US20130200917A1

US20130200917A1 - Test System with Hopper Equipment

Info

Publication number: US20130200917A1
Application number: US13/478,600
Authority: US
Inventors: Peter G. Panagas
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2012-02-06
Filing date: 2012-05-23
Publication date: 2013-08-08
Also published as: TWI461716B; WO2013119392A1; TWI489120B; US20130200916A1; TW201337290A; CN104204826B; CN104245248B; US20130200912A1; WO2013119393A3; WO2013119335A2; CN104245248A; WO2013119394A2; TWI502337B; CN104205784B; TW201337544A; WO2013119335A3; TW201337289A; CN104205784A; CN104204826A; CN104205786A

Abstract

A test system may be provided in which devices under test (DUTs) are loaded into test trays. Test trays may be moved between test stations using a test conveyor belt. The test system may include loading equipment for placing test trays on the test conveyor belt at desired intervals. The loading equipment may include a feed conveyor belt, tray support structure, and at least one computer-controlled grabber. Test trays may be placed on the feed conveyor belt by test personnel or automated loader. The grabber may be used to transport an incoming test tray from the feed conveyor belt to the support structure. The test tray may be temporarily docked at the support structure. The grabber may then transport the test tray from the support structure to the test conveyor belt so that the DUT on the test tray can be passed to the various test stations for testing.

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 automation, and more particularly, to automated equipment for use in manufacturing operations such as testing.
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 and the manual operations associated with performing tests at test stations 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.
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 loaded into test trays. Test trays in the test system may be tested at test stations. A test conveyor belt may be used to move test trays from one test station to another. The test system may include loading equipment for placing test trays onto the test conveyor belt at predetermined intervals.
In one suitable arrangement, the loading equipment may include a feed conveyor belt, a fixed support structure, and a computer-controlled loader. A test operator or automated test tray loader may provide test trays to the feed conveyor belt. A safety wall may be placed above the feed conveyor belt so that only a single test tray may pass between an upper surface of the feed conveyor belt and a lower surface of the safety wall at any given time. A first sensor associated with the feed conveyor belt may be used to determine when an incoming test tray is available for pickup.
The loader may be used to move an incoming test tray from the feed conveyor belt to the fixed support structure. In particular, the loader may include loader engagement features configured to mate with corresponding test tray engagement features in the test tray. A second sensor (e.g., a radio-frequency identification sensor) may be used to identify a serial number associated with each test tray being transferred from the feed conveyor belt to the fixed support structure.
The test tray may be stored temporarily on the fixed support structure. More than one test tray may be stored on the fixed support structure. Sensors associated with the fixed support structure may be used to determine whether the fixed support structure is capable of receiving additional test trays from the test conveyor belt (e.g., whether the fixed support structure has a vacant test tray spot or whether the fixed support structure is fully occupied by test trays).
The loader may be directed to move a selected test tray from the fixed support structure to the test conveyor belt. The rate at which test trays are deposited on the fixed support structure may at most be equal to the rate at which test trays are transferred from the fixed support structure to the test conveyor belt. In another suitable arrangement, the test system may include an additional computer-controlled loader that is used to move a selected test tray from the fixed support structure to the test conveyor belt.
Further features of the present invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative electronic device such as a handheld device of the type that may be manufactured using automated equipment in accordance with an embodiment of the present invention.

FIG. 2 is a schematic diagram of an illustrative electronic device with input/output devices and wireless communications circuitry 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. 4A is an exploded perspective view of an illustrative device under test, pad extender, and test tray in accordance with an embodiment of the present invention.

FIG. 4B is a perspective view of an illustrative device under test, pad extender, and test tray in accordance with an embodiment of the present invention.

FIG. 5A is a top perspective view of an illustrative test tray in accordance with an embodiment of the present invention.

FIG. 5B is a bottom perspective view of an illustrative test tray in accordance with an embodiment of the present invention.

FIG. 5C is a perspective view of an illustrative test tray in which a device under test has been mounted in accordance with an embodiment of the present invention.

FIG. 6 is a diagram of a portion of a test system in which test trays are automatically moved from a first conveyor to a pedestal and from the pedestal to a second conveyor in accordance with an embodiment of the present invention.

FIG. 7 is a top view of the first conveyor belt in showing how a test tray on the first conveyor belt may be picked up by a first device under test grabber in accordance with an embodiment of the present invention.

