Electronic tester

Abstract

A test fixture is described. Various components contribute to the functionality of the test fixture, including an insertion and removal device, a thermal post, a separate universal joint, a combination including a light detector, a thermal control method, a detection circuit in a socket cover, a standoff, and voltage redirection.

Description

[0001] This application is a divisional application of the Chinese patent application with application number 201880015746.6, application date 2018-02-27, and name “Electronic Tester”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to 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 by reference into this application. Technical Field

[0004] The invention relates to a testing device for testing a microelectronic circuit. Background Art

[0005] Microelectronic circuits are typically fabricated in and on semiconductor wafers. Such wafers are subsequently "singulated" or "diced" into individual die. Such dies are typically mounted on a support substrate to provide rigidity to the support substrate and to electronically communicate with the integrated or microelectronic circuits of the die. The final packaging may include packaging of the die, and the resulting package may then be shipped to the customer.

[0006] The die or package needs to be tested before it is shipped to the customer. Ideally, the die should be tested at an early stage to identify defects that occur early in the manufacturing process.

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

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

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

[0010] After the wafer is singulated, the individual dies may again need to be tested, and the dies may also need to be tested after being mounted to a supporting substrate. Summary of the invention

[0011] The present invention provides a testing device, which includes: a frame; a slot assembly, which is arranged on the frame; a slot assembly interface, which is arranged on the slot assembly; a holding structure, which is used to place a box that holds multiple microelectronic devices; a horizontal conveying device, which is operable to move the box horizontally from a first position to a second position to enter the slot assembly; a vertical conveying device, which is operable to move the box and the slot assembly relative to each other along a first vertical direction so that the slot assembly interface engages with the box interface on the box; and a tester, which is connected to the box interface through the first slot assembly interface to provide power to at least each microelectronic device to measure the performance of the microelectronic device, the vertical conveying device is operable to move the box and the slot assembly relative to each other in a second vertical direction, which is opposite to the first vertical direction, so that the slot assembly interface is disengaged from the box interface, and the horizontal conveying device is operable to move the box horizontally from the second position to a first position outside the slot assembly.

[0012] The present invention also provides a method for testing electronic devices, comprising: holding a box holding multiple microelectronic devices in a first position, at least partially located outside a slot assembly on a frame, moving the box horizontally from the first position to a second position to enter the slot assembly, moving the box and the slot assembly relative to each other along a first vertical direction so that the slot assembly interface on the slot assembly engages with the box interface on the box, providing at least power to each microelectronic device through the first slot assembly interface and the box interface to test the microelectronic device, and measuring the performance of the microelectronic device, moving the box and the slot assembly relative to each other along a second vertical direction, the second vertical direction being opposite to the first vertical direction, so that the slot assembly interface disengages from the box interface, and moving the box horizontally from the second position to the first position to remove it from the slot assembly.

[0013] The present invention also provides a box, comprising: a socket, which is made of insulating material and has an upper side and a lower side, the upper side having a first structure for releasably holding a first electronic device, and the socket having a first socket thermal opening formed through the socket from the lower side to the upper side; an interface, which is connected to the socket for connecting the first device to an electrical tester; a chuck, which is a chuck of thermally conductive material; and a first thermal column, which is connected to the chuck, the first thermal column is inserted into the first socket thermal opening, and one end of the first thermal column is thermally connected to the first device, so that heat is mainly transferred through the first thermal column 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, the socket is made of an insulating material and has an upper side and a lower side, the upper side has a first structure for releasably holding a first electronic device, the socket has a first socket thermal opening formed through the socket from the lower side to the upper side, and a first thermally conductive column can be inserted into the first socket thermal opening from the lower side; a first group of pins, the first group of pins is fixed in the socket and connects the first device to a circuit board, the first group of pins is elastically pressable; and a cover, the cover can be moved relative to the socket to press down the first group of pins so that the first electronic device contacts the end of the first thermal column.

[0015] The present invention also provides a test piece, comprising: a chuck, which is a chuck of heat-conducting material; and a first thermal column, which is connected to the chuck and can be inserted into a thermal opening of a first socket, and one end of the first thermal column is thermally connected to a first device, so that heat is mainly transferred through the first thermal column 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 the upper side of a socket made of insulating material; connecting the first device to an electrical tester via an interface connected to the socket; inserting a first thermal column connected to a chuck of thermally conductive 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 thermal column thermally connected to the first device; and transferring heat between the chuck and the first electronic device, the heat being transferred mainly through the first thermal column rather than the insulating material of the socket.

[0017] The present invention also provides a box, comprising: a socket, the socket is an insulating material and has an upper side and a lower side, the first structure of the upper side is used to hold a first electronic device, and the second structure of the upper side is used to hold a second electronic device; a cover; a first push plate, the first push plate is rotatably mounted on the cover; a second push plate, the second push plate is rotatably mounted on the cover, the cover can be positioned on the socket and can be moved toward the socket, the rotatable mounting of the first push plate allows the first electronic device to rotate the first push plate relative to the cover, and the rotatable mounting of the second push plate allows the second electronic device to rotate the second push plate relative to the cover independently of the first push plate; a first group of contacts, the first group of contacts is held in the socket to connect to the first electronic device; a first group of terminals, the first group of terminals is connected to the first group of contacts; a second group of contacts, the second group of contacts is held in the socket to connect to the second electronic device; and a second group of terminals, the second group of terminals is connected to the second group of contacts.

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

[0019] The present invention also provides a box, comprising: an electronic device holder, the electronic device holder having a structure for detachably holding an electronic device having input contacts and a light emitter; the input contacts on the electronic device holder are 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, the light detector is mounted on the electronic device holder and is positioned to detect light and generate output power in response to light intensity; and output contacts, the output contacts are 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, comprising: 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 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.

