Electronic Test Equipment

Abstract

After the wafer is singulated, the individual die may need to be tested again, and the die may need to be tested again after it is attached to a support plate. A tester apparatus is disclosed. Various components contribute to the functionality of the tester apparatus and facilitate movement of the wafer pack to maintain a vacuum without human supervision. These functionalities include a latching system that holds the wafer pack intact and a pressure sensing means that detects and relays pressure within the wafer pack.

Description

[Background technology]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0001] This application claims priority from U.S. Provisional Patent Application No. 63 / 088,635, filed October 7, 2020, the entire contents of which are incorporated by reference into this application.

[0002] 1) Field of the invention

[0002] The present invention relates to tester equipment used to test microelectronic circuits.

[0003] 2) Consideration of related technologies

[0003] Microelectronic circuits are typically fabricated within and on top of semiconductor wafers. Such wafers are then "singulated" or "diced" into individual die. Such die are typically attached to a support plate to provide rigidity to the support plate and to electronically communicate with the integrated circuits or microelectronic circuits of the die. The final package may include encapsulation of the die, and the resulting package can be shipped to a customer.

[0004]

[0004] Dies or packages must be tested before being shipped to customers. Ideally, dies should be tested at an early stage in order to identify defects that occur during early stage manufacturing. Wafer-level testing involves providing contacts to a processor and contactor, and then using the processor to move the wafer so that the contacts on the wafer make contact with the contacts of the contactor. Power and electronic signals are then passed through the contactor to and from the microelectronic circuits formed on the wafer.

[0005] According to various embodiments, a wafer includes a substrate, such as a silicon substrate or a printed circuit board, and one or more devices fabricated within or attached to the substrate.

[0006] Alternatively, the wafers can be placed in a portable wafer pack having an electrical interface and a thermal chuck, which can be heated or cooled to thermally control the temperature of the wafer while power and signals can be transferred to and from the wafer via the electrical interface.

[0007]

[0007] After the wafer is singulated, the individual dies may need to be tested again, and the dies may need to be tested again after they are attached to a support plate. Summary of the Invention

[0008]

[0008] The present invention provides a microelectronic circuit test pack, the microelectronic circuit test pack comprising a portable support structure including first and second components for holding a substrate therebetween, the substrate carrying a microelectronic circuit and having a plurality of terminals connected to the microelectronic circuit, a plurality of contacts on the second component and coinciding with and contacting the terminals, a pressure differential cavity seal between the first and second components and forming an enclosed pressure differential cavity together with surfaces of the first and second components, a pressure reducing passage formed through one of the first and second components and having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity, and a pressure reducing valve connected to the pressure reducing passage, the opening of which allows air outside the pressure differential cavity to bring the first and second components into relative proximity to each other ensuring proper contact between the contacts and the terminals, and the closing of which allows air from entering the pressure differential cavity; a first connecting portion on the portable support structure and connected to the contact, the first connecting portion connecting to a second connecting portion on the stationary structure when the portable support structure is removably held by the stationary structure; and a latch system including a first latch assembly including a first part that engages with the first component, a second part that engages with the second component, connecting parts having opposite ends that are secured to the first and second parts, respectively, to form a locking device, and an engagement mechanism connected to and operable to move the locking device, the locking device including the latch system that moves between a locked position that maintains the first and second components in a locked state in a closed position and an unlocked position that moves the first and second components from the closed relationship to a spaced apart relationship.

[0009]

[0009] The microelectronic circuit test pack may include an engagement mechanism that moves the second component between a locked position and an unlocked position.

[0010] The microelectronic circuit test pack can include a second component that rotates between a locked position and an unlocked position.

[0011]

[0011] The microelectronic circuit test pack may include an engagement mechanism including a surface on the first component that forms a seat for contact with a surface on the jaw of the tool, the jaw of the tool being rotatable to rotate the first component, and the first component rotating the second component via the connecting component to move between a locked position and an unlocked position.

[0012] The microelectronic circuit test pack can include wherein the surface of the first component that forms the seat is an exterior surface of the first component.

[0013] The microelectronic circuit test pack can include a first component having tool pin openings therein for aligning pins of a tool with the first component.

[0014]

[0014] The microelectronic circuit test pack may include a second component having a body and at least a first wing extending from the body, the first wing moving over a shoulder of the first component when moving to a first locked position and moving away from the shoulder when moving out of the first locked position toward an unlocked position.

[0015]

[0015] The microelectronic circuit test pack may include a second component having a second wing extending from the body, the second wing moving over a shoulder of the first component when moving to a second locked position and moving away from the shoulder when moving out of the second locked position toward an unlocked position.

[0016]

[0016] The microelectronic circuit test pack may include a latching system that may further include a harmonic block mounted in a stationary position relative to the first component, the harmonic block having a level surface above which the second wing piece is positioned when the first wing piece is positioned above the shoulder, the second component being adjustable relative to the first component to adjust the gap between the level surface and the second wing piece.

[0017]

[0017] The microelectronic circuit test pack may further include a latch system that includes a lock nut having threads that engage with threads on the connecting part to rotate the second part relative to the connecting part.

[0018]

[0018] The microelectronic circuit test pack may include a latch system further including a shim between the harmonic block and the first component for adjusting the distance between the level surface and the first component.

[0019]

[0019] The microelectronic circuit test pack may further include a latch system that includes a snap mechanism having a snap surface that snaps into a first snap recess to resist movement of the second component out of the locked position and that snaps into a second snap recess to resist movement of the second component out of the unlocked position.

[0020] The microelectronic circuit test pack can include first and second snap recesses disposed on the locking device.

[0021] The microelectronic circuit test pack can include first and second snap recesses disposed on the second component.

[0022]

[0022] The microelectronic circuit test pack may include a first component including a back plate and a signal distribution board, a portion of the signal distribution board being positioned between the back plate and the second component, the signal distribution board having an opening through which a connecting part is inserted, the opening having a first dimension on an axis toward a center point of the signal distribution board that is greater than a second dimension across the axis, the connecting part having a first portion that is smaller than the first dimension in the direction of the axis to allow the signal distribution board and the back plate to thermally expand relative to each other, and the first portion being dimensioned to slidably fit within the second dimension of the opening to prevent movement of the signal distribution board relative to the back plate in a direction across the axis.

[0023]

[0023] The microelectronic circuit test pack may include a connecting part having a second portion, the second portion having a first thickness that can fit into the opening in the axial direction during said insertion and that is greater than the second dimension of the opening, and a second thickness that transverses the first thickness and can fit into the second dimension of the opening during said insertion.

[0024]

[0024] The microelectronic circuit test pack may further include a latch system that includes a second latch assembly, each respective latch assembly including a first part that engages with the first component, a second part that engages with the second component, a connecting part having opposite ends fixed to the first and second parts respectively to form a locking device, and an engaging mechanism connected to the locking device and operable to move the locking device, wherein the locking device may include movement between a locked position that maintains the first and second components locked in a closed position and an unlocked position that moves the first and second components from the closed relationship to a spaced apart relationship.

[0025] The microelectronic circuit test pack can include the first and second latch assemblies having their respective second components on different sides of the second component.

[0026]

[0026] The microelectronic circuit test pack can include a pressure differential cavity seal surrounding the contacts and terminals.

[0027] The microelectronic circuit test pack can include, when the first and second components are separated, the pressure differential cavity seal is secured to the first component.

[0028]

[0028] The microelectronic circuit test pack can include, wherein the pressure differential cavity seal is a lip seal.

[0029]

[0029] The microelectronic circuit test pack may include: the pressure reducing valve is a pressure reducing check valve; a vacuum release passage is formed through a component having the pressure reducing check valve; the vacuum release passage has an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; and a second valve which is a vacuum release valve connected to the vacuum release passage; opening of the vacuum release valve allows air to enter the pressure differential cavity; and closing of the vacuum release valve prevents air from escaping from the pressure differential cavity.

[0030]

[0030] The microelectronic circuit test pack can include wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

[0031]

[0031] The microelectronic circuit test pack may include a structure in which the contacts are pins, each pin having a spring, and when each contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

[0032]

[0032] The present invention also provides a tester apparatus, the tester apparatus comprising: a portable support structure including first and second components for holding a substrate therebetween, the substrate carrying a microelectronic circuit and having a plurality of terminals connected to the microelectronic circuit; a plurality of contacts on the second component and coinciding with and contacting the terminals; a pressure differential cavity seal between the first and second components and forming an enclosed pressure differential cavity together with surfaces of the first and second components; a pressure reduction passage formed through one of the first and second components and having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; a pressure reduction valve connected to the pressure reduction passage, the opening of which allows air outside the pressure differential cavity to bring the first and second components into relative proximity to ensure proper contact between the contacts and the terminals and the closing of which prevents air from entering the pressure differential cavity; a first connecting portion on the portable support structure and connected to the contacts; and a first latch assembly, the first component engaging the second component. a second part that engages with the part; a connecting part having opposite ends that are secured to the first and second parts, respectively, to form a locking device; and an engaging mechanism connected to the locking device and operable to move the locking device, the locking device moving between a locked position that maintains the first and second components locked in a closed position and an unlocked position that moves the first and second components from the closed relationship to a spaced apart relationship; a stationary structure that is receivable to hold the portable support structure and from which the portable support structure is removable; a second connecting part on the stationary structure that connects to the first connecting part when the portable support structure is held by the stationary structure and that is disconnected from the first connecting part when the portable support structure is removed from the stationary structure; and an electrical tester that is connected to the terminal via the second connecting part, the first connecting part, and the contact, and wherein a signal is transmitted to and from the microelectronic circuit to test the microelectronic circuit.

[0033]

[0033] The tester device may include an engagement mechanism that moves the second component between a locked position and an unlocked position.

[0034] The tester device can include a second component that rotates between a locked position and an unlocked position.

[0035]

[0035] The tester apparatus may include an engagement mechanism including a surface on the first part that forms a seat for contacting a surface on the jaw of the tool, the jaw of the tool being rotatable to rotate the first part, and the first part rotating the second part via the connecting part to move it between a locked position and an unlocked position.

[0036] The tester apparatus may include, wherein the surface of the first part that forms the seat is an outer surface of the first part.

[0037]

[0037] The tester apparatus can include the first part having a tool pin opening therein for aligning a pin of a tool with the first part.

[0038]

[0038] The tester device may include a second part having a body and at least a first wing extending from the body, the first wing moving over a shoulder of the first component when moving to the first locked position and moving away from the shoulder when moving out of the first locked position towards the unlocked position.

[0039]

[0039] The tester device may include a second component having a second wing extending from the body, the second wing moving over a shoulder of the first component when moving to the second locked position and moving away from the shoulder when moving out of the second locked position towards the unlocked position.

[0040]

[0040] The tester apparatus may further include a harmonic block mounted in a stationary position relative to the first component by the latch system, the harmonic block having a level surface above which the second wing piece is positioned when the first wing piece is positioned above the shoulder, the second component being adjustable relative to the first component to adjust the gap between the level surface and the second wing piece.

[0041]

[0041] The tester device may include a latch system further including a lock nut having threads that engage with threads on the connecting part to rotate and adjust the second part relative to the connecting part.

[0042]

[0042] The tester apparatus may include a latch system further including a shim between the harmonic block and the first component for adjusting the distance between the level surface and the first component.

[0043]

[0043] The tester device may include a latch system further including a snap mechanism having a snap surface that snaps into a first snap recess to resist movement of the second component out of the locked position and that snaps into a second snap recess to resist movement of the second component out of the unlocked position.

[0044] The tester device can include, wherein the first and second snap recesses are disposed on the locking device.

[0045] The tester device can include, wherein the first and second snap recesses are disposed on the second component.

[0046]

[0046] The tester apparatus may include a first component including a back plate and a signal distribution board, a portion of the signal distribution board being positioned between the back plate and the second component, the signal distribution board having an opening through which a connecting part is inserted, the opening having a first dimension on an axis toward a center point of the signal distribution board that is greater than a second dimension across the axis, the connecting part having a first portion that is smaller than the first dimension in the direction of the axis to allow the signal distribution board and the back plate to thermally expand relative to each other, and the first portion being dimensioned to slidably fit within the second dimension of the opening to prevent movement of the signal distribution board relative to the back plate in a direction across the axis.

[0047]

[0047] The tester device may include a connecting part having a second portion, the second portion having a first thickness that can fit into the opening in the axial direction during the insertion and that is greater than a second dimension of the opening, and a second thickness that transverses the first thickness and can fit into the second dimension of the opening during the insertion.

[0048]

[0048] The tester apparatus may include a latch system further including a second latch assembly, each respective latch assembly including a first part that engages with the first component, a second part that engages with the second component, a connecting part having opposite ends secured to the first and second parts respectively to form a locking device, and an engaging mechanism connected to the locking device and operable to move the locking device, the locking device being movable between a locked position that maintains the first and second components locked in a closed position and an unlocked position that moves the first and second components from the closed relationship to a spaced apart relationship.

[0049] The tester apparatus can include, wherein the first and second latch assemblies have their respective second parts on different sides of the second component part.

[0050]

[0050] The tester device can include a pressure differential cavity seal surrounding the contacts and terminals.

[0051] The tester apparatus can include, when the first and second components are separated, the pressure differential cavity seal is secured to the first component.

[0052]

[0052] The tester device may include, wherein the pressure differential cavity seal is a lip seal.

[0053]

[0053] The tester device may include: the pressure reducing valve is a pressure reducing check valve; a vacuum release passage is formed through a component having the pressure reducing check valve; the vacuum release passage has an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; and a second valve which is a vacuum release valve connected to the vacuum release passage; opening of the vacuum release valve allows air to enter the pressure differential cavity; and closing of the vacuum release valve prevents air from escaping from the pressure differential cavity.