FIG. 8 is a cross-sectional side view of a device under test grabber arm that has engaged a mating test tray in accordance with an embodiment of the present invention.

FIG. 9 is a perspective view of a device under test grabber arm that is holding a test tray in accordance with an embodiment of the present invention.

FIGS. 10 and 11 are perspective views of a test system in which a first loader is being used to load test trays onto a pedestal while a second loader is being used to load test trays onto a conveyor from the pedestal in accordance with an embodiment of the present invention.

FIGS. 12-14 are perspective views of a test system in which a single loader is used to load test trays onto a pedestal and to load test trays onto a conveyor from the pedestal in accordance with an embodiment of the present invention.

FIG. 15 is a flow chart of illustrative steps involved in operating the test system of FIG. 6 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. 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 (DUTs). Devices under test may be provided to the test stations using a conveyor belt, using robotic arms, or using other loading equipment.
Any suitable device may be tested using 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 (i.e., 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. Port 28 may include audio input-output ports, analog input-output ports, digital data input-output ports, or other ports.
Sensors such as the sensors associated with region 26 of FIG. 1, cameras such as camera 24, 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.). For example, buttons such as button 21 may be located on a sidewall portion of housing 12.
A schematic diagram of an electronic device such as electronic device 10 is shown in FIG. 2. As shown in FIG. 2, electronic device 10 may include storage and processing circuitry 27. Storage and processing circuitry 27 may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, application specific integrated circuits, etc.
Storage and processing circuitry 27 may be used to run software on device 10, such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, storage and processing circuitry 27 may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry 27 include internet protocols, wireless local area network (WLAN) protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, cellular telephone protocols, etc.
Circuitry 27 may be configured to implement control algorithms that control the use of antennas in device 10. For example, to support antenna diversity schemes and MIMO schemes or beam forming or other multi-antenna schemes, circuitry 27 may perform signal quality monitoring operations, sensor monitoring operations, and other data gathering operations and may, in response to the gathered data, control which antenna structures within device 10 are being used to receive and process data. As an example, circuitry 27 may control which of two or more antennas is being used to receive incoming radio-frequency signals, may control which of two or more antennas is being used to transmit radio-frequency signals, may control the process of routing incoming data streams over two or more antennas in device 10 in parallel, etc.
Input/output circuitry 29 may be used to allow data to be supplied to device 10 and to allow data to be provided from device 10 to external devices. Input/output circuitry 29 may include input/output devices 31. Input/output devices 31 may include touch screens, displays without touch sensor capabilities, buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, sensors, light-emitting diodes and other status indicators, light sources, audio jacks and other audio port components, data ports, light sensors, motion sensors (accelerometers), capacitance sensors, proximity sensors, etc. A user can control the operation of device 10 by supplying commands through input/output devices 31 and may receive status information and other output from device 10 using the output resources of input/output devices 31.
Wireless communications circuitry 33 may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications).
Wireless communications circuitry 33 may include satellite navigation system receiver circuitry 35, transceiver circuitry such as transceiver circuitry 37 and 39, and antenna circuitry such as antenna circuitry 41. Satellite navigation system receiver circuitry 35 may be used to support satellite navigation services such as United States' Global Positioning System (GPS) (e.g., for receiving satellite positioning signals at 1575 MHz) and/or other satellite navigation systems.
Transceiver circuitry 37 may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and may handle the 2.4 Bluetooth® communications band. Circuitry 37 may sometimes be referred to as wireless local area network (WLAN) transceiver circuitry (to support WiFi® communications) and Bluetooth® transceiver circuitry. Circuitry 33 may use cellular telephone transceiver circuitry (sometimes referred to as cellular radio) 39 for handling wireless communications in cellular telephone bands such as bands at 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, and 2100 MHz or other cellular telephone bands of interest.