[0021] The present invention also provides a testing device, comprising: a socket, the socket having a structure for detachably holding an electronic device having an input terminal and a light emitter; input contacts on the socket 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, the 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, the heat sink on a side of the socket opposite to the temperature regulating device, the heat sink having a surface for absorbing light, absorbing light that generates heat in the heat sink; and a heat sink, the heat sink being 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 input terminals on the electronic device; providing 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 to generate a temperature difference between the temperature regulating device and the electronic device, generating transfer 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 using a heat sink 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, the contact group being held in the socket for connecting the electronic device; a terminal group, the terminal group being connected to the contact group held by the socket; a circuit board, the terminal group connected to the contact group being connected to the contact group on the circuit board; a cover; a detector, the detector being mounted on the cover, the cover 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, the 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 the 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 cover with a detector mounted on 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, the support plate having a column opening passing therethrough; a support structure, the support structure is located on a first side of the support plate, and the support structure includes at least a circuit board having contacts; a conductor, the conductor having contacts that contact terminals 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 terminals connected to the contacts on the circuit; a spring; a force generating device, the force generating device is on a side of the electronic device opposite to the support plate, the force generating device and the support plate being able to move relative to each other to bring the electronic device closer to the support plate and deform the spring; and a pillar, the 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: a support structure is arranged on a first side of a support plate, the support structure includes at least a circuit board with contacts; the contacts of the conductor are connected 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 having a portion held by the support plate and terminals connected to the contacts on the circuit board; a force generating device is positioned on a side of the electronic device opposite to the support plate; the force generating device and the support plate are moved relative to each other, so that the electronic device moves closer to the support plate, and the spring force of the spring is overcome to deform the spring; a pillar with a support is used to prevent the electronic device from moving close to the support plate, the support having a surface in a plane separated from the plane of the support plate surface; a force is received from the electronic device through the support of the pillar; a force transfer portion of the pillar is used to transfer the force from the support at least partially through the opening, the force transfer portion extends from the support and at least partially passes through the pillar opening formed on the support plate; a force is received using a force transmission portion of the pillar, the force transmission portion extends from the force transfer portion, and the force transmission portion is held by the support structure; and the force is transmitted to the support structure.

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

[0028] The present invention also provides a method for testing a plurality of electronic devices, comprising: maintaining 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 of the first cluster to provide a first test voltage in parallel to the electronic devices of the first cluster, and being connectable to the electronic devices of the second cluster to provide the first test voltage in parallel to the electronic devices of the second cluster; connecting at least one voltage source to the electronic devices of the second cluster to provide the first test voltage in parallel to the electronic devices of the second cluster; measuring a first test current from the devices of the second cluster using at least one current detector, the first test current from the devices of the first cluster being measured by the current detector as the total current of the devices of the first cluster connected in parallel; measuring the first test current from the devices of the second cluster using at least one current detector, the first test current from the devices of the first cluster being measured by the current detector as the total current of the devices of the first cluster connected in parallel; measuring the first test current from the devices of the second cluster using at least one current detector, the first test current from the devices of the first cluster being measured by the current detector as the total current of the devices of the first cluster connected in parallel A first test current of the device is measured by a current detector as a total current of the devices of a first cluster connected in parallel; a first comparison is performed using a voltage aiming system by comparing the first test currents of the devices from the first cluster measured with a target current; a first voltage regulator is used to adjust the first test voltage to a second test voltage of the first cluster in response to the first comparison, so that the first test current of the devices from the second cluster is adjusted to a second test current that is closer to the target current; a second comparison is performed using the voltage aiming system by comparing the first test currents of the devices from the second cluster measured with the target current; and a second voltage regulator is used to adjust the first test voltage to a second test voltage of the second cluster in response to the second comparison, so that the first test current of the devices from the second cluster is adjusted to a second test current that is 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 device having a slot assembly according to one embodiment of the present invention;

[0031] Figure 2 yes Figure 1 A cross-sectional side view of the test device shown in 2-2;

[0032] Figure 3 yes Figure 1 A cross-sectional side view of the test device shown in 3-3;

[0033] Figure 4 yes Figure 2 and Figure 3 A cross-sectional side view of the test device shown in 4-4;

[0034] Figure 5A , 5B and 5C are perspective views of the test apparatus showing the insertion or removal of the portable box into or out of the oven defined by the frame;

[0035] Figure 6 is a timing diagram showing how one cassette is inserted and used to test the electronics of a wafer and then inserted into another cassette;

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

[0037] Fig. 8A and 8B is a cross-sectional side view showing the Figure 1-7 The support used in the construction of the described box;

[0038] Fig. 9 A, 9B and 10 are side views showing means for inserting and removing the portable box into and from the oven;

[0039] Fig.11 is a perspective view showing a box according to another embodiment of the present invention;

[0040] Fig.12 yes Fig.11 a cross-sectional side view of a portion of a box in;

[0041] Fig.13 It is shown Fig.12 A cross-sectional side view of a detail of a portion of the view;

[0042] Fig.14A and 14B It is explained in Figure 11-13 A cross-sectional side view of a support used in a configuration of;

[0043] Fig.15 Components of a test device for controlling voltages of various electronic devices are shown;

[0044] Fig.16 It shows Fig.15 A flowchart of the operation of the components in;

[0045] Fig.17 It shows that Fig.16 A graph of the voltage recalibration process;

[0046] FIG. 18 shows a diagram for explaining the Fig.16 Histogram of the static filtering performed in ;

[0047] FIG. 19 shows a diagram for explaining the Fig.16 A histogram of the outlier filtering performed in ; and

[0048] FIG. 20 shows a diagram for explaining the Fig.16 Histogram of the sample size filtering performed in . DETAILED DESCRIPTION

[0049] In the attached figure Figure 1 A test device 10 according to an embodiment of the present invention is shown, and 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 pipeline 24A, a cold liquid return pipeline 24B, a control liquid supply pipeline 24C, a control liquid return pipeline 24D, a vacuum line 24E, a first and second box 28A and 28B, and a first and second wafer 30A and 30B.

[0050] The slot assembly 18A includes a slot assembly body 32, a heat 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 multiple second slot assembly interfaces, the multiple second slot assembly interfaces include a control interface 44, a power interface 46 and a cold liquid supply interface 48A, a cold liquid return interface 48B, a control liquid supply interface 48C, a control liquid return interface 48D and a vacuum interface 48E.

[0051] The first slot assembly interface 40 is located within and mounted on the slot assembly body 32. A control interface 44, a power interface 46 and a second interface 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 can be removed from the frame 14 from right to left. The tester cable 20, the power cable 22 and the pipelines 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 pipelines 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 assembly 18A includes a main board 60 with test electronics, a plurality of channel module boards 62 with test electronics, a flexible connector 64, and a connection board 66. The control interface 44 and the power interface 46 are connected to the main board 60, and the thermal controller 50 is mounted on the main board 60. The channel module board 62 is electrically connected to the main board 60. The flexible connector 64 connects the channel module board 62 to the connection board 66. Control functions are provided by connecting electrical conductors connecting 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 to the channel module board 62 from the main board 60 through conductors. The flexible connector 64 provides conductors connecting the channel module board 62 to the connection board 66. The connection board 66 includes conductors connecting the flexible connector 64 to the first slot assembly interface 40. The first slot assembly interface 40 is thus connected to the control interface 44 and the power interface 46 through various conductors, so that power and control can be provided to the first slot assembly interface 40 through the control interface 44 and the power interface 46.