[0054]

[0054] The tester apparatus may include a stationary structure including a thermal chuck, and a second component of the portable support structure including a thin chuck in contact with the thermal chuck to enable heat transfer between the portable support structure and the thermal chuck.

[0055]

[0055] The tester apparatus can include wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

[0056]

[0056] The tester device may include a contact point being a pin, each pin having a spring, and when the respective contact point is depressed by a respective one of the terminals, the spring is depressed against its spring force.

[0057]

[0057] The present invention also provides a method for testing a microelectronic circuit carried by a substrate, the method comprising the steps of holding the substrate between first and second components of a portable support structure, the second component having contacts for terminals of the substrate connected to the microelectronic circuit, a pressure reduction passageway formed through one of the first and second components, the pressure reduction passageway having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; arranging a pressure differential cavity seal between the first and second components to form a cavity surrounded by surfaces of the first and second components and the pressure differential cavity seal; opening a pressure reduction valve to allow air to exit the pressure differential cavity and reduce the pressure in the pressure differential cavity to bring the first and second components into relative proximity, thus ensuring proper contact between the contacts and the terminals; and closing the pressure reduction valve to allow the air to exit the pressure differential cavity. the first and second components in a closed position and a second component in a spaced apart position, the locking device may include a first part that engages with the first component, a second part that engages with the second component, and a connecting part having opposite ends fixed to the first and second parts, respectively; receiving the portable support structure by the stationary structure with the first connecting part on the portable support structure connected to the second connecting part on the stationary structure; and transmitting signals between the electrical tester and the microelectronic circuit through the terminals, contacts, and the first and second connecting parts to test the microelectronic circuit.

[0058]

[0058] The method can include the engagement mechanism moving the second component between a locked position and an unlocked position.

[0059]

[0059] The method can include the second component rotating between a locked position and an unlocked position.

[0060]

[0060] The method may include the engagement mechanism including a surface on the first part forming a seat for contacting a surface on the jaw of the tool, the jaw of the tool being rotatable to rotate the first part, and the first part rotating the second part via the connecting part to move between a locked position and an unlocked position.

[0061]

[0061] The method may include, wherein the surface of the first part that forms the seat is an outer surface of the first part.

[0062]

[0062] The method can include the first part having a tool pin opening therein for aligning a pin of a tool with the first part.

[0063]

[0063] The method may include the second component having a body and at least a first wing extending from the body, the first wing moving over a shoulder of the first component when moving to a first locked position and moving away from the shoulder when moving out of the first locked position towards an unlocked position.

[0064]

[0064] The method may include the second component having a second wing extending from the body, the second wing moving over a shoulder of the first component when moving to the second locked position and moving away from the shoulder when moving out of the second locked position towards the unlocked position.

[0065]

[0065] The method may include the latch system further comprising a harmonic block mounted in a stationary position relative to the first component, the harmonic block having a level surface above which the second wing piece is positioned when the first wing piece is positioned above the shoulder, the second component being adjustable relative to the first component to adjust the gap between the level surface and the second wing piece.

[0066]

[0066] The method may include the latch system further comprising a lock nut having threads that engage with threads on the connecting part to rotate and adjust the second part relative to the connecting part.

[0067]

[0067] The method may include the latch system further including a shim positioned between the harmonic block and the first component to adjust the distance between the level surface and the first component.

[0068]

[0068] The method may include the latch system further including a snap mechanism having a snap surface that snaps into the first snap recess to resist movement of the second component out of the locked position and snaps into the second snap recess to resist movement of the second component out of the unlocked position.

[0069]

[0069] The method can include, the first and second snap recesses being disposed on the locking device.

[0070]

[0070] The method can include, the first and second snap recesses being disposed on the second component.

[0071]

[0071] The method may include: a first component including a back plate and a signal distribution board; a portion of the signal distribution board being positioned between the back plate and the second component; the signal distribution board having an opening through which a connecting part is inserted; the opening having a first dimension on an axis toward a center point of the signal distribution board that is greater than a second dimension across the axis; the connecting part having a first portion that is smaller than the first dimension in the direction of the axis to allow the signal distribution board and the back plate to thermally expand relative to one another; and the first portion being dimensioned to slidably fit within the second dimension of the opening to prevent movement of the signal distribution board relative to the back plate in a direction across the axis.

[0072]

[0072] The method may include the connecting part having a second portion, the second portion having a first thickness that can fit into the opening in the axial direction during said insertion and that is greater than a second dimension of the opening, and a second thickness that transverses the first thickness and can fit into the second dimension of the opening during said insertion.

[0073]

[0073] The method may include the latch system including a second latch assembly, each respective latch assembly having a first part that engages with the first component, a second part that engages with the second component, a connecting part having opposite ends fixed to the first and second parts respectively to form a locking device, and an engaging mechanism connected to the locking device and operable to move the locking device, the locking device being movable between a locked position that maintains the first and second components locked in a closed position and an unlocked position that moves the first and second components from the closed relationship to a spaced apart relationship.

[0074]

[0074] The method can include the first and second latch assemblies having their respective second parts on different sides of the second component part.

[0075]

[0075] The method may include a pressure differential cavity seal surrounding the contacts and terminals.

[0076]

[0076] The method can include, when the first and second components are separated, the pressure differential cavity seal is secured to the first component.

[0077]

[0077] The method may include, wherein the pressure differential cavity seal is formed with a lip seal.

[0078]

[0078] The method may include the step of: the pressure reducing valve being a pressure reducing check valve; a vacuum release passage being formed through a component having the pressure reducing check valve; the vacuum release passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; and the method may further include the step of opening a second valve, which is a vacuum release valve connected to the vacuum release passage, to allow air to enter the pressure differential cavity.

[0079]

[0079] The method can include the stationary structure including a thermal chuck and the second component of the portable support structure including a thin chuck.

[0080]

[0080] The method can include the substrate being a wafer comprising a plurality of microelectronic circuits.

[0081]

[0081] The method may include the contacts being pins, each pin having a spring, and when the respective contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

[0082]

[0082] The present invention also provides a microelectronic circuit test pack, the microelectronic circuit test pack comprising a portable support structure, first and second components for holding a substrate therebetween, the substrate carrying a microelectronic circuit and having a plurality of terminals connected to the microelectronic circuit, a plurality of contacts on the second component and coinciding with and contacting the terminals, a pressure differential cavity seal between the first and second components and forming an enclosed pressure differential cavity together with surfaces of the first and second components, and a pressure differential seal formed through one of the first and second components and having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity. a pressure reducing valve connected to the pressure reducing passage, the pressure reducing valve opening to allow air outside the pressure differential cavity to bring the first and second components relatively close to each other to ensure proper contact between the contacts and the terminals, and closing to prevent air from entering the pressure differential cavity; a first connecting portion located on the portable support structure and connected to the contacts, the first connecting portion connecting to the second connecting portion on the stationary structure when the portable support structure is removably held by the stationary structure; a pressure sensor positioned to detect the pressure in the pressure differential cavity; and an electric pressure sensor connecting portion connected to the pressure sensor to communicate the pressure to an electric tester.

[0083]

[0083] The microelectronic circuit test pack can include a pressure sensor positioned away from the pressure differential cavity, and a pressure sensing passage connecting the pressure differential cavity with the pressure sensor.

[0084] The microelectronic circuit test pack can include a vacuum passage formed in the first component.

[0085]

[0085] The microelectronic circuit test pack may include a first component including a back plate and a signal distribution board, a portion of the signal distribution board being positioned between the back plate and the second component, and a pressure sensing passage being formed in the back plate.

[0086]

[0086] The microelectronic circuit test pack may include a pressure sensing passage formed through the signal distribution board.

[0087]

[0087] The microelectronic circuit test pack can include a pressure sensor secured to a portable support structure.

[0088] The microelectronic circuit test pack can include, when the first and second components are separated, the pressure differential cavity seal is secured to the first component.

[0089]

[0089] The microelectronic circuit test pack can include, wherein the pressure differential cavity seal is a lip seal.

[0090]

[0090] The microelectronic circuit test pack may include: the pressure reducing valve is a pressure reducing check valve; a vacuum release passage is formed through a component having the pressure reducing check valve; the vacuum release passage has an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; and may further include a second valve which is a vacuum release valve connected to the vacuum release passage; opening of the vacuum release valve allows air to enter the pressure differential cavity; and closing of the vacuum release valve prevents air from escaping from the pressure differential cavity.

[0091]

[0091] The microelectronic circuit test pack can include wherein the substrate is a wafer having a plurality of microelectronic circuits.

[0092]

[0092] The microelectronic circuit test pack may include a structure in which the contacts are pins, each pin having a spring, and when each contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

[0093]

[0093] The present invention further provides a tester apparatus comprising a portable support structure including first and second components for holding a substrate therebetween, the substrate carrying a microelectronic circuit and having a plurality of terminals connected to the microelectronic circuit, a plurality of contacts on the second component and coinciding with and contacting the terminals, a pressure differential cavity seal between the first and second components and forming an enclosed pressure differential cavity together with surfaces of the first and second components, a pressure reducing passage formed through one of the first and second components and having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity, and a pressure reducing valve connected to the pressure reducing passage, the opening of which allows air outside the pressure differential cavity to bring the first and second components into relative proximity to each other to ensure proper contact between the contacts and the terminals, and the closing of which prevents air from entering the pressure differential cavity. the pressure reducing valve; a first connection portion on the portable support structure and connected to the contacts; a stationary structure that is receivable to hold the portable support structure and from which the portable support structure is removable; a second connection portion on the stationary structure that is connected to the first connection portion when the portable support structure is held by the stationary structure and that is disconnected from the first connection portion when the portable support structure is removed from the stationary structure; an electric tester that is connected to the terminal via the second connection portion, the first connection portion and the contacts, and that transmits signals to and from the microelectronic circuit to test the microelectronic circuit; and a pressure monitoring system that includes a pressure sensor positioned to detect pressure in the pressure differential cavity and an electric pressure sensor connection portion connected to the pressure sensor and communicating the pressure to the electric tester.

[0094]

[0094] The tester apparatus can include a pressure sensor positioned away from the pressure differential cavity, and a pressure sensing passage connecting the pressure differential cavity with the pressure sensor.

[0095]

[0095] The tester device can include, wherein the reduced pressure passage is formed in the first component.

[0096]

[0096] The tester device may include a first component including a back plate and a signal distribution board, a portion of the signal distribution board being positioned between the back plate and the second component, and a pressure sensing passage being formed in the back plate.

[0097]

[0097] The tester device may include a pressure sensing passage formed through the signal distribution board.

[0098]

[0098] The tester device may include a pressure sensor fixed to a portable support structure.

[0099]

[0099] The tester apparatus may include a pressure monitoring system including an electrical pressure connector connection portion on a stationary structure, and an electrical pressure sensor connection portion in releasable contact with the electrical pressure connector connection portion to communicate pressure to the electrical tester.

[0100]

[0100] The tester device may include: an electrical pressure sensor connection portion including at least a first contact; a pressure monitoring system including at least a first terminal; when the portable support structure is housed by the stationary structure, the first contact engages with the first terminal; and when the portable support structure is removed from the stationary structure, the first contact separates from the first terminal.

[0101]

[0101] The tester device can include the electrical pressure sensor connection being in a printed circuit board having a substrate, and the first contact being formed on the substrate.

[0102]

[0102] The tester device may include: the electrical pressure sensor connection portion including at least a second contact; the pressure monitoring system including at least a second terminal; when the portable support structure is housed by the stationary structure, the second contact engages with the second terminal; and when the portable support structure is removed from the stationary structure, the second contact separates from the second terminal.

[0103]

[0103] The tester device can include a pressure differential cavity seal surrounding the contacts and terminals.

[0104]

[0104] The tester apparatus can include, when the first and second components are separated, the pressure differential cavity seal is secured to the first component.

[0105]

[0105] The tester device may include, wherein the pressure differential cavity seal is a lip seal.

[0106]

[0106] The tester apparatus may include: the pressure reducing valve is a pressure reducing check valve; a vacuum release passage is formed through a component having the pressure reducing check valve; the vacuum release passage has an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; and may further include a second valve which is a vacuum release valve connected to the vacuum release passage; opening of the vacuum release valve allows air to enter the pressure differential cavity; and closing of the vacuum release valve prevents air from escaping from the pressure differential cavity.

[0107]

[0107] The tester apparatus may include a stationary structure including a thermal chuck, and a second component of the portable support structure including a thin chuck in contact with the thermal chuck to enable heat transfer between the portable support structure and the thermal chuck.

[0108]

[0108] The tester apparatus can include wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

[0109]

[0109] The tester device may include the contacts being pins, each pin having a spring, and when the respective contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

[0110]

[0110] The present invention also provides a method for testing a microelectronic circuit carried by a substrate, the method comprising the steps of holding the substrate between first and second components of a portable support structure, the second component having contacts for terminals of the substrate connected to the microelectronic circuit, a pressure reduction passageway formed through one of the first and second components, the pressure reduction passageway having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; arranging a pressure differential cavity seal between the first and second components to form a cavity surrounded by surfaces of the first and second components and the pressure differential cavity seal; and opening a pressure reducing valve to allow air to escape from the pressure differential cavity. the pressure in the pressure differential cavity to reduce the pressure in the pressure differential cavity and bring the first and second components into relative proximity, thereby ensuring proper contact between the contacts and the terminals; closing the pressure reducing valve to prevent air from entering the pressure differential cavity; housing the portable support structure with the stationary structure with the first connection portion on the portable support structure connected to the second connection portion on the stationary structure; transmitting signals between the electrical tester and the microelectronic circuit via the terminals, the contacts, and the first and second connection portions to test the microelectronic circuit; detecting the pressure in the pressure differential cavity of the pressure monitoring system; and communicating the pressure to the electrical tester.