Examples of cellular telephone standards that may be supported by wireless circuitry 33 and device 10 include: the Global System for Mobile Communications (GSM) “2G” cellular telephone standard, the Evolution-Data Optimized (EVDO) cellular telephone standard, the “3G” Universal Mobile Telecommunications System (UMTS) cellular telephone standard, the “3G” Code Division Multiple Access 2000 (CDMA 2000) cellular telephone standard, and the “4G” Long Term Evolution (LTE) cellular telephone standard. Other cellular telephone standards may be used if desired. These cellular telephone standards are merely illustrative.
Wireless communications circuitry 33 may include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry 33 may include wireless circuitry for receiving radio and television signals, paging circuits, etc. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens of hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles.
Wireless communications circuitry 33 may include one or more antennas 41. Antennas 41 may be formed using any suitable antenna type. For example, antennas 41 may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, hybrids of these designs, etc. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna.
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 for performing one or more tests on device under test 10. For example, a first type of test station 36 may have equipment for testing a display in DUT 10. A second type of test station 36 may have equipment for testing an audio component in DUT 10. Yet another type of test station 36 may have equipment for testing light sensors in DUT 10. Yet another type of test station 36 may have equipment for testing wireless communications circuitry in DUT 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 DUTs 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. Device under test 10 that is mounted in test tray 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). DUT 10 may be tested using at least some of test stations 36 as DUT 10 travels down conveyor belt 38.
It may be desirable to regulate the rate at which devices under test are placed on conveyor 38 in system 30. Test system 30 may include loading equipment such as loading equipment 200 configured to place test trays 32 on conveyor belt 38 so that test trays 32 are not spaced too closely or too far apart from one another. With this type of arrangement, test tray 32 may serve as an interface between DUT 10 and loading equipment 200. Test tray 32 may, for example, be more robust than DUT 10, may have engagement features that are configured to mate with loading equipment 200, may have an identification number that facilitates tracking, and may have other features that facilitate loading of DUT 10 onto conveyor belt 38.
For example, loading equipment 200 may be provided with one or more computer-controlled positioning arms. The positioning arms in loading equipment 200 may be used in picking up a test tray (i.e., a test tray that is loaded with DUT 10) that is provided from a test operator, placing the test tray on a temporary test tray dock, picking up the test tray from the temporary test tray dock at a later point in time, and then placing the test tray on conveyor belt 38 for testing. Handling test trays 32 in this way serves to synchronize the rate at which the test operator provides test trays 32 to loading equipment 200 with the rate at which the automated positioning arms in loading equipment 200 place test trays 32 on conveyor belt 38 for optimal test throughput.
Using the system of FIG. 3, an operator may place test trays 32 on a feed conveyor belt that is part of loading equipment 200. Test trays 32 may be sequentially loaded onto conveyor belt 38 at predetermined time intervals so that DUT 10 on each test tray 32 can be tested using test stations 36. After testing, test trays 32 may be picked up at the end of conveyor 38 by another operator. The test trays that are retrieved from the end of conveyor 38 may, as an example, be placed in a test tray cart or may be fed into additional systems.
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 controlling the rate at which loading equipment 200 loads test trays onto conveyor belt 38 (e.g., by sending commands via path 41), may be used in sending test commands to test stations 36 (e.g., by sending commands via path 43), may track individual trays and devices under test as the trays and devices pass through system 30, and may perform other control operations.
FIG. 4A is a diagram showing how device under test 10 may be received within test tray 32. As shown in FIG. 4A, test tray 32 may have sidewalls 100 that are configured to receive a device under test such as DUT 10. Device under test 10 may have one or more connector ports such as port 28 (see, e.g., FIG. 1).
