Abstract: A burn-in and electrical test system (20) includes a temperature controlled zone (22) and a cool zone (24) separated by a transition zone 25. The temperature controlled zone (22) is configured to receive a plurality of wafer cartridges (26) and connect the cartridges (26) to test electronics (28) and power electronics (30), which are mounted in the cool zone (24). Each of the wafer cartridges (26) contains a semiconductor wafer incorporating a plurality of integrated circuits. The test electronics (28) consists of a pattern generator PCB (100) and a signal driver and fault analysis PCB (102) connected together by a parallel bus (104). The pattern generator PCB (100) and the fault analysis PCB (102) are connected to a rigid signal probe PCB (104) in cartridge (26) to provide a straight through signal path.

Abstract: A cartridge (10) includes a chuck plate (12) for receiving a wafer (74) and a probe plate (14) for establishing electrical contact with the wafer. In use, a mechanical connecting device (90) locks the chuck plate and the probe plate fixed relative to one another to maintain alignment of the wafer and the probe plate. Preferably, electrical contact with the wafer is established using a probe card (50) that is movably mounted to the probe plate by means of a plurality of leaf springs (52). The mechanical connecting device is preferably a kinematic coupling including a male connector (94) and first and second opposed jaws (122, 124). The cartridge can then be removed from the alignment device and placed in a burn-in or test chamber that does not itself require means for aligning the wafer or for providing a probing force.

Abstract: A burn-in and electrical test system (20) includes a temperature controlled zone (22) and a cool zone (24) separated by a transition zone 25. The temperature controlled zone (22) is configured to receive a plurality of wafer cartridges (26) and connect the cartridges (26) to test electronics (28) and power electronics (30), which are mounted in the cool zone (24). Each of the wafer cartridges (26) contains a semiconductor wafer incorporating a plurality of integrated circuits. The test electronics (28) consists of a pattern generator PCB (100) and a signal driver and fault analysis PCB (102) connected together by a parallel bus (104). The pattern generator PCB (100) and the fault analysis PCB (102) are connected to a rigid signal probe PCB (104) in cartridge (26) to provide a straight through signal path.

Abstract: A cartridge (10) includes a chuck plate (12) for receiving a wafer (74) and a probe plate (14) for establishing electrical contact with the wafer. In use, a mechanical connecting device (90) locks the chuck plate and the probe plate fixed relative to one another to maintain alignment of the wafer and the probe plate. Preferably, electrical contact with the wafer is established using a probe card (50) that is movably mounted to the probe plate by means of a plurality of leaf springs (52.) The mechanical connecting device is preferably a kinematic coupling including a male connector (94) and first and second opposed jaws (122, 124.) Each of the jaws is pivotable from a retracted position in which the male connector can be inserted between the jaws and an engaging position in which the jaws prevent withdrawal of the male connector from between the jaws. The male connector is movable between an extended and a retracted position, and is biased towards the retracted position.

Abstract: A kinematic coupling includes a male connector (94) and first and second opposed jaws (122, 124.) Each of the jaws is pivotable from a retracted position in which the male connector can be inserted between the jaws and an engaging position in which the jaws prevent withdrawal of the male connector from between the jaws. The male connector is movable between an extended and a retracted position, and is biased towards the retracted position. This provides a positive clamping force when the kinematic coupling is engaged.

Abstract: A cartridge (10) includes a chuck plate (12) for receiving a wafer (74) and a probe plate (14) for establishing electrical contact with the wafer. In use, a mechanical connecting device (90) locks the chuck plate and the probe plate fixed relative to one another to maintain alignment of the wafer and the probe plate. Preferably, electrical contact with the wafer is established using a probe card (50) that is movably mounted to the probe plate by means of a plurality of leaf springs (52.) The mechanical connecting device is preferably a kinematic coupling including a male connector (94) and first and second opposed jaws (122, 124.) Each of the jaws is pivotable from a retracted position in which the male connector can be inserted between the jaws and an engaging position in which the jaws prevent withdrawal of the male connector from between the jaws. The male connector is movable between an extended and a retracted position, and is biased towards the retracted position.

Abstract: A system for testing semiconductor devices on device test boards has a single tester channel connected to multiple DUTs in a loop. Outputs from DUTs are received at a comparator and latch after a period of Round Trip Delay (RTD). The comparator is connected in a parallel configuration with the return path of the loop, where the point of connection is in greater proximity to DUT output pins than the test channel and is a path different from the tester I/O driver path, thus preventing input signals from test drivers from interfering with output signals from DUTs that will serve as inputs to test circuitry. The time it takes a new input cycle state to reach the output comparator is long after the output from a prior cycle has been tested. A diode clamp and resistor are connected in a series with the comparator at the input stage near the comparator in order to reduce ringing at the input of the comparator, which limits tester speed.