[0111]

[0111] The method may include: the pressure sensor being positioned away from the pressure differential cavity, and a pressure sensing passage connecting the pressure differential cavity to the pressure sensor.

[0112]

[0112] The method can include, the vacuum passage is formed in the first component.

[0113]

[0113] The method may include the first component including a back plate and a signal distribution board, a portion of the signal distribution board being positioned between the back plate and the second component, and a pressure sensing passage being formed in the back plate.

[0114]

[0114] The method may include forming a pressure sensing passage through the signal distribution board.

[0115]

[0115] The method may include the pressure sensor being fixed to a portable support structure.

[0116]

[0116] The method may include the pressure monitoring system including an electrical pressure connector connection portion on the stationary structure, and the electrical pressure sensor connection portion being in releasable contact with the electrical pressure connector connection portion to communicate pressure to an electrical tester.

[0117]

[0117] The method may include the electrical pressure sensor connection portion including at least a first contact, the pressure monitoring system including at least a first terminal, the first contact engaging the first terminal when the portable support structure is housed by the stationary structure, and the first contact separating the first terminal when the portable support structure is removed from the stationary structure.

[0118]

[0118] The method can include the electrical pressure sensor connection being in a printed circuit board having a substrate, and the first contact being formed on the substrate.

[0119]

[0119] The method may include the electrical pressure sensor connection portion including at least a second contact, the pressure monitoring system including at least a second terminal, the second contact engaging the second terminal when the portable support structure is housed by the stationary structure, and the second contact separating the second terminal when the portable support structure is removed from the stationary structure.

[0120]

[0120] The method may include a pressure differential cavity seal surrounding the contacts and terminals.

[0121]

[0121] The method can include, when the first and second components are separated, the pressure differential cavity seal is secured to the first component.

[0122]

[0122] The method may include, wherein the pressure differential cavity seal is formed by a lip seal.

[0123]

[0123] The method may include the pressure reducing valve being a pressure reducing check valve, a vacuum release passageway being formed through a component having the pressure reducing check valve, the vacuum release passageway having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity, and may further include the step of opening a second valve, the second valve being a vacuum release valve connected to the vacuum release passageway to allow air to enter the pressure differential cavity.

[0124]

[0124] The method can include the stationary structure including a thermal chuck and the second component of the portable support structure including a thin chuck.

[0125]

[0125] The method can include, wherein the substrate is a wafer having a plurality of microelectronic circuits.

[0126]

[0126] The method may include the contacts being pins, each pin having a spring, and when the respective contacts are depressed by each of the terminals, each pin is depressed against the force of its spring.

[0127]

[0127] The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0128] [Figure 1] 1 is a cross-sectional side view of a tester device having a slot assembly according to one embodiment of the invention. [Figure 2] FIG. 2 is a cross-sectional side view of the tester device of FIG. 1 taken along line 2-2. [Figure 3] FIG. 3 is a cross-sectional side view of the tester device of FIG. 1 taken along line 3-3. [Figure 4] FIG. 4 is a cross-sectional side view of the tester apparatus of FIGS. 2 and 3 taken along line 4-4. [Figure 5A] FIG. 1 is a perspective view of the tester apparatus showing the insertion and removal of the portable wafer pack into and from the oven defined by the frame. [Figure 5B]FIG. 1 is a perspective view of the tester apparatus showing the insertion and removal of the portable wafer pack into and from the oven defined by the frame. [Figure 5C] FIG. 1 is a perspective view of the tester apparatus showing the insertion and removal of the portable wafer pack into and from the oven defined by the frame. [Figure 6] 1 is a timing diagram showing how one wafer pack is inserted into the wafer electronics and used for testing, followed by the insertion of another wafer pack. [Figure 7] FIG. 10 is a perspective view of the tester device showing the insertion or removal of one slot assembly. [Figure 8A] FIG. 8 is a cross-sectional side view illustrating the use of standoffs in the wafer pack configuration described with respect to FIGS. 1-7. [Figure 8B] FIG. 8 is a cross-sectional side view illustrating the use of standoffs in the wafer pack configuration described with respect to FIGS. 1-7. [Figure 9A] FIG. 1 is a side view showing a device used to transfer portable wafer packs to and from an oven. [Figure 9B] FIG. 1 is a side view showing a device used to transfer portable wafer packs to and from an oven. [Figure 10] FIG. 1 is a side view showing a device used to transfer portable wafer packs to and from an oven. [Figure 11] FIG. 2 is a perspective view of the first wafer pack as seen from above. [Figure 12] FIG. 2 is a perspective view of the first wafer pack as seen from below. [Figure 13] 13 is a cross-sectional view of the first wafer pack taken along line 13-13 of FIGS. 11 and 12. FIG. [Figure 14] FIG. 14 is a cross-sectional view of the first wafer pack taken along line 14-14 of FIG. 13. [Figure 15] 15 is a cross-sectional view of the first wafer pack taken along line 15-15 of FIG. 12. FIG. [Figure 16] 15 from the direction of arrow A with components removed from FIG. 15. FIG. [Figure 17]FIG. 17 is a cross-sectional view of FIG. 15 taken along line 17-17. [Figure 18a(i)] 15 in the direction of arrow A with the latch mechanism in the unlocked configuration. FIG. [Figure 18a(ii)] 15 in the direction of arrow B with the latch mechanism in the unlocked configuration. [Figure 18b(i)] 18a(i) is a view similar to FIG. 18a(i), but with the latch mechanism in the locked position. [Figure 18b(ii)] 18a(ii) is a view similar to FIG. 18a(ii), but with the latch mechanism in the locked position. [Figure 19] FIG. 10 is a perspective view showing how shims are used to set the height of the winglets of the latch mechanism. [Figure 20] FIG. 1 is a perspective view showing components of a pressure monitoring system. [Figure 21] FIG. 10 is a perspective view showing further components of the pressure monitoring system. [Figure 22a] FIG. 1 is a perspective view showing the components prior to engagement with the pressure monitoring system. [Figure 22b] FIG. 1 is a side view showing the components prior to engagement with the pressure monitoring system. [Figure 23a] FIG. 22b is a view similar to FIG. 22a showing the components of the pressure monitoring system after engagement. [Figure 23b] FIG. 22b is a view similar to FIG. 22b showing the components of the pressure monitoring system after engagement. DETAILED DESCRIPTION OF THE INVENTION

[0129]

[0151] 1 of the accompanying drawings shows a tester apparatus 10 according to one embodiment of the invention, the tester apparatus 10 comprising (i) a stationary structure including 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 cooling liquid supply line 24A, a cooling liquid return line 24B, a control liquid supply line 24C, a control liquid return line 24D, and a vacuum line 24E, (ii) a portable support apparatus including first and second wafer packs 28A and 28B, and (iii) first and second wafers 30A and 30B. The first and second wafer packs 28A and 28B are referred to herein as "wafer packs," and their use for testing wafers is described. It should be understood that the first and second wafer packs 28A and 28B may be used generally for testing microelectronic circuits and may alternatively be classified as "first and second microelectronic circuit test packs 28A and 28B."

[0130]

[0152] The slot assembly 18A includes a slot assembly body 32, a thermal chuck 34, a temperature detector 36, a temperature compensation device in the form of a heating resistor 38, a first slot assembly connection portion 40 and a plurality of second slot assembly connection portions, the second slot assembly connection portions including a control connection portion 44, a power connection portion 46 and a coolant supply connection portion 48A, a coolant return connection portion 48B, a control liquid supply connection portion 48C, a control liquid return connection portion 48D and a vacuum connection portion 48E.

[0131]

[0153] A first slot assembly connection portion 40 is disposed within and attaches to the slot assembly body 32. A second connection portion in the form of a control connection portion 44, a power connection portion 46, and connection portions 48A-48E attaches to the left wall of the slot assembly body 32.

[0132]

[0154] Slot assembly 18A can be inserted into frame 14 from left to right and removed from frame 14 from right to left. Tester cable 20, power cable 22, and various lines 24A to 24E are manually connected to control connection portion 44, power connection portion 46, and connections 48A to 48E, respectively. Before removing slot assembly 18A from frame 14, tester cable 20, power cable 22, and various lines 24A to 24E are first manually disconnected from control connection portion 44, power connection portion 46, and connections 48A to 48E, respectively.

[0133]

[0155] The slot assembly 18A includes a motherboard 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 connection portion 44 and the power connection portion 46 are connected to the motherboard 60, and the thermal controller 50 is attached to the motherboard 60. The channel module boards 62 are electrically connected to the motherboard 60. The flexible connector 64 connects the channel module boards 62 to the connection board 66. Control functions are provided via conductors connecting the control connection portion 44 to the motherboard 60. Power is provided to the motherboard 60 via the power connection portion 46. Both power and control are provided to the channel module boards 62 from the motherboard 60 via conductors. The flexible connector 64 provides conductors connecting the channel module boards 62 to the connection board 66. The connection board 66 includes conductors connecting the flexible connector 64 to the first slot assembly connection portion 40. This first slot assembly connection portion 40 is connected to the control connection portion 44 and the power connection portion 46 via various conductors so that power and control can be supplied to the first slot assembly connection portion 40 via the control connection portion 44 and the power connection portion 46.

[0134]

[0156] The second slot assembly 18B includes similar components to the first slot assembly 18A, and like reference numerals indicate like components. The second slot assembly 18B is inserted into the frame 14, and the control connection portion 44, the power connection portion 46, and the connection portions 48A-48E of the second slot assembly 18B are manually connected to a set of separate connection structure components, including the separate tester cable 20, the separate power supply cable 22, and the separate lines 24A-24E, respectively.

[0135]

[0157] Wafer pack 28A includes a wafer pack body formed by a thin chuck 72 and a backplate 74. Wafer 30A has multiple microelectronic devices formed thereon. Wafer 30A is inserted within the wafer pack body between thin chuck 72 and backplate 74. Multiple wafer pack contacts 76 contact respective contacts (not shown) on wafer 30A. Wafer pack 28A further includes a wafer pack connecting portion 78 on backplate 74. Conductors in backplate 74 connect wafer pack connecting portion 78 to wafer pack contacts 76.

[0136]

[0158] Wafer pack 28A has a lip seal 77 (also referred to herein as a "pressure differential cavity seal") connected between backplate 74 and thin chuck 72. A vacuum is applied to the area defined by lip seal 77, backplate 74, and thin chuck 72. The vacuum holds wafer pack 28A together and ensures proper contact between wafer pack contacts 76 and contacts on wafers 30A.

[0137]

[0159] Temperature detector 36 is positioned within thermal chuck 34 and is therefore close to wafer 30A or within 5 degrees Celsius, preferably 1 or 2 degrees Celsius, of wafer 30A to detect the temperature of wafer 30A.

[0138]

[0160] The slot assembly 18A further includes a door 82 connected to the slot assembly body 32 by a hinge 84. When the door 82 is rotated to an open position, the wafer pack 28A can be inserted into the slot assembly body 32 through a door opening 86. The wafer pack 28A is then lowered onto the thermal chuck 34, and the door 82 is closed. The thermal chuck 34 attaches to the slot assembly body 32. The thermal chuck 34 thus essentially forms a holder with a test station for the wafer.

[0139]

[0161] Slot assembly 18A further includes a thermal interface cavity seal 88 disposed between thermal chuck 34 and thin chuck 72. A vacuum is applied to the area defined by thermal interface cavity seal 88, thermal chuck 34, and thin chuck 72 via vacuum interface 48E and vacuum line 90. This provides a good thermal connection between thermal chuck 34 and thin chuck 72. When heat is generated by heating resistor 38, the heat is conducted through thermal chuck 34 and thin chuck 72 to wafer 30A. When thermal chuck 34 is at a lower temperature than wafer 30A, heat is conducted in the opposite direction.

[0140]

[0162] The wafer pack connection portion 78 is engaged with the first slot assembly connection portion 40. Power and signals are supplied to the wafer 30A via the first slot assembly connection portion 40, the wafer pack connection portion 78, and the wafer pack contacts 76. The performance of the devices in the wafer 30A is measured via the wafer pack contacts 76, the wafer pack connection portion 78, and the first slot assembly connection portion 40.

[0141]

[0163] Door 82 of slot assembly 18B is shown in the closed position. A front seal 100 is attached to the top of slot assembly 18A and seals against the underside of slot assembly 18B. A front seal 102 is attached to the top of slot assembly 18B and seals against the underside of frame 14. Door 82 and front seals 100 and 102 of slot assemblies 18A and 18B together provide a continuous, sealed front wall 104.

[0142]

[0164] The slot 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 through the power connection 46 and a power line 54 so that the heating resistor 38 heats up. The heating resistor 38, in turn, heats the thermal chuck 34 and the wafer 30A thereon. The heating resistor 38 is controlled by the thermal controller 50 based on the temperature detected by the temperature detector 36.

[0143]

[0165] Thermal chuck 34 has thermal fluid passages 224 formed therein. Thermal fluid passages 224 hold a thermal fluid. The thermal fluid is preferably a liquid rather than a gas because liquids are incompressible and heat convects to and from liquids more quickly. Different thermal fluids are used for different applications, with oil being used for the highest temperature applications.

[0144]

[0166] Control fluid supply and return lines 226 and 228 connect opposite ends of the thermal fluid passage 224 to cooling fluid supply and return connections 48C and 48D, respectively. Heating resistor 38 serves as a fixed-position heater that heats the thermal chuck 34, which in turn heats the thermal fluid. By recirculating the thermal fluid through thermal fluid passage 224, thermal chuck 222 provides a more uniform heat distribution to the thermal chuck 34 and ultimately to the wafer 30A. The temperature of the fluid can also be controlled to heat or cool the thermal chuck 34.