A pad extender such as pad extender 144 may have a mating connector such as plug 146. Plug 146 may be configured to mate with a connector in port 28 when DUT 10 has been mounted in test tray 32 and when pad extender 144 has been moved towards DUT 10 in direction 148.
Following insertion of DUT 10 into test tray 32 and following insertion of plug connector 146 of pad extender 144 into connector 28 of DUT 10, test tray 32 of FIG. 4A may appear as shown in FIG. 4B. Pad extender 144 may contain signal paths that connect pins in connector 28 to corresponding contacts 62 on pad extender 144. Contacts 62 may be configured to mate with corresponding contacts coupled to tester 44 and/or test host 42 during testing in system 30.
Because DUT 10 is connected to test contacts 62 in test tray 32 using pad extender 144 associated with test tray 32, it is not necessary to repeatedly connect and disconnect device under test 10 from cabling at each test station 36. Rather, connections between DUT 10 and the test equipment at each test station 36 by may be formed by coupling contacts 62 in test tray 32 to corresponding contacts (e.g., spring-loaded pins) in each test station 36. 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.
The use of test tray 32 and loader 46 may allow DUT 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. In general, DUT 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 the base of test tray 32.
FIG. 5A is a perspective view of one suitable embodiment of test tray 32. Tray 32 may be formed using non-marring material such as acetyl plastic, Delrin® (a polyoxymethylene plastic), other plastics, or other suitable non-marring materials. The use of non-marring materials may help avoid scratches or other damage to DUT 10 when DUT 10 is placed within test tray 32. In the example of FIG. 5A, a layer of material 156 may be formed to line the base of recess 154. As an example, material 156 may be formed using the same material that is used to form tray 32. As another example, material 156 may be formed using elastomeric material such as rubberized foam. Material 156 may, in general, be formed using any suitable non-marring material.
Test tray 32 may be provided with guide structures configured to accurately place device under test 10 in a desired location within a recess 154 in tray 32. As shown in FIG. 5A, a guide structure on the end of tray 32 may have an exposed end guide surface such as guide surface 152. Guide structures on the side of tray 32 may have exposed side guide surfaces such as guide surfaces 150.
FIG. 5C is a perspective view of test tray 32 after a device under test has been inserted into test tray 32. As shown in FIG. 5C, test tray 32 may have clamps 162 for holding device under test 10 within test tray 32. The inner surfaces of clamps 162 may serve as guide surfaces 150 (FIG. 5A).
Test tray 32 may also include engagement features such as holes 160 formed on both ends of tray 32 (see, e.g., top perspective view of tray 32 in FIG. 5A and bottom perspective view of tray 32 in FIG. 5B). Holes such as holes 160 in test tray 32 or other engagement features may be configured to mate with corresponding engagement features on automated loading equipment such as equipment 200 for loading test trays onto conveyor belt 38 and loading equipment in each test station 36 for picking up an incoming test tray for testing. For example, holes 160 may be configured to receive corresponding pins from at least one robotic arm in loading equipment 200. The example of FIG. 5A, 5B, and 5C in which tray 32 includes eight holes for engaging with automated loading equipment is merely illustrative. If desired, tray 32 may include at least four holes, at least six holes, at least ten holes, etc.
FIG. 6 is a diagram showing one suitable configuration of loading equipment 200. As shown in FIG. 6, loading equipment 200 may include a feed conveyor belt 270, a fixed test tray support fixture (sometimes referred to herein as a temporary test tray dock or “pedestal”) 282, and loaders such as loaders 280 and 284.
Initially, a test system operator or automated loading equipment may place devices in test trays 32 onto conveyor belt 270 at location 290. Safety wall 268 may prevent the operator or automated loading equipment from placing test tray 32 farther along conveyor 270. The height H of safety wall 268 may be configured so that only a single test tray 32 can pass between the upper surface of conveyor belt 270 and the lower surface of safety wall 268 at a time. The presence of safety wall 268 may therefore be used to ensure that there is only one layer of test trays 32 on conveyor 270. The speed of conveyor 270 may be computer controlled (if desired). Light sensor 272 may be used to monitor the flow of test trays 32 on conveyor 270. For example, conveyor 270 may run continuously until sensor 272 detects the presence of a test tray, at which point conveyor 270 may be temporarily halted to await unloading using loader 280. If desired, a tray stop structure such as tray stop structure 400 may be placed at an end of conveyor 270 for guiding the test tray to a desired position for pickup.
