PATENT DOCUMENT

Publication Number: US-9423420-B2
Application Number: US-201213472399-A
Country: US
Kind Code: B2

Title: Testing system with test trays

Abstract:
A test system may be provided in which devices under test are loaded into test trays and tested at a plurality of test stations. To test a device under test at a given test station, the test tray may be installed into a test fixture at the test station. Test equipment at each test station may communicate with the device under test via the test fixture and the test tray. Each test tray may have a spring-loaded corner portion that may be used to secure the device under test to the test tray. The test tray may have contacts that mate with corresponding contacts at each test fixture and may have a built in cable that connects to the device under test. The test fixture may have a detector that can detect whether or not a test tray is present on the test fixture.

Claims:
What is claimed is: 
     
       1. Test apparatus for housing a device under test during testing, comprising:
 a device under test receiving structure configured to receive a device under test; 
 at least one movable portion of the device under test receiving structure that is configured to hold the device under test within the device under test receiving structure; 
 an actuating member configured to move the movable portion to release the device under test from the device under test receiving structure; 
 a plurality of contacts configured to electrically couple the device under test to a test station during testing; 
 a cable having a first and second ends, wherein the first end is electrically coupled to the plurality of contacts and wherein the second end is configured to mate with an input-output port in the device under test; and 
 a groove formed in the device under test receiving structure, wherein the device under test receiving structure comprises first and second opposing surfaces, wherein the first surface comprises a planar portion, wherein the groove comprises a recessed portion in the planar portion of the first surface, wherein the cable is embedded in the groove such that a portion of the cable protrudes into the recessed portion below the planar portion of the first surface, and wherein the second surface comprises an additional recessed portion in which the device under test is received. 
 
     
     
       2. The test apparatus defined in  claim 1 , wherein the at least one movable portion comprises a movable corner portion and wherein the movable corner portion is biased towards a central portion of the device under test receiving structure. 
     
     
       3. The test apparatus defined in  claim 2 , wherein the movable corner portion comprises at least one spring-loaded member. 
     
     
       4. The test apparatus defined in  claim 1 , wherein the device under test receiving structure comprises a base portion and at least one sidewall, wherein the base portion and the at least one sidewall define the additional recessed portion, and wherein the movable portion is configured to hold the device under test within the additional recessed portion. 
     
     
       5. The test apparatus defined in  claim 1 , wherein the cable comprises a signal line selected from the group consisting of: a positive power supply line, a ground power supply line, a data line, a Universal Serial Bus signal line, a Universal Asynchronous Receiver/Transmitter line, and a control line. 
     
     
       6. The test apparatus defined in  claim 1 , wherein the device under test receiving structure is rotatable about a rotational axis and wherein the device under test receiving structure comprises at least one weight balancing feature configured to balance a weight of the device under test receiving structure with respect to the rotational axis when the device under test is received within the device under test receiving structure. 
     
     
       7. The test apparatus defined in  claim 6 , wherein the at least one weight balancing feature comprises a plurality of holes in the device under test receiving structure. 
     
     
       8. A test system for testing a device under test comprising:
 a test tray configured to receive the device under test, wherein the test tray includes a plurality of test tray contacts configured to be electrically coupled to the device under test when the device under test is received by the test tray; and 
 a test fixture configured to receive the test tray, wherein the test fixture includes a plurality of test fixture contacts configured to mate with the plurality of test tray contacts when the test tray is received by the test fixture, wherein the device under test comprises an ambient light sensor, wherein the test fixture comprises test equipment for testing the ambient light sensor, wherein the test tray comprises first and second opposing surfaces, wherein the test tray comprises sidewalls that extend from the first surface to surround the device under test and at least one opening that extends from the first surface to the second surface, wherein light signals are exchanged through the opening between the test equipment and the ambient light sensor. 
 
     
     
       9. The test system defined in  claim 8 , wherein the test tray comprises a cable having first and second ends, wherein the first end is electrically coupled to the plurality of test tray contacts, wherein the second end is configured to mate with a connector in the device under test, and wherein the cable is configured to convey signals between the device under test and the plurality of test tray contacts. 
     
     
       10. The test system defined in  claim 8 , wherein the plurality of test tray contacts comprises a plurality of contact pads and wherein the plurality of test fixture contacts comprises a plurality of conductive pins. 
     
     
       11. The test system defined in  claim 10 , wherein the plurality of conductive pins comprises a plurality of spring-loaded pins, wherein each spring-loaded pin in the plurality of spring-loaded pins has an associated height with respect to a surface of the test fixture, and wherein the heights of at least two spring-loaded pins in the plurality of spring-loaded pins are different. 
     
