to systems and methods for connecting electronic circuits and devices to test stations. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is common practice to connect electronic circuits and devices (herein called DUTs) to test stations for the purpose of verifying the integrity of the DUT. The testing routines of each device are different for each DUT since each test routine is dependent upon the nature of the DUT. It goes without saying that as devices become more complex, so does the test routine employed for verification of proper operation. In many situations, the test routines extend to vibration testing as well as temperature (hot as well as cold) testing. Thus, it is necessary to connect each DUT to one or more test stations and to make proper electrical contact between the test station and the DUT. When the DUT is to be electrically tested while being vibrated, it is necessary to make both electrical connection to the DUT as well as a mechanical connection to a vibration mechanism. In some situations it is also necessary to perform the electrical testing (and sometimes both electrical and vibration testing) while the DUT is being subjected to various environmental factors, such as, for example, heat and cold. 
         [0004]    Compounding the problem is the fact that different devices have different connection terminals which must be electrically and physically mated with the various inputs/outputs of the test station. Traditionally, these connections are made with cords having one end adapted for physical mating with the DUT and the other end adapted for mating with the test station. These cords then must be manually connected, usually at both ends. Compounding the problem even further, is the fact that when environmental testing or vibration testing is being performed, the cords and/or connectors have a physical presence within the environmental chamber surrounding the DUT. Thus the cords and/or connectors are subjected to varying test conditions as the temperatures and device movement (or other environmental factors) change, thereby allowing for possible variations in test results. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    The problems inherent with connecting a DUT to a test station have been solved by the use of a tray designed to allow a wide variety of different DUTs to be physically connected individually to a test station using a universal test station connector. The tray allows for the association therewith of a personality module which serves to provide the proper physical connections and to electrically condition the test station to the electrical characteristics of the DUT. The tray allows for sealed environmental testing of the DUT without impacting any physical connections between the DUT and the test station. The tray also allows for the DUT to be vibrated from externally applied motion without interfering with either the sealed environment around the DUT and without imparting motion to the physical connection between the DUT and the test station. 
         [0006]    A mounting pedestal is designed to hold a DUT in position for both electrical testing and vibration testing. The design is such that the pedestal can remain thermally sealed from an environment created within a confined area so as to impart vibration to a DUT positioned within the environmentally protected area, the vibration coming from a vibrator outside the environmentally sealed area. The pedestal, in one embodiment, extends through the base of a DUT holding tray while still preserving the environment within the sealed area. In one embodiment, the pedestal can position the DUT in any of several selected orientations. 
         [0007]    The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
           [0009]      FIG. 1  shows one embodiment of a tray for holding a device under test (DUT) on a pedestal so as to allow for vibration testing of the DUT in accordance with the concepts of the invention; 
           [0010]      FIG. 2  shows one embodiment of a personality module for controlling test parameters with respect to a DUT in accordance with the concepts of the invention; 
           [0011]      FIG. 3  shows a personality module) in accordance with  FIG. 2 , positioned within a test tray as shown in  FIG. 1 ; 
           [0012]      FIG. 4  shows one embodiment of a vibration machine temporarily attached to the pedestal of the holding tray shown in  FIG. 1 ; 
           [0013]      FIG. 5  shows a cut-away schematic view of the attachment of a vibration device to the DUT support pedestal of the holding tray; and 
           [0014]      FIG. 6  shows the holding tray of  FIG. 1  mounted in a test stand and connected electrically to a test facility. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]      FIG. 1  shows one embodiment of a tray, such as tray  10 , for holding a device under test (DUT) (not shown) within a confined chamber defined by tray sides  11  surrounding pedestal  14  so as to allow for vibration testing of the DUT. The confined chamber can be environmentally controlled as will be discussed. Tray  10  is designed such that a cover (not shown) can be secured over the top of the DUT and inflated with environmentally conditioned air, or other elements, via one or more ducts, such as via ducts  150 . The inflatable cover can be affixed to lip  16  of tray  10 . The base or bottom of the confined area is defined by surface  18  ( FIG. 2 ) and the top of the confined area by the inside of the cover. 