Loader 280 may be used to pick up test tray 32 from conveyor 270. Loader 280 may include a computer-controlled positioner such as positioner 274 and a grabber head such as grabber 276 that is positioned by positioner 274. Positioner 274 may be controlled using commands sent from test host 42 over path 41. Grabber 276 may contain computer-controlled actuators and engagement features such as pins that mate with corresponding engagement features such as holes 160 in test tray 32. Loader 280 may be used to move test trays 32 from conveyor belt 270 to pedestal 282.
As test tray 32 is being moved from conveyor 270 to pedestal 282, a sensor such as sensor 273 may be used to identify the test tray. For example, sensor 202 may be a radio-frequency identification (RFID) sensor configured to identify a serial number associated with the incoming tray 32 and may forward the identified serial number to test host 42 via path 41. Operated in this way, test host 42 may be used to keep track of each test tray 32 that is provided to test system 30 for testing.
Loader 280 may be configured to place an incoming test tray onto one of multiple possible locations on pedestal 282. In the example of FIG. 6, pedestal 282 includes first, second, and third regions on which test trays 32 may be placed. Light-based sensors such as sensors 283-1, 283-2, and 283-3 may be used to detect whether each of the three regions is currently vacant. In particular, sensor 283-1 may be used to determine whether a test tray is currently placed on the first region of pedestal 282; sensor 283-2 may be used to determine whether a test tray is currently placed on the second region of pedestal 282; and sensor 283-3 may be used to determine whether a test tray is currently placed on the third region of pedestal 282. Loader 280 may be configured to place the incoming test tray onto a vacant region on pedestal 282. If all the regions on pedestal 282 are occupied, loader 280 may wait until at least one region on pedestal 282 becomes available.
Loader 284 may be used to unload pedestal 282 (e.g., to move test trays 32 from pedestal 282 to conveyor 38). Loader 284 may include computer-controlled positioner 286 and a grabber head such as grabber 288 that is positioned by positioner 286. Positioner 286 may be controlled using commands sent from test host 42 over path 41. Grabber 288 may also contain computer-controlled actuators for grasping test trays 32 (e.g., grabber 288 may also include engagement features such as pins that mate with corresponding holes 160 in test tray 32).
The speed of conveyor 38 is preferably fixed. At even time intervals (e.g., every 15 seconds plus or minus an allowed variation of a few seconds), loader 284 may move a selected one of test trays 32 from pedestal 282 to end position 292 of conveyor belt 38, thereby ensuring that test trays 32 are evenly spaced at a desired distance D from each other along the surface of conveyor belt 38. Conveyor belt 38 may be used to convey test trays 32 to test stations 36 in test system 30 for testing.
Pedestal 282 used as such may therefore serve as an input buffer for test system 30. In general, the rate at which test trays are being transferred from conveyor 270 to pedestal 282 is at least equal to or greater than the rate at which test trays are being transferred from pedestal 282 onto conveyor 38. This ensures that there is at least one test tray on pedestal 282 at any given point in time available to be moved onto conveyor 38 for optimal test throughput. The example of FIG. 6 in which pedestal 282 provides three possible regions on which test trays can be placed is merely illustrative. In other suitable arrangements, pedestal 282 may provide at least one test tray region, at least two test tray regions, at least four test tray regions, etc. Any suitable number of light-based sensors may be used to facilitate detection of test trays on the different test tray regions.
Each of grabbers 276 and 288 may include a contractible member such as member 402 that can be actuated using air-driven or motor-driven actuators. FIG. 7 is a top view of an end portion of conveyor 270 in test system 30. Initially, DUT 10 and test tray 32 may be located on the left hand side of conveyor belt 270. As conveyor belt 270 moves to the right, DUT 10 and test tray 32 may make physical contact with corresponding guide surfaces of tray stop structure 400 (e.g., tray stop structure 400 may help horizontally situate test tray 32 on the top surface of conveyor 270 so that grabber 276 can properly engage with test tray 32). Grabber 276 may have engagement features such as pins 404 for mating with holes 160 in test tray 32.
