Electronic tester

Abstract

A test apparatus is described. Various components facilitate testing the functionality of the device, including insertion and removal of the device, thermal columns, independent universal joints, combinations including photodetectors, thermal control methods, detection circuitry in the socket cover, standoff, and voltage redirection.

Description

[0001] This application is a divisional application of divisional application 202210265243.2 of Chinese patent application with application number 201880015746.6, application date February 27, 2018, and title "Electronic Tester".

[0002] Cross - reference to related applications

[0003] This application claims the priority of U.S. Provisional Patent Application No. 62 / 466,462 filed on March 3, 2017 and U.S. Patent Application No. 62 / 526,089 filed on June 28, 2017, the entire contents of which are incorporated herein by reference. Technical field

[0004] The present invention relates to a test device for testing microelectronic circuits. Background art

[0005] Microelectronic circuits are typically fabricated in and on semiconductor wafers. Subsequently, such wafers are "singulated" or "diced" into individual die. Such die are typically mounted on a support substrate to provide rigidity to the support substrate and to enable electrical communication with the integrated or microelectronic circuits of the die. Final packaging may include encapsulation of the die, and the resulting package can then be shipped to a customer.

[0006] The die or package need to be tested before being shipped to a customer. Ideally, the die should be tested at an early stage to identify defects that occur during the early manufacturing process.

[0007] Wafer - level testing can be achieved by providing a processor with contacts and a contactor, and then using the processor to move the wafer so that the contacts on the wafer contact the contacts on the contactor. Power and electrical signals can then be provided to the microelectronic circuits formed in the wafer through the contactor.

[0008] According to various embodiments, a wafer includes a substrate (such as a silicon substrate or a substrate of a printed circuit board) and one or more devices fabricated in or mounted to the substrate.

[0009] Optionally, the wafer can be located in a portable cassette having an electrical interface and a thermal chuck. Power and signals can be provided to the wafer through the electrical interface, while the temperature of the wafer can be thermally controlled by heating or cooling the thermal chuck.

[0010] After the wafer is singulated, it may be necessary to test the individual die again, and it may also be necessary to test the die after mounting the die on the support substrate. Summary of the invention

[0011] The present invention provides a testing device, the testing device comprising: a frame; a slot component, the slot component being provided on the frame; a slot component interface, the slot component interface being provided on the slot component; a holding structure for placing and holding a cassette of a plurality of microelectronic devices; a horizontal conveying device operable to horizontally move the cassette from a first position to a second position to enter the slot component; a vertical conveying device operable to move the cassette and the slot component relative to each other in a first vertical direction to engage the slot component interface with a cassette interface on the cassette; and a tester connected through a first slot component interface and the cassette interface to supply power to at least each microelectronic device to measure the performance of the microelectronic device, the vertical transmission device being operable to move the cassette and the slot component relative to each other in a second vertical direction opposite to the first vertical direction to disengage the slot component interface from the cassette interface, and the horizontal conveying device being operable to horizontally move the cassette from the second position to the first position outside the slot component.

[0012] The present invention also provides a method for testing electronic devices, comprising: holding a cassette of a plurality of microelectronic devices at a first position, at least partially outside a slot component on a frame, horizontally moving the cassette from the first position to a second position to enter the slot component, moving the cassette and the slot component relative to each other in a first vertical direction to engage a slot component interface on the slot component with a cassette interface on the cassette, supplying power to at least each microelectronic device through the first slot component interface and the cassette interface to test the microelectronic device and measure the performance of the microelectronic device, moving the cassette and the slot component relative to each other in a second vertical direction opposite to the first vertical direction to disengage the slot component interface from the cassette interface, and horizontally moving the cassette from the second position to the first position to remove it from the slot component.

[0013] The present invention also provides a cassette, comprising: a socket made of an insulating material and having an upper side and a lower side, the upper side having a first structure for releasably holding a first electronic device, the socket having a first socket thermal opening formed through the socket from the lower side to the upper side; an interface connected to the socket for connecting the first device to an electrical tester; a chuck, the chuck being a chuck made of a thermally conductive material; and a first heat post connected to the chuck, the first heat post being inserted into the first socket thermal opening, one end of the first heat post being thermally connected to the first device such that heat is mainly transferred through the first heat post rather than through the insulating material of the socket between the chuck and the first electronic device.

[0014] The present invention also provides a test piece, comprising: a socket made of an insulating material and having an upper side and a lower side, the upper side having a first structure for releasably holding a first electronic device, the socket having a first socket thermal opening formed therethrough from the lower side to the upper side, and a first heat conducting post being insertable from the lower side into the first socket thermal opening; a first set of pins fixed in the socket and connecting the first device to a circuit board, the first set of pins being elastically pressable; and a lid capable of moving relative to the socket to press down the first set of pins so that the first electronic device contacts an end of the first heat post.

[0015] The present invention also provides a test piece, comprising: a chuck which is a heat conducting material chuck; and a first heat post connected to the chuck, the first heat post being insertable into the first socket thermal opening, and one end of the first heat post being thermally connected to the first device such that heat is mainly transferred through the first heat post rather than through the insulating material of the socket between the chuck and the first electronic device.

[0016] The present invention provides a method for testing one or more electronic devices, comprising: releasably holding a first device in a first structure on an upper side of a socket made of an insulating material; connecting the first device to an electrical tester through an interface connected to the socket; inserting a first heat post connected to a chuck of a heat conducting material into a first socket thermal opening formed through the socket from the lower side to the upper side, with one end of the first heat post being thermally connected to the first device; and transferring heat between the chuck and the first electronic device, the heat being mainly transferred through the first heat post rather than through the insulating material of the socket.

[0017] The present invention also provides a box, comprising: a socket made of an insulating material and having an upper side and a lower side, a first structure on the upper side for holding a first electronic device and a second structure on the upper side for holding a second electronic device; a lid; a first push plate rotatably mounted on the lid; a second push plate rotatably mounted on the lid, the lid being capable of being positioned on the socket and moving towards the socket, the rotatable mounting of the first push plate allowing the first electronic device to rotate the first push plate relative to the lid, and the rotatable mounting of the second push plate allowing the second electronic device to rotate the second push plate independently of the first push plate relative to the lid; a first set of contacts held in the socket for connecting the first electronic device; a first set of terminals connected to the first set of contacts; a second set of contacts held in the socket for connecting to the second electronic device; and a second set of terminals connected to the second set of contacts.

[0018] The present invention also provides a method for testing one or more electronic devices, including: releasably holding a first electronic device in a first structure on an upper side of a socket of an insulating material; releasably holding a second electronic device in a second structure on the upper side of the socket; positioning a lid on the socket, the lid having a first push plate rotatably mounted to the lid and a second push plate rotatably mounted to the lid; moving the lid towards the socket, the rotatable mounting of the first push plate allowing the first electronic device to rotate the first push plate relative to the lid, and the rotatable mounting of the second push plate allowing the second electronic device to rotate the second push plate independently of the first push plate relative to the lid; and connecting the first and second electronic devices to an electrical tester through an interface connected to the socket.

[0019] The present invention also provides a cartridge, including: an electronic device holder having a structure for removably holding an electronic device having input contacts and a light emitter; the input contacts on the electronic device holder being connected to the input contacts on the electronic device to provide input power to the input contacts on the electronic device through the input contacts on the electronic device holder, the input power causing the light emitter to emit light; a light detector mounted on the electronic device holder and positioned to detect light and generate output power in response to the light intensity; and output contacts connected to the light detector to measure the output power.

[0020] The present invention also provides a method for testing one or more electronic devices, including: inserting an electronic device having input contacts and a light emitter into a device holder; connecting the input contacts on the electronic device holder to the input contacts on the electronic device; providing input power to the input contacts on the electronic device through the input contacts on the electronic device holder, the input power causing the light emitter to emit light; detecting the light; converting the detected light into output power; measuring the output power through output contacts; and removing the electronic device from the electronic device holder.

[0021] The present invention also provides a testing device, including: a socket having a structure for removably holding an electronic device having input terminals and a light emitter; the input contacts on the socket being connected to the input terminals on the electronic device to provide input power to the input terminals on the electronic device through the input contacts on the socket, the input power causing the light emitter to emit light; a temperature regulating device on a first side of the socket, the temperature regulating device changing the temperature during operation to cause a temperature difference between the temperature regulating device and the electronic device and heat transfer between the temperature regulating device and the electronic device to change the temperature of the electronic device; a heat sink on a side of the socket opposite to the temperature regulating device, the heat sink having a surface for absorbing light, the absorbed light generating heat in the heat sink; and a heat dissipation device thermally connected to the heat sink to remove heat from the heat sink.

[0022] The present invention also provides a method for testing one or more electronic devices, comprising: inserting an electronic device having input contacts and a light emitter into a socket; connecting the input contacts on the socket to the input terminals on the electronic device; providing input power through the input contacts on the socket to the input terminals on the electronic device, the input power causing the light emitter to emit light; changing a temperature regulating device on a first side of the socket for creating a temperature difference between the temperature regulating device and the electronic device, generating heat transfer between the temperature regulating device and the electronic device to change the temperature of the electronic device; absorbing light on a surface of a heat sink on a side of the socket opposite to the temperature regulating device, the absorbed light generating heat in the heat sink; removing heat from the heat sink by a heat dissipation device thermally connected to the heat sink; and removing the electronic device from the socket.

[0023] The present invention also provides a box, comprising: a socket of insulating material, the socket having an upper side and a lower side and a structure on the upper side for holding an electronic device; a contact group held in the socket for connecting to the electronic device; a terminal group connected to the contact group held by the socket; a circuit board, the terminal group connected to the contact group being connected to a contact group on the circuit board; a lid; a detector mounted on the lid, the lid being movable to be positioned above the socket so that when power is supplied to the electronic device through at least one terminal in the terminal group held by the socket, the detector is located at a position for detecting characteristics of the electronic device, and a measurement channel connecting the detector to an interface on the circuit board.

[0024] The present invention also provides a method for testing one or more electronic devices, comprising: releasably holding an electronic device in a socket of insulating material, the socket having an upper side and a lower side and a structure on the upper side for holding the electronic device; connecting a contact group held in the socket to the electronic device; connecting a terminal group connected to the contact group to a contact group on a circuit board; moving a lid mounted with a detector onto the socket; connecting the detector to an interface on the circuit board through a measurement channel; supplying power to the electronic device through at least one contact held by the socket; detecting characteristics of the electronic device when power is supplied to the electronic device through at least one contact held by the socket; and measuring the characteristics through the interface.

[0025] The present invention also provides a box, comprising: a support plate having a column opening therethrough; a support structure located on a first side of the support plate, and the support structure at least includes a circuit board having contacts; a conductor having a contact contacting a terminal on an electronic device, the electronic device being located on a second side of the support plate opposite to the first side of the support plate, the conductor having a portion held by the support plate and a terminal connected to the contact on the circuit; a spring; a force generating device located on a side of the electronic device opposite to the support plate, the force generating device and the support plate being movable relative to each other to move the electronic device closer to the support plate and deform the spring; and a pillar having a support, a force transfer portion and a force transmission portion, the support having a surface in a plane spaced apart from a plane of a surface of the support plate to prevent the electronic device from moving closer to the support plate, the force transfer portion extending from the support and at least partially passing through the column opening, the force transmission portion extending from the force transfer portion, and the force transmission portion being held by the support structure.

[0026] The present invention also provides a box, comprising: providing a support structure on a first side of a support plate, the support structure at least including a circuit board having contacts; connecting a contact of a conductor to a terminal of an electronic device, and the electronic device being located on a second side of the support plate opposite to the first side of the support plate, the conductor having a portion held by the support plate and a terminal connected to the contact on the circuit board; positioning a force generating device on a side of the electronic device opposite to the support plate; moving the force generating device and the support plate relative to each other to move the electronic device closer to the support plate and deform the spring against the spring force of the spring; preventing the electronic device from moving closer to the support plate by using a pillar having a support, the support having a surface in a plane spaced apart from a plane of the surface of the support plate; receiving a force from the electronic device through the support of the pillar; transmitting the force at least partially through an opening from the support through a force transfer portion of the pillar, the force transfer portion extending from the support and at least partially passing through a pillar opening formed in the support plate; receiving the force by using a force transmission portion of the pillar, the force transmission portion extending from the force transfer portion, and the force transmission portion being held by the support structure; and transmitting the force to the support structure.