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

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

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

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

[0058] The slot assembly 18A also has a door 82, which is connected to the door 86 of the socket assembly body 32 by a hinge 84. When the door 82 is rotated to the open position, the cassette 28A can be inserted into the socket assembly through the door opening 86. The cassette 28A is then lowered onto the thermal chuck 34 and the door 82 is closed. The thermal chuck 34 is mounted on the socket assembly body 32. The thermal chuck 34 then essentially forms a support having a test table for a wafer.

[0059] The socket assembly 18A also has a seal 88 located between the thermal chuck 34 and the thin chuck 72. A vacuum is applied to the area defined by the seal 88, the thermal chuck 34 and the thin chuck 72 through the vacuum port 48E and the vacuum line 90. This provides a good thermal connection between the thermal chuck 34 and the thin chuck 72. When the heating resistor 38 generates heat, the heat is conducted through the thermal chuck 34 and the thin chuck 72 to the wafer 30A. When the thermal 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 socket assembly interface 40. Power and signals are provided to the wafer 30A through the first socket assembly interface 40, the cartridge interface 78 and the cartridge contacts 76. The performance of the devices within the wafer 30A is measured through the cartridge contacts 76, the cartridge interface 78 and the first socket assembly interface 40.

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

[0062] The socket assembly 18A further includes a thermal controller 50. The temperature detector 36 is connected to the thermal controller 50 via a temperature feedback line 52. Power is supplied to the heating resistor 38 via the power interface 46 and the power line 54 so that the heating resistor 38 is heated. Then, the heating resistor 38 heats the thermal chuck 34 and the wafer 30A on the thermal 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 thermal chuck 34 has a thermal fluid channel 224 formed in the thermal chuck. The thermal fluid channel 224 holds a thermal fluid. The thermal fluid is preferably a liquid rather than a gas because liquids are 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 highest temperature applications.

[0064] Controlled liquid supply and return lines 226 and 228 connect opposite ends of the hot fluid channel 224 to cold liquid supply and return interfaces 48C and 48D, respectively. The heating resistor 38 acts as a heater, which is installed at a location that heats the thermal chuck 34, which heats 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 the hot chuck 34 downward.

[0065] The test apparatus 10 also includes a cooling system 240, a temperature control system 242, and a vacuum pump 244. The two cold liquid supply lines 24A connected to the first and second difference 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 line 24B to the cooling system 240, connects the control liquid supply line 24C to the temperature control system 242, connects the control liquid return line 24D to the temperature control system 242, and connects the vacuum line 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 fluid through the fluid channel 248 to cool the cold plate 246. The cold plate 246 then keeps the channel module plate 62 cool. The temperature control system 242 circulates fluid through the hot fluid channel 224 to control the temperature of the thermal chuck 34 and transfer heat to or from the wafers 30A and 30B. The vacuum pump 244 supplies air at vacuum pressure to the vacuum line 90 .

[0066] Socket assembly 18A includes separator seal 108 mounted on the upper surface of socket assembly body 32 and located above the inner wall 106 of socket assembly body 32. Separator seal 108 seals with the lower surface of socket assembly 18B. Socket assembly 18B has separator seal 110 mounted on the upper surface of socket assembly body 32 of socket assembly 18B. Separator seal 110 seals with the lower surface of frame 14. A continuous sealed separator wall 112 is provided by the inner walls 106 of socket assemblies 18A and 18B and separator seals 108 and 110.

[0067] Figure 2 Shows Figure 1 2-2 of the test device 10. 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 to an open air path, in which 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 testing apparatus 10 further includes a first fan 122 , a first fan motor 124 , and a temperature regulating device in the form of a water cooler 126 .

[0069] The first fan 122 and the first fan motor 124 are mounted at an 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] Cassettes 28A and 28B are positioned with socket assemblies 18A and 18B and are located within the lower half of first closed-loop air path 120 .

[0071] In use, current is provided to the first fan motor 124. The first fan motor 124 rotates the first fan 122. The first fan 122 recirculates air through the first closed-loop air path 120 in a clockwise direction.

[0072] The water cooler 126 then cools the air in the first closed-loop air path 120. The air then flows through the box 28A or 28B through the slot assemblies 18A and 18B. The box 28A or 28B is then cooled by air convection.

[0073] Figure 3 Shows Figure 1 The test device 10 at 3-3 in FIG. The frame 14 defines a second closed-loop air path 150. The test device 10 also includes a second fan 152, a second fan motor 154, and a temperature control device in the form of a water cooler 156. No Figure 2 The air inlet and outlet (not shown) may be opened to change the second closed-loop air path 150 to an open air path in which room temperature air passes through the frame 14 without being circulated.

[0074] The closed loop path is particularly useful in a clean room environment because it results in less particulate material being released into the air. A second fan 152 and a second fan motor 154 are located in the upper portion of the second closed loop air path 150. A water cooler 156 is located within the second closed loop air path 150 and slightly downstream of the second fan 152. The main board 60 and the channel module board 62 forming part of the slot assemblies 18A and 18B are located within the lower portion 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 through the main board 60 and the channel module plate 62, so that heat is transferred from the main board 60 and the channel module plate 62 to the air by convection.

[0076] pass Figure 1 The air recirculated in the first closed-loop air path 120 passes through Figure 1 The continuous sealing partition wall 112 shown in FIG. Figure 3 The air in the second closed-loop air path 150 in the air chamber remains separated. Figure 1 The continuously sealed front wall 104 shown in 1 prevents air from escaping from the first closed-loop air path 120 .

[0077] like Figure 2 and 3 As shown, Figure 1 The same cooling system 240 used in is also used to cool the water cooler 126. Figure 4 As shown, plenum 160 separates first closed loop air path 120 from second closed loop air path 150 in all areas except those areas provided by continuous sealed divider wall 112. Frame 14 has left and right walls 162, 164 that further define closed loop air paths 120 and 150.

[0078] Figure 5A , 5B and 5C show how cassettes 30C, 30D and 30E may be inserted or removed at any time while all other cassettes are used for wafer side view devices and may be placed in various temperature ramp states. Figure 6 This aspect is described in more detail. At time T1, the first box is inserted into the frame 14, while the second box is outside the frame 14. At T1, the first box is heated. Between T1 and T2, the temperature of the first box increases from room temperature (i.e., about 22°C) to a test temperature that is 50°C to 150°C higher than the room temperature at T2. At T2, power is applied to the first box and the device in the first box is tested. At T3, the second box is inserted into the frame 14 and heating of the second box is started. At T4, the test of the first box is terminated. At T4, cooling of the first box is also started. At T5, the second box reaches the test temperature and power is provided to the second box and the wafers in the second box are tested. At T6, the second box reaches a temperature close to room temperature and is removed from the frame 14. The third box can then be inserted to replace the first box. At T7, the test of the second box is terminated and cooling begins. At T8, the second box 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 cartridge can be inserted and tested at room temperature. Another test can be performed during a temperature ramp up. A further test can be performed at an elevated temperature. A further test can be performed during a temperature ramp down. Two of these tests can be a single test run from one temperature stage to the next.