When test tray 32 is ready to be picked up, grabber 276 may be lowered to a pick-up position so that pins 404 are aligned with test tray holes 160. Initially, pins 404 may be held in a retracted position. After pins 404 and holes 160 are aligned, actuators such as actuators 406 may be used to extend pins 404 into holes 160 (see, e.g., perspective view of FIG. 9). Once grabber 276 has grasped test tray 32 in this way, grabber 276 may deliver test tray 32 to pedestal 282.
FIG. 8 is a cross-sectional end view of grabber 276 showing how actuators may insert pins 404 into holes 160 in test tray 32 so that test tray 32 may be picked up from conveyor belt 270. As with grabber 276, grabber 288 may similarly be configured to grasp test tray 32 when transporting test tray 32 from pedestal 282 to conveyor belt (e.g., using actuator-driven pins 404 to engage with holes 160 on test tray 32).
As shown in FIG. 10, loader 280 may include a horizontally extending rail such as rail 300 and a vertically extending rail such as rail 302. Grabber 276 may travel up and down vertical rail 302 along vertical axis Y. Vertical rail 302 may move laterally along rail 300 along horizontal axis X. Loader 284 may likewise include horizontal and vertical rails. Grabber 288 may move up and down vertical rail 306. Rail 306 may move laterally along rail 304.
In the configuration shown in FIG. 10, loader 280 is being used to pick up a test tray from conveyor 270 to deposit on pedestal 282, whereas loader 284 is being used to deposit a test tray that was picked up from pedestal 282 on conveyor 38. In the configuration shown in FIG. 11, loader 280 is using grabber 276 to deposit a test tray on pedestal 282, whereas loader 284 is being used to pick up a test tray from pedestal 282 that is to be moved to conveyor 38.
The arrangement of FIGS. 6, 10, and 11 in which loading equipment 200 includes two loaders 280 and 284 is merely illustrative and does not serve to limit the scope of the present invention. If desired, loading equipment 200 may include a single loader 280 that can be used to transport test trays from conveyor 270 to pedestal 282 and to transport test trays from pedestal 282 to conveyor 38 (see, e.g., FIGS. 12, 13, and 14). As shown in FIG. 12, loader 280 may include a horizontal rail such as rail 300 that extends from the end portion of feed conveyor 270 to a leading portion of conveyor 38. Loader 280 may also include a vertically extending rail such as rail 302 that can travel along rail 300 (parallel to axis X). Grabber 276 may travel up and down vertical rail 302 along vertical axis Y.
In the configuration shown in FIG. 12, loader 280 is being used to pick up a test tray from conveyor 270 to deposit on pedestal 282. In the configuration shown in FIG. 13, loader 280 is using grabber 276 to deposit a test tray on pedestal 282. In the configuration shown in FIG. 14, loader 280 is using grabber 276 to deposit a test tray that has been picked up from pedestal 282 on conveyor 38.
Pedestal 282 as shown in FIGS. 10-14 having five possible regions for receiving test trays is merely illustrative. In general, pedestal 282 may include any number of test tray receiving regions, and any number of loaders and associated grabbers may be used to transport test trays from feed conveyor 270 to pedestal 282 and from pedestal 282 to test conveyor 38.
A flow chart of illustrative steps involved in using system 30 of FIG. 6 is shown in FIG. 15. At step 310, an operator or automated loading equipment may place one of test trays 32 on feed conveyor 270. Conveyor 270 may move test tray 32 until sensor 272 detects the presence of test tray 32. Once sensor 272 detects test tray 32 (step 312), conveyor 270 may be momentarily halted.
At step 314, grabber head 276 of loader 280 may be positioned over test tray 32. At step 316, grabber head 276 may be used to grab test tray 32.
At step 318, positioner 280 may move test tray 32 from conveyor 270 to pedestal 282. At step 320, positioner 280 may release test tray 32 on pedestal 282. Once the test tray has been transferred from conveyor 270 to pedestal 282 in this way, another test tray may be moved into position under sensor 272 using conveyor 270 (step 322).
As the test tray loading process of steps 310, 312, 314, 316, 318, 320, and 322 is being performed to load test trays onto pedestal 282, loader 284 may be independently used to transfer test trays 32 from pedestal 282 to conveyor 38 (step 324). In particular, loader 284 may, in response to control commands from a computer, move test trays 32 one at a time from pedestal 282 and to conveyor 38, depositing test trays 32 on conveyor 38 at desired time intervals (e.g., at a fixed time period of about 3 seconds). By loading test trays 32 onto conveyor 38 at fixed time intervals, the spacing D between adjacent test trays may be controlled (e.g., so that D has a fixed value of about 1 m). If desired, loader 280 may also be used to move test trays 32 from pedestal 282 to conveyor 38 in response to control commands from test host 42 (e.g., second loader 284 need not be used).
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. The foregoing embodiments may be implemented individually or in any combination.

