Abstract: Resilient spring contact structures are manufactured by plating the contact structures on a reusable mandrel, as opposed to forming the contact structures on sacrificial layers that are later etched away. In one embodiment, the mandrel includes a form or mold area that is inserted through a plated through hole in a substrate. Plating is then performed to create the spring contact on the mold area of the mandrel as well as to attach the spring contact to the substrate. In a second embodiment, the mandrel includes a form that is initially plated to form the resilient contact structure and then attached to a region of a substrate without being inserted through the substrate. Attachment in the second embodiment can be achieved during the plating process used to form the spring contact, or by using a conductive adhesive or solder either before or after releasing the spring contact from the mandrel.

Abstract: Semiconductor dies are stacked offset from one another so that terminals located along two edges of each die are exposed. The two edges of the dies having terminals may be oriented in the same direction. Electrical connections may connect terminals on one die with terminals on another die, and the stack may be disposed on a wiring substrate to which the terminals of the dies may be electrically connected.

Abstract: Methods are provided for making plated through holes usable for inserting and attaching connector probes. In a first method, a curved plated through hole is formed by bonding curved etchable wires to a first substrate, plating the wires with a non-etchable conductive material, encasing the plated wires with a dielectric material to form a second substrate, planing the second substrate to expose the etchable wire, and etching the wires to leave plated through holes. In a second method, wires coated with a first etchable layer are initially bonded to a substrate, a second non-etchable plating layer is then applied over the first layer, and the first layer is etched away leaving plated through holes with wires disposed inside.

Abstract: Methods of fabricating an array of aligned microstructures on a substrate are disclosed. The microstructures may be spring contacts or other microelements. The methods disclosed include construction of an alignment substrate, alignment of die elements with the alignment substrate, and fixation of the aligned die elements to a backing substrate.

Abstract: A probe board provides signal paths between an integrated circuit (IC) tester and probes accessing terminals on the surfaces of ICs formed on a semiconductor wafer for receiving test signals form the IC tester. A branching signal path within the probe board distributes a test signal produced by one channel of the IC tester to several probes. Resistors within the branching signal path resistively isolate the probes from one another so that a fault occurring at any one IC terminal will not affect the logic state of the test signal arriving at any other IC terminal. The isolation resistors are sized relative to signal path characteristic impedances so as to substantially minimize test signal reflections at the branch points.

Abstract: A system is provided to enable leakage current measurement or parametric tests to be performed with an isolation buffer provided in a channel line. Multiple such isolation buffers are used to connect a single signal channel to multiple lines. Leakage current measurement is provided by providing a buffer bypass element, such as a resistor or transmission gate, between the input and output of each buffer. The buffer bypass element can be used to calibrate buffer delay out of the test system by using TDR measurements to determine the buffer delay based on reflected pulses through the buffer bypass element. Buffer delay can likewise be calibrated out by comparing measurements of a buffered and non-buffered channel line, or by measuring a device having a known delay.

Abstract: SU-8 photoresist compositions are modified to improve their adhesion properties by adding 1% to 6% of an adhesion promoter selected from the group consisting of glycidoxypropanetrimethoxysilane, mercaptopropyltrimethoxysilane, and aminopropyltrimethoxysilane. SU-8 photoresist compositions are modified to improve their resistance to cracking and film stress by adding 0.5% to 3% of a plasticizer selected from the group consisting of dialkylphthalates, dialkylmalonates, dialkylsebacates, dialkyladipates, and diglycidyl hexahydrophthalates. The improvements can be obtained simultaneously by adding both the adhesion promoter and the plasticizer to SU-8 photoresist compositions.

Abstract: A microelectronic spring contact for making electrical contact between a device and a mating substrate and method of making the same are disclosed. The spring contact has a compliant pad adhered to a substrate of the device and spaced apart from a terminal of the device. The compliant pad has a base adhered to the substrate, and side surfaces extending away from the substrate and tapering to a smaller end area distal from the substrate. A trace extends from the terminal of the device over the compliant pad to its end area. At least a portion of the compliant pad end area is covered by the trace, and a portion of the trace that is over the compliant pad is supported by the compliant pad. A horizontal microelectronic spring contact and method of making the same are also disclosed. The horizontal spring contact has a rigid trace attached at a first end to a terminal of a substrate.

Abstract: Resilient spring contacts for use in wafer test probing are provided that can be manufactured with a very fine pitch spacing and precisely located on a support substrate. The resilient contact structures are adapted for wire bonding to an electrical circuit on a space transformer substrate. The support substrates with attached spring contacts can be manufactured together in large numbers and diced up and tested before attachment to a space transformer substrate to improve yield. The resilient spring contacts are manufactured using photolithographic techniques to form the contacts on a release layer, before the spring contacts are epoxied to the support substrate and the release layer removed. The support substrate can be transparent to allow alignment of the contacts and testing of optical components beneath. The support substrate can include a ground plane provided beneath the spring contacts for improved impedance matching.

Abstract: The present invention discloses a method and system compensating for thermally induced motion of probe cards used in testing die on a wafer. A probe card incorporating temperature control devices to maintain a uniform temperature throughout the thickness of the probe card is disclosed. A probe card incorporating bi-material stiffening elements which respond to changes in temperature in such a way as to counteract thermally induced motion of the probe card is disclosed including rolling elements, slots and lubrication. Various means for allowing radial expansion of a probe card to prevent thermally induced motion of the probe card are also disclosed. A method for detecting thermally induced movement of the probe card and moving the wafer to compensate is also disclosed.