Abstract: A kinematic coupling includes a male connector (94) and first and second opposed jaws (122, 124.) Each of the jaws is pivotable from a retracted position in which the male connector can be inserted between the jaws and an engaging position in which the jaws prevent withdrawal of the male connector from between the jaws. The male connector is movable between an extended and a retracted position, and is biased towards the retracted position. This provides a positive clamping force when the kinematic coupling is engaged.

Abstract: A thermal chuck or heat sink (10) has a lower surface (12) covered with fins (14) parallel to air flow (16), to increase the surface area and promote heat transfer. A pair of slots (32) near pedestal (20) (along the fins) effectively lowers the conductivity of the metal in the direction across the fins. Heat flowing through this region of lowered conductivity experiences a greater temperature drop. This raises the temperature at the adjacent parts of the top surface, and (for properly sized slots) results in circular isotherms. The circular isotherms are turned into a nearly isothermal surface by a precisely dimensioned groove (36) parallel to the top surface (22), extending around the circumference of the pedestal (20). Heat flowing into the outer regions of the circular surface (22) is forced to travel radially inward, thus raising the edge temperature (which would naturally be lower than the center).

Abstract: A reusable carrier 10 for temporarily holding an integrated circuit 12 during burn-in and electrical test includes a base 14 and a lid 16 attached to the base 14 by hinges 18. A flexible substrate 19 is attached to the base 14. Alignment posts 20 have tapered surfaces 22 that engage corners 24 of the integrated circuit 12 to position the integrated circuit 12 precisely on upper surface 26 of the substrate 19. A spring-loaded latch 28 engages projection 30 in aperture 32 of the base 14 to hold the lid 16 closed over the integrated circuit 12. Electrically conductive traces 34 on the surface 26 have contact bumps which engage contact pads on the underside of the integrated circuit 12 to connect the integrated circuit 12 to peripheral contact pads 38 around edges 40 of the substrate 19.

Abstract: A novel system and method for testing semiconductor devices has a pattern generator implementing a test signal algorithm uniquely coupled with a recording system which is an individual hardware system for each device under test. The improved pattern generator and recording system functions in conjunction with a system designed to perform parallel test and burn-in of semiconductor devices, such as the Aehr Test MTX System. The MTX can functionally test large quantities of semiconductor devices in parallel. It can also compensate for the appropriate round trip delay value for each chip select state for each device under test. This system of testing provides an effective and practical method for reducing overall test cost without sacrificing quality.

Abstract: A reusable carrier (10) for temporarily holding an integrated circuit (12) during burn-in and electrical test includes a base (14) and a lid (16) attached to the base (14) by hinges (18). A flexible substrate (19) is attached to the base (14) with a suitable adhesive. Alignment posts (20) have tapered surfaces (22) that engage corners (24) of the integrated circuit (12) to position the integrated circuit (12) precisely on upper surface (26) of the substrate (19). A spring-loaded latch (28) engages projection (30) in aperture (32) of the base (14) to hold the lid (16) closed over the integrated circuit (12). Electrically conductive traces (34) on the surface (26) have contact bumps which engage contact pads on the underside of the circuit (12) to connect the integrated circuit (12) to peripheral contact pads (38) around edges (40) of the substrate (19).

Abstract: A high density interconnect system (30) employs contact fingers (32) on both surfaces (34) and (36) of burn-in PCB (38), feed-through PCB (40) and driver PCB (42). Each of the PCBs (38), (40) and (42) has a card-edge connector (44), (46) and (48). The feed-through PCB (40) has a second card-edge connector (40) and a second set of contact fingers (32), since it mates with both the burn-in PCB (38) and the driver PCB (42). The contact fingers (32) and the card-edge connectors (44), (46), (48) and (50) of each PCB (38), (40) and (42) mate inversely with each other on adjacent PCBs, i.e., the card-edge connector (44) of the burn-in PCB (38) mates with the contact fingers (32) of the feed-through PCB (40), and the card-edge connector (46) of the feed-through PCB (40) mates with the contact fingers (32) of the burn-in PCB (38), for example.

Abstract: A printed circuit board loader and unloader in which a printed circuit board carrier is horizontally translationally moved in a straight line along a first axis and a pick and place head unit is horizontally translationally moved above the carrier in a straight horizontal line along a second axis perpendicular to the first axis. A device stager holds a tube containing integrated circuit devices fed to it by a tube transporter. In a straight path from the opening of the tube facing the carrier is a slideway operatively connected with the tube holder. The slideway has gating and device fixing vacuum ports. The device stager is pivotable to (i) a pivot down position to slide devices from the tube onto the slideway and vacuum arrest and gate them, (ii) a pivot level position in which the devices are picked up from over the forward ports on the slideway, and (iii) a pivot up position which devices slide from the forward portion of the slideway into a tube in the tube holder of the device stager.