     
       12. The test system defined in  claim 8 , wherein the test fixture comprises a plurality of test fixture engagement features, wherein the test tray comprises a plurality of test tray engagement features, and wherein the test fixture engagement features are configured to engage with the test tray engagement features when the test tray is received by the test fixture. 
     
     
       13. The test system defined in  claim 12 , wherein at least one test fixture engagement feature in the plurality of test fixture engagement features comprises a spring-loaded member. 
     
     
       14. The test system defined in  claim 13 , wherein at least one test tray engagement feature in the plurality of test tray engagement features comprises a recess. 
     
     
       15. The test system defined in  claim 8 , wherein the test fixture comprises a test tray detector configured to detect whether or not the test tray is present on the test fixture. 
     
     
       16. The test system defined in  claim 8 , wherein the device under test comprises an electrical component, wherein the test fixture comprises test equipment for testing the electrical component, and wherein the test tray comprises at least one additional opening through which the test equipment and the electrical component communicate. 
     
     
       17. The test system defined in  claim 8 , wherein the test tray comprises a movable portion that is configured to move with respect to a central portion of the test tray and that is configured to hold the device under test within the test tray. 
     
     
       18. The test system defined in  claim 17 , wherein the test tray further comprises an actuating member configured to move the movable portion to release the device under test from the test tray. 
     
     
       19. The test system defined in  claim 18 , wherein the movable portion comprises a movable corner portion and wherein the movable corner portion is biased towards the central portion. 
     
     
       20. Test apparatus for housing a device under test during testing, comprising:
 a device under test receiving structure configured to receive a device under test, wherein the device under test receiving structure comprises a base portion on which the device under test rests and at least one sidewall, wherein the base portion and the at least one sidewall define a substantially rectangular recessed portion with four corners; 
 at least one movable portion of the device under test receiving structure that is configured to hold the device under test within the device under test receiving structure, wherein the at least one movable portion comprises a movable corner portion that makes up a selected one of the four corners; and 
 an actuating member configured to move the movable portion to release the device under test from the device under test receiving structure. 
 
     
     
       21. The test apparatus defined in  claim 20 , wherein the movable corner portion is biased towards a central portion of the device under test receiving structure. 
     
     
       22. The test apparatus defined in  claim 21 , wherein the movable corner portion comprises at least one spring-loaded member. 
     
     
       23. The test apparatus defined in  claim 22 , wherein the movable corner portion is configured to hold the device under test within the recessed portion. 
     
     
       24. The test apparatus defined in  claim 23 , wherein the base portion of the device under test receiving structure, the movable corner portion, and the spring-loaded member are coplanar.