Abstract: A wafer test assembly includes multiple probe head substrates arranged like tiles with connectors attached to one side and probes supported on the opposing side. In one embodiment, flexible cable connectors directly connect the connectors on the probe head tile to a test head, while in another embodiment the flexible cables connect the probe head tile to a PCB providing horizontal routing to test head connectors. In one embodiment, leveling pins provide a simplified support structure connecting to a retaining element attached to the tiles to provide for applying a push-pull leveling force. A test head connector interface frame enables rearrangement of connectors between the test head and the probe card to provide for both full wafer contact or partial wafer contact. The test head connectors are rearranged by being slidable on rails, or pluggable and unpluggable enabling movement over a range of positions.

Abstract: The present invention discloses a method and system compensating for thermally induced motion of probe cards used in testing die on a wafer. A probe card incorporating temperature control devices to maintain a uniform temperature throughout the thickness of the probe card is disclosed. A probe card incorporating bi-material stiffening elements which respond to changes in temperature in such a way as to counteract thermally induced motion of the probe card is disclosed including rolling elements, slots and lubrication. Various means for allowing radial expansion of a probe card to prevent thermally induced motion of the probe card are also disclosed. A method for detecting thermally induced movement of the probe card and moving the wafer to compensate is also disclosed.

Abstract: A robust mechanical structure is provided to prevent small foundation structures formed on a substrate from detaching from the substrate surface. The strengthened structure is formed by plating a foundation metal layer on a seed layer and then embedding the plated foundation structure in an adhesive polymer material, such as epoxy. Components, such as spring probes, can then be constructed on the plated foundation. The adhesive polymer material better assures the adhesion of the metal foundation structure to the substrate surface by counteracting forces applied to an element, such as a spring probe, attached to the plated foundation.

Abstract: An electronic device tester channel transmits a single test signal to multiple terminals of electronic devices under test (DUTs) through a set of isolation resistors. The tester channel employs feedback to automatically adjust the test signal voltage to compensate for affects of faults at any of the DUT terminals to prevent the faults from substantially affecting the test signal voltage.

Abstract: A probe system for providing signal paths between an integrated circuit (IC) tester and input/output, power and ground pads on the surfaces of ICs to be tested includes a probe board assembly, a flex cable and a set of probes arranged to contact the IC's I/O pads. The probe board assembly includes one or more rigid substrate layers with traces and vias formed on or within the substrate layers providing relatively low bandwidth signal paths linking the tester to probes accessing some of the IC's pads. The flex cable provides relatively high bandwidth signal paths linking the tester to probes accessing others of the IC's pads.

Abstract: A probe card covering system includes a probe card for testing a die on a wafer, the probe card having contacts adapted for electrical engagement with the die; a removable cover connected to the probe card and positionable in a first position over the contacts of the probe card, the cover being movable to a second position exposing said contacts for the engagement with the die; and, wherein the cover is movable from the first position to the second position while the probe card is located in a wafer testing machine.

Abstract: A probe card for a wafer test system is provided with a number of on board features enabling fan out of a test system controller channel to test multiple DUTs on a wafer, while limiting undesirable effects of fan out on test results. On board features of the probe card include one or more of the following: (a) DUT signal isolation provided by placing resistors in series with each DUT input to isolate failed DUTs; (b) DUT power isolation provided by switches, current limiters, or regulators in series with each DUT power pin to isolate the power supply from failed DUTs; (c) self test provided using an on board micro-controller or FPGA; (d) stacked daughter cards provided as part of the probe card to accommodate the additional on board test circuitry; and (e) use of a interface bus between a base PCB and daughter cards of the probe card, or the test system controller to minimize the number of interface wires between the base PCB and daughter cards or between the base PCB and the test system controller.

Abstract: An interconnection contact structure assembly including an electronic component having a surface and a conductive contact carried by the electronic component and accessible at the surface. The contact structure includes an internal flexible elongate member having first and second ends and with the first end forming a first intimate bond to the surface of said conductive contact terminal without the use of a separate bonding material. An electrically conductive shell is provided and is formed of at least one layer of a conductive material enveloping the elongate member and forming a second intimate bond with at lease a portion of the conductive contact terminal immediately adjacent the first intimate bond.

Abstract: A high fidelity “loop-back” or interconnection of terminal pads of an IC on a wafer being tested in production is provided, while simultaneously a DC or low frequency path is provided back to a test system. Two or more IC pads are connected by probes forming the “loop-back,” each probe forming an inductor, the probes being connected together through a trace in a substrate. A capacitor is then provided on a layer of the substrate connected to the trace to form a three-pole filter. To provide isolation of high frequency self-test signals between the probes and lower frequency signals of the test system, an inductor is placed in the path between the tester and probes. The inductor provides an “AC” or high frequency block between the test system and probes, while still allowing the test system to use DC or low frequency signals to verify continuity, leakage, and perform other DC parametric tests.

Abstract: A microelectronic spring contact for making electrical contact between a device and a mating substrate and method of making the same are disclosed. The spring contact has a compliant pad adhered to a substrate of the device and spaced apart from a terminal of the device. The compliant pad has a base adhered to the substrate, and side surfaces extending away from the substrate and tapering to a smaller end area distal from the substrate. A trace extends from the terminal of the device in a coil pattern over the compliant pad to its end area, forming a helix. At least a portion of the compliant pad end area is covered by the trace, and a portion of the trace that is over the compliant pad is supported by the compliant pad. In an alternative embodiment, the pad is removed to leave a freestanding helical contact.