[0027] The present invention also provides a test device, comprising: a voltage targeting system; a holder for holding a plurality of electronic devices in at least a first cluster and a second cluster; at least one voltage source capable of being connected to the electronic devices in the first cluster to provide a first test voltage to the electronic devices in the first cluster in parallel, and capable of being connected to the electronic devices in the second cluster to provide a first test voltage to the electronic devices in the second cluster in parallel; at least one current detector capable of being connected to the devices in the first cluster to measure a first test current from the devices in the first cluster, the first test current from the devices in the first cluster being measured by the current detector as the total current of the devices in the first cluster in parallel, the current detector being capable of being connected to the devices in the second cluster to measure a first test current from the devices in the second cluster, the first test current from the devices in the second cluster being measured by the current detector as the total current of the devices in the second cluster in parallel, wherein the voltage targeting system makes a first comparison by comparing the first test current of the devices in the first cluster measured with a target current; a first voltage regulator that, in response to the first comparison, adjusts the first test voltage to a second test voltage for the first cluster such that the first test current of the devices in the first cluster is adjusted to a second test current closer to the target current, wherein the voltage targeting system makes a second comparison by comparing the first test current of the devices in the second cluster measured with the target current; and a second voltage regulator that, in response to the second comparison, adjusts the first test voltage to a second test voltage for the second cluster such that the first test current of the devices in the second cluster is adjusted to a second test current closer to the target current.

[0028] The present invention also provides a method for testing a plurality of electronic devices, comprising: holding the plurality of electronic devices in at least a first cluster and a second cluster; connecting at least one voltage source to the electronic devices in the first cluster to provide a first test voltage to the electronic devices in the first cluster in parallel and being capable of connecting to the electronic devices in the second cluster to provide a first test voltage to the electronic devices in the second cluster in parallel; connecting at least one voltage source to the electronic devices in the second cluster to provide a first test voltage to the electronic devices in the second cluster in parallel; measuring a first test current of the devices from the second cluster by using at least one current detector, and measuring the first test current of the devices from the first cluster as the total current of the devices in the first cluster in parallel by the current detector; measuring a first test current of the devices from the second cluster by using at least one current detector, and measuring the first test current of the devices from the first cluster as the total current of the devices in the first cluster in parallel by the current detector; performing a first comparison by using a voltage targeting system by comparing the first test current of the devices in the first cluster measured with a target current; regulating the first test voltage to a second test voltage for the first cluster in response to the first comparison by using a first voltage regulator such that the first test current of the devices from the second cluster is regulated to a second test current closer to the target current; performing a second comparison by using a voltage targeting system by comparing the first test current of the devices in the second cluster measured with a target current; and regulating the first test voltage to a second test voltage for the second cluster in response to the second comparison by using a second voltage regulator such that the first test current of the devices from the second cluster is regulated to a second test current closer to the target current. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described by way of example with reference to the accompanying drawings, in which:

[0030] Figure 1 is a cross-sectional side view of a test apparatus having a slot assembly according to an embodiment of the present invention;

[0031] Figure 2 is Figure 1 a cross-sectional side view of the test apparatus taken on line 2-2 in

[0032] Figure 3 is Figure 1 a cross-sectional side view of the test apparatus taken on line 3-3 in

[0033] Figure 4 is Figure 2 and Figure 3 a cross-sectional side view of the test apparatus taken on line 4-4 in

[0034] Figure 5A , 5B and 5C are perspective views of the test apparatus showing a portable cassette being inserted into or removed from an oven defined by a frame;

[0035] Figure 6 is a timing diagram showing how to insert a cassette and use the electronic device for testing the wafer and then insert another cassette;

[0036] Figure 7 is a perspective view of the test apparatus showing the insertion or removal of a slot assembly;

[0037] Figure 8A and 8B is a cross-sectional side view showing the support used in the construction of the cassette described with respect to Figures 1-7 ;

[0038] Figure 9A , 9B and 10 are side views showing the apparatus for inserting and removing the portable cassette from the oven;

[0039] Figure 11 is a perspective view showing the cassette according to another embodiment of the present invention;

[0040] Figure 12 is Figure 11 a cross-sectional side view of a part of the cassette in

[0041] Figure 13 is a cross-sectional side view showing the details of a part of the view showing Figure 12 ;

[0042] Figure 14A and 14B are cross-sectional side views illustrating the support used in the configuration of Figures 11-13 ;

[0043] Figure 15 shows the components of the test apparatus for controlling the voltage of each electronic device;

[0044] Figure 16 is a flowchart showing the operation of the components in Figure 15 ;

[0045] Figure 17 is a graph showing the voltage re-scaling with the process in Figure 16 ;

[0046] FIG. 18 shows a histogram for illustrating the static filtering performed in Figure 16 ;

[0047] FIG. 19 shows a histogram for illustrating the outlier filtering performed in Figure 16 ; and

[0048] FIG. 20 shows a histogram for illustrating the sample size filtering performed in Figure 16 ; DETAILED DESCRIPTION

[0049] In the accompanying drawings Figure 1 Figure 1 shows a test device 10 according to an embodiment of the present invention. The test device 10 includes a tester 12, a frame 14, a power bus 16, first and second slot assemblies 18A and 18B, a tester cable 20, a power cable 22, a cold liquid supply line 24A, a cold liquid return line 24B, a control liquid supply line 24C, a control liquid return line 24D, a vacuum line 24E, first and second cartridges 28A and 28B, and first and second wafers 30A and 30B.

[0050] The slot assembly 18A includes a slot assembly body 32, a thermal chuck 34, a temperature detector 36, a temperature regulating device in the form of a heating resistor 38, a first slot assembly interface 40, and a plurality of second slot assembly interfaces. The plurality of second slot assembly interfaces include a control interface 44, a power interface 46, and cold liquid supply interfaces 48A, cold liquid return interfaces 48B, control liquid supply interfaces 48C, control liquid return interfaces 48D, and vacuum interfaces 48E.

[0051] The first slot assembly interface 40 is located within and mounted on the slot assembly body 32. The control interface 44, the power interface 46, and the second interfaces in the form of interfaces 48A to 48E are mounted in the left wall of the slot assembly body 32.

[0052] The slot assembly 18A can be inserted into the frame 14 from left to right and removed from the frame 14 from right to left. The tester cable 20, the power cable 22, and the lines 24A to 24E are manually connected to the control interface 44, the power interface 46, and the interfaces 48A to 48E, respectively. Before removing the slot assembly 18A from the frame 14, the tester cable 20, the power cable 22, and the lines 24A to 24E are manually disconnected from the control interface 44, the power interface 46, and the interfaces 48A to 48E, respectively.

[0053] The slot component 18A includes a main board 60 having test electronics, a plurality of channel module boards 62 having test electronics, a flexible connector 64, and a connection board 66. A control interface 44 and a power interface 46 are connected to the main board 60, and a thermal controller 50 is mounted on the main board 60. The channel module boards 62 are electrically connected to the main board 60. The flexible connector 64 connects the channel module boards 62 to the connection board 66. Control functions are provided through conductor connections that connect the control interface 44 to the main board 60. Power is provided to the main board 60 through the power interface 46. Power and control are provided from the main board 60 to the channel module boards 62 through conductors. The flexible connector 64 provides conductors that connect the channel module boards 62 to the connection board 66. The connection board 66 includes conductors that connect the flexible connector 64 to the first slot component interface 40. The first slot component interface 40 is thus connected through various conductors to the control interface 44 and the power interface 46, such that power and control can be provided to the first slot component interface 40 through the control interface 44 and the power interface 46.

[0054] The second slot component 18B includes components similar to those of the first slot component 18A, and like reference numerals denote like components. The second slot component 18B is inserted into the frame 14, and the control interface 44, the power interface 46, and the interfaces 48A through 48E of the second slot component 18B can be manually connected, respectively, to a separate set of connection components, the separate set of connection components including a separate tester cable 20, a separate power line 22, and separate lines 24A through 24E.

[0055] The cassette 28A includes a cassette body formed by a thin chuck 72 and a backplane 74. The wafer 30A has a plurality of microelectronic devices formed therein. The wafer 30A is inserted into the cassette body and is located between the thin chuck 72 and the backplane 74. The cassette contacts 76 contact corresponding contacts (not shown) on the wafer 30A. The cassette 28A also includes a cassette interface 78 on the backplane 74. Conductors in the backplane 74 connect the cassette interface 78 to the cassette contacts 76.

[0056] The cassette 28A has a seal 77 connected between the backplane 74 and the thin chuck 72. A vacuum is applied to the area defined by the seal 77, the backplane 74, and the thin chuck 72. The vacuum holds the cassette 28A together and ensures proper contact between the cassette contacts 76 and the contacts on the wafer 30A.

[0057] The temperature detector 36 is located in the thermal chuck 34 and is thus close enough to the wafer 30A to detect the temperature of the wafer 30A within 5 degrees Celsius, preferably within 2 degrees Celsius of the wafer 30A.

[0058] The differential slot component 18A also has a door 82, which is connected to the door 82 of the slot component body 32 through a hinge 84. When the door 82 rotates to the open position, the cartridge 28A can be inserted into the slot component through the door opening 86. Then the cartridge 28A is lowered onto the hot chuck 34, and the door 82 is closed. The hot chuck 34 is mounted on the slot component body 32. Then, the hot chuck 34 substantially forms a bracket that has a test bench for the wafer.

[0059] The slot component 18A also has a seal 88 located between the hot chuck 34 and the thin chuck 72. A vacuum is applied through the vacuum interface 48E and the vacuum line 90 to the area defined by the seal 88, the hot chuck 34, and the thin chuck 72. This provides a good thermal connection between the hot chuck 34 and the thin chuck 72. When the heating resistor 38 generates heat, the heat is conducted through the hot chuck 34 and the thin chuck 72 to reach the wafer 30A. When the hot chuck 34 is at a lower temperature than the wafer 30A, the heat is conducted in the opposite direction.

[0060] The cartridge interface 78 engages with the first slot component interface 40. Through the first slot component interface 40, the cartridge interface 78 and the cartridge contact 76 supply power and signals to the wafer 30A. Through the cartridge contact 76, the cartridge interface 78 and the first slot component interface 40 measure the performance of the devices within the wafer 30A.

[0061] The door 82 of the slot component 18B is shown in the closed position. The front seal 100 is mounted on the upper surface of the slot component 18A and seals with the lower surface of the slot component 18B. The front seal 102 is mounted to the upper surface of the slot component 18B and seals with the lower surface of the frame 14. The continuously sealed front wall 104 is provided by the doors 82 of the slot components 18A and 18B and the front seals 100 and 102.

[0062] The slot component 18A also includes a thermal controller 50. The temperature detector 36 is connected to the thermal controller 50 through a temperature feedback line 52. Power is supplied to the heating resistor 38 through the power interface 46 and the power line 54 so that the heating resistor 38 heats up. Then, the heating resistor 38 heats the hot chuck 34 and the wafer 30A on the hot chuck 34. The heating resistor 38 is controlled by the thermal controller 50 according to the temperature detected by the temperature detector 36.

[0063] The hot chuck 34 has a thermal fluid channel 224 formed therein. The thermal fluid channel 224 holds the thermal fluid. The thermal fluid is preferably a liquid rather than a gas because a liquid is incompressible and heat can be transferred to or from the liquid more quickly. Different thermal fluids are used for different applications, with oil being used for the applications with the highest temperatures.

[0064] The control liquid supply and return pipelines 226 and 228 respectively connect the opposite ends of the hot fluid channel 224 to the cold liquid supply and return interfaces 48C and 48D. The heating resistor 38 serves as a heater, which is installed at the position of the heated chuck 34 to heat the hot fluid. By recirculating the hot fluid through the hot fluid channel 224, the hot chuck 222 provides a more uniform heat distribution to the hot chuck 34 and ultimately to the wafer 30A. The temperature of the fluid can also be controlled to add heat to the hot chuck 34 to cool down the hot chuck 34.