[0080] like Figure 7 As shown, one socket assembly 18A can be removed from or inserted into the frame 14. The socket assembly 18A can be inserted or removed, while other socket assemblies in the frame 14 are used to test the device of the wafer, as shown in FIG. Figure 6 described.

[0081] like Fig. 8A As shown, the backplane 74 includes a circuit board 500 , a contactor 502 , a plurality of pins 504 , a retaining ring 506 , fasteners 508 , and posts 510 .

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

[0083] The contactor 502 has a plurality of pin openings 518, post openings 520, and fastener openings 522 formed from an upper side 524 to a lower side 526. Each pin opening 518 has a first portion 528 and a second portion 530. When viewed in plan, the first and second portions 528 and 530 are both circular. The diameter of the first portion 528 is greater than the diameter of the second portion 530. When compared to the diameter of the second portion 530, the diameter of the first portion 528 is larger, which makes it easier to see when viewed from the upper side 524. Fig. 8A When viewed in a cross-sectional side view of , the first portion 528 is wider than the second portion 530 .

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

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

[0086] The upper surface of the first tip 552 is formed with a terminal 560. The lower end of the second tip 556 is formed with a contact 562. The coil spring 544 and the first and second end members 546 and 548 are made of metal and are therefore conductive materials. The coil 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 pin is inserted into the corresponding pin opening 518 through the upper side 524, and the second tip 556 is slightly smaller than the second portion 530, so that the second tip 556 passes through the second portion 530 and protrudes from the lower side 526. The retainer 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 on the circuit board 500, the first tip 552 still protrudes above the upper side 524 of the contactor 502.

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

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

[0090] The support 510 has a surface 572. When the support 510 is Fig. 8A When fully inserted as shown, surface 572 lies in a plane parallel to and below the surface of lower side 526. When post 510 is fully inserted, force transfer portion 568 has a surface 574 that is in the same plane as 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. Because the terminals 560 are located 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 contact 502. The threaded shaft 578 is inserted from the bottom through the annular opening 582 and then through the fastener opening 522. The head 580 contacts the lower surface of the ring 506. The head 580 is then 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 contact 502 and the ring 506. The lower side 514 eventually contacts the upper side 524. The contact 512 moves the first end piece 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 the first end piece 546 to move relative to the second end piece 548.

[0093] The underside 514 has a portion that is stationary relative to a surface 574 that forms part of the support 510. Because the support 510 abuts the circuit board 500, the support 510 is in a position to transfer forces 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 back plate 74 and the first wafer 32A are put together, the first wafer 32A is aligned with the back plate 74 to ensure that each terminal 588 contacts with a corresponding one of the contacts 562.

[0095] A vacuum pressure is created in the area between the upper surface 590 and the underside 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 differential creates equal and opposite forces F1 and F2 on the circuit board 500 and the thin chuck 72.

[0096] like Figure 8BAs shown, forces F1 and F2 relatively move back plate 74 toward wafer 32A and thin chuck 72. Coil spring 544 is compressed more to allow second end piece 548 to move into pin hole. Each coil spring 544 is deformed to overcome its spring force, such as F3. However, force F1 is still greater than the sum of all forces F3 added together. Upper surface 590 eventually rests on surface 572 of support 564. Because support 510 abuts against circuit board 500, support 564 prevents upper surface 590 from approaching and contacting lower side 526 of contactor 502. First wafer 32A transfers force F4 to support 564. Force transfer portion 566 transfers force F4 through second portion 536 of support opening 520. Force transfer portion 568 receives force F4 from force transfer portion 566 and transfers force F4 to circuit board 500 via surface 574.

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

[0098] exist Fig. 8A and 8B In the described embodiment, the contactor 502 is used as a support plate having a column opening 520 passing therethrough. On a first side of the support plate, a circuit board 500 is used as a support structure and includes at least a circuit board having a contact 512. The pin 504 is used as a conductor having a contact 562 to contact a terminal 508 of an electronic device disposed on a second side of the support plate, the second side of the support plate being opposite to the first side of the support plate. The retainer portion 542 is used as a portion of the conductor held by the support plate. The conductor also has a terminal 560, which is connected to the contact 512 on the circuit board 500. A spring in the form of a coil spring 544 is provided. The thin chuck 72 is used as a force generating device on one side of the electronic device in the form of a first wafer 32A and is opposite to the support plate. The force generating device and the support plate can be moved relative to each other to move the electronic device closer to the support plate and deform the spring. The support 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 close to the support plate, a force transfer portion 566 extending from the support 564 at least partially passes through the column opening 520, and a force transfer portion 568 extends from the force transfer portion 566, and the force transfer portion 568 is held by the support structure.

[0099] Fig. 9 A shows a portion of the testing apparatus 10 that is used to insert and remove a cartridge into each slot assembly, such as slot assembly 18A. Fig. 9The components of the test apparatus 10 shown in A include a frame 300 , a portion of the first slot assembly 18A, a first slot assembly interface 40 , a retaining structure 302 , a horizontal transport device 304 , a vertical transport 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 transport device 304 is a slide mounted between the first and second mounting members 312 and 314. The retaining structure 302 is mounted to slide along the horizontal transport device 304. The opposite ends of the beam spring 308 are mounted on the first and second brackets 312 and 314, respectively.

[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 on a pivot connection 322. The vertical conveying device 306 is a rigid beam. The 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 connecting rod 326 rotatably connected to the control rod 318 and a second connecting rod 328 rotatably connected to the end of the vertical conveying device 306. Fig. 9 In the unlocked configuration shown in A, the line 330 connects the pivot connection 322 and the second link 328 , and the first link 326 is located to the left of the line 330 .

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

[0103] The holding structure 302 slides along the horizontal conveyor 304. The connecting rod 316 connects one end of the control rod 318 to the holding structure 302. When the holding structure 302 moves in the horizontal direction along the horizontal conveyor 304, the connecting rod 316 rotates the control rod 318 about the pivot connection 322 in the counterclockwise direction.

