Abstract: An interconnect system for linking integrated circuits (ICs) mounted on a surface of a printed circuit board (PCB) includes a trace positioned below the surface, one or more vias linking the trace to the surface of the PCB, and other conductors linking pads on the ICs to the vias. Impedances of the various components of the interconnect system are sized relative to one another to optimize interconnect system frequency response.
Abstract: An interconnect structure employs a closed-grid bus to link an integrated circuit tester channel to an array of input/output (I/O) pads on a semiconductor wafer so that the tester channel can concurrently communicate with all of the I/O pads. The interconnect structure includes a circuit board implementing an array of bus nodes, each corresponding to a separate one of the I/O pads. The circuit board includes at least two layers. Traces mounted on a first layer form a set of first daisy-chain buses, each linking all bus nodes of a separate row of the bus node array. Traces mounted on a second circuit board layer form a set of second daisy-chain buses, each linking all bus nodes of a separate column of the bus node array. Vias and other circuit board interconnect ends of the first and second daisy-chain buses so that they form the closed-grid bus. Each bus node is connected though a separate isolation resistor to a separate contact pad mounted on a surface of the circuit board.
Abstract: One embodiment of the present invention concerns an integrated circuit that includes bond pads and special contact pads or points. The bond pads are for interfacing the integrated circuit as a whole with an external circuit, and are to be bonded to a package or circuit board. The bond pads are disposed on the die in a predetermined alignment such as a peripheral, grid, or lead-on-center alignment. The special contact pads are used to provide external test patterns to internal circuits and/or to externally monitor results from testing the internal circuits. The special contact pads may be advantageously located on the integrated circuit with a high degree of positional freedom. For one embodiment, the special contact pads may be disposed on the die at a location that is not in the same alignment as the bond pads. The special contact pads may be smaller than the bond pads so as not to increase the die size due to the special contact pads.
Type:
Grant
Filed:
December 29, 2000
Date of Patent:
August 5, 2003
Assignee:
FormFactor, Inc.
Inventors:
Benjamin N. Eldridge, Igor Y. Khandros, David V. Pedersen, Ralph G. Whitten
Abstract: An integrated circuit that includes bond pads and special contact pads or points. The bond pads are for interfacing the integrated circuit as a whole with an external circuit, and are to be bonded to a package or circuit board. The bond pads are disposed on the die in a predetermined alignment such as a peripheral, grid, or lead-on-center alignment. The special contact pads are used to provide external test patterns to internal circuits and/or to externally monitor results from testing the internal circuits. The special contact pads may be advantageously located on the integrated circuit with a high degree of positional freedom. For one embodiment, the special contact pads may be disposed on the die at a location that is not in the same alignment as the bond pads. The special contact pads may be smaller than the bond pads so as not to increase the die size due to the special contact pads. The special contact points may also be used to externally program internal circuits (e.g.
Type:
Grant
Filed:
December 29, 2000
Date of Patent:
July 22, 2003
Assignee:
FormFactor, Inc.
Inventors:
Benjamin N. Eldridge, Igor Y. Khandros, David V. Pedersen, Ralph G. Whitten
Abstract: A system for testing a number of integrated circuit (IC) devices under test (DUTs) having interface circuitry coupled to a single or multi-channel tester for receiving data values from the tester and providing error information concerning the DUTs. The interface circuitry forwards data values (received from the tester over a single channel) to a number of DUTs in parallel. The circuitry performs comparisons using data values read from the DUTs, and in response generates error values indicative of the comparison. The error values may then be returned to the tester over the same or a different channel.
Abstract: A method and apparatus for detecting an arc condition in a semiconductor test system is disclosed. While probes in a semiconductor test system are being moved into or out of contact with a semiconductor wafer, the voltage level of power supplied to selected ones of the probes is monitored. If the voltage level of the power exceeds a level that could cause an arc between the probes and the semiconductor wafer while the wafer is being moved, an indication is generated that an arc condition has been detected.
Type:
Application
Filed:
December 28, 2001
Publication date:
July 3, 2003
Applicant:
FormFactor, Inc.
Inventors:
Benjamin N. Eldridge, Stefan Jan Juergen Zschiegner
Abstract: A method for heat-treating a plurality of microelectronic structures attached to a non-metallic substrate is disclosed. Each of the plurality of microelectronic structures is comprised of a metallic material, and ones of the plurality of metallic microelectronic structures are insulated from other ones of the plurality of microelectronic structures. An application of the method is for heat-treatment of resilient microstructures.
Abstract: A method for replacing a microelectronic spring contact bonded to a terminal of a substrate is disclosed. The method comprises removing the microelectronic spring contact from the terminal, such as by cutting the microelectronic spring contact in two adjacent to the terminal. Then, a bonding material, such as a solder paste, is applied to the terminal and a replacement spring contact is positioned on the bonding material. The bonding material is then cured to fix the replacement spring contact in place. The replacement spring contact includes a base configured to fit on or over any protruding material left on the terminal, and at least one resilient cantilever arm extending from the base. In an embodiment of the invention, the base comprises at least two legs extending from the base in a direction opposite to the cantilever arm. In an alternative embodiment, the base of the replacement spring contact has a flat bottom, or one or more recesses to receive protrusions on the terminal.
Abstract: A method for designing integrated circuits (ICs) and their interconnect systems includes IC component cells and interconnect component cells in a cell library. Each IC component cell provides both a physical and behavioral model of a component that may be incorporated into the IC while each interconnect component cell includes both a physical and behavioral model of a separate internal or external component of an interconnect system that may link the IC to external nodes. Both the IC and its interconnect systems are designed by selecting and specifying interconnections between component cells included in the cell library. Interconnect systems are flexibily designed to act like filters tuned to optimize desired frequency response characteristics.