[0065] The test device 10 further includes a cooling system 240, a temperature control system 242, and a vacuum pump 244. Two cold liquid supply pipelines 24A connected to the first and second slot assemblies 18A and 18B are also connected to the cooling system 240 through a manifold (not shown). An additional manifold connects the cold liquid return pipeline 24B to the cooling system 240, the control liquid supply pipeline 24C to the temperature control system 242, the control liquid return pipeline 24D to the temperature control system 242, and the vacuum pipeline 24E to the vacuum pump 244. Each slot assembly 18A or 18B has a corresponding cold plate 246, and the cold plate 246 has a corresponding fluid channel 248. The cooling system 240 circulates the fluid through the fluid channel 248 to cool the cold plate 246. The cold plate 246 then keeps the channel module plate 62 cooled. The temperature control system 242 circulates the fluid through the hot fluid channel 224 to control the temperature of the hot chuck 34, and transfers heat to or from the wafers 30A and 30B. The vacuum pump 244 supplies air under vacuum pressure to the vacuum pipeline 90.

[0066] The slot assembly 18A includes a separator seal 108, which is installed on the upper surface of the slot assembly body 32 and above the inner wall 106 of the slot assembly body 32. The separator seal 108 seals with the lower surface of the slot assembly 18B. The slot assembly 18B has a separator seal 110, which is installed on the upper surface of the slot assembly body 32 of the slot assembly 18B. The separator seal 110 seals with the lower surface of the frame 14. The continuously sealed separator wall 112 is provided by the inner walls 106 of the slot assemblies 18A and 18B and the separator seals 108 and 110.

[0067] Figure 2 Shown is Figure 1 the test device 10 in 2-2. The frame 14 defines a first closed-loop air path 120. The air inlet and outlet (not shown) can be opened to change the first closed-loop air path 120 into an open air path, in which the room-temperature air passes through the frame 14 without recirculation. The closed-loop path is particularly useful in a clean room environment because it results in less particulate material being released into the air.

[0068] The test apparatus 10 further includes a temperature regulating device in the form of a first fan 122, a first fan motor 124, and a water cooler 126.

[0069] The first fan 122 and the first fan motor 124 are mounted on the upper portion of the first closed-loop air path 120. The water cooler 126 is mounted to the frame 14 within the upper portion of the first closed-loop air path 120.

[0070] The cartridges 28A and 28B are positioned with the slot assemblies 18A and 18B and are located within the lower half of the first closed-loop air path 120.

[0071] In use, current is supplied to the first fan motor 124. The first fan motor 124 causes the first fan 122 to rotate. The first fan 122 causes air to recirculate clockwise through the first closed-loop air path 120.

[0072] Then, the water cooler 126 cools the air in the first closed-loop air path 120. Then the air flows through the cartridges 28A or 28B via the slot assemblies 18A and 18B. Then the cartridges 28A or 28B are cooled by air convection.

[0073] Figure 3 Shown is Figure 1 the test apparatus 10 taken on 3-3 in. The frame 14 defines a second closed-loop air path 150. The test apparatus 10 further includes a temperature regulating device in the form of a second fan 152, a second fan motor 154, and a water cooler 156. No Figure 2 electric heater or damper as provided in is provided. Air inlets and outlets (not shown) can be opened to change the second closed-loop air path 150 into an open air path, in which room temperature air passes through the frame 14 and is not recirculated.

[0074] Closed-loop paths are particularly useful in a clean room environment because they result in less particulate material being released into the air. The second fan 152 and the second fan motor 154 are located on the upper portion of the second closed-loop air path 150. The water cooler 156 is located within the second closed-loop air path 150 and is located slightly downstream of the second fan 152. The main board 60 and the channel module boards 62 forming part of the slot assemblies 18A and 18B are located within the lower half of the second closed-loop air path 150.

[0075] In use, current is supplied to the second fan motor 154, which rotates the second fan 152. The second fan 152 then recirculates air in a clockwise direction through the second closed-loop air path 150. The air is cooled by the water cooler 156. The cooled air then passes over the motherboard 60 and the channel module board 62, such that heat is transferred from the motherboard 60 and the channel module board 62 to the air by convection.

[0076] Air recirculated through the first closed-loop air path 120 in Figure 1 is kept separate from the air in the second closed-loop air path 150 in Figure 1 by the continuous sealed partition wall 112 shown in Figure 3 . Figure 1 The continuous sealed front wall 104 shown in

[0077] prevents air from escaping from the first closed-loop air path 120. Figure 2 and 3 As shown in Figure 1 , the same cooling system 240 used in Figure 4 is also used to cool the water cooler 126. As shown in

[0078] Figure 5A , FIGS. 5B and 5C illustrate how cassettes 30C, 30D, and 30E can be inserted or removed at any time while all other cassettes are used for wafer side-viewing devices and can be in various temperature ramp states. Figure 6 This aspect is described in more detail. At time T1, a first cassette is inserted into the frame 14 while a second cassette is outside the frame 14. At T1, heating of the first cassette is started. Between T1 and T2, the temperature of the first cassette increases from room temperature (i.e., about 22° C.) to a test temperature that is 50° C. to 150° C. higher than room temperature at T2. At T2, power is applied to the first cassette and the device in the first cassette is tested. At T3, the second cassette is inserted into the frame 14 and heating of the second cassette is started. At T4, the test of the first cassette is terminated. At T4, cooling of the first cassette is also started. At T5, the second cassette reaches the test temperature and power is supplied to the second cassette and the wafer in the second cassette is tested. At T6, the second cassette reaches a temperature close to room temperature and is removed from the frame 14. Then a third cassette can be inserted in place of the first cassette. At T7, the test of the second cassette is terminated and cooling is started. At T8, the second cassette has cooled to room temperature or close to room temperature and is removed from the frame 14.

[0079] Different tests can be performed at different temperatures. For example, a cassette can be inserted and the test can be performed at room temperature. Another test can be performed during the temperature rise. Further tests can be performed at elevated temperatures. Further tests can be performed during the temperature drop. Two of these tests can be a single test that runs from one temperature stage to the next.

[0080] As Figure 7 shown, a slot component 18A can be removed from or inserted into the frame 14. The slot component 18A can be inserted or removed while other slot components within the frame 14 are for the device to test the wafer, as described in reference Figure 6 stated.

[0081] As Figure 8A shown, the backplane 74 includes a circuit board 500, a contactor 502, a plurality of pins 504, a fixing ring 506, a fastener 508, and a pillar 510.

[0082] The circuit board 500 is mainly made of insulating material and has a circuit (not shown) formed therein. The contacts 512 are formed on the lower side 514 of the circuit board 500. The threaded openings 516 are formed in the lower side 514.

[0083] The contactor 502 has a plurality of pin openings 518, a column opening 520, and a fastener opening 522 formed from the upper side 524 to the lower side 526. Each pin opening 518 has a first part 528 and a second part 530. When observed in a plan view, both the first and second parts 528 and 530 are circular. The diameter of the first part 528 is larger than the diameter of the second part 530. When compared with the diameter of the second part 530, the diameter of the first part 528 is larger, which makes the first part 528 wider than the second part 530 when observed from the Figure 8A cross-sectional side view.

[0084] The column opening 520 has a first part 534 and a second part 536. When observed in a plan view, both the first part 534 and the second part 536 are circular. The diameter of the first part 534 is larger than the diameter of the second part 536. Since the diameter of the first part 534 is larger than the diameter of the second part 536, the first part 534 is wider than the second part 536 when observed in the Figure 8A cross-sectional side view. The first and second parts 534 and 536 have vertical side walls. The horizontal platform 538 connects the vertical side walls of the first and second parts 534 and 536.

[0085] Each pin 504 includes a conductive holder portion 542, a helical spring 544, and first and second end members 546 and 548. The first end member 546 has a first inner portion 550 and a first tip 552. The second end member 548 has a second inner portion 554 and a second tip 556. The helical spring 544 and the first and second inner portions 550 and 554 are held together with the holder portion 542, and the helical spring 544 is located between the first and second inner portions 550 and 554. The first and second tips 552 and 556 project from the upper and lower ends of the holder portion 542, respectively.

[0086] A terminal 560 is formed on the upper surface of the first tip 552. A contact 562 is formed at the lower end of the second tip 556. The helical spring 544 and the first and second end members 546 and 548 are made of metal and are thus conductive materials. The helical spring 544 and the first and second end members 546 and 548 form a conductor that can conduct current between the terminal 560 and the contact 562.

[0087] The corresponding pins are inserted through the upper side 524 into the corresponding pin openings 518. The second tip 556 is slightly smaller than the second portion 530 such that the second tip 556 passes through the second portion 530 and projects from the lower side 526. The holder portion 542 is slightly narrower than the first portion 528 but wider than the second portion 530 to prevent the pin 504 from falling out of the lower side 526. When the pin 504 is fully inserted into the pin opening 518 and before the contactor 502 is mounted to the circuit board 500, the first tip 552 still projects above the upper side 524 of the contactor 502.

[0088] The post 510 has a seat 564, a force transfer portion 566, and a force transmission portion 568. The post 510 is made of a single piece of metal or other material because, compared with the strength and brittleness of the ceramic material of the contactor 502, the single piece of metal or other material is selected precisely because of its strength.

[0089] The post 510 is inserted through the upper side 524 into the post opening 520. The seat 564 and the force transfer portion 566 are slightly narrower than the second portion 536. The force transmission portion 568 is slightly narrower than the first portion 534 but wider than the second portion 536. The lower surface 570 of the force transmission portion 568 abuts against the platform 538. Thereby preventing the post 510 from falling out of the lower side 526.

[0090] The post 510 has a surface 572 that, when the post 510 is fully inserted as Figure 8A shown, is in a plane parallel to and below the surface of the lower side 526. When the post 510 is fully inserted, the force transmission portion 568 has a surface 574 that is in the same plane as the upper side 524.

[0091] The circuit board 500 is located on top of the contactor 502. Each contact 512 contacts a corresponding one of the terminals 560. Since the terminals 560 are in a plane above the plane of the upper side 524, the lower side 514 is initially spaced apart from the upper side 524.

[0092] The fastener 508 has a threaded shaft 578 and a head 580. The ring 506 has an annular opening 582. The ring 506 is located on the lower surface 584 of the contactor 502. The threaded shaft 578 is inserted through the annular opening 582 from the bottom and then through the fastener opening 522. The head 580 contacts the lower surface of the ring 506. Then the head 580 is rotated so that the threads on the threaded shaft 578 are screwed into the threads on the threaded opening 516. The threading action brings the circuit board 500 closer to the contactor 502 and the ring 506. The lower side 514 eventually contacts the upper side 524. The contact 512 moves the first end member 546 downward into the pin opening 518 until the terminal 560 is in the same plane as the upper side 524. The coil spring 544 is compressed and thus slightly deformed to allow relative movement of the first end member 546 relative to the second end member 548.

[0093] The lower side 514 has a portion that is stationary relative to the surface 574 that forms part of the support post 510. Since the support post 510 abuts against the circuit board 500, the support post 510 is in a position to transfer force through the surface 572 to the circuit board 500.

[0094] The first wafer 32A has a plurality of electronic devices formed in the first wafer. Each electronic device has a plurality of terminals 588 at the upper surface 590 of the first wafer 32A. When the backplane 74 and the first wafer 32A are placed together, the first wafer 32A is aligned with the backplane 74 to ensure that each terminal 588 contacts a corresponding one of the contacts 562.

[0095] A vacuum pressure is generated in the region between the upper surface 590 and the lower side 526, while the pressure below the lower surface 592 of the thin chuck 72 and the upper surface 594 of the circuit board 500 is maintained at atmospheric pressure. The pressure difference generates equal and opposite forces F1 and F2 on the circuit board 500 and the thin chuck 72.

[0096] As Figure 8BAs shown, forces F1 and F2 move the backplane 74 towards the wafer 32A and the thin chuck 72. The helical springs 544 are compressed more to allow the second end piece 548 to move into the pin holes. Each helical spring 544 deforms against its spring force, such as F3. However, the force F1 is still greater than the sum of all the forces F3 added together. The upper surface 590 finally rests on the surface 572 of the support 564. Since the support post 510 abuts against the circuit board 500, the support 564 prevents the upper surface 590 from approaching and contacting the lower side 526 of the contactor 502. The first wafer 32A transfers the force F4 to the support 564. The force transfer portion 566 transfers the force F4 through the second portion 536 of the support post opening 520. The force transfer portion 568 receives the force F4 from the force transfer portion 566 and transfers the force F4 to the circuit board 500 via the surface 574.