Description:
This application claims the benefit of provisional patent application No. 61/595,572, filed Feb. 6, 2012, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to testing systems, and, more particularly, to testing systems that use test trays as an interface between test equipment and devices under test. 
     Electronic devices are often tested following assembly to ensure that device performance meets design specifications. For example, a device may be tested at a series of test stations to ensure that components and software in the device are operating satisfactorily. At each test station, an operator may couple a device to test equipment using a cable. Following successful testing at all test stations, a device may be shipped to an end user. 
     The process of attaching and detaching test cable connectors can reduce the lifetime of the test cable connectors and can be cumbersome and burdensome to test system operators. If care is not taken, tests may be less accurate and more time consuming than desired. Additionally, excessive contact between a test system operator and a device under test may increase the risk of cosmetic damage to the device under test. 
     It would therefore be desirable to be able to provide improved ways of performing manufacturing operations such as testing operations on electronic devices. 
     SUMMARY 
     A test system may be provided in which devices under test are installed in test trays and tested at a plurality of test stations. To test a device under test at a given test station, the test tray may be installed in a test fixture at the test station. Test equipment at each test station may communicate with the device under test via the test tray. 
     Each test tray may have a movable corner portion that moves with respect a central portion of the tray. One or more spring-loaded members may be used to bias the movable corner portion towards the central portion of the tray. When it is desired to install a device under test in the test tray, a lever on the test tray may be actuated to move the corner portion away from the central portion of the tray. After placing the device under test onto the central portion of the test tray, the lever may be released to allow the corner portion to return to its equilibrium position, thereby securing the device under test to the test tray. 
     The test tray may have test tray contacts that may be used to electrically couple the device under test in the test tray to a test fixture at a test station. The test fixture may have corresponding test fixture contacts that mate with the contacts on the test tray. 
     The test tray may be provided with one or more cables. The cables may be embedded in grooves in the test tray. A test tray cable may have a first end that is configured to mate with an input-output port in the device under test and a second end that is electrically coupled to the test tray contacts. The cable may be used to convey signals between the test fixture and the device under test when the test tray is installed in the test fixture. 
     The test tray may have weight balancing features such as holes for balancing the weight of the test tray with respect to a rotational axis of the test tray. The weight balancing features may be used to align the center of mass of the tray with the center of mass of the device under test when it is installed in the tray. 
     The test fixture may have engagement features such as one or more spring-loaded members that engage with corresponding engagement features on the test tray when it is installed in the test fixture. 
     The test fixture may have one or more detectors that are configured to detect whether or not a test tray is present on the test fixture. 
     The test fixture may have test equipment that may be used to test one or more electrical components in a device under test. The test tray may be provided with one or more openings to allow the test equipment to communicate with the electrical component being tested. 
     After installing a device under test into a test tray, a test tray cable may be connected to the device under test. The test tray may then be installed in a test fixture at a test station by mating the test tray contacts with the test fixture contacts. Following installation of the test tray in the test fixture, the device under test may be tested at the test fixture. The device under test may be tested at additional test stations without requiring the step of removing the device under test from the test tray or detaching the test tray cable from the device under test. The device under test may be tested at additional test stations by installing the test tray into the test fixture associated with each additional test station. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative electronic device such as a tablet computer that may be manufactured using a test tray in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of an illustrative electronic device such as a handheld device of the type that may be manufactured using a test tray in accordance with an embodiment of the present invention. 
         FIG. 3  is a diagram of manufacturing equipment of the type that may be used in manufacturing an electronic device in accordance with an embodiment of the present invention. 
         FIG. 4  is a diagram showing how a device under test may be mounted in a test tray that is configured to be received within a test station test fixture in accordance with an embodiment of the present invention. 
         FIG. 5  is a front perspective view of a test tray in accordance with an embodiment of the present invention. 
         FIG. 6  is a rear perspective view of a test tray in accordance with an embodiment of the present invention. 
         FIG. 7  is top perspective view of an illustrative test station test fixture configured to receive a test tray in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional side view of an illustrative test station test fixture in accordance with an embodiment of the present invention. 
         FIG. 9  is a perspective view of a test tray in which a device under test has been mounted in accordance with an embodiment of the present invention. 