[0145]

[0167] The tester apparatus 10 further includes a cooling system 240, a temperature control system 242, and a vacuum pump 244. Two cooling liquid supply lines 24A connected to the first and second slot assemblies 18A and 18B are also connected to the cooling system 240 via a manifold (not shown). Additional manifolds connect the cooling liquid return line 24B to the cooling system 240, the control liquid supply line 24C to the temperature control system 242, the control liquid return line 24D to the temperature control system 242, and the vacuum line 24E to the vacuum pump 244. Each slot assembly 18A or 18B has a respective cooling plate 246 with a respective fluid passage 248. The cooling system 240 circulates fluid through the fluid passages 248 to cool the cooling plate 246. The cooling plate 246, in turn, keeps the channel module board 62 cool. A temperature control system 242 circulates fluid through thermal fluid passages 224 to control the temperature of thermal chuck 34 and to transfer heat to and from wafers 30A and 30B. A vacuum pump 244 supplies air at vacuum pressure to vacuum line 90.

[0146]

[0168] Slot assembly 18A includes a separator seal 108 that is attached to the upper surface of slot assembly body 32 above inner wall 106. Separator seal 108 seals against the underside of slot assembly 18B. Slot assembly 18B has a separator seal 110 attached to the upper surface of its slot assembly body 32. Separator seal 108 seals against the underside of frame 14. The inner walls 106 of slot assemblies 18A and 18B and separator seals 108 and 110 provide a continuously sealed separator wall 112.

[0147]

[0169] Figure 2 is a diagram of the tester apparatus 10 of Figure 1 taken along line 2-2. The frame 14 defines a first closed-loop air path 120. Air inlet and outlet openings (not shown) can be opened to convert the first closed-loop air path 120 to an open air path in which room temperature air flows through the frame 14 without recirculation. A closed-loop path is particularly useful in cleanroom environments because cleanroom environments emit less particulate matter into the air.

[0148]

[0170] The tester apparatus 10 further includes temperature compensation equipment in the form of a first fan 122 , a first fan motor 124 , and a water cooler 126 .

[0149]

[0171] A first fan 122 and a first fan motor 124 are mounted in the upper portion of the first closed-loop air path 120. A water chiller 126 is mounted to the frame 14 within the upper portion of the first closed-loop air path 120.

[0150]

[0172] Wafer packs 28A and 28B are positioned with slot assemblies 18A and 18B within the bottom half of first closed-loop air path 120.

[0151]

[0173] In use, current is supplied 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.

[0152]

[0174] The water chiller 126 then cools the air in the first closed-loop air path 120. The air then flows through slot assemblies 18A and 18B and over wafer pack 28A or 28B, which is then cooled by the convective air.

[0153]

[0175] Figure 3 is a diagram of the tester apparatus 10 of Figure 1 taken along line 3-3. The frame 14 defines a second closed-loop air path 150. The tester apparatus 10 further includes temperature compensation equipment in the form of a second fan 152, a second fan motor 154, and a water chiller 156. No electric heaters or dampers are provided as shown in Figure 2. The air inlet and outlet openings (not shown) can be opened to convert the second closed-loop air path 150 to an open air path in which room temperature air passes through the frame 14 without being recirculated.

[0154]

[0176] Closed-loop paths are particularly useful in clean room environments because they emit less particulate matter 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 chiller 156 is located slightly downstream from the second fan 152 within the second closed-loop air path 150. The motherboard 60 and the channel module board 62, which form part of the slot assemblies 18A and 18B, are located within the lower half of the second closed-loop air path 150.

[0155]

[0177] In use, current is supplied to the second fan motor 154, causing the second fan 152 to rotate. The second fan 152 then recirculates the 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 is then channeled over the motherboard 60 and channel module boards 62, resulting in heat being transferred by convection from the motherboard 60 and channel module boards 62 to the air.

[0156]

[0178] The air recirculating through the first closed-loop air path 120, Figure 2, is separated from the air in the second closed-loop air path 150, Figure 3, by the continuously sealed separator wall 112, shown in Figure 1. The continuously sealed front wall 104, shown in Figure 1, prevents air from leaking from the first closed-loop air path 120.

[0157]

[0179] 2 and 3, the same cooling system 240 used in Figure 1 is also used to cool the water chiller 126. As shown in Figure 4, a plenum 160 separates the first closed-loop air path 120 from the second closed-loop air path 150 in all areas except the area provided by the continuously sealed separator wall 112. The frame 14 has left and right walls 162, 164 that further define the closed-loop air paths 120 and 150.

[0158]

[0180] Figures 5A, 5B, and 5C illustrate how wafer packs 30C, 30D, and 30E can be inserted or removed at any time, while all other wafer packs are used to test wafer devices and are subject to various temperature gradients. Figure 6 illustrates the concept in more detail. At time T1, a first wafer pack is inserted into frame 14 while a second wafer pack is outside of frame 14. At T1, heating of the first wafer pack begins. Between T1 and T2, the temperature of the first wafer pack increases from room temperature, approximately 22°C, to a test temperature of 50°C to 150°C above room temperature at T2. At T2, power is applied to the first wafer pack, and the devices within the first wafer pack are tested. At T3, a second wafer pack is inserted into frame 14, and heating of the second wafer pack begins. At T4, testing of the first wafer pack ends. At T4, cooling of the first wafer pack also begins. At T5, the second wafer pack reaches the test temperature, power is applied to the second wafer pack, and the wafers in the second wafer pack are tested. At T6, the second wafer pack reaches a temperature near room temperature and is removed from frame 14. A third wafer pack can then be inserted in place of the first wafer pack. At T7, testing of the second wafer pack ends and cooling begins. At T8, the second wafer pack is cooled to room temperature or near room temperature and is removed from frame 14.

[0159]

[0181] Various tests can be performed at various temperatures. As an example, a wafer pack can be inserted and the test can proceed at room temperature. Another test can be performed while the temperature is increased. Further tests can continue at the increased temperature. Further tests can be performed while the temperature is decreased. Two of these tests can be a single test that continues from one temperature step to the next.

[0160]

[0182] As shown in Figure 7, one slot assembly 18A can be removed from or inserted into frame 14. While slot assembly 18A can be inserted or removed, other slot assemblies in frame 14 can be used to test wafer devices, as will be described with reference to Figure 6.

[0161]

[0183] FIG. 8A also shows signal distribution board 500, contactor 502, a number of pins 504, contactor retainer ring 506, fastener 508 and post 510.

[0162]

[0184] Signal distribution board 500 is made primarily of insulating material and has circuitry (not shown) formed therein. Contacts 512 are formed on an underside 514 of signal distribution board 500. Threaded openings 516 are formed in underside 514.

[0163]

[0185] The contactor 502 has a plurality of pin openings 518, post openings 520, and fastener openings 522 formed therethrough from a top side 524 to a bottom side 526. Each one of the pin openings 518 has a first area 528 and a second area 530. The first and second areas 528 and 530 are both circular when viewed in a plan view. The first area 528 has a larger diameter than the second area 530. Because the diameter of the first area 528 is larger compared to the diameter of the second area 530, the first area 528 is wider than the second area 530 when viewed in the cross-sectional side view of FIG. 8A .

[0164]

[0186] The post opening 520 has a first section 534 and a second section 536. The first section 534 and the second section 536 are both circular when viewed in plan. The diameter of the first section 534 is larger than the diameter of the second section 536. Because the diameter of the first section 534 is larger than the diameter of the second section 536, the first section 534 is wider than the second section 536 when viewed in the cross-sectional side view of FIG. 8A . The first and second sections 534 and 536 have vertical sidewalls. A horizontal landing 538 connects the vertical sidewalls of the first and second sections 534 and 536.

[0165]

[0187] Each pin 504 includes a conductive retaining 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 retained by the retaining portion 542, with the coil spring 544 disposed 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 retaining portion 542, respectively.

[0166]

[0188] The upper surface of first tip 552 forms terminal 560. The lower end of second tip 556 forms contact 562. Coil spring 544 and first and second end pieces 546 and 548 are made of a metallic and therefore electrically conductive material. Coil spring 544 and first and second end pieces 546 and 548 form a conductor capable of conducting electrical current between terminal 560 and contact 562.

[0167]

[0189] Each pin is inserted through the top side 524 and into a respective pin opening 518. The second tip 556 is slightly narrower than the second section 530 so as to extend through the second section 530 and out the bottom side 526. The retention section 542 is slightly narrower than the first section 528 but wider than the second section 530 to prevent the pin 504 from slipping out the bottom side 526. When the pin 504 is fully inserted into the pin opening 518 and before the contactor 502 is installed in the signal distribution board 500, the first tip 552 still protrudes above the top side 524 of the contactor 502.

[0168]

[0190] Post 510 has a stand-off 564, a force transmission portion 566, and a force delivery portion 568. Post 510 is made from a single piece of metal or other material selected for its strength compared to the strength and brittleness of the ceramic material of contactor 502.

[0169]

[0191] The post 510 is inserted into the post opening 520 through the upper side 524. The standoff 564 and force transfer portion 566 are slightly narrower than the second section 536. The force transfer portion 568 is slightly narrower than the first section 534 but wider than the second section 536. A lower surface 570 of the force transfer portion 568 abuts the landing 538. This prevents the post 510 from slipping out of the underside 526.

[0170]

[0192] Post 510 has a surface 572 that lies in a plane parallel to and below the surface of lower side 526 when post 510 is fully inserted, as shown in Figure 8A. Force-delivery portion 568 has a surface 574 that lies in the same plane as upper side 524 when post 510 is fully inserted.

[0171]

[0193] Signal distribution board 500 is positioned on top of contactor 502. Each one of contacts 512 contacts a respective one of terminals 560. Lower side 514 is initially spaced apart from upper side 524 because terminals 560 lie in a plane above the plane of upper side 524.

[0172]

[0194] Fastener 508 has a threaded shaft 578 and a head 580. Contactor retainer ring 506 has a ring opening 582. Contactor retainer ring 506 is positioned on the underside 584 of contactor 502. Threaded shaft 578 passes through ring opening 582 from the bottom and then through fastener opening 522. Head 580 contacts the underside of contactor retainer ring 506. Head 580 is rotated, causing the threads of threaded shaft 578 to thread into the threads of threaded opening 516. The threading action brings signal switchboard 500 closer to contactor 502 and contactor retainer ring 506. Underside 514 eventually contacts upper side 524. Contact 512 lowers first end piece 546 into pin opening 518 until terminal 560 is flush with upper side 524. The coil spring 544 compresses and therefore deforms slightly, allowing relative movement of the first end piece 546 towards the second end piece 548 .

[0173]

[0195] The underside 514 has an area that rests against a surface 574 that forms part of the mast 510. The mast 510 abuts the signal distribution board 500 and is therefore in a position to transmit forces through the surface 574 to the signal distribution board 500.

[0174]

[0196] A plurality of electronic devices are formed on the first wafer 32A, each having a plurality of terminals 588 on a top surface 590 of the first wafer 32A. When the backplate 74 and the first wafer 32A are brought together, the first wafer 32A aligns with the backplate 74 to ensure that each one of the terminals 588 contacts each one of the contacts 562.

[0175]

[0197] A vacuum pressure is created in the region between the upper surface 590 and the underside 526, while the pressure below the lower surface 592 of the thin chuck 72 and at the upper surface 594 of the signal distribution board 500 remains at atmospheric pressure. The pressure difference creates equal and opposite forces F1 and F2 on the signal distribution board 500 and on the thin chuck 72.

[0176]

[0198] As shown in FIG. 8B , forces F1 and F2 cause relative movement of the backplate 74 toward the first wafer 32A and thin chuck 72. The coil springs 544 further compress, allowing the second end pieces 548 to move into the pin openings 518. Each coil spring 544 deforms against its spring force, e.g., F3. However, force F1 is still greater than the sum of all forces F3 combined. The top surface 590 ultimately rests on the surface 572 of the standoff 564. Because the post 510 abuts the signal distribution board 500, the standoff 564 prevents the top surface 590 from approaching and contacting the underside 526 of the contactor 502. The first wafer 32A transmits force F4 to the standoff 564. The force transmitting portion 566 transmits force F4 through the second section 536 of the post opening 520. Force delivery portion 568 receives force F4 from force transmission portion 566 and delivers force F4 to signal distribution board 500 via surface 574.

[0177]

[0199] It can thus be seen that force F4 is not transmitted through contactor 502, thereby preventing stresses that could damage the brittle ceramic material of contactor 502. Instead, force F4 is transmitted directly from the electronics in the form of first wafer 32A through support posts 510 to signal distribution board 500.

[0178]

[0200] In the embodiment illustrated in FIGS. 8A and 8B, the contactor 502 serves as a support plate having post openings 520 therethrough. The signal distribution board 500 serves as a backing structure on a first side of the support plate and including at least a circuit board having contacts 512. The pins 504 serve as conductors having contacts 562 for contacting terminals 588 on the electronics, which are positioned on a second side of the support plate opposite the first side of the support plate. The retaining portions 542 serve as part of the conductors retained by the support plate. The conductors further have terminals 560 that connect to the contacts 512 on the signal distribution board 500. A spring 544 in the form of a coil spring is provided. The thin chuck 72 serves as a force-generating device for the electronics in the form of the first wafer 32A opposite the support plate. The force-generating device and the support plate are movable relative to one another to move the electronics closer to the support plate and to deform the springs. The support post 510 has a standoff 564 with a surface 572 located in a plane spaced apart from the plane of the surface of the support plate, and a force transfer portion 566 extends from the standoff 564 and at least partially through the support post opening 520 and extends from the force transfer portion 566 to a force transfer portion 568, which is held by a backing structure.