[0097] Thus, it can be seen that the force F4 is not borne by the contactor 502, thereby preventing stresses that could damage the brittle ceramic material of the contactor 502. Instead, the force F4 is directly transferred from the electronic device in the form of the first wafer 32A through the support post 510 to the circuit board 500.

[0098] In Figure 8A and 8B the described embodiment, the contactor 502 serves as a support plate having a post opening 520 therethrough. On the first side of the support plate, the circuit board 500 serves as a support structure and at least includes a circuit board having contacts 512. The pins 504 serve as conductors having contacts 562 to contact the terminals 508 of the electronic device provided on the second side of the support plate, the second side of the support plate being opposite to the first side of the support plate. The holder portion 542 serves as a part of the conductor held by the support plate. The conductor also has terminals 560 that are connected to the contacts 512 on the circuit board 500. A spring in the form of a helical spring 544 is provided. The thin chuck 72 serves as a force generating device on one side of the electronic device in the form of the first wafer 32A and is opposite to the support plate. The force generating device and the support plate are movable relative to each other to move the electronic device closer to the support plate and deform the spring. The support post 510 has a support 564 having a surface 572 in a plane spaced apart from the plane of the surface of the support plate to prevent the electronic device from moving closer to the support plate, the force transfer portion 566 extending from the support 564 at least partially through the support post opening 520, and the force transfer portion 568 extending from the force transfer portion 566 and being held by the support structure.

[0099] Figure 9A A portion of the test device 10 is shown for inserting a cartridge into each slot assembly, such as into the slot assembly 18A, and removing it from each slot assembly. Figure 9AThe components of the test device 10 shown in the figure include a frame 300, a part of the first slot assembly 18A, a first slot assembly interface 40, a holding structure 302, a horizontal conveying device 304, a vertical conveying device 306, a beam spring 308, and a locking mechanism 310.

[0100] The frame 300 includes first and second mounting members 312 and 314 spaced apart from each other. The horizontal conveying device 304 is a slider mounted between the first and second mounting members 312 and 314. The holding structure 302 is mounted to slide along the horizontal conveying device 304. Opposite ends of the beam spring 308 are respectively mounted on the first and second brackets 312 and 314.

[0101] The locking mechanism 310 includes a connecting rod 316, a control rod 318, and a pressure rod 320. The control rod 318 is mounted to the first mounting member 312 at a pivot connection 322. The vertical conveying device 306 is a rigid beam. A connection 324 connects the center points of the vertical conveying device 306 and the beam spring 308 to each other. The pressure rod 320 has a first link 326 rotatably connected to the control rod 318 and a second link 328 rotatably connected to the end of the vertical conveying device 306. In Figure 9A the unlocked configuration shown, a wire 330 connects the pivot connection 322 and the second link 328, and the first link 326 is located to the left of the wire 330.

[0102] In use, the first cassette 28A is located on the holding structure 302. Then, the first cassette 28A together with the holding structure 302 is moved from left to right into the first slot assembly 18A. The placement and movement of the first cassette 28A can be performed manually or can be performed using a robot.

[0103] The holding structure 302 slides along the horizontal conveying device 304. The connecting rod 316 connects one end of the control rod 318 to the holding structure 302. When the holding structure 302 moves horizontally along the horizontal conveying device 304, the connecting rod 316 causes the control rod 318 to rotate counterclockwise about the pivot connection 322.

[0104] The first link 326 rotates counterclockwise together with the control lever 318. The pressure lever 320 converts the movement of the first link 326 into a downward movement of the second link 328. First, the downward movement is minimal, but when the first cassette 28A is fully inserted into the first slot assembly 18A, the vertical movement becomes more pronounced, and the vertical transport device 306 engages the first cassette 28A and the first slot assembly 18A. Thus, the horizontal transport device 304 is operable to horizontally move the first cassette 28A from a first position to a second position to enter the first slot assembly 18A, and the vertical transport device 306 is operable to move the first cassette 28A and the first slot assembly 18A relative to each other in a first vertical direction to engage the slot assembly interface 40 with the cassette interface on the first cassette 28A.

[0105] The control lever 318 is shown in Figure 9A the unlocked position, where the first link 326 is located on the first side of the line 330 connecting the pivot connection 322 and the second link 328. The control lever 318 rotates from Figure 9A the shown unlocked position through the compression position, in which the beam spring 308 is deformed by the vertical transport device 306 through the connection 324 to bend the beam spring 308 to overcome the spring force of the beam spring, and the first link 326 is aligned with the pivot connection 322 and the second link 328. As shown in Figure 9B and 10 shown, the control lever 318 continues to rotate from the compression position to the locked position. In the locked position, the first link 326 is located on the right side of the line 330, and thus on the second side of the line 330 opposite the first side. Since the first link 326 has passed through the line 330 and the beam spring 308 is deformed against its spring force, the first cassette 28A is locked in position against the slot assembly interface 40.

[0106] The system can be unlocked by moving the holding structure 302 from right to left. The control lever 318 rotates clockwise, and the first link 326 moves from right to left past the line 330. The vertical transport device 306 moves in an upward direction (i.e., a second vertical direction opposite to the first vertical direction) to release the first cassette 28A from the slot assembly interface 40. The holding structure 302 is further moved along the horizontal transport device 304 to remove the first cassette 28A from the first slot assembly 18A.

[0107] Figure 11 A cassette 340 according to another embodiment of the present invention is shown, the cassette 340 including a thermal component 342, a plate - seat assembly 344, and a plurality of lids 346.

[0108] Figure 12 A portion of the thermal component 342, a portion of the plate - seat assembly 344, and one of the lids 346 are shown.

[0109] Figure 13 shows Figure 12 detail A in Figure 13 and includes a portion of the thermal component 342, a portion of the board - socket component 344, and a portion of the lid 346.

[0110] The thermal component 342 includes a thin chuck 350, a first thermal anchor 352, and a first thermal post 354. The thin chuck 350 has an upper surface 356 on which an opening 358 is formed. The first thermal anchor 352 and the first thermal post 354 are machined from a single piece of metal. When viewed in a plan view, both the first thermal anchor 352 and the first thermal post 354 have a circular cross - section in a respective plane parallel to the axis of the first thermal post 354. The cross - section of the first thermal anchor 352 is larger than the cross - section of the first thermal post 354.

[0111] The first thermal anchor 352 is inserted through the upper surface 356 into the opening 358. The first thermal post 354 extends upward from the first thermal anchor 352. Most of the first thermal post 354 is located above the upper surface 356. The first thermal anchor 352 has an upper end with a first thermal surface 360. The first thermal anchor 352 is press - fit into the opening 358 until a desired depth, where the first thermal surface 360 is at a desired distance from the upper surface 356.

[0112] The first thermal post 354, the first thermal anchor 352, and the thin chuck 350 are all made of metal and are thus good thermal conductors. The larger cross - section of the first thermal anchor 352 causes more heat to be transferred from the first thermal anchor 352 to the thin chuck 350 when compared with the cross - section of the first thermal post 354.

[0113] The board - socket component 344 includes a circuit board 362, a socket 364, a first set of pins 366 for an electronic device, and a first set of pins 368 for a detector. The pins 366 and 368 are spring pins that include a spring and can be compressed against the spring force of the spring.

[0114] The socket 364 includes a lower part 370 and an upper part 372. Each of the pins 366 and 368 is held within the socket 364 between the lower part 370 and the upper part 372. The upper part 372 has a first recessed structure 376 for holding the first electronic device 348. Each of the pins 366 has a corresponding contact 378 that extends above the surface of the first recessed structure 376. Each of the pins 368 has a corresponding contact 380 that extends above the upper surface 382 of the upper part 372.

[0115] The contacts 380 of pin 368 are all in the same plane. The contacts 378 of pin 366 are all in the same plane. The plane of contacts 380 is parallel to the plane of contacts 378 and is located above the plane of contacts 378. The terminals 392 of pin 368 are all in the same plane as the terminals 392 of pin 366.

[0116] The circuit board 362 has a circuit (not shown) formed therein. The contact 388 is formed in the upper surface 390 of the circuit board 362.

[0117] The socket 364 is positioned on the circuit board 362. The circuit board 362 is thus located between the thin chuck 350 and the socket 364. Each of the pins 366 and 368 has a corresponding terminal 392 that initially extends below the lower surface 394 of the lower part 370. The corresponding one of the terminals 392 contacts the corresponding one of the contacts 388. The pins 366 and 368 are compressed against their spring forces until the lower surface 394 contacts the upper surface 390. The terminals 392 of the pins 366 and 368 move into the socket 364 until they are in the same plane as the lower surface 394. Then, the socket 364 is permanently mounted to the circuit board 362.

[0118] The socket 364 has a first socket thermal opening 398 that is formed from the lower side to the upper side of the socket 364. The circuit board 362 has a first circuit board thermal opening 400 that is formed from the lower side to the upper side. The first socket thermal opening 398 is aligned with the first circuit board thermal opening 400. The thermal component 342 and the board - socket assembly 344 are initially disconnected from each other, as Figure 11 shown. The board - socket sub - assembly 344 is then positioned above the thermal component 342. The first circuit board thermal opening 400 is positioned on the upper end of the first thermal post 354. The board - socket assembly 344 is further lowered until the first thermal post 354 passes through the first socket thermal opening 398. The lower surface 402 of the circuit board 362 docks on the upper surface 356 of the thin chuck 350. The first thermal post 354 fits loosely within the first socket thermal opening 398 and the first circuit board thermal opening. The first thermal post 354 extends above the upper surface 356 because the first thermal post 354 is slightly longer than the combined length of the first socket thermal opening 398 and the first socket thermal opening 398. The first thermal surface 360 is thus located slightly above the upper surface of the first recessed structure 376. The contacts 378 are in a plane above the plane of the first thermal surface 360 at this stage.

[0119] The socket 364 is made of an electrically insulating material and a thermally insulating material. The pins 366 and 368 provide electrical conductors through the socket 364. The circuit board 362 is also made of an electrically insulating material and a thermally insulating material. The contact 388 forms part of the circuit within the insulating material of the circuit board 362. The first thermal post 354 provides a heat conduction path between the first recessed structure 376 and the first thermal anchor 352 connected to the thin chuck 350. The thermal post 354 is electrically and thermally insulated from the electrical conductors within the socket 364 and the circuit board 362. Heat will be conducted mainly through the first thermal post 354 rather than the insulating materials of the socket 364 and the circuit board 362.

[0120] The cover 346 includes a circuit board 406 and a heat sink 408. The cassette 340 also has a first light detector 410, a first adjustable member 412, and a first helical spring 414.

[0121] The circuit board 406 is made of an electrically insulating material and a thermally insulating material. The conductive terminals 416 are formed on the lower surface 418 of the circuit board 406. The terminals 416 are part of a circuit (not shown) formed within the circuit board 406.

[0122] The first light detector 410 is attached to the upper surface 420 of the circuit board 406. The first light detector 410 is connected to the terminal 416 through the circuit in the circuit board 406. For example, one of the terminals 416 can supply power to the first light detector 410. When light falls on the first light detector 410, the first light detector 410 converts the energy of the light to output electric power. Another terminal 416 can be used as an output contact connected to the first light detector 410 to measure the output electric power.

[0123] The first adjustable member 412 has a push plate 422, side walls 424 extending upward from the push plate 422, and a lip 426 extending outward from the side walls 424. The circuit board 406 has a first opening 428 formed therein. The first adjustable member 412 is inserted into the first opening 428. The push plate 422 then extends below the lower surface 418. The lip 426 abuts against the upper surface 420. The first opening 428 is slightly larger than the width between the side walls 424. The difference in width allows the first adjustable member 412 to rotate a small number of degrees about a first axis 432 relative to the circuit board 406. The difference in width also allows the first adjustable member 412 to rotate clockwise and counterclockwise about a second axis 434, which enters the paper relative to the circuit board 406 and is orthogonal to the first axis 432. This orthogonal rotation allows a small amount of gimbal of the first adjustable member 412 relative to the circuit board 406.