         FIG. 10  is a cross-sectional side view of a device under test in a test tray that has been mounted in a mating test station test fixture in accordance with an embodiment of the present invention. 
         FIG. 11  is a cross-sectional side view of a device under test in an upside down configuration in a test tray in accordance with an embodiment of the present invention. 
         FIG. 12  is a cross-sectional side view of a device under test in a right side up configuration in a test tray in accordance with an embodiment of the present invention. 
         FIG. 13  is a cross-sectional side view of a device under test in a test tray with an opening to accommodate tests in accordance with an embodiment of the present invention. 
         FIG. 14  is an exploded perspective view of a device under test and associated test station test fixture with a presence detection mechanism in accordance with an embodiment of the present invention. 
         FIG. 15  is a cross-sectional side view of a test station test fixture and test tray with mating engagement features in accordance with an embodiment of the present invention. 
         FIG. 16  is a perspective view of an illustrative automated test tray loader that may be used to assist an operator in loading devices under test into test trays in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as electronic device  10  of  FIG. 1  may be manufactured using automated manufacturing equipment. The automated manufacturing equipment may include equipment for assembling device components together to form an electronic device. The automated manufacturing equipment may also include testing systems for evaluating whether devices have been properly assembled and are functioning properly. 
     Devices such as device  10  of  FIG. 1  may be assembled and tested using an automated manufacturing system and associated test apparatus. The manufacturing system may include one or more stations such as one or more test stations for performing testing operations. 
     Devices that are being tested in a test system may sometimes be referred to as devices under test. Devices under test may be provided to the test stations using a conveyor belt, using robotic arms, and/or using other loading equipment. If desired, devices under test may be conveyed between test stations by a test system operator. 
     Test equipment at each test station may be used to perform an associated test on a device. For example, one test station may have equipment for testing a display in the device. Another test station may have equipment for testing an audio component in the device. Yet another test station may have equipment for testing light sensors in the device. Yet another test station may have equipment for testing wireless communications circuitry in the device. Automated equipment in the test system may be used in loading and unloading devices under test, in conveying devices under test between test stations, and in performing tests and maintaining a database of test results. 
     Any suitable devices may be tested using the test equipment. As an example, device  10  of  FIG. 1  may be tested. Device  10  may be a computer monitor with an integrated computer, a desktop computer, a television, a notebook computer, other portable electronic equipment such as a cellular telephone, a tablet computer, a media player, a wrist-watch device, a pendant device, an earpiece device, other compact portable devices, or other electronic equipment. In the configuration shown in  FIG. 1 , device  10  is a handheld electronic device such as a cellular telephone, media player, navigation system device, or gaming device. 
     As shown in  FIG. 1 , device  10  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material. In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. Display  14  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrophoretic display elements, electrowetting display elements, liquid crystal display (LCD) components, or other suitable image pixel structures. A cover glass layer may cover the surface of display  14 . Openings for buttons such as button  20 , openings for speaker ports such as speaker port  22 , and other openings may be formed in the cover layer of display  14 , if desired. 
     The central portion of display  14  (e.g., active region  16 ) may include active image pixel structures. The surrounding rectangular ring-shaped inactive region (region  18 ) may be devoid of active image pixel structures. If desired, the width of inactive region  18  may be minimized (e.g., to produce a borderless display). 
     Device  10  may include components such as front-facing camera  24 . Camera  24  may be oriented to acquire images of a user during operation of device  10 . Device  10  may include sensors in portion  26  of inactive region  18 . These sensors may include, for example, an infrared-light-based proximity sensor that includes an infrared-light emitter and a corresponding light detector to emit and detect reflected light from nearby objects. The sensors in portion  26  may also include an ambient light sensor for detecting the amount of light that is in the ambient environment for device  10 . Other types of sensors may be used in device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     Device  10  may include input-output ports such as port  28 . Ports such as port  28  may include audio input-output ports, analog input-output ports, digital data input-output ports, or other ports. Each port may have an associated connector. For example, an audio port may have an associated four-contact audio connector, a digital data port may have a connector with two or more pins (contacts), a connector with four or more pins, a connector with thirty pins, or other suitable data port connector. 
     Sensors such as the sensors associated with region  26  of  FIG. 1 , cameras such as camera  24 , audio ports such as speaker port  22 , buttons such as button  20 , and ports such as port  28  may be located on any suitable portion of device housing  12  (e.g., a front housing face such as a display cover glass portion, a rear housing face such as a rear planar housing wall, sidewall structures, etc.). 