Abstract: Techniques for performing wafer-level burn-in and test of semiconductor devices include a test substrate having active electronic components such as ASICs mounted to an interconnection substrate or incorporated therein, metallic spring contact elements effecting interconnections between the ASICs and a plurality of devices-under-test (DUTs) on a wafer-under-test (WUT), all disposed in a vacuum vessel so that the ASICs can be operated at temperatures independent from and significantly lower than the burn-in temperature of the DUTs. The spring contact elements may be mounted to either the DUTs or to the ASICs, and may fan out to relax tolerance constraints on aligning and interconnecting the ASICs and the DUTs.
Abstract: A forming tool with one or more embossing tooth, and preferably, a plurality of such embossing teeth, arranged on a substantially planar substrate, is disclosed. Each embossing tooth is configured for forming a sacrificial layer to provide a contoured surface for forming a microelectronic spring structure. Each embossing tooth has a protruding area corresponding to a base of a microelectronic spring, and a sloped portion corresponding to a beam contour of a microelectronic spring. Numerous methods for making a forming tool are also disclosed. The methods include a material removal method, a molding method, a repetitive-stamping method, tang-bending methods, and segment-assembly methods.
Abstract: A system for testing integrated circuit devices is disclosed in which a tester communicates with a known good device through a channel. Tester-DUT interface circuitry is provided for monitoring the channel while the tester is writing data as part of a test sequence to locations in the known good device. In response, the interface circuitry writes the data to corresponding locations in each of a number of devices under test (DUTs). The interface circuitry monitors the channel while the tester is reading from the locations in the known good device (KGD), and in response performs a comparison between DUT data read from the corresponding locations in the DUTs and expected responses obtained form the KGD.
Abstract: An unsingulated semiconductor wafer is provided. Electrical interconnect elements are formed on the unsingulated wafer such that the interconnect elements are electrically connected to terminals of the semiconductor dice composing the wafer. At least a portion of the interconnect elements extend beyond the boundaries of the dice into the scribe streets separating the individual dice. Thereafter, the wafer is singulated into individual dice.
Abstract: A printed circuit board (PCB) via, providing a conductor extending vertically between microstrip or stripline conductors formed on separate layers of a PCB, includes a conductive pad surrounding the conductor and embedded within the PCB between those PCB layers. The pad's shunt capacitance and the magnitudes of capacitances of other portions of the via are sized relative to the conductor's inherent inductance to optimize frequency response characteristics of the via.
Abstract: One embodiment of the present invention concerns a test assembly for testing product circuitry of a product die. In one embodiment, the test assembly includes at test die and an interconnection substrate for electrically coupling the test die to a host controller that communicates with the test die. The test die may be designed according to a design methodology that includes the step of concurrently designing test circuitry and a product circuitry in a unified design. The test circuitry can be designed to provide a high degree of fault coverage for the corresponding product circuitry generally without regard to the amount of silicon area that will be required by the test circuitry. The design methodology then partitions the unified design into the test die and the product die. The test die includes the test circuitry and the product die includes the product circuitry. The product and test die may then be fabricated on separate semiconductor wafers.
Type:
Grant
Filed:
December 31, 1998
Date of Patent:
April 22, 2003
Assignee:
FormFactor, Inc.
Inventors:
Benjamin N. Eldridge, Igor Y. Khandros, David V. Pedersen, Ralph G. Whitten
Abstract: Described herein is a probe card assembly providing signal paths for conveying high frequency signals between bond pads of an integrated circuit (IC) and an IC tester. The frequency response of the probe card assembly is optimized by appropriately distributing, adjusting and impedance matching resistive, capacitive and inductive impedance values along the signal paths so that the interconnect system behaves as an appropriately tuned Butterworth or Chebyshev filter.
Abstract: An initial graph of nodes is created within a routing space, and the number and locations of the nodes in the graph are adjusted. Links are created between nodes of the graph, and traces between specified nodes are created through the linked graph.
Abstract: Temporary connections to spring contact elements extending from an electronic component such as a semiconductor device are made by urging the electronic component, consequently the ends of the spring contact elements, vertically against terminals of an interconnection substrate, or by horizontally urging terminals of an interconnection substrate against end portions of the spring contact elements. A variety of terminal configurations are disclosed.
Type:
Application
Filed:
November 19, 2002
Publication date:
April 10, 2003
Applicant:
FormFactor, Inc.
Inventors:
Thomas H. Dozier, Benjamin N. Eldridge, Gary W. Grube, Igor Y. Khandros, Gaetan L. Mathieu, David V. Pedersen, Michael A. Stadt
Abstract: Spring contact elements are attached to terminals of an electronic component, which may be a semiconductor die. The spring contact elements may comprise a flexible precursor element. The precursor element may be over coated with a resilient material. The spring contact elements may be elongate and attached to the terminals at one end. The other end of the spring contacts may be spaced away from the electronic component.
Abstract: A method of fabricating a large area, multi-element contactor. A segmented contactor is provided for testing semiconductor devices on a wafer that comprises a plurality of contactor units mounted to a substrate. The contactor units are formed, tested, and assembled to a backing substrate. The contactor units may include leads extending laterally for connection to an external instrument such as a burn-in board. The contactor units include conductive areas such as pads that are placed into contact with conductive terminals on devices under test.
Type:
Application
Filed:
July 25, 2002
Publication date:
March 27, 2003
Applicant:
FormFactor, Inc.
Inventors:
Mohammad Eslamy, David V. Pedersen, Harry D. Cobb