[0179]

[0201] 9A shows a portion of tester apparatus 10 that is used to insert and remove wafer packs into and from each slot assembly, such as slot assembly 18A. The components of tester apparatus 10 shown in FIG. 9A are stationary structural components, including frame 300, a portion of first slot assembly 18A, first slot assembly connecting portion 40, retaining structure 302, horizontal transfer device 304, vertical transfer device 306, push bar vanes 308, and locking device 310.

[0180]

[0202] Frame 300 includes first and second spaced apart mounts 312 and 314. Horizontal transfer device 304 is a slide mounted between first and second mounts 312 and 314. Retaining structure 302 is mounted for sliding movement along horizontal transfer device 304. Opposite ends of push bar vanes 308 are mounted to first and second mounts 312 and 314, respectively.

[0181]

[0203] The locking device 310 includes a connecting lever 316, a control lever 318, and a pressure lever 320. The control lever 318 attaches to the first mount 312 at a pivot connection 322. The vertical transfer device 306 is a rigid beam. A connection 324 connects the vertical transfer device 306 and the pushrod vane 308 at their center points. The pressure lever 320 has a first link 326 rotatably connected to the control lever 318 and a second link 328 rotatably connected to the end of the vertical transfer device 306. In the unlocked configuration shown in FIG. 9A , a line 330 connects the pivot connection 322 to the second link 328, with the first link 326 to the left of the line 330.

[0182]

[0204] In use, the first wafer pack 28A is placed on the holding structure 302. The first wafer pack 28A then moves from left to right along with the holding structure 302 into the first slot assembly 18A. The placement and movement of the first wafer pack 28A can be performed manually or using a robot.

[0183]

[0205] The retaining structure 302 slides along the horizontal transfer device 304. A connecting lever 316 connects an end of a control lever 318 to the retaining structure 302. As the retaining structure 302 moves horizontally along the horizontal transfer device 304, the connecting lever 316 causes the control lever 318 to rotate counterclockwise about the pivot connection 322.

[0184]

[0206] The first link 326 rotates counterclockwise with the control lever 318. The pressure lever 320 converts the movement of the first link 326 into downward movement of the second link 328. Initially, the downward movement is minimal, but once the first wafer pack 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 wafer pack 28A with the first slot assembly 18A. The horizontal transfer device 304 is therefore operable to move the first wafer pack 28A horizontally from a first position to a second position into the first slot assembly 18A, and the vertical transfer device 306 is operable to move the first wafer pack 28A and the first slot assembly 18A relative to each other in a first vertical direction so that the slot assembly connection portion 40 engages with the wafer pack connection portion on the first wafer pack 28A.

[0185]

[0207] 9A in an unlocked position in which 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 rotates from the unlocked position shown in FIG. 9A through a compressed position in which the push bar vanes 308 are deflected by the vertical transfer device 306 through connection 324 by bending the push bar vanes 308 against their spring force, and the first link 326 is aligned with the pivot connection 322 and the second link 328. 9B and 10, the control lever 318 continues to rotate from the compressed position to the locked position. In the locked position, the first link 326 is to the right of the line 330 and is therefore on the second side of the line 330 opposite the first side. As the first link 326 passes through the line 330 and the push bar vane 308 deforms against its spring force, the first wafer pack 28A is locked in place relative to the slot assembly connecting portion 40.

[0186]

[0208] The system can be unlocked by moving the retaining structure 302 from right to left. The control lever 318 rotates clockwise, and the first link 326 moves from right to left past the line 330. The vertical transfer device 306 moves upward, i.e., in a second vertical direction opposite the first vertical direction, to release the first wafer pack 28A from the slot assembly connection portion 40. Further movement of the retaining structure 302 along the horizontal transfer device 304 removes the first wafer pack 28A from the slot assembly connection portion 40.

[0187]

[0209] 11 and 12 show further components of the first wafer pack 28A, including a pressure reducing check valve 600, a vacuum relief check valve 602, latch system components including first, second, third and fourth latch assemblies 604A to 604D, and an electrical pressure sensor connection 606 that forms part of a pressure monitoring system.

[0188]

[0210] 11 and 12. A pressure reduction passage 608 is formed in the back plate 74. The pressure reduction passage 608 has an outlet opening 610 and an intermediate location 612 arranged in the same plane. The outlet opening 610 is connected to the pressure reduction check valve 600. The intermediate location 612 is closer to the center point of the back plate 74 than the outlet opening 610. The pressure reduction passage 608 is formed by first drilling four passages in the back plate 74 and then closing one end of three of the passages, so that the resulting pressure reduction passage 608 is completely isolated from atmospheric pressure outside the back plate 74.

[0189]

[0211] FIG. 14 is a cross-sectional view taken along line 14-14 of FIG. 13. The vacuum passage 608 extends downward from the intermediate arrangement 612 through the back plate 74 and the signal distribution board 500. The vacuum passage 608 has an inlet opening 624 that communicates with the pressure differential cavity 622. The lip seal 77 is disposed within a recess in the thin chuck 72. The pressure differential cavity 622 is jointly formed by the thin chuck 72, the contactor 502, and the contactor retainer ring 506, which form the lower side of the pressure differential cavity 622; the signal distribution board 500, which form the upper side of the pressure differential cavity 622; and the lip seal 77, which forms the connection between the upper and lower sides of the pressure differential cavity 622. The lip seal 77 is perfectly circular and completely surrounds the contactor 502 and the wafer disposed between the contactor 502 and the thin chuck 72.

[0190]

[0212] 14 form a portable support structure 626. The portable support structure 626 has a first component 628 including the signal distribution board 500 and the backplate 74, and a second component 630 including the low-profile chuck 72.

[0191]

[0213] In use, the first component 628 separates from the second component 630. The wafer is then placed on the thin chuck 72. The first component 628 is then positioned over the second component 630. The upper edge of the lip seal 77 contacts the signal distribution board 500. The wafer is thus held within the portable support structure 626.

[0192]

[0214] 13 and 14 in combination, a pump is connected to the pressure-reducing check valve 600. The pressure-reducing check valve 600 is then opened. The pressure-reducing passage 608 can initially be at atmospheric pressure, after which the pump reduces the pressure in the pressure-reducing passage 608. The pressure differential cavity 622 is exposed to a pressure lower than atmospheric pressure. The outer surface of the first wafer pack 28A remains exposed to atmospheric pressure. As a pressure differential is created between the pressure differential cavity 622 and the outer surface of the first wafer pack 28A, the spring in the contactor 502 compresses, as described above with reference to FIG. 8B. The lip seal 77 is made of a resilient elastomeric material, which causes the lip seal to compress against its spring force. As the lip seal 77 compresses against its spring force, an improved seal is formed between the lip seal 77 and the signal distribution board 500, thereby maintaining the pressure in the pressure differential cavity 622. The pressure-reducing check valve 600 is then closed, thereby isolating the pressure-reducing passage 608 from the outside atmospheric pressure. The pump can then be disconnected from the pressure-reducing check valve 600.

[0193]

[0215] The first wafer pack 28A, with wafers loaded therein, can now be moved within the assembly environment without being connected to a pump or tester. If the wafers need to be removed later, positive pressure can be applied to the vacuum relief check valve 602 shown in FIGS. 11 and 12. The vacuum relief check valve 602 is spring-loaded, requiring a predetermined amount of pressure to be applied before it opens. Air can then flow through the vacuum relief passage in the backplate 74 into the pressure differential cavity 622, bringing the pressure differential cavity 622 to atmospheric pressure. The first and second components 628 and 630 can then be separated from each other, and the wafers can be removed. When the first wafer pack 28A is loaded with new wafers and the pressure in the pressure differential cavity 622 needs to be reduced using the pressure reduction check valve 600, the vacuum relief check valve 602 then closes.

[0194]

[0216] Figure 15 is a cross-sectional view taken along line 15-15 of Figure 12. The first latch assembly 604A includes a first part 640, a second part 642, a connecting part 644, an engagement mechanism 646, a matching block 648, a lock nut 650, a spacer 652A, a shim 652B, and a snap mechanism 654.

[0195]

[0217] First piece 640 and connecting piece 644 are machined from one piece and are therefore secured together. First piece 640 has a length 660 and a width 662. Only half of width 662 is shown in cross section. Length 660 is greater than width 662. Length 660 is greater than the diameter of connecting piece 644. First piece 640 has a tool pin opening 664 formed therein.

[0196]

[0218] Second component 642 has a body 666 and first and second winglets 668A and 668B extending from body 666. Second component 642 has a length 670, which includes winglets 668A and 668B, and a width 672. Only half of width 672 is visible in the cross-sectional view. Because first and second winglets 668A and 668B form part of length 670 but not part of width 672, length 670 is much greater than width 672. Body 666 further has an opening 674 through which connecting component 644 can be inserted.

[0197]

[0219] The connecting piece 644 includes a first portion 678 and a second portion 680. The second portion 680 has external threads formed thereon.

[0198]

[0220] The engagement feature 646 is formed by opposing surfaces that define a width 662 of the first part 640. The opposing surfaces that form the engagement feature 646 are parallel to one another, which facilitates engagement between parallel surfaces on the jaws of a tool that may rotate the first part 640.

[0199]

[0221] The harmonic block 648 is attached to the spacer 652A in a fixed position. The thin chuck 72 includes a metal portion 682 and a protective piece 684. The protective piece 684 forms a shoulder 686 on the thin chuck 72. A shim 652B is positioned between the spacer 652A and the signal distribution board 500. Only a single shim 652B is shown. Additional shims are inserted, typically one above the other, until the leveling surface 690 of the harmonic block 648 is at the same vertical height as the shoulder 686.

[0200]

[0222] The snap mechanism 654 includes a retainer body 694, a spherical ball 696, and a spring 698. The body 666 of the second part 642 forms part of the snap mechanism 654 because the body 666 has a first snap recess 700A formed therein.

[0201]

[0223] The retainer body 694 has an outer surface with threads 702. The retainer body 694 further has an end with a slot 704 formed therein, which can receive a tool such as a screwdriver. A spring 698 is disposed within the retainer body 694. A spherical ball 696 is positioned within the mouth of the retainer body 694. The mouth of the retainer body 694 is slightly reduced in size to prevent the spherical ball 696 from slipping out of the retainer body 694. The outer surface of the spherical ball 696 forms a snap surface 706. The threads 702 engage complementary threads in the matching block 648. A tool such as a screwdriver is inserted into the slot 704 and then rotated to adjust the spacing of the snap surface 706 from the matching block 648.

[0202]

[0224] The intermediate protective component 708 is inserted into a complementary recess in the upper surface of the back plate 74. Openings 710, 712, and 714 are formed in the intermediate protective component 708, the back plate 74, and the signal distribution board 500, respectively. The second portion 680 of the connection component 644 is inserted through the openings 710, 712, and 714 from above. The length 660 of the first component 640 is greater than the length of any one of the openings 710, 712, and 714 in the same direction, thereby preventing the first component 640 from entering the openings 710, 712, and 714. The lower surface of the first component 640 rests on the upper surface formed in the intermediate protective component 708. The first portion 678 of the connection component 644 is then placed in the openings 710, 712, and 714, and the second portion 680 of the connection component 644 is placed below the openings 710, 712, and 714. The spring loaded washer 720, shim 652B and spacer 652A are then positioned from below over the connecting piece 644. The second piece 642 is then positioned from below over the connecting piece 644. The opening 674 forms a snug fit with the outer diameter of the threads on the second portion 680 of the connecting piece 644.

[0203]

[0225] As the second part 642 slides upward over the connecting part 644, the first snap recess 700A also contacts the snap surface 706. The spherical ball 696 moves a small distance from right to left against the force of the spring 698. The lock nut 650 then engages the protruding end of the second part 680. Rotating the lock nut 650 tightens the body 666 of the second part 642 against the spring force of the washer 720. A feeler gauge or other tool can be used to determine the clearance between the second wing 668B and the leveling surface 690. The lock nut 650 can be rotated until an acceptable clearance is formed between the second wing 668B and the leveling surface 690. This clearance will generally be the same as the desired clearance between the first wing 668A and the shoulder 686. The locking device is then formed by a first part 640 , a second part 642 and a connecting part 644 .

[0204]

[0226] As the lock nut 650 is rotated, the first snap recess 700A also moves upward. The first snap recess 700A is an elongated slot. Thus, the snap surface 706 and the first snap recess 700A can slide over each other as the second part 642 continues to move upward with continued rotation of the lock nut 650.

[0205]

[0227] As shown in the drawings, the thin chuck 72 is in place while the first latch assembly 604A is assembled. Additionally, a negative pressure exists in the pressure differential cavity 622. By placing the first wafer pack 28A in compression, it is possible to measure whether the first and second wing pieces 668A and 668B are equally spaced from the shoulder 686 and the leveling surface 690. The first latch assembly 604A can also be assembled without the thin chuck 72 in place by simply measuring the spacing between the second wing piece 668B and the leveling surface 690, provided that the leveling surface 690 is set at the correct height using one or more shims, such as shim 652B.

[0206]

[0228] FIG. 16 is a view seen from the direction A in FIG. 15, but shows only the connection part 644 and the signal distribution board 500.

[0207]

[0229] The opening 712 has a first dimension 724 along an axis 726 toward a center point of the signal distribution board 500 that is greater than a second dimension 728 transverse to the axis 726. In the direction of the axis 726, a first portion 678 of the connecting piece 644 is smaller than the first dimension 724 to allow for thermal expansion of the signal distribution board 500 and the back plate 74 (see FIG. 15 ) relative to one another. The first portion 678 is dimensioned to slidably fit within the second dimension 728 to prevent movement of the signal distribution board 500 relative to the back plate 74 in a direction transverse to the axis 726.