[0124] The heat sink 408 has a first groove 436. A first helical spring 414 is inserted between the side walls 424. The lower end of the first helical spring 414 bears against the upper surface 438 of the push plate 422. The upper end of the first helical spring 414 extends above the lip 426. The heat sink 408 is located above the circuit board 406, and the upper end of the first helical spring 414 is located within the first groove 436. The lower surface 440 of the heat sink 408 is initially spaced apart from the upper surface 420. When the heat sink 408 moves towards the circuit board 406, the first helical spring 414 is compressed and thus deformed against its spring force. The lower surface 440 contacts the upper surface 420. Then the heat sink 408 is fixed to the circuit board 406 using fasteners (not shown). The small force generated by the first helical spring 414 then biases the first adjustable member 412 in the outward direction of the lower surface 418.

[0125] The push plate 422 has a first opening 442. The heat sink 408 defines a first cavity 444. A light-absorbing coating is formed on the surface of the first cavity 444.

[0126] In use, the first electronic device 348 is inserted into the first recessed structure 376. The terminals 446 on the lower side of the first electronic device 348 contact the contacts 378. The lower surface 448 of the first electronic device 348 is spaced apart from the first heat surface 360 at this stage.

[0127] The lid 346 is positioned above the board-seat assembly 344. Then the lid 346 moves towards the board-seat assembly 344. Each terminal 416 contacts a corresponding one of the contacts 380. The lower surface 450 of the push plate 422 contacts the upper surface 452 of the first electronic device 348. The lower surface 448 of the first electronic device 348 remains spaced apart from the first heat surface 360.

[0128] The operator manually presses, causing the lid 346 to move further towards the board-seat assembly 344. Each of the pins 366 and 368 compresses its spring force, thereby elastically pressing down the contacts 378 and 380 against the spring forces of the springs in the pins 366 and 368. The lower surface 448 of the first electronic device 348 contacts the first heat surface 360.

[0129] If there is an angular misalignment between the first hot surface 360 and the lower surface 448 of the first electronic device 348, the first electronic device 348 rotates through the first hot surface 360 until the lower surface 448 and the first hot surface 360 are in the same plane. The rotation of the first adjustable member 412 relative to the lid 346 allows the lower surface 448 of the first electronic device 348 to abut against the first hot surface 360. This ensures good thermal contact between the first hot surface 360 and the lower surface 448. The first helical spring 414 is compressed to accommodate the height of the first electronic device 348. Additionally, the first adjustable member 412 is rotatably mounted on the lid 346 such that the first electronic device 348 can rotate the first adjustable member 412 relative to the first hot surface 360. The lid 346 is then fixed to the board - seat assembly 344.

[0130] The socket 364 and the lid 346 together form an electronic device holder for holding the first electronic device 348. A cartridge interface (not shown) on the circuit board 362 supplies power and communication to the contacts 388. The pins 366 supply power and communication to the first electronic device 348 through the terminals 446.

[0131] The first electronic device 348 can include, for example, a laser or other light emitter. The first electronic device 348 can have a laser emitter, for example, in its upper surface 452. When power and communication are supplied to one of the contacts 378 acting as an input contact and one of the terminals 446 acting as an input terminal, the laser emitted by the laser emitter of the first electronic device 348 passes through the first opening 442 and through the helical spring 414 and the side wall 424 into the first cavity 444.

[0132] Most of the light is absorbed by the light - absorbing material on the surface of the first cavity 444 and is thus converted into heat. The heat is conducted through the heat sink 408.

[0133] A small portion of the light is reflected from the surface of the first cavity 444 and is detected by the first light detector 410. The first light detector 410 is powered by an electrical conductor formed by one of the contacts 388, one of the pins 368, one of the terminals 416, and a circuit formed within the circuit board 406. When the first light detector 410 detects light, it converts the light into electrical energy. The magnitude of the electrical power is related to the intensity of the light detected by the light detector 410. Then, the first light detector 410 supplies power to the circuit board 362 through a conductor formed by a circuit in the circuit board 406, one of the terminals 416, one of the pins 368, and one of the contacts 388, and ultimately reaches the cartridge interface on the circuit board 362.

[0134] The circuit board 406 and the pins 368 provide a measurement channel for connecting the first photodetector 410 to the circuit board 362, even if the first photodetector 410 is located on the side of the first electronic device 348 opposite to the circuit board 362. In a similar manner, another type of detector other than the photodetector can be used to detect characteristics of the electronic device other than the light transmitted by the electronic device. For example, the current on the terminals on the upper surface of the electronic device can be detected, and a similar measurement channel can be created for the circuit board below the electronic device through the circuit board above the electronic device and the pins in the socket. In such an arrangement, pins such as the pin 368 can be used as detector measurement pins held by the socket and forming part of the measurement channel.

[0135] The temperature of the first electronic device 348 is controlled by conducting heat through the first thermal post 354. The first electronic device 348 can be heated or cooled, for example, through the first thermal post 354. For example, the first electronic device 348 can be cooled by transferring the heat from the first electronic device 348 to the thin chuck 350 through the first thermal post 354 and the first thermal anchor 352. The first electronic device 348 can be heated by transferring the heat from the thin chuck 350 to the first electronic device 348 through the first thermal anchor 352 and the first thermal post 354.

[0136] The thin chuck 350 is located on the side of the first electronic device 348 opposite to the heat sink 408. Thus, it can be seen that due to the transmission of the laser through the first electronic device 348, the temperature of the first electronic device 348 can be controlled independently of the heat dissipation of the heat sink 408.

[0137] Referring again to Figure 12 , a socket 364 and a lid 346 can be used to test multiple electronic devices. The socket 364 includes, for example, a second thermal anchor 352A, a second thermal post 354A, a second thermal surface 360A, a second set of pins 366A for the second electronic device, a second set of pins 368A, a second recessed structure 376A for the second electronic device (not shown), a second socket thermal opening 398A, a second circuit board thermal opening 400A, a second photodetector 410A, a second adjustable element 412A, a second helical spring 414A, a second opening 428A, a second groove 436A, a second opening 442A, and a second cavity 444A. The same reference numerals denote the same components and functions.

[0138] The light transmitted by the first and second electronic devices can be independently detected by the first and second photodetectors 410 and 410A. The heat generated due to the light of the first and second electronic devices is dissipated through the same heat sink 408. A plurality of fins 454 are connected to and extend from the heat sink 408. The heat is conducted to the fins 454 and then convected from the fins 454 to the surrounding air. Thus, the fins 454 serve as heat dissipating means thermally connected to the heat sink 408 to remove heat from the heat sink 408.

[0139] The temperature of the first and second electronic devices is jointly controlled by the same thin chuck 350. If the electronic devices are cooled, for example, the heat is conducted through the first and second heat posts 354 and 354A to the first and second heat anchors 352 and 352A respectively, and then from the first and second heat anchors 352 and 352A to the thin chuck 350.

[0140] The first and second electronic devices can be independently rotated to contact the first and second heat surfaces 360 and 360A respectively. The independent universal joints of the first and second adjustable members 412 and 412A relative to the lid 346 allow and control the independent rotation of the first and second electronic devices.

[0141] See again Figure 11 , sixteen sockets 364 are connected to the circuit board 362. Each socket 364 has a corresponding lid 346. Each lid 346 has a corresponding fixing structure 460, and each socket 364 has a corresponding fixing structure 462. The lid 346 moves towards the socket 364. Then the lid 346 is pressed onto the socket 364 as described above. Then, the fixing structures 460 and 462 engage with each other to fix the lid 346 to the socket 364 and maintain thermal and electrical integrity.

[0142] The thin chuck 350 has a plurality of heat posts fixed in sixteen groups of sixteen. Each group of heat posts is inserted through a corresponding one of the sockets 364. The electronic devices held by all sixteen sockets 364 use a single thin chuck 350 to maintain the temperature of the electronic devices.

[0143] A cartridge interface 464 is formed on the lower surface of the circuit board 362. The cartridge interface 464 is connected to the Figure 13 contacts 388 shown in. The cartridge interface 464 is used to connect the cartridge 340 to the electrical tester as described above. As described above, the thin chuck 350 is thermally connected to the thermal chuck. The thermal chuck serves as a temperature regulating device to control the heat transferred to or from the thin chuck 350.

[0144] After testing the electronic devices, the cartridge 340 is removed from the system, the lid 346 is removed, and the electronic devices are removed from the sockets 364.

[0145] The heat post 354 also serves toFigure 8A and 8B A column that transfers force in a manner similar to the embodiments described in Figure 8A . The lid 346 serves as a force generating device. Some of the force generated by the lid 346 is balanced by the force generated by the springs within the pins 366 and 368. The remainder of the force not balanced by the pins 366 and 368 is taken up by the support of the column 354. The support has a surface 360 to support the electronic device 348 and prevent the electronic device 348 from moving closer to the base of the recessed structure 376. The central portion of the column 354 serves as a force transfer portion that extends from the support through the opening 398. The circuit board 362 and the thin chuck 350 together form a support structure. The lower portion of the column 354 generally transfers force to the support structure. Specifically, the force is transferred through the thermal anchor 352 to the thin chuck 350 that forms part of the support structure. The press fit between the thermal anchor 352 and the thin chuck 350 is strong enough to maintain integrity such that the force does not cause the thermal anchor 352 to move relative to the thin chuck 350.

[0146] Figure 14A shows Figure 11 , the embodiments of 12 and 13, further showing the details thereof, including the fastener 600 and the column 602.

[0147] The column opening 604 and the fastener opening 606 are formed through the socket 364. The column opening 520 has a first portion 608 and a second portion 610. The second portion 610 is wider than the first portion 608. The first portion 608 can be formed, for example, by the upper portion 372, and the second portion 610 can be formed by the lower portion 370. The platform 612 connects the first portion 608 to the second portion 610.

[0148] The column 602 includes a support 614, a force transfer portion 616, and a force transfer portion 618. The column 602 is inserted into the column opening 604 from the bottom until the surface 620 of the force transfer portion 618 abuts against the platform 612. The threaded shaft 622 of the fastener 600 is inserted through the fastener opening 606 from the top. Then the head 624 is rotated such that the threads on the threaded shaft 622 are screwed into the threads in the threaded opening 626 in the thin chuck 350. Since the thin chuck 350 is made of metal, it provides good fixation for the fastener 600. When the fastener 600 is further rotated, the head 624 moves closer to the circuit board 362. The spring of the pin 366 is slightly compressed and the lower side 630 of the column 602 contacts the circuit board 362.

[0149] As Figure 14BAs shown, when the operator presses the lid 346 onto the socket 364, the force F1 generated by the push plate 422 is equal and opposite to the reaction force F2 generated in the thin chuck 350. The spring of the spring compression spring of the pin 366. The push plate 422 and the first electronic device 348 continue to move closer to the socket 364 until the lower surface 448 of the electronic device 348 contacts the surface 632 of the support 614. The surface 632 prevents the electronic device 348 from moving further towards the socket 364.

[0150] The support 614 receives the force F4 from the electronic device 348. The force transfer portion 566 transmits the force through the first portion 608 of the column opening 604. The force transfer portion 618 receives the force from the force transfer portion 566 and transmits the force to the circuit board 362. The circuit board 362 transmits the force to the thin chuck 350.

[0151] Therefore, it can be seen that the material of the socket 364 is not exposed to the force F4, thereby eliminating damage to the socket 364.

[0152] The socket 364 provides a support plate having a column opening 604 therethrough. On the first side of the support plate, the circuit board 362 provides a support structure and has contacts 388. The pin 366 forms a conductor having contacts 378 to contact the terminals 446 on the electronic device 348 located on the side of the support plate opposite to the first side of the support plate. The conductor has a portion held in the support plate and a terminal 392 connected to the contact 388 on the circuit board 362. A spring is disposed within the pin 366. The push plate 422 forms a force generating device on the side of the electronic device 348 opposite to the support plate. The force generating device and the support plate are movable relative to each other to move the electronic device 348 closer to the support plate and deform the spring. The column 602 has a support 614 having a surface 632 located in a plane spaced from the plane of the surface of the support plate to prevent the electronic device 348 from moving closer to the support plate. The force transfer portion 616 extends at least partially through the column opening 604 from the support 614. The force transfer portion 618 extends from the force transfer portion 616. The force transfer portion 618 is held by the support structure.

[0153] Figure 15 Other components of the test device 10 are shown, which are used to precisely control the voltage supplied to the electronic device 634 being tested. For example, the electronic device 634 may be located on the surface of the wafer 636 or may be a single device held within the socket layout.