         [0016]    Pedestal  14  while providing support for holding a DUT has bracket support  501  (shown in  FIG. 5 ) resting on tray base  18  when vibration is not occurring. A holding device (not shown) for the DUT is locked to pedestal  14  via, for example, tapped holes  140 . The DUT (shown as item  602  in  FIG. 6 ) can be held in any desired position by the holding device. When in the non-vibrating state, pedestal  14  rests on tray base  18 . When vibration occurs, as will be discussed, pedestal  14  is raised from tray base  18  and is thus free to move in any desired direction. 
         [0017]    Opening  17  allows a personality module, such as module  20 , to be inserted therein. As will be more fully discussed, personality module  20  contains connectors  24  and/or any other desired devices, such as calibration circuitry, calibration data, error-correction circuitry/data, signal level setting, cable correction data, DUT identification data, etc. Module  20  allows for connection to a test facility when the module is inserted into opening  17  such that electrical terminals, such as connectors  24  of the module, appear through opening  13 . Also contained on tray  10  are electrical terminals, such as RF connectors  31  and connector  32 . Wheels  101  facilitate tray  10  sliding into and out of a test stand (not shown in  FIG. 1 ). Wheels are not necessary for the operation of the tray and or other aspects of this disclosure. Connector  43 , as will be discussed in more detail, is positioned below tray base  18  at the distal end of pedestal  14  and serves to releasably connect pedestal  14  to a vibration device. 
         [0018]      FIG. 2  shows one embodiment of a personality module, such as module  20 , for controlling test parameters with respect to a DUT. In the embodiment shown, module  20  has handles  23  extending from top structure  21 . Structure  21  sits above sides  22  which serve to protect connectors  24 . Structure  21 , in one embodiment, provides thermal isolation between the inner area of tray  10  and the outer area of the tray so as to help maintain the thermal environment within the test chamber. Connectors  24  are electrically connected to connectors  25  which can, if desired, be fitted with thermal protection as well. One function of handles  23  is to physically protect connectors  25 . In one embodiment, connectors  24  are positioned perpendicular to the top surface of module  20 . 
         [0019]    The purpose of connectors  25 , which could be eliminated by hard wiring, if desired, is to cross-connect between the DUT and connectors  24  which connectors are arranged for standard interfacing with universal electrical terminals of test stations. This then allows connectors  24  to be uniform for all personality modules which in-turn eliminates the need for specialized cables to be used for each different DUT even though the electrical terminals could be different for each DUT. In one embodiment, the cross-connect cables are relatively short, i.e., between 6 inches and two feet. The positioning of connectors  24  in a second portion of the module below the top (first) portion of the module and below the bottom surface of tray  10  (on the outside of the environmentally conditioned area) protects the cables from heat and cold stresses. In addition, because the connectors are uniform across all DUTs it is easier to establish a blind-mate connection with a test system. This blind-mate connection can be as a result of a human positioning one or more trays into a test system or the positioning being accomplished by a robot or other automatic (non-human) system. A third portion of the module, also positioned below the bottom surface of the tray, can contain elements for controlling the testing of the DUT. 
         [0020]    The personality module, which in one embodiment has an outer dimension of approximately 8 inches by 11 inches by 12 inches high, serves a number of different roles all such that a particular DUT can be conditioned to be tested using a standard interface connection between the DUT and the test facility. Thus, when a particular DUT is to be tested, a module  20  designed specifically for that particular DUT is selected and associated with the DUT. Both the particular DUT and the selected module are positioned within tray  10  in association with the pedestal upon which the DUT is clamped. The DUT is electrically connected to the module using test cables, such as test cables  601 , either permanently affixed to the module or connected thereto (as shown in  FIG. 6 ). The selected module is designed having circuitry (not shown) for providing conditioning information test signals from the connected test facility and for optionally instructing the test facility as to what test to be performed. Some of this conditioning information can take the form of control signals that can be, for example, calibration elements, calibration data, error-correction data, signal level setting data, power supply data, cable correction data, device identification. 