[0208]

[0230] The second portion 680 of the connecting piece 644 has a first thickness 730 and a second thickness 732. The first thickness 730 is capable of fitting into the opening 712 along the axis 726 and is larger than the second dimension 728 of the opening 712. The second thickness 732 is transverse to the first thickness 730 and is capable of fitting into the second dimension 728 of the opening 712. Because the second dimension 728 is relatively large, a thread can be formed thereon and still be relatively strong. The entire second portion 680 is positioned below the opening 712, which allows the connecting piece 644 to rotate about its longitudinal axis without the second portion 680 hitting the relatively narrow opening 712. The first portion 678 has a circular cross-section whose diameter is less than or equal to the second dimension 728, which allows the first portion 678 to rotate freely within the relatively narrow second dimension 728 of the opening 712.

[0209]

[0231] An additional opening 734 is formed in the signal distribution board 500 to further fasten one or more shims. The opening 734 is similarly proportioned to the opening 712, with a longer dimension along an axis 736 toward the center point of the signal distribution board 500. The fasteners passing through the opening 734 do not need to rotate when used in an assembly environment, and the size of the opening 734 only serves to allow for thermal expansion of the signal distribution board 500 relative to the back plate 74.

[0210]

[0232] Figure 17 is a cross-sectional view taken along line 17-17 of Figure 15. Fasteners 740 are inserted through openings 734 shown in Figure 16 to secure spacers 652A and shims 652B to backplate 74. Fasteners 740 include a bolt and nut with the bolt head on one side and the nut on the other side.

[0211]

[0233] The body 666 has a circular outer surface 742 with first, second, third, and fourth snap recesses 700A-700D formed therein. The snap surface 706 of the spherical ball 696 is positioned within the first snap recess 700A, thereby preventing the body 666 from rotating. The opening 674 in the body 666 is keyed to receive the shape of the second part 680, such that the second part 680 cannot rotate when the body 666 is stationary.

[0212]

[0234] A small torque is required to rotate the body 666 and eject the spherical ball 696 from the first snap indentation 700A. When the body 666 rotates clockwise, the snap surface 706 rests on the circular outer surface 742 between the first snap indentation 700A and the second snap indentation 700B. As the body 666 rotates, the second portion 680 rotates with the body 666 through the same angle. As the body 666 approaches 90 degrees of rotation, the snap surface 706 snaps into the second snap indentation 700B. The second snap indentation 700B then resists rotation of the body 666 and second portion 680. The first through fourth snap indentations 700A through 700D lightly lock the body 666 at four different rotational angles, including 0, 90, 180, and 270 degrees.

[0213]

[0235] FIGS. 18a(i) and 18a(ii) show views from the direction of arrows A and B shown in FIG. 15 with the locking device rotated to the unlocked position. The operator can compare the orientation of the first part 640 with the reference 750 on the top surface of the thin chuck 72, which indicates that the first latch assembly 604A is unlocked in FIG. 18a(ii). The shoulder 686 is not obstructed from below by either the first wing 668A or the second wing 668B. The wing pieces 668A and 668B are held in the position shown in FIG. 18a(i) by the snap mechanism 654 shown in FIGS. 15 and 17. The pressure within the first wafer pack 28A is released, and the thin chuck 72 can be removed to insert or replace wafers. After the wafers are replaced, the pressure within the first wafer pack 28A is again released, and the first wafer pack 28A is held together.

[0214]

[0236] When the first wafer pack 28A is fully assembled, an additional fail-safe may be required to maintain electrical contact with the wafers even if a system failure prevents the negative pressure within the first wafer pack 28A from being maintained. An operator may use a tool (not shown) having jaws and pins. The pins are inserted into the tool pin openings 664. The tool pin openings 664 are tapered, so that the further the pins are inserted into the tool pin openings 664, the better the tool aligns with the first component 640. The operator then engages the opposing parallel surfaces of the tool's jaws with the opposing parallel surfaces formed by the engagement feature 646. Once the tool engages the engagement feature 646, the operator rotates the tool, which rotates the first component 640. The connecting component 644 and the second component 642, together with their first and second wings 668A and 668B, rotate with the first component 640. 17, the snap surface 706 slides away from the fourth snap recess 700D over the circular outer surface 742. The snap surface 706 then snaps into the first snap recess 700A.

[0215]

[0237] 18b(i) and 18b(ii) show the first latch assembly after the first and second parts 640 and 642 have been rotated through a 90-degree angle. The operator can verify that the orientation of the first part 640 is aligned with the locked position, as indicated by datum 750. The first wing 668A is now positioned above the shoulder 686, preventing the thin chuck 72 from moving vertically downward and away from the remainder of the wafer pack 28A. The second wing 668B is positioned above the matching block 648. The first wing 668A can be disengaged from the shoulder 686 by rotating the first part 640 clockwise or counterclockwise through a 90-degree angle 752. Either wing 668A or 668B can be used to lock the thin chuck 72 in place.

[0216]

[0238] 19 shows how one or more shims 652B-652F can be used to adjust the height of the leveling surface 690 of the matching block 648. Ideally, the matching block 648 should be flush with the shoulder 686. Because the matching block 648 is attached to the spacer 652A, it moves up and down with the spacer 652A as more shims 652B-652F are inserted. If the leveling surface 690 is below the shoulder 686, more shims can be inserted to raise the leveling surface 690, or if the leveling surface 690 is above the height of the shoulder 686, a shim can be removed.

[0217]

[0239] The engagement feature 646 is conveniently located directly on the first component 640. In alternative configurations, the engagement feature can be formed directly on the second component 642 or directly on the connecting component 644.

[0218]

[0240] In further embodiments, the engagement feature can be a feature separate from the first and second parts 640 and 642 and separate from the connecting part 644. For example, a worm gear can be formed on the connecting part 644 and the engagement feature can be a separate rotatable feature that rotates the worm gear.

[0219]

[0241] The engagement mechanism can also be located between the first part 640 and the connecting part 644. For example, the first winglet 668A can be pivoted downwardly away from and back toward the shoulder 686 using a cam system located between the first part 640 and the connecting part 644. Alternatively, a cam system can be located between the connecting part 644 and the second part 642 to serve as the engagement mechanism. Alternatively, the connecting part 644 can be made of two parts, and the engagement mechanism can connect the two parts and adjust the spacing between them, which allows the winglet to pivot.

[0220]

[0242] The first latch assembly 604A uses primarily incompressible and inflexible materials. In alternative embodiments, straps or other flexible materials may be used, with the same or similar materials in mind.

[0221]

[0243] Instead of having the engagement feature 646 on the exterior surface of the first component 640, the engagement feature can instead be located on the interior surface of either component.

[0222]

[0244] 12 , the first, second, third, and fourth latch assemblies 604A through 604D are identical except for their respective locations and orientations. The first and third latch assemblies 604A and 604C are on opposite sides of the thin chuck 72, and the second and fourth latch assemblies 604B and 604D are on opposite sides of the thin chuck 72. Because the latch assemblies 604A through 604D are positioned on more than one side of the thin chuck 72, i.e., they wrap around the edge of the thin chuck 72 by 180 degrees or more, the four latch assemblies can collectively hold all sides of the thin chuck 72 in place around the entire edge of the thin chuck 72.

[0223]

[0245] The latching system provided by the first, second, third, and fourth latch assemblies 604A-604D facilitates easy movement of the first wafer pack 28A through the assembly environment without the need for human supervision. Without the latching system, human supervision may be required to determine when the wafers 28A break apart due to a lack of negative pressure within the first wafer pack 28A. The latching system provides a structural fail-safe to prevent the first wafer pack 28A from breaking apart, even if air is introduced from the outside.

[0224]

[0246] Figures 20, 21, 22a and 22b show various further components of the pressure monitoring system, including a pressure sensing passage 760 (Figure 21), a pressure sensor 762 (Figures 22a and 22b), the electrical pressure sensor connection 606 (Figures 20, 21, 22a and 22b) described with reference to Figure 11, an electrical pressure connector connection 764, a mounting bracket 766, a ribbon cable 768 having first and second connectors 770 and 772 at opposite ends (Figures 20, 22a and 22b), a connector block 774, and a stiffener plate 776.

[0225]

[0247] The pressure sensing passage 760 is formed in the back plate 74 in a manner similar to the reduced pressure passage 608 described with reference to Figure 13. The pressure sensing passage 760 has a first end within the pressure differential cavity 622 shown in Figure 14. The pressure sensing passage 760 has a second end opposite the first end near the outer edge of the back plate 74.

[0226]

[0248] The electrical pressure sensor connection portion 606 is in the form of a printed circuit board having a substrate 780 and a plurality of contacts including first, second and third contacts 782A, 782B and 782C formed on the substrate 780.

[0227]

[0249] The pressure sensor 762 is mounted on the substrate 780, i.e., on the side of the substrate 780 opposite the first, second, and third contacts 782A, 782B, and 782C. The pressure sensor 762 is electrically connected to the first, second, and third contacts 782A, 782B, and 782C through the substrate 780. The pressure sensor 762 can sense the pressure of a gas, in this case air, and convert the pressure into an electrical signal, with the magnitude of the pressure indicated by the signal magnitude or another variable. Pressure can conveniently be detected using a diaphragm that displaces a known distance as pressure increases or decreases. Other pressure sensors, such as pressure sensors using piezoelectric crystals or pressure sensors using stress gauges, are also within the scope of the invention. In the case of a movable diaphragm, the movement can be converted into a voltage, for example by moving an induction coil, and the magnitude then indicates the displacement and therefore the pressure. The pressure sensor can be, for example, the MLX90809 sold by Melexis (www.melexis.com). The electrical pressure sensor interface 606 attaches to the backplate 74 using fasteners 784. The diaphragm of the pressure sensor 762 is then exposed to air at the second end of the pressure sensing passage 760. The pressure sensor 762 can therefore sense the pressure within the pressure differential cavity 622.

[0228]

[0250] The electrical pressure connector interface 764 has a base plate 790 and a plurality of terminals, including first through sixth terminals 792A through 792F, secured to the base plate 790. The base plate 790 is attached to a mounting bracket 766 via fasteners 794. A stiffener plate 776 is secured between the two push bar vanes 308. The mounting bracket 766 is secured to the stiffener plate 776 using fasteners 796. The slot assembly body 32, together with the push bar vanes 308 and the stiffener plate 776, form part of a stationary structure, and thus the electrical pressure connector interface 764 is attached to the stationary structure.

[0229]

[0251] Connector block 774 attaches to slot assembly body 32. Connectors 770 and 772 are connected to electrical pressure connector interface 764 and connector block 774, respectively. First through sixth terminals 792A through 792F are connected to the pressure sensing board of the electrical tester by first connector 770, ribbon cable 768 and second connector 772.

[0230]

[0252] 23a and 23b show the engagement between the electrical pressure sensor interface 606 and the electrical pressure connector interface 764 when the first wafer pack 28A is inserted into the slot assembly. The first, second, and third contacts 782A, 782B, and 782C initially contact the first, second, and third terminals 792A, 792B, and 792C, respectively. As the electrical pressure sensor interface 606 moves further, the first, second, and third contacts 782A, 782B, and 782C engage the fourth, fifth, and sixth terminals 792D, 792E, and 792F, respectively. Thus, the first contact 782A contacts both the first terminal 792A and the fourth terminal 792D. Similarly, each one of contacts 782B and 782C contacts two of terminals 792B, 792C, 792E and 792F.

[0231]

[0253] Terminals 792A through 792F can be resiliently depressed against substrate 790 to ensure proper contact with contacts 782A through 782C. Ribbon cable 768 allows stiffener plate 776 to move slightly relative to slot assembly body 32 when first wafer pack 28A is inserted.

[0232]

[0254] While the wafer is being tested, the pressure within pressure differential cavity 622 can be monitored throughout the process. If a wafer fails to test, the tester can be programmed to determine if such test is due to insufficient negative pressure within pressure differential cavity 622.

[0233]

[0255] While certain exemplary embodiments have been described and illustrated in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not limiting of the invention, and that, since modifications will occur to those skilled in the art, the invention is not limited to the specific constructions and arrangements shown and described. [Explanation of symbols]

[0234] 10 Testing equipment 12 Testing equipment 28A and 28B First and Second Microelectronic Circuit Test Packs 77 Pressure Differential Cavity Seal 602 Pressure reducing valve 604A to 604D First to Fourth Latch Assemblies 626 Portable Support Device 628 and 630 First and second components 790 PCB 782A to 782C 1st to 3rd contacts

Claims

1. 1. A microelectronic circuit test pack comprising: a portable support structure including first and second components for holding the substrate therebetween, the substrate carrying a microelectronic circuit and having a plurality of terminals connected to the microelectronic circuit; a plurality of contacts on the second component that align with and contact the terminals; a pressure differential cavity seal between the first and second components and forming, together with surfaces of the first and second components, an enclosed pressure differential cavity; a pressure reduction passage formed through one of the components and having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; a pressure reducing valve connected to the pressure reducing passage, the pressure reducing valve opening to allow air outside the pressure differential cavity to bring the first and second components closer together to ensure proper contact between the contacts and the terminals, and the pressure reducing valve closing to prevent air from entering the pressure differential cavity; a first connection portion on the portable support structure and connected to the contact, the first connection portion connecting to a second connection portion on the stationary structure when the portable support structure is removably held by the stationary structure; a first latch assembly, a first part that engages the first component; a second part that engages the second component; a connecting piece having opposite ends secured to the first piece and the second piece, respectively, to form a locking device; and a first latch assembly including an engagement mechanism connected to and operable to move the locking device, the first latch assembly moving between a locked position to maintain the first and second components locked in the closed position and an unlocked position to move the first and second components from the closed relationship to the spaced apart relationship.