[0154] Many semiconductor devices require a constant current supply rather than a constant voltage supply. An example in this regard is the aging (or burn-in) of vertical cavity surface emitting laser (VCSEL) wafers. The following challenges arise:

[0155] · A VCSEL wafer has a large number of devices in a very small area. For example, imagine a VCSEL wafer with 50,000 devices within a 3-inch circumference.

[0156] · The cost of 50,000 constant current sources would make the system too expensive to achieve cost-effective aging.

[0157] · Routing 50,000 power lines to a 3-inch circle is very difficult if not impossible.

[0158] For further explanation purposes, the following assumptions can be made:

[0159] · A VCSEL is a diode, so there are few grounded short circuits to the power supply.

[0160] · "Open circuits" may occur at a higher frequency due to VSCELs being "open" or due to poor contact with the wafer.

[0161] · The internal resistance of a VCSEL is very large (about 100 ohms for a VCSEL at 10 mA) and is very consistent across the entire wafer (within 1%).

[0162] · It is very likely to construct a very precise voltage source (within 1%).

[0163] · The current of the voltage source can be measured quite accurately.

[0164] · Most VCSEL wafers have a common cathode, which limits the ability to place VCSELs in series.

[0165] · For ease of explanation, assume:

[0166] · VCSEL aging requires approximately 2.5 volts and 10 mA.

[0167] · Assume the system has 1024 power channels, each with a maximum of 5 volts and 200 mA.

[0168] · Assume the system can provide a constant current or a constant voltage for each channel.

[0169] · Assume the goal is to age 1 / 4 of the wafer (12,500 VCSELs) in one step.

[0170] The following is a list of existing aging circuit options:

[0171] (1) Individual constant current sources. This provides an accurate and measurable current for each VCSEL, but there are the following problems:

[0172] · Only about 2% of the wafer (1024 channels for 50,000 devices) can be burned per step.

[0173] · The "cost" of each VCSEL is 1 channel. Even if additional channels can be added, the cost of each VCSEL remains 1 channel.

[0174] · Even if the system can be scaled up to 12,500 channels (the minimum number of channels required for 1 / 4 of the burn-in wafers), it is impossible or cost-prohibitive to route 12,500 power channels to a 3-inch wafer area.

[0175] (2) Series wiring. This would require approximately 13 VCSELs to be connected in series and driven using a constant current source, but there are the following problems:

[0176] · Since all VCSELs have a common cathode, it is not possible to connect the VCSEL wafers in series.

[0177] · This requires a current source of 10 mA and a current above 30 V. Protecting against current surges at this high voltage is very difficult.

[0178] (3) Parallel wiring with a current source. Approximately 13 VCSELs are driven in parallel using a constant current source. This would require a 2.5 V, 130 mA current source. The following problems exist with this system:

[0179] · For each VCSEL with an "open" or bad probe contact, the extra current will be distributed to the remaining VCSELs in the group. Thus, for each bad VCSEL in the group, each VCSEL will receive an extra 8% current (130 mA / 12 VCSELs).

[0180] · If there is no significant voltage shift due to a VCSEL being open, it will not be known that the other 12 VCSELs are receiving the wrong aging current, so the bad device may escape detection.

[0181] (4) Parallel wiring with a voltage source. Such a system would drive 13 VCSELs in parallel with a constant voltage source. The voltage source is selected to be the voltage required for all 13 VCSELs to receive 10 mA current. The following problems exist with this system:

[0182] · If a VCSEL is open, the total current in the group will decrease slightly. For each open VCSEL, the group current will decrease by 10 mA (e.g., the group is 140 mA as opposed to 150 mA). The remaining VCSELs in the group will still reach 10 mA.

[0183] · The current stability for each VCSEL in the group is very good. In the worst case, it is the accuracy of the voltage supply (<1%) and the consistency of the internal resistance of the good VCSELs (<1% across the wafer). Thus, the current through each VCSEL will be within 2% across the wafer using a parallel voltage source.

[0184] · If the VCSEL shorts (highly unlikely), the overcurrent protection on the power channel will turn off that power channel while the other channels remain operational.

[0185] Thus, the existing solutions can be summarized as follows:

[0186] · Circuit 1 is an ideal circuit, but cost and technical issues are not included.

[0187] · Circuit 2 cannot be implemented on a common cathode VCSEL wafer.

[0188] · Circuit 3 produces very poor results in the most common fault mode, "open" devices.

[0189] · Circuit 4 provides very good results in almost all cases and is very cost-effective.

[0190] Circuit 4 (parallel wiring with a voltage source) has the following problems:

[0191] · The correct voltage needs to be selected for the voltage source so that the VCSEL receives the appropriate current.

[0192] · The appropriate voltage is a function of several factors:

[0193] · VCSEL structure. The design of the VCSEL determines the voltage for the required current.

[0194] · Variation in the VCSEL manufacturing process from wafer to wafer. Due to process variations, the voltage at a given current may vary from wafer to wafer.

[0195] · Variation in the VCSEL manufacturing process on the wafer. The voltage at a given current can vary between devices near the edge of the wafer and devices at the center of the wafer.

[0196] · The voltage at a specific current varies with temperature. Not only the heat added for aging, but also the internal heating of the device itself can change the voltage at a given current.

[0197] As the VCSEL ages, its voltage / current relationship changes. Thus, even if the voltage is correct at the start of the aging cycle, the final appropriate voltage may be lower.

[0198] Figure 15 Only the first set (Set 1) of the clusters (Clusters 1 to 4) of the electronic devices 634 located in the area near the edge of the wafer 636 is shown. It should be understood that there are 16 sets (Sets 1 to 4) of clusters and each set has 64 clusters, each cluster having 12 electronic devices 634.

[0199] The electronic devices 634 of the first cluster (cluster 1) are connected in parallel either through conductors forming part of the wafer 636 or through external devices forming part of the test device 10. Other clusters (clusters 2 - 4) of electronic devices (not shown) are located in other regions of the first group (group 1). Each cluster has a corresponding set of twelve electronic devices that are connected in parallel with each other. The electronic devices forming one cluster are not electrically connected to the electronic devices forming part of any other cluster.

[0200] The test device 10 includes a cluster selector switch 638, a current detector 640, a static filter 642, an outlier filter 644, a sample size filter 646, a voltage targeting system 648, a voltage source 650, and first and second voltage regulators 652 and 654.

[0201] Each cluster provides a separate current output to the cluster selector switch 638. The cluster selector switch 638 is adjustable to selectively connect the current detector 640 to a corresponding one of the current outputs 660. The current from the corresponding current output 660 is delivered to ground 662 through the current detector 640.

[0202] The cluster selector switch 638 is normally operated to connect each of the current outputs 660 to the current detector 640. The current detector 640 thus detects the current from each cluster.

[0203] The current detector 640 provides an output to the static filter 642. The static filter 642 is adapted to remove the current readings of the corresponding clusters that are above or below a set limit. The static filter 642 typically processes the data of all clusters simultaneously to remove the data of the clusters having current readings above or below the set limit.

[0204] The static filter 642 passes the data to the outlier filter 644. The outlier filter 644 removes the current readings of the corresponding clusters that are too far from or below the median for a set of clusters. The outlier filter 644 passes the data to the sample size filter 646. If the number of channels (devices) of a cluster is too small, the sample size filter 646 stops calculating the mean of the current readings of the cluster set including the cluster.

[0205] The voltage source 650 is connected to the input voltage terminals of the electronic devices 634 of the first group through the voltage regulator 652. The voltage source 650 is also connected to the input terminals of the electronic devices of the second group through the voltage regulator 654. Similarly, the voltage source 650 is connected to the electronic devices of other groups through additional voltage regulators (not shown).

[0206] The voltage targeting system 648 receives data from the sample size filter 646 and adjusts the voltage regulators 652 and 654 based on this data.

[0207] Figure 16 shows a method of testing a plurality of electronic devices 634 using the components of the test apparatus 10 in Figure 15 .

[0208] At 700, as described above, a plurality of electronic devices are held in a cluster. At 702, a voltage source 650 is connected to the electronic devices 634 of the first cluster. As described above, the voltage source 650 is connected to the electronic devices 634 to provide a voltage to the electronic devices 634 of the first cluster in parallel. At 704, the voltage source 650 is connected to the electronic devices of the second cluster through a voltage regulator 652 to provide a voltage to the electronic devices of the second cluster in parallel. Similarly, at 706, the voltage source 650 is connected to the electronic devices of the third cluster through a voltage regulator 652 to provide a voltage to the electronic devices of the third cluster in parallel. The voltage source 650 can be similarly connected to other clusters of electronic devices through the voltage regulator 652 to provide a voltage to the electronic devices of each cluster in parallel.

[0209] Referring to Figure 17 , the slope of the curve is calculated by first determining voltage guesses "A" and "B". Figure 16 Steps 708 to 724 in

[0210] correspond to the calculation of the slope. A At 708, a first initial voltage guess "V Figure 15 " is made, and a first initial current "I A " measured using the current detector 640 in Figure 15 is obtained. The voltage source 650 in

[0211] Figure 15 provides the first initial voltage guess to the electronic devices 634 of the first cluster in parallel. Second, third, and other clusters receive similar treatment to the first cluster. For example, the voltage source 650 provides the first initial voltage guess to the electronic devices of the second cluster in parallel. Figure 16 The cluster selector switch 638 in

[0212] The current detector 640 provides a current measurement value to Figure 15 the static filter 642 in Figure 16 As can be seen more clearly in Figure 16 , a multi-stage filtering 710 is performed, which includes static filtering 712, outlier filtering 714, and sample size filtering 716. As Figure 15 shown,

[0213] Figure 18 shows the static filtering in more detail. The individual currents from the first and second groups are shown. The static filtering eliminates the current readings above and below the set limits; for example, below 2 and above 6. The static filtering can, for example, remove the first initial current readings of the corresponding clusters in the corresponding groups above and below the set limits. Any given cluster may have "open" VCSELs, so the correct total current is not returned for all VCSELs. The current limit can be used to determine whether any given reading is correct.

[0214] After the static filtering, the data is processed at Figure 16 714 in Figure 15 to perform outlier filtering using the outlier filter 644 in

[0215] Figure 19 shows the outlier filtering in more detail. The outlier filtering removes the data above and below the data median; for example, + / - 20%. The outlier filtering can, for example, remove the first initial current readings that are far above or below the median of the corresponding cluster for the group. Additional filtering can use statistical methods to determine whether the first initial current readings of a given channel are abnormal. Figure 16 After the outlier filtering, the data is processed at Figure 15 716 in

[0216] to perform sample size filtering using the sample size filter 646 in Figure 16 Sample size filtering is shown in Figure 20. If the number of remaining clusters is too small (e.g., < 10), the sample size filtering stops calculating the average of the first initial current readings of the group. If any group has too few clusters for proper calculation, the average calculation of the surrounding groups can be used. Two sample groups are included to show how the filtering will progress. After the outlier filtering, the second group has too few remaining clusters to give a reliable voltage calculation. In this case, the average of another group is used. B At 720 in B , a second voltage guess "V

[0217] At 722, multi - stage filtering is performed on data including the second initial current from the cluster. The multi - stage filtering performed at 722 is the same as the multi - stage filtering performed at 710.

[0218] Figure 17 The positions of the first and second initial currents after multi - stage filtering at 710 and 722 are shown. Current measurements are shown on the Y - axis and time is shown on the X - axis. The current slope is given by:

[0219] Slope=(V B - V A ) / (I B - I A )

[0220] Thus, the slope is calculated by dividing the difference between the second and first initial voltages of the first set of electronic devices by the difference between the second and first initial currents of the first set of electronic devices.

[0221] The above - described steps 708, 712, and 724 are performed by Figure 15 the voltage targeting system 648. The voltage targeting system 648 controls the voltage regulator 652 to supply voltage to the electronic devices of each cluster. The voltage targeting system 648 then stores the calculated slope in the memory.

[0222] At Figure 17 724 in, after calculating and storing the slope, the voltage targeting system 648 can use the slope to set and re - position the test voltage applied to each cluster of the electronic devices 634. The setting and redirecting of the test voltage are illustrated by Figure 16 the steps 726 to 736 in.

[0223] At 726, a guess is made for the first test voltage (V G ) and the resulting first test current (I G ) is measured. From the above description and Figure 15 it should be understood that the voltage targeting system 648 sets the voltage regulator 652 such that the voltage source 650 applies the first test voltage in parallel to the electronic devices 634 of the first cluster. It should also be understood that the first test current from the electronic devices 634 of the first cluster measured by the current detector 640 is the total current of the electronic devices 634 of the first cluster in parallel.

