Test System with Test Trays and Automated Test Tray Handling

Abstract

A test system may be provided in which devices under test (DUTs) are loaded into test trays. Test trays may be tested at test stations. Test trays may be moved between test stations using a conveyor belt system. Each test station may include test equipment for testing DUTs and automated loading equipment for latching incoming test trays moving along the conveyor belt. The automated loading equipment may include a first movable arm configured to pick up a test tray from the conveyor belt and a second movable arm. The first arm may hand off (transfer) the test tray to the second arm. The second arm may move the test tray towards associated test equipment for testing. Upon completion of testing, the second arm may drop off the test tray onto the conveyor belt. Multiple layers of test stations may be stacked on top of each other for improved test throughput.

What is claimed is: 
     
         1 . A method for using a test system to test a device under test, wherein the test system includes a conveyor belt, loading equipment, and test equipment, the method comprising:
 with a first arm in the loading equipment, picking up the device under test from the conveyor belt;   handing off the device under test from the first arm to a second arm in the loading equipment; and   with the second arm, moving the device under test towards the test equipment so that the device under test is tested using the test equipment.   
     
     
         2 . The method defined in  claim 1 , wherein the device under test is placed within a test tray, and wherein picking up the device under test comprises picking up the test tray from the conveyor belt with the first arm. 
     
     
         3 . The method defined in  claim 1 , further comprising:
 when the test equipment has completed testing the device under test, dropping off the device under test onto the conveyor belt with the second arm.   
     
     
         4 . The method defined in  claim 1 , wherein the device under test is placed within a test tray having first and second test tray engagement features, wherein the first arm includes first arm engagement features, and wherein picking up the device under test comprises mating the first arm engagement features with the first test tray engagement features to secure the test tray within the first arm. 
     
     
         5 . The method defined in  claim 4 , wherein the second arm includes second arm engagement features, and wherein handing off the device under test from the first arm to the second arm comprises:
 while the first arm engagement features are mated with the first test tray engagement features, mating the second arm engagement features with the second test tray engagement features to secure the test tray within the second arm; and   while the second arm engagement features are mated with the second test tray engagement features, disengaging the first arm engagement features from the first test tray engagement features.   
     
     
         6 . The method defined in  claim 5 , wherein the first and second arm engagement features comprises pins, wherein the first and second test tray engagement features comprise holes, wherein mating the first arm engagement features with the first test tray engagement features comprises inserting pins in the first arm into corresponding holes in the test tray, and wherein mating the second arm engagement features with the second test tray engagement features comprises inserting pins in the second arm into corresponding holes in the test tray. 
     
     
         7 . The method defined in  claim 1 , wherein the loading equipment comprises computer-controlled positioning equipment configured to move the first and second arms along three different axes. 
     
     
         8 . The method defined in  claim 1 , wherein the loading equipment comprises a screw-based lifting mechanism for raising and lowering the first and second arms with respect to the conveyor belt. 
     
     
         9 . A method for using a test system to test a device under test, wherein the test system includes a conveyor belt, loading equipment, a first sensor, and a second sensor, the method comprising:
 with the first sensor, detecting an incoming device under test on the conveyor belt;   in response to detection of the device under test, lowering a first arm in the loading equipment to receive the incoming device under test;   with the second sensor, detecting whether the device under test has been successfully received by the first arm; and   in response to detecting that the device under test has been successfully received by the first arm, latching onto the device under test and lifting the device under test from the conveyor belt with the first arm.   
     
     
         10 . The method defined in  claim 9 , further comprising:
 transferring the device under test from the first arm to a second arm in the loading equipment.   
     
     
         11 . The method defined in  claim 10 , wherein test system further includes test equipment, the method further comprising:
 with the second arm, moving the device under test towards the test equipment so that desired testing can be performed on the device under test using the test equipment.   
     
     
         12 . The method defined in  claim 9 , wherein the device under test is placed within a test tray having test tray engagement features, wherein the first arm includes arm engagement features, and wherein lowering the first arm to receive the incoming device under test comprises lowering the first arm to a position that allows the arm engagement features of the first arm to mate with the test tray engagement features. 
     
     
         13 . The method defined in  claim 9 , wherein the device under test is placed within a test tray, wherein the first sensor comprises a radio-frequency identification sensor, and wherein detecting the incoming device under test on the conveyor belt comprises identifying a serial number associated with the test tray with the radio-frequency identification sensor. 
     
     
         14 . The method defined in  claim 9 , wherein the second sensor comprises a laser-based distance sensor, and wherein detecting whether the device under test has been successfully received by the first arm comprises detecting whether the device under test has been successfully received by the first arm with the laser-based distance sensor. 
     
     
         15 . A test system configured to test a plurality of devices under test, comprising:
 a first layer of test stations;   a first conveyor belt configured to convey devices under test past the test stations in the first layer;   a second layer of test stations on top of the first layer of test stations; and   a second conveyor belt configured to convey devices under test past the test stations in the second layer.   
     
     
         16 . The test system defined in  claim 15 , wherein at least one test station in the first layer comprises:
 test equipment; and   loading equipment that is configured to pick-up a device under test in the plurality of devices under test from the first conveyor belt and that is configured to move the device under test towards the test equipment so that the device under test can be tested using the test equipment.   
     
     
         17 . The test system defined in  claim 15 , wherein at least one test station in the second layer comprises:
 test equipment; and   loading equipment that is configured to pick-up a device under test in the plurality of devices under test from the second conveyor belt and that is configured to move the device under test towards the test equipment so that the device under test can be tested using the test equipment.   
     
     
         18 . The test system defined in  claim 15 , wherein the plurality of devices under test comprises a plurality of wireless handheld electronic devices under test. 
     
     
         19 . The test system defined in  claim 15 , wherein each device under test in the plurality of devices under test is mounted within a respective test tray. 
     
     
         20 . The test system defined in  claim 15  wherein each test station in the first and second layers comprises:
 loading equipment having a first arm for latching onto a test tray in which an incoming device under test is mounted and a second arm for receiving the test tray from the first arm; and 
 test equipment configured to test the incoming device under test, wherein the second arm is configured to move the test tray towards the test equipment after receiving the test tray from the first arm.