2. 2. The microelectronic circuit test pack of claim 1, wherein the engagement mechanism moves the second component between the locked position and the unlocked position.

3. 3. The microelectronic circuit test pack of claim 2, wherein said second component is adapted to rotate between said locked position and said unlocked position.

4. 4. The microelectronic circuit test pack of claim 3, wherein the locking mechanism includes a surface on the first component that forms a seat for contacting a surface on a jaw of a tool, the jaw of the tool being rotatable to rotate the first component, and the first component, via the connecting component, rotates the second component to move it between the locked and unlocked positions.

5. 5. The microelectronic circuit test pack of claim 4, wherein the surface of the first component that forms the seat is an exterior surface of the first component.

6. 6. The microelectronic circuit test pack of claim 5, wherein the first component has tool pin openings therein for aligning pins of the tool with the first component.

7. 4. The microelectronic circuit test pack of claim 3, wherein the second part has a body and at least a first wing extending from the body, the first wing moving over a shoulder of the first component when moved to a first locked position and moving away from the shoulder when moved out of the first locked position toward the unlocked position.

8. 8. The microelectronic circuit test pack of claim 7, wherein the second part has second wings extending from the body, the second wings moving over a shoulder of the first component when moved to a second locked position and moving away from the shoulder when moved out of the second locked position toward the unlocked position.

9. 9. The microelectronic circuit test pack of claim 8, wherein the latching system further includes a matching block mounted in a stationary position relative to the first component, the matching block having a leveling surface above which the second wing is positioned when the first wing is positioned above the shoulder, the second component being adjustable relative to the first component to adjust a gap between the leveling surface and the second wing.

10. 10. The microelectronic circuit test pack of claim 1, wherein the latching system further includes a locking nut having threads that engage the treads on the connecting component to rotationally adjust the second component relative to the connecting component.

11. 10. The microelectronic circuit test pack of claim 9, wherein the latching system further includes a shim between the matching block and the first component for adjusting the distance between the leveling surface and the first component.

12. 4. The microelectronic circuit test pack of claim 3, wherein the latch system further includes a snap mechanism having a snap surface that snaps into a first snap recess to resist movement of the second component out of the locked position and a second snap recess to resist movement of the second component out of the unlocked position.

13. 13. The microelectronic circuit test pack of claim 12, wherein the first and second snap recesses are disposed on the locking device.

14. 14. The microelectronic circuit test pack of claim 13, wherein the first and second snap recesses are located on the second component.

15. 4. The microelectronic circuit test pack of claim 3, wherein the first component includes a backplate and a signal distribution board, a portion of the signal distribution board disposed between the backplate and the second component, the signal distribution board having an opening through which the connecting piece passes, the opening having a first dimension on an axis toward a center point of the signal distribution board that is greater than a second dimension transverse to the axis, the connecting piece having a first portion smaller than the first dimension in the direction of the axis to allow thermal expansion of the signal distribution board and the backplate relative to one another, the first portion being dimensioned to slidably fit within the second dimension of the opening to prevent movement of the signal distribution board relative to the backplate in a direction transverse to the axis.

16. 16. The microelectronic circuit test pack of claim 15, wherein the connecting piece has a second portion, the second portion having a first thickness that can fit into the opening in the axial direction during said insertion and that is greater than the second dimension of the opening, and a second thickness that is transverse to the first thickness and can fit into the second dimension of the opening during said insertion.

17. The latch system includes a second latch assembly, each respective latch assembly comprising: a first part that engages the first component; a second part that engages the second component; a connecting piece having opposite ends fixed to the first and second pieces, respectively, to form a locking device; and 10. The microelectronic circuit test pack of claim 1, including an engagement mechanism connected to and operable to move the locking device between a locked position that maintains the first and second components locked in a closed position and an unlocked position that moves the first and second components from the closed relationship to a spaced apart relationship.

18. 20. The microelectronic circuit test pack of claim 17, wherein the first and second latch assemblies have their respective second parts on different sides of the second component part.

19. 2. The microelectronic circuit test pack of claim 1, wherein said pressure differential cavity seal surrounds said contacts and said terminals.

20. 2. The microelectronic circuit test pack of claim 1, wherein the pressure differential cavity seal is secured to the first component when the first and second components are separated.

21. 10. The microelectronic circuit test pack of claim 1, wherein the pressure differential cavity seal is a lip seal.

22. the pressure reducing valve is a pressure reducing check valve, a vacuum relief passage is formed through the component having the pressure reducing check valve, the vacuum relief passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; 10. The microelectronic circuit test pack of claim 1, further comprising a second valve that is a vacuum release valve connected to a vacuum release passage, wherein opening of the vacuum release valve allows air to enter the pressure differential cavity and closing of the valve prevents air from escaping from the pressure differential cavity.

23. 10. The microelectronic circuit test pack of claim 1, wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

24. 2. The microelectronic circuit test pack of claim 1, wherein the contacts are pins, each pin having a spring, and when the respective contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

25. 1. A tester apparatus comprising: a portable support structure including first and second components for holding the substrate therebetween, the substrate carrying a microelectronic circuit and having a plurality of terminals connected to the microelectronic circuit; a plurality of contacts on the second component that align with and contact the terminals; a pressure differential cavity seal between the first and second components and forming, together with surfaces of the first and second components, an enclosed pressure differential cavity; a pressure reduction passage formed through one of the components and having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; a pressure reducing valve connected to the pressure reducing passage, the pressure reducing valve opening to allow air outside the pressure differential cavity to bring the first and second components closer together to ensure proper contact between the contacts and the terminals, and the pressure reducing valve closing to prevent air from entering the pressure differential cavity; a first connection portion on the portable support structure and connected to the contact; a first latch assembly, a first part that engages the first component; a second part that engages the second component; a connecting piece having opposite ends secured to the first and second pieces, respectively, to form a locking device; and a first latch assembly including an engagement mechanism connected to and operable to move the locking device, the locking device moving between a locked position that maintains the first and second components locked in the closed position and an unlocked position that moves the first and second components from the closed relationship to the spaced apart relationship; a stationary structure receivable to hold the portable support structure and from which the portable support structure can be removed; a second connection portion on the stationary structure that connects to the first connection portion when the portable structure is held by the stationary structure and that disconnects from the first connection portion when the portable support structure is removed from the stationary structure; and an electrical tester connected to the terminal via the second connection portion, the first connection portion and the contact, and adapted to transmit signals to and from the microelectronic circuit to test the microelectronic circuit.

26. 26. The tester apparatus of claim 25, wherein the engagement mechanism moves the second component between the locked position and the unlocked position.

27. 27. The tester apparatus of claim 26, wherein the second component rotates between the locked position and the unlocked position.

28. 28. The tester apparatus of claim 27, wherein the locking mechanism includes a surface on the first part that forms a seat for contacting a surface on a jaw of a tool, the jaw of the tool being rotatable to rotate the first part, and the first part, via the connecting part, rotates the second part to move between the locked and unlocked positions.

29. 30. The tester apparatus of claim 28, wherein the surface of the first part that forms the seat is an exterior surface of the first part.

30. 30. The tester apparatus of claim 29, wherein the first part has a tool pin opening therein for aligning the pin of the tool with the first part.

31. 28. The tester apparatus of claim 27, wherein the second part has a body and at least a first wing extending from the body, the first wing moving over a shoulder of the first component when moving to a first locked position and moving away from the shoulder when moving out of the first locked position toward an unlocked position.

32. 32. The tester apparatus of claim 31 , wherein the second part has a second wing extending from the body, the second wing moving over a shoulder of the first component when moving to a second locked position and moving away from the shoulder when moving out of the second locked position toward the unlocked position.

33. 33. The tester apparatus of claim 32, wherein the latch system further includes a matching block mounted in a stationary position relative to the first component, the matching block having a leveling surface above which the second wing is positioned when the first wing is positioned above the shoulder, the second component being adjustable relative to the first component to adjust a gap between the leveling surface and the second wing.

34. 26. The tester apparatus of claim 25, wherein the latch system further includes a lock nut having threads that engage the tread on the connecting component to rotationally adjust the second part relative to the connecting part.

35. 34. The tester apparatus of claim 33, wherein the latch system further includes a shim between the matching block and the first component for adjusting the distance between the leveling surface and the first component.

36. 28. The tester apparatus of claim 27, wherein the latch system further includes a snap mechanism having a snap surface that snaps into a first snap recess to resist movement of the second component out of the locked position and a second snap recess to resist movement of the second component out of the unlocked position.

37. 37. The tester device of claim 36, wherein the first and second snap recesses are disposed on the locking device.

38. 38. The tester apparatus of claim 37, wherein the first and second snap recesses are located on the second part.

39. 28. The tester apparatus of claim 27, wherein the first component includes the back plate and the signal distribution board, a portion of the signal distribution board being disposed between the back plate and the second component, the signal distribution board having an opening through which the connecting piece passes, the opening having a first dimension on an axis toward a center point of the signal distribution board that is greater than a second dimension transverse to the axis, the connecting piece having a first portion that is smaller than the first dimension in the direction of the axis to allow thermal expansion of the signal distribution board and the back plate relative to one another, the first portion being dimensioned to slidably fit within the second dimension of the opening to prevent movement of the signal distribution board relative to the back plate in a direction transverse to the axis.

40. 40. The tester apparatus of claim 39, wherein the connecting piece has a second portion, the second portion having a first thickness that can fit into the opening in the axial direction during said insertion and that is greater than a second dimension of the opening, and a second thickness that is transverse to the first thickness and can fit into the second dimension of the opening during said insertion.

41. The latch system further includes a second latch assembly, each respective latch assembly comprising: a first part that engages the first component; a second part that engages the second component; a connecting piece having opposite ends secured to the first and second pieces, respectively, to form a locking device; and 26. The tester apparatus of claim 25, including an engagement mechanism connected to and operable to move the locking device, the locking device moving between a locked position that maintains the first and second components locked in a closed position and an unlocked position that moves the first and second components from the closed relationship to a spaced apart relationship.

42. 42. The tester apparatus of claim 41, wherein the first and second latch assemblies have respective second parts on different sides of the second component part.

43. 26. The tester apparatus of claim 25, wherein the pressure differential cavity seal surrounds the contacts and the terminals.

44. 26. The tester apparatus of claim 25, wherein the pressure differential cavity seal is secured to the first component when the first and second components are separated.

45. 26. The tester apparatus of claim 25, wherein the pressure differential cavity seal is a lip seal.

46. the pressure reducing valve is a pressure reducing check valve, a vacuum relief passage is formed through the component having the pressure reducing check valve, the vacuum relief passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; 26. The tester apparatus of claim 25, further comprising a second valve that is a vacuum relief valve connected to the vacuum relief passage, wherein opening of the vacuum relief valve allows air to enter the pressure differential cavity and closing of the valve prevents air from escaping from the pressure differential cavity.

47. 26. The tester apparatus of claim 25, wherein the stationary structure includes a thermal chuck, and the second component of the portable support structure includes a thin chuck in contact with the thermal chuck to enable heat transfer between the portable support structure and the thermal chuck.

48. 26. The tester apparatus of claim 25, wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

49. 26. The tester apparatus of claim 25, wherein the contacts are pins, each pin having a spring, and when the respective contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

50. 1. A method for testing a microelectronic circuit carried by a substrate, comprising: holding the substrate between first and second components of a portable support structure, the second component having contacts for terminals of the substrate connected to the microelectronic circuit, a reduced pressure passage formed through one of the components, the reduced pressure passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; disposing a pressure differential cavity seal between the first and second components to form a cavity bounded by surfaces of the first and second components and the pressure differential cavity seal; opening a pressure reducing valve to allow air to exit the pressure differential cavity, reducing the pressure within the pressure differential cavity seal cavity and bringing the first and second components closer together, thereby ensuring proper contact between the contacts and the terminals; closing the pressure reducing valve to prevent air from entering the pressure differential cavity; activating an engagement mechanism to move the locking device between a locked position that maintains the first and second components locked in the closed position and an unlocked position that moves the first and second components from the closed relationship to the spaced apart relationship; The locking device is a first part that engages the first component; a second part that engages the second component part; and a connecting piece having opposite ends secured to said first and second pieces, respectively; receiving the portable support structure with a stationary structure with a first connection portion on the portable support structure connected to a second connection portion on the stationary structure; and transmitting signals between an electrical tester and the microelectronic circuit through the terminals, contacts, and first and second connections to test the microelectronic circuit.

51. 51. The method of claim 50, wherein the engagement mechanism moves the second component between the locked position and the unlocked position.

52. 52. The method of claim 51, wherein the second component is rotated between the locked position and the unlocked position.

53. 53. The method of claim 52, wherein the locking mechanism includes a surface on the first part forming a seat for contacting a surface on a jaw of a tool, the jaw of the tool being rotatable to rotate the first part, and the first part, via the connecting part, rotates the second part to move between the locked and unlocked positions.

54. 54. The method of claim 53, wherein the surface of the first part that forms the seat is an exterior surface of the first part.

55. 55. The method of claim 54, wherein the first part has a tool pin opening therein for aligning a pin of the tool with the first part.

56. 53. The method of claim 52, wherein the second part has a body and at least a first wing extending from the body, the first wing moving over a shoulder of the first component when moving to a first locked position and moving away from the shoulder when moving out of the first locked position toward the unlocked position.

57. 57. The method of claim 56, wherein the second part has a second wing extending from the body, the second wing moving over a shoulder of the first component when moving to a second locked position and moving away from the shoulder when moving out of the second locked position toward the unlocked position.