[0224] The second and third clusters of the first set receive similar treatment. Thus, each additional cluster has a corresponding first test voltage that is applied to the devices of the cluster and has a first test current measured from the devices.

[0225] After measuring the first test current from the cluster, the data of the first test current is passed through a multistage filter 730 again. The multistage filter 730 is performed on the first test current in a manner similar to the multistage filter 710 performed on the first initial current from the clusters of the first group and the multistage filter 722 performed on the second initial current from the clusters.

[0226] At 732, a first comparison is made between the first test current and the target current. Specifically, the measured first test current is subtracted from the target current. The difference is recorded as the amount of current error that must be corrected. Figure 17 Shows the first initial current as the result of the first initial guess ("G"), the target current (I T ), and the current error (I T -I G ).

[0227] At Figure 16 734, rescaling is performed. A second test voltage is calculated and the first test voltage is adjusted to the second test voltage. As Figure 17 shown, the second test voltage is calculated according to the formula:

[0228] V G +(I T -I G )*slope

[0229] Thus, the first comparison at 732 forms the basis for the voltage adjustment at 734.

[0230] Figure 16 736 in

[0231] Figure 16 indicates that the process starting from 726 can be repeated by using the redirected voltage as the first test voltage, then measuring the test current and calculating the redirected voltage.

[0232] The dashed lines of 702 and 706 in Figure 16

[0232] indicate that the clusters of the second and third groups are subjected to a similar process as the clusters of the first group. In the given example, the voltage source 650 supplies voltage to the electronic devices of the second group through the voltage regulator 654. The voltages applied to the electronic devices of the first and second groups can be independently controlled in the above manner. In a similar manner, separate voltage regulators supply voltage to the electronic devices of separate groups. Although only a single current detector 640 is shown, it should be understood that multiple current detectors can be included in the system to detect the current from one or more clusters in one or more groups.

[0233] Clusters can be selected to match wafer processing (or other) factors that may affect the voltage / current relationship.

[0234] · It is not uncommon for devices near the wafer edge to have different characteristics from those near the wafer center.

[0235] · Clusters can be selected so that edge devices are analyzed using other edge devices and center devices are analyzed using other center devices.

[0236] The redirection process is highly convergent and insensitive to minor errors.

[0237] · For example, assume that the initial voltage / current calculation is poorly performed, resulting in a slope deviation of 20%.

[0238] · Assume that in the first repositioning step, the calculated voltage error is 50% (i.e., the current error is 50%).

[0239] · The first repositioning will attempt to correct a 50% current error using a slope with a 20% error. Then the net correction rate will be in error by 10% (50% * 20%).

[0240] · Then, the next redirection step will correct this 10% error and miscalculate by 20% again. This correction will only be in error by 2% (10% * 20%).

[0241] · Thus, after only 2 redirection steps, with a starting error of 50% and a slope error of 20%, the resulting current is now within 2%.

[0242] · This illustrates the rapid convergence of this redirection algorithm. More typically, the slope will be calculated within about 5% and the initial current will be within 20%. Then, only one step is required to be within 1% of the correct current.

[0243] Although certain exemplary embodiments have been described and illustrated in the drawings, it should be understood that these embodiments are merely illustrative and not limiting of the invention, and the invention is not limited to the specific structures and arrangements shown and described, as those of ordinary skill in the art can make modifications.

Claims

1. A box, comprising: a socket, the socket being made of an insulating material and having an upper side and a lower side, a first structure on the upper side for holding a first electronic device, and a second structure on the upper side for holding a second electronic device; a lid; a first pusher plate rotatably mounted on the lid; a second pusher plate rotatably mounted on the lid, the lid being capable of being positioned on the socket and moving towards the socket, the rotatable mounting of the first pusher plate allowing the first electronic device to rotate the first pusher plate relative to the lid, and the rotatable mounting of the second pusher plate allowing the second electronic device to rotate the second pusher plate independently of the first pusher plate relative to the lid; a first set of contacts held in the socket for connecting to the first electronic device; a first set of terminals connected to the first set of contacts; a second set of contacts held in the socket for connecting to the second electronic device; and a second set of terminals connected to the second set of contacts.

2. The box according to claim 1, wherein the first pusher plate is capable of rotating relative to the lid about first and second orthogonal axes, and the second pusher plate is capable of rotating relative to the lid about first and second orthogonal axes.

3. The box according to claim 1, further comprising: a first heat surface within the first structure, wherein rotation of the first pusher plate relative to the lid allows the lower surface of the first electronic device to abut against the first heat surface; and a second heat surface within the second structure, wherein rotation of the second pusher plate relative to the lid allows the lower surface of the second electronic device to abut against the second heat surface.

4. The box according to claim 3, wherein the first set of contacts is elastically pressable to bring the first electronic device into contact with the first heat surface, and the second set of contacts is elastically pressable to bring the second electronic device into contact with the second heat surface.

5. The box according to claim 1, further comprising: a first spring connected between the lid and the first pusher plate, the first pusher plate being capable of linearly moving relative to the lid by the first electronic device to cause deformation of the first spring; and a second spring connected between the lid and the second pusher plate, the second pusher plate being capable of linearly moving relative to the lid by the second electronic device to cause deformation of the second spring.

6. The box according to claim 5, wherein the first pusher plate has a first pusher plate lip, and the lid has a first lid flange, wherein the first pusher plate lip abuts against the first lid flange to prevent the first spring from moving the first pusher plate out of the lid, the second pusher plate has a second pusher plate lip, and the lid has a second lid flange, wherein the second pusher plate lip abuts against the second lid flange to prevent the second spring from moving the second pusher plate out of the lid.

7. The box according to claim 1, further comprising: a fixing structure on the lid; and a fixing structure on the socket, the fixing structures being capable of engaging with each other to fix the lid to the socket after moving the lid towards the socket.

8. The box according to claim 1, wherein the socket has a third structure on the upper side for holding a third device, and the box further comprising: A third push plate, rotatably mounted on the lid, the rotatable mounting of the third push plate allowing a third device to rotate the third push plate relative to the lid independently of the second push plate; A third set of terminals, held in a socket to connect a third device; A third set of contacts, connected to the third set of terminals.

9. A method of testing one or more electronic devices, comprising: Releaseably holding a first electronic device in a first structure on an upper side of a socket of an insulating material; Releaseably holding a second electronic device in a second structure on an upper side of the socket; Positioning a lid on the socket, the lid having a first push plate rotatably mounted to the lid and a second push plate rotatably mounted to the lid; Moving the lid towards the socket, the rotatable mounting of the first push plate allowing the first electronic device to rotate the first push plate relative to the lid, and the rotatable mounting of the second push plate allowing the second electronic device to rotate the second push plate relative to the lid independently of the first push plate; and Connecting the first and second electronic devices to an electrical tester via an interface connected to the socket.

10. A box, comprising: An electronic device holder having a structure for removably holding an electronic device having input contacts and a light emitter; Input contacts on the electronic device holder are connected to input contacts on the electronic device to supply input power to the input contacts on the electronic device via the input contacts on the electronic device holder, the input power causing the light emitter to emit light; A light detector mounted on the electronic device holder and positioned to detect light and generate output power in response to light intensity; and Output contacts connected to the light detector to measure the output power.

11. The box according to claim 10, wherein the electronic device holder defines a cavity into which the light is directed and through which the light is transmitted from the light emitter to the light detector.

12. The box according to claim 11, further comprising: A light absorption coating provided on a surface of the cavity.

13. The box according to claim 10, further comprising: A socket having a structure for holding an electronic device; A lid, the socket and the lid together forming the electronic device holder; and A push plate mounted to move relative to the lid, the lid being positionable on and movable towards the socket, the movable mounting of the push plate allowing the electronic device to move the push plate relative to the lid, the push plate having an opening through which the light is transmitted from the light emitter to the light detector.

14. The box according to claim 13, further comprising: A spring connected between the lid and the push plate, the push plate being linearly movable relative to the lid by a first device to cause deformation of the spring, the spring being a helical spring through which the light propagates.

15. The box according to claim 10, further comprising: A temperature regulating device on a first side of the device holder, which when operated changes the temperature to cause a temperature difference between the temperature regulating device and the electronic device and heat transfer between the temperature regulating device and the electronic device to change the temperature of the electronic device.

16. The box according to claim 15, further comprising: A heat sink, the heat sink being on the side of the device holder opposite to the temperature regulating device, the heat sink having a surface for absorbing light, the light that generates heat in the heat sink; and A heat dissipating device, the heat dissipating device being thermally connected to the heat sink to remove heat from the heat sink.

17. The cartridge according to claim 16, further comprising: A light detector, the light detector being mounted on the electronic device holder and positioned to detect light and generate output power in response to the light intensity; Output contacts, the output contacts being connected to the light detector to measure the output power.

18. A method for testing one or more electronic devices, comprising: Inserting an electronic device having input contacts and a light emitter into the device holder; Connecting the input contacts on the electronic device holder to the input contacts on the electronic device; Providing input power through the input contacts on the electronic device holder to the input contacts on the electronic device, the input power causing the light emitter to emit light; Detecting the light; Converting the detected light into output power; Measuring the output power through the output contacts; and Removing the electronic device from the electronic device holder.

19. A testing device, comprising: A socket, the socket having a structure for removably holding an electronic device having input terminals and a light emitter; The input contacts on the socket are connected to the input terminals on the electronic device to provide input power through the input contacts on the socket to the input terminals on the electronic device, the input power causing the light emitter to emit light; A temperature regulating device, the temperature regulating device being on the first side of the socket, the temperature regulating device changing the temperature during operation to cause a temperature difference between the temperature regulating device and the electronic device and heat transfer between the temperature regulating device and the electronic device to change the temperature of the electronic device; A heat sink, the heat sink being on the side of the socket opposite to the temperature regulating device, the heat sink having a surface for absorbing light, the light that generates heat in the heat sink; and A heat dissipating device, the heat dissipating device being thermally connected to the heat sink to remove heat from the heat sink.

20. The cartridge according to claim 19, further comprising: A thin chuck, the thin chuck together with the socket, the heat sink and the heat dissipating device forms a cartridge; and A thermal chuck, the cartridge being movable to engage the thin chuck with the thermal chuck, the temperature regulating device being located within the thermal chuck.

21. The cartridge according to claim 19, wherein the temperature regulating device is a heater.

22. The cartridge according to claim 21, wherein the heater is a resistive heater.

23. The cartridge according to claim 20, wherein the temperature regulating device is a cooler.

24. The cartridge according to claim 23, wherein the cooler is a fluid channel through which fluid circulates.

25. The cartridge according to claim 19, further comprising: A light absorption coating on the surface of the heat sink.

26. The cartridge according to claim 19, wherein, The heat sink defines a cavity, the light is guided into the cavity, and the light is transmitted from the light emitter through the cavity to the surface to absorb the light.

27. The cartridge according to claim 19, wherein, The heat dissipating device includes a plurality of fins, heat is conducted from the heat sink to the fins and convected from the fins.

28. A method for testing one or more electronic devices, comprising: inserting an electronic device having input contacts and a light emitter into a socket; connecting the input contacts on the socket to the input terminals on the electronic device; supplying input power to the input terminals on the electronic device through the input contacts on the socket, the input power causing the light emitter to emit light; changing a temperature regulating device on a first side of the socket for creating a temperature difference between the temperature regulating device and the electronic device, and transferring heat between the temperature regulating device and the electronic device to change the temperature of the electronic device; absorbing light on a surface of a heat sink on a side of the socket opposite to the temperature regulating device, the absorbed light generating heat in the heat sink; removing heat from the heat sink by using a heat dissipating device thermally connected to the heat sink; and removing the electronic device from the socket.

29. A box, comprising: a socket of insulating material having an upper side and a lower side and a structure on the upper side for holding an electronic device; a contact group held in the socket for connecting the electronic device; a terminal group connected to the contact group held by the socket; a circuit board, the terminal group connected to the contact group being connected to a contact group on the circuit board; a lid; a detector mounted on the lid, the lid being movable to be positioned above the socket so that when power is supplied to the electronic device through at least one terminal in the terminal group held by the socket, the detector is located at a position for detecting characteristics of the electronic device, and a measurement channel connecting the detector to an interface on the circuit board.