[0104] The first link 326 rotates in a counterclockwise direction with the control rod 318. The pressure rod 320 converts the movement of the first link 326 into a downward movement of the second link 328. At first, the downward movement is minimal, but when the first box 28A is fully inserted into the first slot assembly 18A, the vertical movement becomes more significant and the vertical transport device 306 engages the first box 28A and the first slot assembly 18A. Therefore, the horizontal transport device 304 is operable to move the first box 28A horizontally 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 box 28A and the first slot assembly 18A relative to each other in a first vertical direction so that the slot assembly interface 40 engages the box interface on the first box 28A.

[0105] Control lever 318 Fig. 9 A is shown in the unlocked position, where the first link 326 is on a first side of a line 330 connecting the pivot connection 322 and the second link 328. The control lever 318 is Fig. 9 The unlocked position shown in A is rotated through a compressed position, in which the beam spring 308 is deformed by the vertical conveyor 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. Fig. 9 B and 10, the lever 318 continues to rotate from the compressed position to the locked position. In the locked position, the first link 326 is located to the right of the line 330, and therefore is located on a second side of the line 330 opposite to the first side. Since the first link 326 has passed through the line 330 and the beam spring 308 has been deformed to overcome its spring force, the first cartridge 28A is locked in a position against the slot assembly interface 40.

[0106] The system can be unlocked by moving the retaining structure 302 from right to left. The control lever 318 is rotated in a clockwise direction, and the first link 326 moves from right to left through 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 cartridge 28A from the slot assembly interface 40. The retaining structure 302 is further moved along the horizontal transport device 304 to remove the first cartridge 28A from the first slot assembly 18A.

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

[0108] Fig.12 A portion of thermal assembly 342 , a portion of plate-seat assembly 344 , and one of covers 346 are shown.

[0109] Fig.13 Shows Fig.12 Detail A in FIG. 3 includes a portion of thermal assembly 342 , a portion of plate-seat assembly 344 , and a portion of cover 346 . Fig.13 A first electronic device 348 is also shown.

[0110] Thermal assembly 342 includes thin chuck 350, first thermal anchor 352, and first thermal column 354. Thin chuck 350 has an upper surface 356 with an opening 358 formed therein. First thermal anchor 352 and first thermal column 354 are machined from a single piece of metal. When viewed in a plan view, first thermal anchor 352 and first thermal column 354 both have circular cross-sections in respective planes parallel to the axis of first thermal column 354. The cross-section of first thermal anchor 352 is larger than the cross-section of first thermal column 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. A majority 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 to a desired depth, with the first thermal surface 360 ​​at a desired distance from the upper surface 356.

[0112] First thermal column 354, first thermal anchor 352 and thin chuck 350 are all made of metal and are therefore good thermal conductors. The larger cross-section of first thermal anchor 352 when compared to the cross-section of first thermal column 354 results in more heat being transferred from first thermal anchor 352 to thin chuck 350.

[0113] The board-socket assembly 344 includes a circuit board 362, a socket 364, a first set of pins 366 for the electronics, and a first set of pins 368 for the detector. Pins 366 and 368 are pogo pins that contain a spring and can be compressed against the spring force of the spring.

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

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

[0116] The circuit board 362 has circuitry (not shown) formed therein. Contacts 388 are formed in an 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, which initially extends below the lower surface 394 of the lower portion 370. A corresponding one of the terminals 392 contacts a corresponding one of the contacts 388. The pins 366 and 368 are compressed against their spring force 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. The socket 364 is then permanently mounted to the circuit board 362.

[0118] The socket 364 has a first socket thermal opening 398 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 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 assembly 342 and the board-holder assembly 344 are initially disconnected from each other, as shown in FIG. Fig.11 As shown. The board-socket subassembly 344 is then positioned above the thermal assembly 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 rests 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 therefore located slightly above the upper surface of the first recessed structure 376. The contact 378 is located 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 column 354 provides a thermally conductive path between the first recessed structure 376 and the first thermal anchor 352 connected to the thin chuck 350. The thermal column 354 is electrically and thermally insulated from the electrical conductors within the socket 364 and the circuit board 362. Heat will be conducted primarily through the first thermal column 354, rather than the insulating material of the socket 364 and the insulating material of the circuit board 362.

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

[0121] The circuit board 406 is made of an electrically insulating material and a thermally insulating material. Conductive terminals 416 are formed on a 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 provide 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 electricity. The other terminal 416 can be used as an output contact connected to the first light detector 410 to measure the output electrical power.

[0123] The first adjustable component 412 has a push plate 422, a side wall 424 extending upward from the push plate 422, and a lip 426 extending outward from the side wall 424. The circuit board 406 has a first opening 428 formed therein. The first adjustable component 412 is inserted into the first opening 428. The push plate 422 then extends below the lower surface 418. The lip 426 rests on 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 component 412 to rotate a small amount of a few degrees about the first axis 432 relative to the circuit board 406. The difference in width also allows the first adjustable component 412 to rotate clockwise and counterclockwise about a second axis 434 that 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 gimbaling of the first adjustable component 412 relative to the circuit board 406.

[0124] The heat sink 408 has a first groove 436. The first coil spring 414 is inserted between the side walls 424. The lower end of the first coil spring 414 rests on the upper surface 438 of the push plate 422. The upper end of the first coil 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 coil spring 414 is located in 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 toward the circuit board 406, the first coil spring 414 is compressed and thus deformed against its spring force. The lower surface 440 contacts the upper surface 420. The heat sink 408 is then fixed to the circuit board 406 using fasteners (not shown). The small force generated by the first coil spring 414 then biases the first adjustable component 412 in the outward direction of the lower surface 418.

[0125] The push plate 422 has a first opening 442 therein. The heat sink 408 defines a first cavity 444. A light absorbing coating is formed on a 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 underside of the first electronic device 348 are in contact with the contacts 378. The lower surface 448 of the first electronic device 348 is spaced apart from the first thermal surface 360 ​​at this stage.

[0127] The cover 346 is positioned over the board-seat assembly 344. The cover 346 is then moved toward 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 is still spaced apart from the first thermal surface 360.

[0128] The operator manually presses, thereby moving the cover 346 further toward the board-holder assembly 344. Each of the pins 366 and 368 compresses its spring force, thereby elastically depressing the contacts 378 and 380 against the spring force of the springs in the pins 366 and 368. The lower surface 448 of the first electronic device 348 contacts the first thermal surface 360.