58. 58. The method of claim 57, wherein the latch system includes a matching block mounted in a stationary position relative to the first component, the matching block having a leveling surface above which the second wing is positioned when the first wing is positioned over the shoulder, the second component being adjustable relative to the first component to adjust a gap between the leveling surface and the second wing.

59. 51. The method of claim 50, wherein the latch system further includes a lock nut having threads that engage the tread on the connecting component to rotationally adjust the second part relative to the connecting part.

60. 59. The method of claim 58, wherein the latch system further includes a shim disposed between the matching block and the first component to adjust the distance between the leveling surface and the first component.

61. 53. The method of claim 52, wherein the latch system further includes a snap mechanism having a snap surface that snaps into a first snap recess to resist movement of the second component out of the locked position and snaps into a second snap recess to resist movement of the second component out of the unlocked position.

62. 62. The method of claim 61, wherein the first and second snap recesses are disposed on the locking device.

63. 63. The method of claim 62, wherein the first and second snap recesses are located on the second component.

64. 53. The method of claim 52, wherein the first component includes a backplate and a signal distribution board, a portion of the signal distribution board disposed between the backplate and the second component, the signal distribution board having an opening through which the connecting piece passes, the opening having a first dimension on an axis toward a center point of the signal distribution board that is greater than a second dimension transverse to the axis, the connecting piece having a first portion smaller than the first dimension in the direction of the axis to allow thermal expansion of the signal distribution board and the backplate relative to one another, the first portion being dimensioned to slidably fit within the second dimension of the opening to prevent movement of the signal distribution board relative to the backplate in a direction transverse to the axis.

65. 65. The method of claim 64, wherein the connecting piece has a second portion, the second portion having a first thickness that can fit into the opening in the axial direction during the insertion and that is greater than a second dimension of the opening, and a second thickness that is transverse to the first thickness and can fit into the second dimension of the opening during the insertion.

66. The latch system includes a second latch assembly, each respective latch assembly comprising: a first part that engages the first component; a second part that engages the second component; a connecting piece having opposite ends fixed to the first and second pieces, respectively, to form a locking device; and 51. The method of claim 50, including an engagement mechanism connected to and operable to move the locking device, the locking device moving between a locked position that maintains the first and second components locked in a closed position and an unlocked position that moves the first and second components from the closed relationship to a spaced apart relationship.

67. 67. The method of claim 66, wherein the first and second latch assemblies have respective second parts on different sides of the second component part.

68. 51. The method of claim 50, wherein the pressure differential cavity seal surrounds the contacts and the terminals.

69. 51. The method of claim 50, wherein the pressure differential cavity seal is secured to the first component when the first and second components are separated.

70. 51. The method of claim 50, wherein the substrate cavity seal is formed with a lip seal.

71. the pressure reducing valve is a pressure reducing check valve, a vacuum relief passage is formed through the component having the pressure reducing check valve, the vacuum relief passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; 51. The method of claim 50, further comprising opening a second valve, the second valve being a vacuum relief valve connected to the vacuum relief passage, to allow air to enter the pressure differential cavity.

72. 51. The method of claim 50, wherein the stationary structure comprises a thermal chuck and the second component of the portable support structure comprises a low profile chuck.

73. 51. The method of claim 50, wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

74. 51. The method of claim 50, wherein the contacts are pins, each pin having a spring, and when the respective contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

75. 1. A microelectronic circuit test pack comprising: a portable support structure including first and second components for holding the substrate therebetween, the substrate carrying a microelectronic circuit and having a plurality of terminals connected to the microelectronic circuit; a plurality of contacts on the second component that align with and contact the terminals; a pressure differential cavity seal between the first and second components and forming an enclosed pressure differential cavity with surfaces of the first and second components; a pressure reduction passage formed through one of the components and having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; a pressure reducing valve connected to the pressure reducing passage, the pressure reducing valve opening to allow air outside the pressure differential cavity to bring the first and second components closer together to ensure proper contact between the contacts and the terminals, and the pressure reducing valve closing to prevent air from entering the pressure differential cavity; a first connection portion on the portable support structure and connected to the contact, the first connection portion being connected to a second connection portion on the stationary structure when the portable support structure is removably held by the stationary structure; a pressure sensor positioned to sense pressure within the pressure differential cavity; an electrical pressure sensor interface connected to the pressure sensor for communicating the pressure to an electrical tester.

76. 76. The microelectronic circuit test pack of claim 75, wherein the pressure sensor is positioned remotely from the pressure differential cavity, and the pressure sensing passage connects the pressure differential cavity with the pressure sensor.

77. 77. The microelectronic circuit test pack of claim 76, wherein the vacuum passage is formed in the first component.

78. 78. The microelectronic circuit test pack of claim 77, wherein the first component includes a backplate and a signal distribution board, a portion of the signal distribution board being disposed between the backplate and the second component, and the pressure sensing passages being formed in the backplate.

79. 79. The microelectronic circuit test pack of claim 78, wherein the pressure sensing passage is formed through the signal distribution board.

80. 76. The microelectronic circuit test pack of claim 75, wherein the pressure sensor is fixed to the portable support structure.

81. 76. The microelectronic circuit test pack of claim 75, wherein the pressure differential cavity seal is secured to the first component when the first and second components are separated.

82. 76. The microelectronic circuit test pack of claim 75, wherein the pressure differential cavity seal is a lip seal.

83. the pressure reducing valve is a pressure reducing check valve, a vacuum relief passage is formed through the component having the pressure reducing check valve, the vacuum relief passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; 76. The microelectronic circuit test pack of claim 75, further comprising a second valve that is a vacuum relief valve connected to the vacuum relief passage, wherein opening of the vacuum relief valve allows air to enter the pressure differential cavity and closing of the valve prevents air from escaping from the pressure differential cavity.

84. 76. The microelectronic circuit test pack of claim 75, wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

85. 76. The microelectronic circuit test pack of claim 75, wherein the contacts are pins, each pin having a spring, and when the respective contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

86. 1. A tester apparatus comprising: a portable support structure including first and second components for holding the substrate therebetween, the substrate carrying a microelectronic circuit and having a plurality of terminals connected to the microelectronic circuit; a plurality of contacts on the second component that align with and contact the terminals; a pressure differential cavity seal between the first and second components and forming an enclosed pressure differential cavity with surfaces of the first and second components; a pressure reduction passage formed through one of the components and having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; a pressure reducing valve connected to the pressure reducing passage, the pressure reducing valve opening to allow air outside the pressure differential cavity to bring the first and second components closer together to ensure proper contact between the contacts and the terminals, and the pressure reducing valve closing to prevent air from entering the pressure differential cavity; a first connection portion on the portable support structure and connected to the contact; a stationary structure receivable to hold the portable support structure and from which the portable support structure can be removed; a second connection portion on the stationary structure that connects to the first connection portion when the portable structure is held by the stationary structure and that disconnects from the first connection portion when the portable support structure is removed from the stationary structure; and an electrical tester connected to the terminal via the second connection portion, the first connection portion and the contact, and adapted to transmit signals to and from the microelectronic circuit to test the microelectronic circuit; a pressure sensor positioned to sense pressure within the pressure differential cavity; an electrical pressure sensor connection portion connected to the pressure sensor for communicating the pressure to an electrical tester.

87. 87. The tester apparatus of claim 86, wherein the pressure sensor is positioned remotely from the pressure differential cavity, and the pressure sensing passage connects the pressure differential cavity with the pressure sensor.

88. 88. The tester apparatus of claim 87, wherein the vacuum passage is formed in the first component.

89. 89. The tester apparatus of claim 88, wherein the first component includes a back plate and a signal distribution board, a portion of the signal distribution board being disposed between the back plate and the second component, and the pressure sensing passageway being formed in the back plate.

90. 90. The tester apparatus of claim 89, wherein the pressure sensing passage is formed through the signal distribution board.

91. 87. The tester apparatus of claim 86, wherein the pressure sensor is fixed to the portable support structure.

92. 87. The tester apparatus of claim 86, wherein the pressure monitoring system includes an electrical pressure connector interface on the stationary structure, the electrical pressure sensor interface being in releasable contact with the electrical pressure connector interface to communicate the pressure to the electrical tester.

93. 93. The tester apparatus of claim 92, wherein the electrical pressure sensor connection portion includes at least a first contact, the pressure monitoring system includes at least a first terminal, the first contact engaging the first terminal when the portable structure is housed by the stationary structure, and the first contact separating the first terminal when the portable structure is removed from the stationary structure.

94. 94. The tester apparatus of claim 93, wherein the electrical pressure sensor connection is in a printed circuit board having a substrate, and the first contact is formed on the substrate.

95. 94. The tester apparatus of claim 93, wherein the electrical pressure sensor connection portion includes at least a second contact, the pressure monitoring system includes at least a second terminal, the second contact engaging the second terminal when the portable structure is housed by the stationary structure, and the second contact separating the second terminal when the portable structure is removed from the stationary structure.

96. 87. The tester apparatus of claim 86, wherein the pressure differential cavity seal surrounds the contacts and the terminals.

97. 87. The tester apparatus of claim 86, wherein the pressure differential cavity seal is secured to the first component when the first and second components are separated.

98. 87. The tester apparatus of claim 86, wherein the pressure differential cavity seal is a lip seal.

99. the pressure reducing valve is a pressure reducing check valve, a vacuum relief passage is formed through the component having the pressure reducing check valve, the vacuum relief passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; 87. The tester apparatus of claim 86, further comprising a second valve that is a vacuum release valve connected to the vacuum release passage, wherein opening of the vacuum release valve allows air to enter the pressure differential cavity and closing of the valve prevents air from escaping the pressure differential cavity.

100. 87. The tester apparatus of claim 86, wherein the stationary structure includes a thermal chuck, and the second component of the portable support structure includes a thin chuck in contact with the thermal chuck to enable heat transfer between the portable support structure and the thermal chuck.

101. 87. The tester apparatus of claim 86, wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

102. 87. The tester apparatus of claim 86, wherein the contacts are pins, each pin having a spring, and when the respective contact is depressed by a respective one of the terminals, the spring is depressed against its spring force.

103. 1. A method for testing a microelectronic circuit carried by a substrate, comprising: holding the substrate between first and second components of a portable support structure, the second component having contacts for terminals of the substrate connected to the microelectronic circuit, a reduced pressure passage formed through one of the components, the reduced pressure passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; disposing a pressure differential cavity seal between the first and second components to form a cavity bounded by surfaces of the first and second components and the pressure differential cavity seal; opening a pressure reducing valve to allow air to exit the pressure differential cavity, reducing the pressure within the pressure differential cavity seal cavity and bringing the first and second components closer together, thereby ensuring proper contact between the contacts and the terminals; closing the pressure reducing valve to prevent air from entering the pressure differential cavity; receiving the portable support structure with the stationary structure with the first connection portion on the portable support structure connected to the second connection portion on the stationary structure; transmitting signals between the electrical tester and the microelectronic circuit via the terminals, the contacts, and the first and second connecting portions to test the microelectronic circuit; sensing a pressure within the pressure differential cavity; and communicating said pressure to said electrical tester.

104. 104. The method of claim 103, wherein the pressure sensor is positioned remotely from the pressure differential cavity, and a pressure sensing passage connects the pressure differential cavity with the pressure sensor.

105. 105. The method of claim 104, wherein the vacuum passage is formed in the first component.

106. 106. The method of claim 105, wherein the first component includes a back plate and a signal distribution board, a portion of the signal distribution board being disposed between the back plate and the second component, and the pressure sensing passageway being formed in the back plate.

107. 107. The method of claim 106, wherein the pressure sensing passage is formed through the signal distribution board.

108. 104. The method of claim 103, wherein the pressure sensor is fixed to the portable support structure.

109. 104. The method of claim 103, wherein the pressure monitoring system includes an electrical pressure connector interface on the stationary structure, the electrical pressure sensor interface releasably contacting the electrical pressure connector interface to communicate the pressure to the electrical tester.

110. 110. The method of claim 109, wherein the electrical pressure sensor connection portion includes at least a first contact, the pressure monitoring system includes at least a first terminal, the first contact engaging the first terminal when the portable structure is housed by the stationary structure, and the first contact separating the first terminal when the portable structure is removed from the stationary structure.

111. 111. The method of claim 110, wherein the electrical pressure sensor connection is in a printed circuit board having a substrate, and the first contact is formed on the substrate.

112. 111. The method of claim 110, wherein the electrical pressure sensor connection portion includes at least a second contact, the pressure monitoring system includes at least a second terminal, the second contact engages the second terminal when the portable structure is housed by the stationary structure, and the second contact separates the second terminal when the portable structure is removed from the stationary structure.

113. 108. The method of claim 107, wherein the pressure differential cavity seal surrounds the contacts and the terminals.

114. 109. The method of claim 108, wherein the pressure differential cavity seal is secured to the first component when the first and second components are separated.

115. 104. The method of claim 103, wherein the substrate cavity seal is formed with a lip seal.

116. the pressure reducing valve is a pressure reducing check valve, a vacuum relief passage is formed through the component having the pressure reducing check valve, the vacuum relief passage having an inlet opening in the pressure differential cavity and an outlet opening outside the pressure differential cavity; 104. The method of claim 103, further comprising opening a second valve, the second valve being a vacuum relief valve connected to the vacuum relief passage, to allow air to enter the pressure differential cavity.

117. 104. The method of claim 103, wherein the stationary structure comprises a thermal chuck and the second component of the portable support structure comprises a thin chuck.

118. 104. The method of claim 103, wherein the substrate is a wafer comprising a plurality of microelectronic circuits.

119. 104. The method of claim 103, wherein the contacts are pins, each pin having a spring, and when the respective contact is depressed by each of the terminals, the pin is depressed against the force of the spring.

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