       FIG. 2  is a perspective view of device  10  in an illustrative configuration in which device  10  is a tablet computer. As shown in  FIG. 2 , device  10  may include a housing such as housing  12 . Housing  12  may be formed from metal, plastic, fiber-based composite material, glass, ceramic, other materials, or combinations of these materials. Device  10  may have an upper (front) surface that is covered with display  14 . Active portion  16  of display  14  may have a rectangular shape (as an example). Inactive portion  18  of display  14  may have an opening to accommodate button  20 , a window region for camera  24 , and a portion such as portion  26  that is associated with one or more optical sensors such as an infrared-based proximity sensor and/or an ambient light sensor. 
       FIG. 3  is a diagram of an illustrative system of the type that may be used for manufacturing operations such as device testing. As shown in  FIG. 3 , system  30  may include one or more stations such as test stations  36 . In general, test system  30  may include automated equipment that is used in loading and unloading devices under test, in conveying devices under test between test stations, and in performing tests and maintaining a database of test results. 
     Each test station  36  may, for example, include test equipment  45  for performing one or more tests on device under test  10  and may therefore sometimes be referred to as a device tester or DUT tester. For example, a first type of test station  36  may have equipment for testing a display in device under test  10 . A second type of test station  36  may have equipment for testing an audio component in device under test  10 . Yet another type of test station  36  may have equipment for testing light sensors in device under test  10 . Yet another type of test station  36  may have equipment for testing wireless communications circuitry in device under test  10 . If desired, test system  30  may include more than one test station of the same type arranged along conveyor belt  38  so that multiple devices under test  10  can be tested in parallel. 
     Device under test  10  may, if desired, be installed in a test tray such as tray  32 . Tray  32  may be configured to receive one or more devices under test. For example, tray  32  may have multiple slots, each of which is configured to receive a corresponding device under test. If desired, tray  32  may be configured to receive only a single device under test. 
     Device  10  may be installed in test tray  32  manually or using automated equipment. To facilitate manual installation, test tray  32  may include features to facilitate human manipulation. For example, test tray  32  may include features that help an operator open and close clamps or other device holding features in test tray  32 . 
     If desired, devices under test  10  that have been mounted in test trays  32  may be conveyed between test stations  36  using a conveyor belt such as conveyor belt  38  (e.g., a belt that moves in direction  40 ). Each test station  36  may be provided with loading mechanisms such as loader  47  (e.g., a robotic loader with one or more computer-controlled positioning arms) and/or may have an associated test system operator. A test system operator and/or loader  47  may transfer test trays  32  between conveyor belt  38  and test stations  36 . For example, a test system operator and/or loader  47  may pick up test tray  32  (e.g., a test tray that is loaded with device  10 ) from conveyor  38  (arrow  50 ), may present the test tray to tester  45  at that test station to perform desired testing of device  10 , and may return the test tray to conveyor  38  following testing (arrow  52 ). Test trays  32  may also, if desired, be transferred directly from one test station to another test station. 
     Test trays  32  may allow a test system operator to handle devices under test  10  without having to make physical contact with devices under test  10 . Test tray  32  may serve as both an interface between device under test  10  and a test system operator as well as an interface between device under test  10  and a test station. Test tray  32  may, for example, be more robust than device under test  10 , may have engagement features that are configured to mate with a test station text fixture at test station  36 , may have an identification number that facilitates tracking, and may have other features that facilitate testing of device under test  10  by test stations  36 . 
     Test stations  36  may provide test results to computing equipment such as test host  42  (e.g., one or more networked computers) for processing. Test host  42  may maintain a database of test results, may be used in sending test commands to test stations  36 , may track individual trays and devices under test as the trays and devices pass through system  30 , and may perform other control operations. 
       FIG. 4  is a diagram showing how device under test  10  may be received within test tray  32  and showing how test tray  32  may be received within guiding structures  50  of test fixture  34 . As shown in  FIG. 4 , test tray  32  (sometimes referred to as device under test receiving structure, device under test holder, or device-to-test-fixture interface structure) may have a base such as base  48  on which device under test  10  rests. Sidewalls  46  may be configured to surround some or all of the sides of device under test  10  and may contain device locating features such as tangential surfaces and notches. A portion of sidewall structures  46  such as corner portion  44  of sidewall structures  46  may be movable relative to a central portion of tray  32  (e.g., relative to device under test  10  when it is installed in tray  32 ). During installation of device under test  10  into the recess formed by sidewalls  46  and base  48 , portion  44  may be moved away from sidewalls  46  to allow device under test  10  to be inserted into the recess. Following insertion of device under test into the recessed portion of tray  32 , portion  44  may move backwards towards device under test  10  to hold device under test  10  within tray  32 . 