[0129] If there is an angular misalignment between the first thermal surface 360 ​​and the lower surface 448 of the first electronic device 348, the first electronic device 348 is rotated by the first thermal surface 360 ​​until the lower surface 448 and the first thermal surface 360 ​​are in the same plane. The rotation of the first adjustable component 412 relative to the cover 346 allows the lower surface 448 of the first electronic device 348 to abut against the first thermal surface 360. Good thermal contact between the first thermal surface 360 ​​and the lower surface 448 is thereby ensured. The first coil spring 414 is compressed to accommodate the height of the first electronic device 348. In addition, the first adjustable component 412 is rotatably mounted on the cover 346 so that the first electronic device 348 can rotate the first adjustable component 412 relative to the first thermal surface 360. The cover 346 is then fixed to the plate-seat assembly 344.

[0130] The socket 364 and the cover 346 together form an electronic device holder that holds the first electronic device 348. A box interface (not shown) on the circuit board 362 provides power and communication to the contacts 388. The pins 366 provide power and communication to the first electronic device 348 through the terminals 446.

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

[0132] Most of the light is absorbed by the light absorbing material on the surface of the first cavity 444 and 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 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 in the circuit board 406. When the first light detector 410 detects light, it converts the light into electrical energy. The amount of electrical power is related to the intensity of the light detected by the light detector 410. The first light detector 410 then provides power to the circuit board 362 through a conductor formed by the circuit in the circuit board 406, one of the terminals 416, one of the pins 368, one of the contacts 388, and ultimately reaches the box interface on the circuit board 362.

[0134] Circuit board 406 and pin 368 provide a measurement channel that connects first light detector 410 to circuit board 362, even though first light detector 410 is located on a side of first electronic device 348 opposite circuit board 362. In a similar manner, another type of detector other than a light detector can be used to detect features of the electronic device other than light transmitted by the electronic device. For example, current can be detected at terminals on the upper surface of the electronic device, and a similar measurement channel can be created for a circuit board below the electronic device through pins in a circuit board and a socket above the electronic device. In such an arrangement, a pin such as pin 368 can be used as a detector measurement pin 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 pillar 354. The first electronic device 348 can be heated or cooled, for example, by the first thermal pillar 354. For example, the first electronic device 348 can be cooled by transferring heat from the first electronic device 348 to the thin chuck 350 through the first thermal pillar 354 and the first thermal anchor 352. The first electronic device 348 can be heated by transferring heat from the thin chuck 350 to the first electronic device 348 through the first thermal anchor 352 and the first thermal pillar 354.

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

[0137] Reference again Fig.12 , multiple electronic devices can be tested using one socket 364 and one cover 346. The socket 364 includes, for example, a second thermal anchor 352A, a second thermal column 354A, a second thermal surface 360A, a second set of pins 366A for a second electronic device, a second set of pins 368A, a second recessed structure 376A for a second electronic device (not shown), a second socket thermal opening 398A, a second circuit board thermal opening 400A, a second optical detector 410A, a second adjustable element 412A, a second coil spring 414A, a second opening 428A, a second groove 436A, a second opening 442A, and a second cavity 444A. The same reference numerals represent the same components and functions.

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

[0139] The temperatures of the first and second electronic devices are jointly controlled by the same thin chuck 350. If the electronic device is cooled, for example, heat is conducted through the first and second thermal pillars 354 and 354A to the first and second thermal anchors 352 and 352A, respectively, and then from the first and second thermal 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 thermal surfaces 360 and 360A, respectively. Independent gimbaling of the first and second adjustable components 412 and 412A relative to the cover 346 allows and controls independent rotation of the first and second electronic devices.

[0141] See again Fig.11 , sixteen sockets 364 are connected to the circuit board 362. Each socket 364 has a corresponding cover 346. Each cover 346 has a corresponding fixing structure 460, and each socket 364 has a corresponding fixing structure 462. The cover 346 is moved toward the socket 364. The cover 346 is then pressed onto the socket 364 as described above. The fixing structures 460 and 462 then engage each other to secure the cover 346 to the socket 364 and maintain thermal and electrical integrity.

[0142] The thin chuck 350 has a plurality of thermal pins, which are fixed in sixteen groups of 16. Each group of thermal pins 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] The cartridge interface 464 is formed on the lower surface of the circuit board 362. The cartridge interface 464 is connected to the Fig.13 The contacts 388 shown in FIG. 4 are used to connect the box 340 to an electrical tester as described above. As described above, the thin chuck 350 is thermally connected to the hot chuck. The hot chuck is used as a temperature regulating device to control the amount of heat transferred to or from the thin chuck 350.

[0144] After testing the electronics, the cartridge 340 is removed from the system, the cover 346 is removed, and the electronics are removed from the receptacle 364 .

[0145] The heat column 354 is also used to Fig. 8A and 8B 398. The cover 346 serves as a force generating device. Some of the force generated by the cover 346 is balanced by the force generated by the springs within the pins 366 and 368. The remaining portion 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 to the base near the recessed structure 376. The central portion of the column 354 serves as a force transmitting portion extending 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 transmits force to the support structure. Specifically, the force is transmitted to the thin chuck 350, which forms part of the support structure, through the heat anchor 352. The press fit between the heat anchor 352 and the thin chuck 350 is strong enough to maintain integrity so that the force does not cause the heat anchor 352 to move relative to the thin chuck 350.

[0146] Fig.14A Shows Fig.11 , embodiments of 12 and 13 are further shown in detail, including fastener 600 and column 602.

[0147] The post opening 604 and the fastener opening 606 are formed by the socket 364. The post 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 post 602 includes a seat 614, a force transfer portion 616, and a force transfer portion 618. The post 602 is inserted into the post opening 604 from the bottom until the surface 620 of the force transfer portion 618 abuts the platform 612. The threaded shaft 622 of the fastener 600 is inserted through the fastener opening 606 from the top. The head 624 is then rotated so 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 a good fixation for the fastener 600. When the fastener 600 is turned further, the head 624 moves closer to the circuit board 362. The spring of the pin 366 is slightly compressed and the underside 630 of the post 602 contacts the circuit board 362.

[0149] like Fig. 14BAs shown, when the operator presses the cover 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 force F3 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 toward the socket 364.

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

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

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

[0153] Fig.15 Other components of the test apparatus 10 are shown for precisely controlling the voltage provided to the electronic device 634 being tested. For example, the electronic device 634 may be located on the surface of a wafer 636, or may be a single device held within a socket layout.

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

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

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

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

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

[0159] VCSELs are diodes, so there is rarely a short circuit to ground.

[0160] • Opens may occur at a higher frequency due to VSCELS being "open" or due to poor contact with the die.

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

[0162] • It is quite possible to build a very accurate voltage source (to within 1%).

[0163] The current of a voltage source can be measured fairly accurately.

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

[0165] For ease of explanation, assume that:

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

[0167] Assume the system has 1024 power channels, each channel is up to 5V, 200mA.