         [0021]    In a robotic situation, the module that is assigned to a tray also can contain routing instructions for a robot so that the module becomes connected to the proper test facility or facilities and associated with the DUT being held by the pedestal. Thus, different DUTs can be assigned different trays with each tray then receiving a module matching the DUT. The tray then controls its destiny through a robotic test system. When robotics is not used for tray movement purposes, the module continues to serve to condition the test facilities to set-up test requirements for the particular DUT associated therewith. 
         [0022]    In some embodiments, the modules can have memory and processors and can be reprogrammed as required. In some embodiments, the modules can be designed using ASICS or PROMs as desired. Wireless technology, as well as near-field transmission, can be employed to change the programmed parameters. 
         [0023]      FIG. 3  shows personality module  20  positioned within test tray  10 . In this view pedestal  14  is shown without a DUT being mounted thereon and positioned against tray base  18 . When a DUT is mounted on pedestal  14  and it is desired to perform vibration testing, pedestal  14  is raised away from tray base  18  and vibrated in the manner to be discussed. If the vibration testing is to performed within a controlled environment, such as under heated or cooled conditions, “tent”  33 ; which in one embodiment can be a flexible covering, can be formed around the top area of tray  10  and conditioned air blown in from below the tray. The tent is made from, for example, thermal material such as neoprene. 
         [0024]    Other test system connections can be made between the DUT and the test system via RF connectors  31  and/or connector  32 . 
         [0025]      FIG. 4  shows system  40  in which vibrator  41  is temporarily attached via connector  43  to connector  42  at the distal end of pedestal  14  which extends downward from tray  10  through the base of the tray. In this manner, the vibrator machinery can be maintained outside of any environment in which the DUT is being tested. Vibrator  41  can be any well-known vibrator or shaker operable for imparting a desired motion (or range of motions) at connector  43  thereby causing the DUT to move in a controlled fashion. In operation, in one embodiment, vibrator  41  causes pedestal  14  to lift away from tray base  18  of tray  10  and then to move in one or more directions under control of connector  42  which extends from a vibrating device, such as vibrator (shaker)  41 . In the embodiment shown, vibrator (shaker)  41  is in a fixed location and tray  10  is moved into proximity therewith for testing a DUT. However, the shaker could be portable and the tray fixed or both units could be portable and/or fixed. Note that pedestal  14  has a portion that slides through the tray from surface  18  exiting on the bottom outside surface of the tray. 
         [0026]      FIG. 5  shows a schematic simplified cut-away view of one embodiment of the attachment of vibrator  41  to DUT support pedestal  14  of the holding tray. Note that this view depicts vibrator  41  fully seated with respect to the connection between the vibrator and the pedestal but not yet applying upward pressure on pedestal  14 . Thus, pedestal  14  is still shown supported by surface  18  via supports  502 . As will be discussed, when tray  10  is further lowered, or when vibrator  41  (or stem  503 ) is raised, or when supports  501  have been withdrawn, pedestal  14  will cease to be supported by surface  18 . Note also that thermal seal barrier  502 , which can be a neoprene boot, is fitted around the surface of pedestal  14  so as to create a thermally sealed area to help reduce thermal leaks so as to maintain the environmental integrity of the treated atmosphere within the sealed chamber confines of tray  10 . Thus, when the air has been heated, or cooled, the modified air temperature can not escape around the openings between pedestal  14  and surface  18  and also can not travel along pedestal  14  because of the thermal barrier. When pedestal  14  is in the vibrate mode, (not supported by surface  18 ) material  502  stretches to accommodate both upward motion as well as any lateral movement of the pedestal. Thereby environmentally sealing the portion of pedestal  14  that communicates with the atmosphere outside the thermally sealed confined area. Using this approach the DUT can be vibrated without also vibrating the pedestal that holds the DUT. 