     Test fixture  34  may have a support structure such as base  52  to which guiding structures  50  are attached. Guiding structures  50  may be configured to receive the exterior portions of sidewalls  46  of test tray  32 . Engagement features on guiding structures  50  and/or tray  32  may help hold tray  32  in place within test fixture  34  during testing. 
       FIG. 5  is a front perspective view of test tray  32 . As shown in the illustrative configuration of  FIG. 5 , test tray  32  may have spring-loaded corner portion  44 . To load device under test  10  into test tray  32 , corner portion  44  and associated bars  58  may be moved in direction  59 . Corner portion  44  may be biased inwardly (e.g., towards a central portion of test tray  32 ) using springs or using other types of spring-loaded members. After device under test  10  has been loaded into test tray  32 , corner portion  44  may be released. The springs associated with corner portion  44  may bias corner portion  44  inwardly in direction  56  to hold device under test  10  within test tray  32 . 
     Test tray  32  may have engagement features such as recesses  60  in sidewalls  46 . Recesses  60  (sometimes referred to as openings, slots, or grooves may be configured to mate with corresponding engagement features on guiding structures  50  of test fixture  34  such as features  51  of  FIG. 4 . 
       FIG. 6  is a rear perspective view of test tray  32 . As shown in  FIG. 6 , base  48  may have an opening such as opening  64  through which an operator may operate an actuating member such as actuating member  66 . In the example of  FIG. 6 , actuating member  66  has been implemented in the form of a lever. When an operator desires to load device under test  10  into the front of tray  32  (or unload device under test  10  from the front of tray  32 ), the operator&#39;s fingers may be placed in finger holes  68  and the operator&#39;s thumb may be placed on lever  66  to pull lever  66  in direction  70 . The lever may pivot (internally) about pivot point  72 , pressing spring-loaded bars  58  and corner portion  44  of sidewalls  46  outwards in direction  59 . If desired, other types of actuating members may be used to control corner portion  44  (e.g., one or more buttons, switches, and/or other types of actuators may be used to control corner portion  44 ). 
     If desired, an automated loader may be used to assist an operator in opening and closing corner portion  44 . The automated loader may contain a computer-controlled actuator that pulls lever  66 . 
     Tray  32  may have holes such as hole  74  to facilitate test measurements on device under test  10  during testing. For example, openings such as hole  74  may be used to allow light from a test light source to reach an ambient light sensor in region  26  of device under test  10  ( FIG. 2 ) (e.g., when device under test  10  has been loaded face down into test tray  32 ). Openings such as hole  74  may also be used to allow a magnetic sensor in device  10  to be tested (e.g., by allowing a magnet to be placed in proximity to a magnetic sensor in device  10 ). 
     Tray  32  may have weight balancing features such as holes  76  to help ensure that tray  32  is rotationally weight balanced with respect to rotational axis  78 . The rotational balancing of the mass (weight) within tray  32  may facilitate positioning of test tray  32  using positioning equipment in system  30  such as loaders  47  and/or loading arms in test stations  36  and may allow device  10  to be rotated for testing (e.g., for testing of motion sensors such as accelerometers). Balancing holes  76  may be configured so that the center of mass of tray  32  is aligned with the center of mass of device under test  10 . 
     It may be desirable to stack test trays during use in system  30 . Stacking features such as stacking features  80  may be formed on portions of sidewalls  46  so that multiple trays such as trays  32  can be stacked on top of each other. When stacked, stacking features such as sidewall stacking feature  80  may rest on mating portions of sidewall  46  such as stacking feature portion  82  in  FIG. 5 . 
     Test tray  32  may have electrical contacts such as contacts  62  (sometimes referred to as pins, contact pads, or pads). When device under test  10  is loaded into tray  32 , a cable may be used to connect one or more connector ports in device under test  10  to contacts  62 . Slot  85  may, if desired, serve as a temporary connector holder for receiving the connector at one end of the cable. Tray  32  may include grooves such as grooves  84  that for routing cables within base  48 . 
     One end of a cable may be configured to mate with a device port such as port  28  of  FIG. 2  using a connector. The opposing end of the cable may be terminated at contacts  62 . Contacts  62  may be, for example, contact pads formed from nickel plated with gold. Contacts  62  may be configured to mate and form electrical connections with corresponding spring-loaded pins or other contacts in test fixture  34 . 
     The use of test tray  32  and test fixture  34  may allow devices under test  10  to be placed accurately within test stations  36  (e.g., with an accuracy of +/−0.1 mm or better, as an example). Test tray  32  may shield device under test  10  from scratches and other damage during testing. The cabling used to attach device under test to contacts  62  may be built into test tray  32 . Loading and unloading may be facilitated using clamping structures such as movable corner  44 . 
     Device under test  10  may be received within test tray  32  in either an upwards facing configuration in which display  14  faces outwards away from tray  32  or a downwards facing configuration in which display  14  faces downwards onto base  48  of test tray  32 . As described in connection with stacking alignment feature  80  of  FIG. 6 , test trays  32  may, if desired, be stacked. Trays  32  may be stacked when no device under test  10  is present (i.e., when trays  32  are empty) or may be stacked following loading of device under test  10 . Test stations  36  may contain detectors that can detect the presence or absence of trays  32 . 