[0168] Assume that the system can provide constant current or constant voltage to each channel.

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

[0170] The following is a list of existing burn-in circuit options:

[0171] (1) Individual constant current sources. This provides a precise, measurable current for each VCSEL, but there are the following issues:

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

[0173] The “cost” of each VCSEL is 1 channel. Even if additional channels can be added, the cost of each VCSEL is still 1 channel.

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

[0175] (2) Series wiring. This would require connecting about 13 VCSELs in series and driving them with a constant current source, but there are the following problems:

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

[0177] This requires a current source of 10mA and over 30V. Protecting this high voltage from current surges is very difficult.

[0178] (3) Connect in parallel with a current source. Use a constant current source to drive about 13 VCSELs in parallel. This will require a 2.5 volt, 130 mA current source. This system has the following problems:

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

[0180] If there is no obvious excursion in voltage due to an open VCSEL, there is no way to know that the other 12 VCSELs are receiving the wrong aging current, so the bad device may escape detection.

[0181] (4) Connect the wires in parallel with a voltage source. Such a system will 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 10mA current. This system has the following problems:

[0182] If a VCSEL is turned on, the total current in the group will be slightly reduced. For each VCSEL that is turned on, the group current will drop by 10mA (e.g., 140mA for the group vs. 150mA.) The remaining VCSELs in the group will still reach 10mA.

[0183] The current stability of 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 a good VCSEL (<1% across the wafer). Therefore, the current through each VCSEL will be within 2% of the parallel voltage source across the wafer.

[0184] If the VCSEL shorts (very unlikely), the overcurrent protection on the power channel will shut down that power channel while the other channels are still operational.

[0185] Therefore, 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 failure mode, an "open" device.

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

[0190] Circuit 4 (parallel wiring with voltage sources) 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 of the required current.

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

[0195] VCSEL manufacturing process variations across the wafer. The voltage at a given current can vary from devices near the edge of the wafer to devices in the center of the wafer.

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

[0197] As a VCSEL ages, its voltage / current relationship changes. Therefore, even if the voltage is correct at the beginning of the aging cycle, the appropriate voltage at the end may be lower.

[0198] Fig.15 Only the electronic devices 634 of the first group (Group 1) of clusters (Clusters 1 to 4) of electronic devices 634 located in the area near the edge of the wafer 636 are shown. It should be understood that there are 16 groups (Groups 1 to 4) of clusters and each group has 64 clusters, each cluster and 12 electronic devices 634.

[0199] The electronic devices 634 of the first cluster (cluster 1) are connected in parallel 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 areas of the first group (group 1). Each cluster has a corresponding set of twelve electronic devices that are connected in parallel to 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 apparatus 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 a static filter 642. The static filter 642 is adapted to remove current readings for the corresponding cluster that are above or below a set limit. The static filter 642 typically processes data for all clusters simultaneously to remove data for clusters having current readings above or below a set limit.

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

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

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

[0207] Fig.16 Shows the use of Fig.15 A method of testing a plurality of electronic devices 634 using a component of a testing apparatus 10 .

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

[0209] refer to Fig.17 , calculate the slope of the curve by first determining the voltage guesses "A" and "B". Fig.16 Steps 708 to 724 in correspond to the calculation of the slope.

[0210] At 708, a first initial voltage guess “V A ", and use Fig.15 The first initial current “I A ”. Fig.15 The voltage source 650 in parallel provides a first initial voltage guess for the electronic devices 634 of the first cluster. The second, third and other clusters receive similar processing as the first cluster. For example, the voltage source 650 provides a first initial voltage guess for the electronic devices of the second cluster in parallel.

[0211] Fig.15 The cluster selector switch 638 in the embodiment is sequentially switched by the current output 660 of the corresponding cluster from the first group. When the cluster selector switch 638 is connected to the current output 660 of the first cluster, the current detector 640 measures the first initial current from the electronic devices 634 of the first cluster. The first initial 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 connected in parallel. When the cluster selector switch 638 is switched to the current output 660 of the second cluster, the second cluster receives similar processing as the first cluster, such as Fig.16 6. Similarly, by continuing to switch the cluster selector switch 638 to the subsequent current output 660, the current detector 640 measures the first initial current of the electronic device of each corresponding cluster.

[0212] The current detector 640 provides the current measurement value to Fig.15 The static filter 642 in FIG. Fig.16 As more clearly seen in FIG. 7 , multiple stages of filtering 710 are performed, including static filtering 712, outlier filtering 714, and sample size filtering 716. Fig.16 As shown, Fig.15 The static filter 642 performs static filtering at 712.

[0213] FIG. 18 illustrates static filtering in more detail. Individual currents from the first and second groups are shown. Static filtering eliminates current readings above and below set limits; for example, below 2 and above 6. Static filtering may, for example, remove the first initial current readings of the corresponding clusters in the corresponding groups that are above and below set limits. Any given cluster may have an "open" VCSEL and therefore not return the correct total current for all VCSELs. The current limits may be used to determine whether any given reading is correct.

[0214] After static filtering, Fig.16 714 of the data are processed to utilize Fig.15 The outlier filter 644 in performs outlier filtering. FIG. 19 illustrates outlier filtering in more detail. Outlier filtering removes data above and below the median of the data; for example, + / - 20%. Outlier filtering may, for example, remove the first initial current reading that is far above or below the median of the group for the corresponding cluster. Additional filtering may use statistical methods to determine whether the first initial current reading for a given channel is abnormal.

[0215] After outlier filtering, Fig.16 716 of them process data to utilize Fig.15 The sample size filter 646 in performs sample size filtering. The sample size filtering is illustrated in FIG20 . 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 reading 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 outlier filtering, the second group has too few clusters remaining to give a reliable voltage calculation. In this case, the average of the other group is used.

[0216] exist Fig.16 At 720, a second voltage guess "V B ", and measure the second initial current "I B A second initial voltage guess is applied in the same manner as the first initial voltage guess at 708. The second initial voltage current is measured for each cluster.

[0217] At 722, multi-stage filtering is performed on the 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] Fig.17 The positions of the first and second initial currents after multiple stages of filtering at 710 and 722 are shown. The current measurement is 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] Therefore, the slope is calculated by dividing the difference between the second and first initial voltages of the electronic devices of the first group by the difference between the second and first initial currents of the electronic devices of the first group.

[0221] Steps 708, 712 and 724 described above are performed by Fig.15 The voltage targeting system 648 in FIG. 6 is executed. The voltage targeting system 648 controls the voltage regulator 652 to provide voltage to the electronic devices of each cluster. The voltage targeting system 648 then stores the calculated slope in a memory.