30. The box according to claim 29, wherein, the detector is a light detector.

31. The box according to claim 30, wherein the light detector converts light power into electric power, the measurement channel is an electrical conductor, and the interface on the circuit board is an electrical contact.

32. The box according to claim 29, further comprising: a first set of pins held by the socket, opposite ends of each pin in the first set of pins forming one of the contacts held by the socket and one of the terminals connected to the corresponding terminal; and detector measurement pins held by the socket and forming part of the measurement channel.

33. The box according to claim 32, further comprising: terminals on the lid, the detector measurement pins having contacts engaging the terminals on the lid.

34. The box according to claim 33, wherein the contacts of the first set of pins are located in a first plane, and the contacts on the detector measurement pins are located in a second plane parallel to and spaced from the first plane.

35. The box according to claim 34, wherein, the measurement pins have terminals at their ends opposite to the contacts, and the terminals on the first set of pins and the terminals on the measurement pins are in the same plane.

36. The box according to claim 35, wherein, by moving the lid towards the socket, the first set of pins and the measurement pins can be pressed simultaneously.

37. The box according to claim 36, further comprising: detector power pins fixed by the socket and supplying power to the detector.

38. A method for testing one or more electronic devices, comprising: An electronic device is releasably held in a socket of an insulating material, the socket having an upper side and a lower side and a structure on the upper side for holding the electronic device; Connecting a contact group held in the socket to the electronic device; Connecting a terminal group connected to the contact group to a contact group on a circuit board; Moving a lid equipped with a detector onto the socket; Connecting the detector to an interface on the circuit board through a measurement channel; Powering the electronic device through at least one contact held by the socket; Detecting characteristics of the electronic device when powering the electronic device through at least one contact held by the socket; and Measuring the characteristics through the interface.

39. A cartridge, comprising: A support plate having a column opening therethrough; A support structure located on a first side of the support plate, and the support structure at least includes a circuit board having contacts; A conductor having a contact that contacts a terminal on the electronic device, the electronic device being located on a second side of the support plate opposite to the first side of the support plate, the conductor having a portion held by the support plate and a terminal connected to the contact on the circuit; A spring; A force generating device on a side of the electronic device opposite to the support plate, the force generating device and the support plate being movable relative to each other to move the electronic device closer to the support plate and deform the spring; and A pillar having a support, a force transfer portion, and a force transmission portion, the support having a surface in a plane spaced apart from the plane of the surface of the support plate to prevent the electronic device from moving closer to the support plate, the force transfer portion extending from the support and at least partially passing through the column opening, the force transmission portion extending from the force transfer portion and the force transmission portion being held by the support structure.

40. The cartridge according to claim 39, further comprising: A pin including a spring and a first tip and a second tip located on opposite sides of the spring, the movement of the first tip and the second tip towards each other compresses the spring.

41. The cartridge according to claim 40, wherein the contact of the conductor is the end of the first tip.

42. The cartridge according to claim 40, wherein the terminal of the conductor is the end of the second tip.

43. The cartridge according to claim 39, wherein the force transmission portion is wider than the force transfer portion.

44. The cartridge according to claim 43, wherein, due to the force transmission portion being wider than the force transfer portion, the column is prevented from falling out of the opening.

45. The cartridge according to claim 44, wherein the column opening has a first portion and a second portion wider than the first portion, such that a platform is defined between the first portion and the second portion, wherein the force transmission portion abuts against the platform.

46. The cartridge according to claim 39, wherein the pillar has a surface on the force transmission portion and on a side of the pillar opposite to the surface of the support, and the surface on the force transmission portion abuts against the support structure to transmit force.

47. The cartridge according to claim 39, wherein the spring deforms the spring against its spring force.

48. The cartridge according to claim 39, wherein, In use, the support receives a force from the electronic device, and the force transfer portion transfers the force from the support at least partially through the opening. The force transmission portion receives the force from the force transfer portion and transmits the force to the support structure.

49. The cassette according to claim 39, wherein the force generating device is a chuck located under a wafer having a plurality of electronic devices, wherein the support plate is a contactor, and wherein the circuit board has a plurality of contacts. The cassette further comprises: a plurality of conductors, each conductor having a corresponding contact for contacting a corresponding terminal on one electronic device, each conductor having a corresponding portion held by the contactor and a corresponding terminal connected to a corresponding one of the contacts on the circuit board.

50. The cassette according to claim 39, wherein the support plate is a socket having a structure for holding the electronic device, wherein the force generating device is a lid located above the electronic device, and wherein the support structure includes a chuck of a heat-conductive material, and the circuit board is supported by the chuck.

51. The cassette according to claim 50, wherein the pillar is a thermal pillar that passes through an opening in the circuit board and is supported by the chuck.

52. The cassette according to claim 51, further comprising a thermal anchor held by the chuck, and the thermal pillar extends from the thermal anchor.

53. The cassette according to claim 50, wherein the pillar has a surface on the force transfer portion and on a side of the pillar opposite to the surface of the support, and the surface on the force transfer portion abuts against the support structure to transfer the force.

54. A cassette, comprising: a support structure is provided on a first side of a support plate, and the support structure at least includes a circuit board having contacts; connecting the contacts of the conductor to the terminals of the electronic device, and the electronic device is located on a second side of the support plate opposite to the first side of the support plate. The conductor has a portion held by the support plate and a terminal connected to the contact on the circuit board; positioning a force generating device on a side of the electronic device opposite to the support plate; moving the force generating device and the support plate relative to each other, moving the electronic device closer to the support plate, and deforming the spring by overcoming the spring force of the spring; using a pillar having a support to prevent the electronic device from moving closer to the support plate, and the support has a surface in a plane spaced apart from the plane of the surface of the support plate; receiving a force from the electronic device through the support of the pillar; transferring the force at least partially through the opening from the support through the force transfer portion of the pillar, and the force transfer portion extends from the support and at least partially passes through the pillar opening formed in the support plate; receiving the force using the force transmission portion of the pillar, and the force transmission portion extends from the force transfer portion and is held by the support structure; and transmitting the force to the support structure.

55. A test device, comprising: a voltage targeting system; a holder for holding a plurality of electronic devices in at least a first cluster and a second cluster; at least one voltage source capable of being connected to the electronic devices in the first cluster to provide a first test voltage to the electronic devices in the first cluster in parallel, and capable of being connected to the electronic devices in the second cluster to provide a first test voltage to the electronic devices in the second cluster in parallel; At least one current detector, which can be connected to the devices in the first cluster to measure a first test current from the devices in the first cluster. The first test current from the devices in the first cluster is measured by the current detector as the total current of the devices in the first cluster connected in parallel. The current detector can be connected to the devices in the second cluster to measure a first test current from the devices in the second cluster. The first test current from the devices in the second cluster is measured by the current detector as the total current of the devices in the second cluster connected in parallel. Wherein, the voltage aiming system makes a first comparison by comparing the first test current from the devices in the first cluster measured with the target current; A first voltage regulator, which, in response to the first comparison, adjusts the first test voltage to a second test voltage for the first cluster, such that the first test current from the devices in the first cluster is adjusted to a second test current closer to the target current. Wherein, the voltage aiming system makes a second comparison by comparing the first test current from the devices in the second cluster measured with the target current; and A second voltage regulator, which, in response to the second comparison, adjusts the first test voltage to a second test voltage for the second cluster, such that the first test current from the devices in the second cluster is adjusted to a second test current closer to the target current.

56. The tester according to claim 55, further comprising: A static filter, which is used to delete the first test current readings of the corresponding clusters that are higher and lower than the set limits.

57. The tester according to claim 55, further comprising: An outlier filter, which is used to delete the first test current readings of the corresponding clusters that are far higher or lower than the median of a group of clusters.

58. The tester according to claim 55, further comprising: A sample size filter, which stops calculating the average value of the first test current readings of the surrounding clusters if the number of electronic devices in the first cluster is too small.

59. The tester according to claim 55, wherein the voltage aiming system: stores the slope of the first cluster representing the relationship between voltage and current; determines a first current difference of the first cluster by subtracting the target current from the first test current of the devices in the first cluster; and determines a voltage difference of the first cluster by multiplying the first current difference of the first cluster by the slope of the first cluster, wherein the voltage regulator adjusts the first test voltage from the devices in the first cluster to the second test voltage of the devices in the first cluster through the voltage difference of the first cluster.

60. The tester according to claim 59, wherein: the voltage aiming system makes a first initial voltage guess for the devices in the first cluster; at least one current detector measures a first initial current of the devices in the first cluster as a result of the first initial voltage guess for the devices in the first cluster; the voltage aiming system makes a second initial voltage guess for the devices in the first cluster; at least one current detector measures a second initial current of the devices in the first cluster as a result of the first initial voltage guess for the devices in the first cluster; and The voltage targeting system calculates the slope of the first cluster by dividing the difference between the second initial voltage and the first initial voltage of the devices in the first cluster by the difference between the second initial current and the first initial current of the devices in the first cluster.

61. The tester according to claim 60, wherein the voltage targeting system: stores the slope of the second cluster representing the relationship between voltage and current; determines a first current difference of the second cluster by subtracting a target current from a first test current of the devices in the second cluster; and determines a voltage difference of the second cluster by multiplying the first current difference of the second cluster by the slope of the second cluster, wherein a voltage regulator adjusts a first test voltage from the devices in the second cluster to a second test voltage of the devices in the second cluster by the voltage difference of the second cluster.

62. The tester according to claim 61, wherein: the voltage targeting system makes a first initial voltage guess for the devices in the second cluster; at least one current detector measures a first initial current of the devices in the second cluster as a result of the first initial voltage guess for the devices in the second cluster; the voltage targeting system makes a second initial voltage guess for the devices in the second cluster; at least one current detector measures a second initial current of the devices in the second cluster as a result of the first initial voltage guess for the devices in the second cluster; and the voltage targeting system calculates the slope of the second cluster by dividing the difference between the second initial voltage and the first initial voltage of the devices in the second cluster by the difference between the second initial current and the first initial current of the devices in the second cluster.

63. The tester according to claim 62, further comprising: a static filter that deletes the first initial current readings of the corresponding cluster that are above and below a set limit.

64. The tester according to claim 62, further comprising: an outlier filter that removes the first initial current readings of the corresponding cluster that are far above or below the median of a set of clusters.

65. The tester according to claim 62, further comprising: a sample size filter that stops calculating the average of the first initial current readings of the surrounding clusters if the number of electronic devices in the first cluster is too small.

66. The tester according to claim 62, further comprising: a static filter that deletes the second initial current readings of the corresponding cluster that are above and below a set limit.

67. The tester according to claim 62, further comprising: an outlier filter that removes the second initial current readings of the corresponding cluster that are far above or below the median of a set of clusters.

68. The tester according to claim 62, further comprising: a sample size filter that stops calculating the average of the second initial current readings of the surrounding clusters if the number of electronic devices in the first cluster is too small.

69. A method of testing a plurality of electronic devices, comprising: holding the plurality of electronic devices in at least a first cluster and a second cluster; connecting at least one voltage source to the electronic devices in the first cluster to provide a first test voltage to the electronic devices in the first cluster in parallel and being capable of connecting to the electronic devices in the second cluster to provide a first test voltage to the electronic devices in the second cluster in parallel; Connect at least one voltage source to the electronic devices of the second cluster to provide a first test voltage to the electronic devices of the second cluster in parallel; Measure a first test current from the devices of the second cluster using at least one current detector, and measure the first test current from the devices of the first cluster as the total current of the devices of the first cluster in parallel by the current detector; Measure a first test current from the devices of the second cluster using at least one current detector, and measure the first test current from the devices of the first cluster as the total current of the devices of the first cluster in parallel by the current detector; Perform a first comparison using a voltage targeting system by comparing the first test current from the devices of the first cluster measured with a target current; Utilize a first voltage regulator to adjust the first test voltage to a second test voltage for the first cluster in response to the first comparison, such that the first test current from the devices of the second cluster is adjusted to a second test current closer to the target current; Perform a second comparison using a voltage targeting system by comparing the first test current from the devices of the second cluster measured with a target current; and Utilize a second voltage regulator to adjust the first test voltage to a second test voltage for the second cluster in response to the second comparison, such that the first test current from the devices of the second cluster is adjusted to a second test current closer to the target current.

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