     Each tray  32  may contain location features such as holes  86  ( FIG. 6 ). As shown in  FIG. 7 , each test station  36  (i.e., each test fixture  34 ) may containing mating features such as protrusions (pins)  88  that mate with features  86  and thereby accurately place tray  32  in a desired location relative to the test station. The use of holes and mating protrusions as features for aligning trays  32  relative to test fixtures  32  is merely illustrative. Alignment features of any suitable shape may be used if desired. 
     Each test fixture  34  may have a respective set of mating contacts (e.g., spring-loaded pins) such as mating contacts  98 . Mating contacts  98  on test fixture  34  may be configured to mate and with contacts  62  on test tray  32 . Because device under test  10  is connected to contacts  62  in test tray  32  using cabling associated with test tray  32 , it is not necessary to repeatedly connect and disconnect device under test  10  from cabling at each test station. Rather, connections between the device under test and the test equipment at each test station by may be formed by coupling contacts  62  in test tray  32  to corresponding contacts  98  (e.g., spring-loaded pins) in each test fixture  34 . By minimizing the number of times that cables need to be connected and disconnected from each device under test, the life of tester cables and connectors may be extended. 
       FIG. 7  shows how test fixture guide structures  50  may be provided with portions such as spring-loaded clips  51 . During insertion of tray  32  into test fixture  34 , sidewalls  46  of tray  32  may press clips  51  inwards. Once tray  32  has been positioned so that clips  51  are aligned with openings  60  in tray  32  ( FIGS. 5 and 6 ), clips  51  may spring into openings  60  to secure tray  32  to fixture  34 . Clips  51  may have angled surfaces that help hold test tray  32  close to base  52  of test fixture  34 . During testing, clips  51  can be used to retain test tray  32  against base  52  within fixture  34 . 
     Structures  90  may form an aperture extension for use in testing an ambient light sensor in region  26  of device under test  10 . Structures  92  may be used in ejecting tray  32  from test fixture  34 . 
       FIG. 8  shows a side view of contacts  98 . If desired, the heights of contacts  98  with respect to surface  99  of test fixture  34  may be staggered in dimension Z to ensure that signal connections occur in a predictable order (e.g., so that a desired contact such as a ground contact makes contact before other signal paths). 
       FIG. 9  is a perspective view of test tray  32  and device under test  10 . As shown in  FIG. 9 , device under test  10  may be retained within test tray  32  using corner portion  44  of test tray  32 . Cable  96  may have one end with wires that are connected to respective contacts  62  and may have an opposing end with a connector such as connector  94 . Before installing device under test  10  in tray  32 , connector  94  may be stored in slot  85 . When it is desired to form an electrical connection between device under test  10  and contacts  62 , an operator (or automated equipment) may remove connector  94  from slot  85  and may insert connector  94  into the connector in device under test  10  that is associated with input-output port  28 . By plugging connector  94  into port  28  of device under test  10  in this way, each of contacts  62  may be connected to a respective contact in port  28 . If desired, cable  96  may be embedded in tray  32  (e.g., may be embedded in a groove in tray  32  such as groove  84  of  FIG. 5 ). 
     Examples of signal lines that may be contained in cable  96  include positive power supply lines, ground power supply lines, D+ and D− data lines in a Universal Serial Bus (USB) signal line pair, control lines, Universal Asynchronous Receiver/Transmitter (UART) lines, and other paths. 
       FIG. 10  is a side view of a test station in system  30 . In the configuration of  FIG. 10 , device under test  10  has been mounted in test tray  32 . Test tray  32  has been mounted in test fixture  34  at test station  36 . Cable  96  ( FIG. 9 ) may be used to electrically connect device under test  10  to contacts  62  in test tray  32 . Each contact  62  may be contacted by a corresponding contact in test fixture  34 , as illustrated by contacts (pins)  98 . A signal path formed from signal lines  100  may be used to couple contacts  98  in test fixture  34  to test station computing equipment  102 . Computing equipment  102  may be implemented using one or more computers or other test equipment. The signal path formed from signal lines  100  and cable  96  may be, for example, a Universal Serial Bus (USB) path (e.g., 1.0, 2.0, 3.0, etc.), may be an I 2 C path, may be a Serial Peripheral Interface (SPI) path, may be a controller area network (CAN) bus, or may be any other suitable communications path. 
       FIG. 11  is a cross-sectional side view of test tray  32  in a configuration in which sidewalls  46  have been provided with angled interior surfaces such as angled surface  46 A and angled surface  46 B. As shown in  FIG. 11 , surfaces  46 A and  46 B may be oriented at non-zero angles with respect to vertical dimension Z. When a device under test is placed in an upside down (inverted) orientation as with device under test  10  of  FIG. 11 , curved edge portion  10 T of device under test  10  may be pressed downwards in direction  104  against surface  106  of test tray  32  by angled surface  46 B. When the device under test is mounted in test tray  32  in a right-side up (non-inverted) configuration as shown in  FIG. 12 , angled surface  46 A may help press device under test  10  downwards in direction  104  to retain device under test within test tray  32 . 
       FIG. 13  is a cross-sectional side view of device under test  10  mounted in test tray  32 . As shown in  FIG. 13 , device under test  10  may contain electrical components such as component  108 . Component  108  may be, for example, an ambient light sensor, a light-based proximity sensor, a capacitive sensor, a light-emitting diode (e.g., for a status indicator), a display component, a magnetic sensor, or other electrical component. Component  108  may be tested using testing equipment  110  in test fixture  34 . Component  108  and testing equipment  110  may communicate through opening  74  in test tray  32 . 