Claims

What is claimed is:

1. A method for operating a test system that is used to test a plurality of electronic devices, wherein the test system includes a first conveyor belt, a second conveyor belt, and a fixed support structure, the method comprising:

moving the plurality of electronic devices from the first conveyor belt to the fixed support structure at a first rate;

moving the plurality of electronic devices from the fixed support structure to the second conveyor belt at a second rate that is at most equal to the first rate; and

with test equipment stationed along the second conveyor belt, testing the plurality of electronic devices.

2. The method defined in claim 1, wherein the plurality of electronic devices comprises a plurality of handheld electronic devices.

3. The method defined in claim 1, wherein the second rate is less than the first rate.

4. The method defined in claim 1, wherein the test system further includes a computer-controlled loader, wherein moving the plurality of electronic devices from the first conveyor belt to the fixed support structure comprises moving the plurality of electronic devices from the first conveyor belt to the fixed support structure with the computer-controlled loader, and wherein moving the plurality of electronic devices from the fixed support structure to the second conveyor belt comprises moving the plurality of electronic devices from the fixed support structure to the second conveyor belt with the computer-controlled loader.

5. The method defined in claim 1, wherein the test system further includes first and second computer-controlled loaders, wherein moving the plurality of electronic devices from the first conveyor belt to the fixed support structure comprises moving the plurality of electronic devices from the first conveyor belt to the fixed support structure with the first computer-controlled loader, and wherein moving the plurality of electronic devices from the fixed support structure to the second conveyor belt comprises moving the plurality of electronic devices from the fixed support structure to the second conveyor belt with the second computer-controlled loader.

6. The method defined in claim 5, further comprising:

installing the plurality of electronic devices within respective test trays, wherein the test trays include test tray engagement features, and wherein the computer-controlled loader includes loader engagement features configured to engage with the test tray engagement features;

with a first sensor associated with the first conveyor belt, detecting whether an incoming electronic device in the plurality of electronic devices is available to be moved from the first conveyor belt to the fixed support structure by the first computer-controlled loader; and

with a second sensor, identifying a serial number associated with each test tray that is being moved from the first conveyor belt to the fixed support structure by the second computer-controlled loader.

7. The method defined in claim 4, further comprising:

installing the plurality of electronic devices within respective test trays, wherein the test trays include test tray engagement features, and wherein the computer-controlled loader includes loader engagement features configured to engage with the test tray engagement features.

8. The method defined in claim 7, wherein the test tray engagement features comprise holes, and wherein the loader engagement features comprise pins.

9. The method defined in claim 1, further comprising:

with sensors associated with the fixed support structure, detecting whether or not the fixed support structure is capable of receiving electronic devices from the first conveyor belt.

10. The method defined in claim 1, further comprising:

with a sensor associated with the first conveyor belt, detecting whether an incoming electronic device in the plurality of electronic devices is available to be moved from the first conveyor belt to the fixed support structure.

11. The method defined in claim 7, further comprising:

with a radio-frequency identification sensor, identifying a serial number associated with each test tray that is being moved from the first conveyor belt to the fixed support structure.

12. A method for operating a test system that is used to test a plurality of electronic devices, wherein the test system includes a test conveyor belt, a fixed support structure, and a loader, the method comprising:

with the fixed support structure, receiving the plurality of electronic devices;

with the loader, transferring the plurality of electronic devices from the fixed support structure to the test conveyor belt at predetermined time intervals; and

with test equipment stationed along the test conveyor belt, testing the plurality of electronic devices.

13. The method defined in claim 12, wherein the test system further includes a feed conveyor belt, the method further comprising:

with the feed conveyor belt, sequentially receiving the plurality of electronic devices; and

with the loader, transferring the received plurality of electronic devices from the feed conveyor belt to the fixed support structure one at a time.

14. The method defined in claim 12, wherein the test system further includes an additional loader and a feed conveyor belt, the method further comprising:

with the additional loader, transferring the received plurality of electronic devices from the feed conveyor belt to the fixed support structure one at a time.

15. The method defined in claim 12, further comprising:

installing the plurality of electronic devices within respective test trays, wherein the test trays include test tray engagement features.

16. The method defined in claim 15, wherein the loader comprises a computer-controlled positioner that controls a grabber, and wherein transferring the plurality of electronic devices from the fixed support structure to the test conveyor belt comprises:

with the grabber, picking up a selected test tray from the fixed support structure by engaging grabber engagement features of the grabber with the test tray engagement features of the selected test tray;

while the grabber engagement features are engaged with the test tray engagement features, transporting the selected test tray from the fixed support structure to the test conveyor belt; and

with the grabber, depositing the selected test tray on the test conveyor belt by disengaging the grabber engagement features of the grabber from the test tray engagement features of the selected test tray.

17. A test system, comprising:

a first conveyor belt configured to receive a plurality of devices under test;

a fixed support structure configured to receive the plurality of devices under test from the first conveyor belt;

a second conveyor belt; and

a loader that is configured to move the devices under test from the fixed support structure to the second conveyor belt at fixed time intervals.

18. The test system defined in claim 17, wherein the loader is further configured to move the plurality of devices under test from the first conveyor belt to the fixed support structure.

19. The test system defined in claim 17, further comprising:

an additional loader that is configured to move the plurality of devices under test from the first conveyor belt to the fixed support structure.

20. The test system defined in claim 17, further comprising:

a plurality of test trays each of which is configured to house a device under tester in the plurality of devices under test; and

a safety wall positioned over the first conveyor belt, wherein the safety wall is configured so that only a single test tray can pass between an upper surface of first conveyor belt and a lower surface of the safety wall at any given time.