[0222] exist Fig.17 After the slope is calculated and stored at 724 in , the voltage targeting system 648 can use the slope to set and reposition the test voltage applied to each cluster of electronic devices 634. Setting and redirecting the test voltage is performed by Fig.16 , as described in steps 726 to 736.

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

[0224] The second and third clusters of the first group receive similar processing. Thus, each additional cluster has a corresponding first test voltage applied to the devices of the cluster and 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 again passed through multi-stage filtering 730. Multi-stage filtering 730 is performed on the first test current in a manner similar to multi-stage filtering 710 performed on the first initial current from the cluster of the first group and multi-stage filtering 722 performed on the second initial current from the cluster.

[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. Fig.17 shows the target current (I T ) and the current error (I T -I G )'s result is the first initial current.

[0227] exist Fig.16 At 734 in the embodiment, recalibration is performed. A second test voltage is calculated and the first test voltage is adjusted to the second test voltage. Fig.17 As 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] Fig.16 736 in the figure indicates that the process starting from 726 can be repeated by using the redirected voltage as the first test voltage and then measuring the test current and calculating the redirected voltage.

[0231] Fig.16 The dashed lines 702 and 706 in indicate that the clusters of the second and third groups receive similar treatment as the clusters of the first group. In the given example, the voltage source 650 provides 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 manner described above. In a similar manner, separate voltage regulators provide voltages to separate groups of electronic devices. 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 current from one or more clusters in one or more groups.

[0232] As described above, parallel wiring with voltage sources has significant economic advantages. In addition, as described above, the voltage repositioning process ensures that accurate voltages are applied to devices connected using parallel wiring with voltage sources to ensure that the devices receive the correct current according to their specifications.

[0233] Clusters may 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 edge of the wafer to have different characteristics than devices near the center of the wafer.

[0235] Clusters can be selected so that edge devices are analyzed with other edge devices, and central devices are analyzed with other central devices.

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

[0237] For example, suppose the initial voltage / current calculation was performed poorly, producing a slope that was off by 20%.

[0238] Assume that for the first repositioning step, the calculated voltage error is 50% (ie the current error is 50%).

[0239] The first repositioning will attempt to correct a 50% current error using a slope with a 20% error. The net correctness will then be 10% wrong (50%*20%).

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

[0241] So after only 2 redirection steps, with a 50% start-up error and a 20% slope error, the resulting current is now within 2%.

[0242] This illustrates the fast 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 shown in the drawings, it is to be understood that these embodiments are merely illustrative and not restrictive of the invention, and that the invention is not limited to the specific construction and arrangements shown and described, since modifications may be made by those skilled in the art.

Claims

1. A box 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 retaining 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 the electrical tester; A chuck, wherein the chuck is a chuck made of a thermally conductive material; a first thermal post connected to the chuck, the first thermal post inserted into the first socket thermal opening, one end of the first thermal post thermally connected to the first device such that heat is primarily transferred through the first thermal post rather than through insulating material of the socket between the chuck and the first electronic device; as well as A first set of contacts is held in the socket and connects terminals of a first electronic device to the circuit board, the first set of contacts being resiliently depressible to bring the first electronic device into contact with an end of a first thermal surface forming a first thermal column.

2. The cartridge of claim 1 , wherein the upper side has a second structure for releasably holding a second electronic device, the socket having a second socket thermal opening formed through the socket from the lower side to the upper side, the interface connecting the second device to an electrical tester, the cartridge further comprising: A second thermal post is connected to the chuck, the second thermal post is inserted into the second socket thermal opening, and one end of the second thermal post is thermally connected to the second device so that heat is mainly transferred through the second thermal post rather than through the insulating material of the socket between the chuck and the first electronic device.

3. The box according to claim 1, further comprising: A circuit board is disposed between the socket and the chuck, the interface is located on the circuit board, the circuit board has a first circuit board thermal opening, and the thermal column is inserted through the first circuit board thermal opening.

4. The box according to claim 1, further comprising: A plurality of pins are mounted on the socket and extend through the socket to connect the first electronic device to the circuit board.

5. The box according to claim 1, further comprising: A cover is movable relative to the socket to depress the first set of contacts to bring the first electronic device into contact with the end of the first thermal post.

6. The cartridge of claim 1, further comprising: A first thermal anchor is provided, from which a first thermal post extends, the first thermal anchor having a surface in contact with the chuck.

7. The cartridge of claim 6, wherein the first thermal anchor has a larger cross-section than the first thermal post in a respective plane parallel to an axis of the first thermal post to improve thermal conductivity between the first thermal anchor and the chuck.

8. The cartridge of claim 7, wherein the first heat anchor is inserted into an opening in an upper surface of the chuck.

9. The cartridge of claim 8, wherein the first heat anchor is press fit to a selected depth in an opening in an upper surface of the chuck.

10. The cartridge of claim 9, wherein the thermal post fits loosely within the first receptacle thermal opening.

11. A test piece, comprising: a socket, the socket being 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, the first thermally conductive column being insertable into the first socket thermal opening from the lower side; a first set of pins, the first set of pins being fixed in the socket and connecting the first device to the circuit board, the first set of pins being elastically depressible; and A cover is movable relative to the socket to depress the first set of pins to bring the first electronic device into contact with the end of the first thermal column.

12. A test piece, comprising: A chuck, the chuck is a chuck made of a heat-conducting material; a first thermal post connected to the chuck, the first thermal post being insertable into the first socket thermal opening, one end of the first thermal post being thermally connected to the first device such that heat is primarily transferred through the first thermal post rather than through insulating material of the socket between the chuck and the first electronic device; a first thermal anchor from which a first thermal column extends, the first thermal anchor having a surface in contact with the chuck, wherein the first thermal anchor has a larger cross-section than the first thermal column in a corresponding plane parallel to an axis of the first thermal column to improve thermal conductivity between the first thermal anchor and the chuck, wherein the first thermal anchor is inserted into an opening in an upper surface of the chuck.

13. A method of testing one or more electronic devices, comprising: releasably retaining a first device in a first structure on an upper side of a socket made of insulating material; connecting the first device to the electrical tester via an interface connected to the socket; inserting a first thermal post attached to a chuck of thermally conductive material into a first socket thermal opening formed through the socket from the lower side to the upper side; resiliently depressing the first set of contacts to hold them in the socket and connecting the terminals of the first electronic device to the circuit board so that the first electronic device contacts the end of the first thermal column, which forms the first thermal surface of the first thermal column and is connected to the first device; and, Heat is transferred between the chuck and the first electronic device, with the heat being transferred primarily through the first thermal post rather than the insulating material of the socket.

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