     If, as an example, component  108  is a light sensor, testing equipment  110  may be a light source that emits a calibrated light signal. The light signal from testing equipment  110  may pass through opening  74  and may be received by sensor  108 . The resulting light sensor signal may be passed from device under test  10  to computing equipment  102  that is associated with test station  36  using a cable such as cable  96  and contacts  62  ( FIGS. 9 and 10 ). 
     If desired, testing equipment  110  may include a magnet for testing component  108  (e.g., when component  108  is a magnetic sensor), may include an audio source for testing component  108  (e.g., when component  108  is an audio component such as a microphone), may contain a microphone for testing component  108  (e.g., when component  108  is a speaker or other audio source), may contain a light sensor for testing component  108  (e.g., when component  108  is a light source), may contain a button pressing device (e.g., when component  108  is a button), or may be based on other testing devices. 
     Test tray  32  may contain one opening such as opening  74  or may contain two or more openings such as opening  74 . Openings such as opening  74  may, if desired, be filled with clear plastic or other window materials (e.g., for supporting optical tests). In configurations in which test tray  32  is provided with multiple openings, test station  36  may have multiple corresponding devices  110  for testing multiple corresponding components in device under test  10 . 
     Test stations  36  can use a short-circuit detection mechanism or other sensor to detect when test trays  32  have been mounted within test fixtures  34 . As shown in  FIG. 14 , for example, each test tray  32  may be provided with a strip of conductor such as metal strip  116 . Pads  118  and  120  may be formed at opposing ends of metal strip  116 . Metal pads  118  and  120  may be configured to mate with corresponding contacts in test fixture  34  such as pins  112  and  114 . Computing equipment  102  may measure the resistance between pins  112  and  114 . When the resistance is high, computing equipment  102  can conclude that there is an open circuit between pins  112  and  114  and can conclude that tray  32  is not present within fixture  34 . When, however, the resistance is low, computing equipment  102  can conclude that there is a short circuit between pins  112  and  114  and can conclude that tray  32  has been properly seated within test fixture  34 . 
       FIG. 15  is a cross-sectional side view of test tray  32  and test fixture  34  showing how features  51  on guide structures  50  of test fixture  34  may be used to both securely fasten and accurately position test tray  32  on test fixture  34 . As shown in  FIG. 15 , engagement features  51  may be configured to rotate on an axle or other type of hinge such as axle  125 . Axle  125  may be formed in a lower portion of feature  51  and may allow an upper portion of feature  51  to move in directions  127  and  129 . One or more spring-loaded members such as spring  124  may be used to bias feature  51  in direction  122 . 
     When test tray  32  is inserted into test fixture  34  in direction  126 , surface  128  of the sidewalls of test tray  32  may press against surface  130  of spring-loaded pin  51  (e.g., engagement feature  51 ), thereby causing the upper portion of pin  51  to retract into structure  50  in direction  129 . Once opening  60  has been brought into alignment with pin  51 , spring  124  may force the upper portion of pin  51  into opening  60  in direction  127 . Because feature  51  rotates about axle  125 , some of the spring force provided by spring  124  will be directed downwards in direction  126 , thereby causing surface  131  of feature  51  to press down on surface  144  of test tray  32  in direction  126 . This may ensure that test tray  32  is both securely fastened to test fixture  34  and that test tray  32  is positioned in a known location relative to test fixture  34  (e.g., feature  51  may be used to position test tray  32  as close as possible to test fixture  34 ). 
     It may be desirable to provide a test system operator with assistance in moving corner portion  44  of tray  32  in direction  59 .  FIG. 16  is a perspective view of an illustrative loader that may be used in moving corner portion  44  of tray  32 . As shown in  FIG. 16 , loader  132  may have a guide plate such as plate  142 . An operator may place test tray  32  face up on plate  142 , so that plate  142  is received within the walls of test tray  32  and so that member  138  rests against lever  66  in test tray  32  ( FIG. 6 ). The operator (or a computer-controlled actuator) may then move member  134  in direction  136 . Movement of member  134  in direction  136  may cause member  138  to move in direction  140 , thereby moving lever  66  of test tray  32  in direction  70  and moving corner  44  in direction  59  to receive a device under test. 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20120515
Publication Date: 20160823
Grant Date: 20160823
Priority Date: 20120206
Inventors: PANAGAS PETER G.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01L21/67727", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/0002", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01R31/01", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/0002", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01R31/2893", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R31/2893", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01R31/01", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01R1/0441", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01L2924/0002", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L21/67727", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/24", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R31/01", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/24", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01R1/0441", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 47891914