         [0027]    A DUT can be directly attached by clamping or otherwise, to the top surface of pedestal  14  and in such a situation the top surface would most likely be sloped. The DUT is connected to the top surface using thermal insulating material, such as pads or gaskets to prevent heat or cold from escaping into the structure of the pedestal. Alternatively, a holding fixture could be employed either on top of boot  502  (again using thermally insulating material for attachment to the pedestal through boot  502 ) or the fixture could be mounted between boot  502  and top surface of pedestal  14 . For the purpose of discussion herein the word pedestal should be understood to include not only the portion that extends downward through opening  51  in the tray bottom surface for communication with the area outside of the confined area and for connection to the vibrator but also upward for attachment to a DUT. 
         [0028]    Vibrator  41  is temporarily attached, when desired, to support pedestal  14  by connector  42  mating with connector  43 . In the embodiment shown, pedestal  14  slides through base surface  18  of tray  10  and when in the ‘support’ position supports  501  prevent pedestal  14  from falling through surface  18 . As will be discussed, supports  501  can be controllably withdrawn, for example, by an actuator (not shown) so as to allow pedestal  14  to float free of surface  18 . This would then allow the movable portion of a mated vibrator (as will be discussed) to impart motion to a DUT mounted on the proximal end of pedestal  14  when the vibrator is mated with the pedestal and activated. 
         [0029]    Note that while pedestal  14  is shown as a single structure it can be multiple structures having different circumferences at different portions thereof. Connector  43  can be part of the unitary structure of the pedestal or a separate structure. Also note that when such support withdrawal is not desired, supports  501  can simply be a widened portion of the pedestal. 
         [0030]    To facilitate a firmly mated connection between connectors  43  and  42  and to also facilitate proper alignment, connector  43 , in the embodiment shown, fits inside the circumference of connector  42  Annular gasket  44  is positioned within groove  404  (similar to an o-ring) on the inside wall of connector  42 . By fitting the gasket properly, such as by pumping the gasket tight after connectors  42  and  43  are seated together air can be pumped out of the space between the bottom surface of connector  43  and the mating surface of connector  42  to create a temporary vacuum seal between connectors  42  and  43 . In order to facilitate the vacuum seal, gasket  44  can have holes therein (not shown) which will allow air to be drawn through the gasket by an air pump or other suction device thereby facilitating a tight mating relationship between stem  503  of the vibrator and connector  43  of pedestal  14 . In other embodiments, the fact that gasket  44  is made to swell may be enough to create an acceptable friction fit between the connector portions. If desired, pads (not shown) can be positioned between connectors  42  and  43  to facilitate the connection. 
         [0031]    In operation, when it is desired to perform vibration testing on a DUT which has been attached to the proximal (top) end of pedestal  14 , either tray  10  is lowered so as to position connector  43 , located at the distal end of pedestal  14 , against connector  42 , as discussed above, from vibrator  41 , or vibrator  41  is raised (hydraulically or pneumatically) so that pedestal  14  is forced upward away from tray base  18  of tray  10 , or bracket stops  501  are withdrawn as above noted. Connectors  42  and  43 , as discussed can be releasable mated together so that whatever motion vibrator stem  503  has is imparted to pedestal  14  and ultimately to the DUT when the vibrator is activated. Note that as discussed, the flexible nature of thermal material  502  allows the motion of stem  503  to be imparted faithfully to the DUT. 
         [0032]      FIG. 6  shows test system  60  in which holding tray  10  is mounted in a test stand, such as testing station  64 . In this embodiment, test system  60  is connected by connector cable  62  to personality module  20  of tray  10 , shown without the environmental cover. Note that personality module  20  is an interface unit between the test device and the DUT. Note also that connector cables  601  connect module  20  to DUT  602  via connectors  63  which connectors, as discussed above, can be thermally insulated as can be connector cables  601 . Also shown is temperature control device  620  which can be used for imparting environmental conditions, for example via ducts  621  and  150  ( FIG. 1)to the  DUT inside the environmental chamber from a position outside of the environmental chamber. 
         [0033]    Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.