International Business Machines Corporation

Charles S Chiu

Patrick H Buffet

Erik Breiland

Timothy W Budell

Eric W Tremble

Craig P Lussier

Yu H Sun

Gulsun Yasar

Umberto Garofano

Prince George

Louis L Hsu

Joseph Natonio

Ivan L Wemple

Francis H Chan

Brian Joel Schuh

Paul Lee Clouser

Charles K Erdelyi

Kurt A Carlsen

Robert A Proctor

Jon David Garlett

James Patrick Libous

Donald S Kent

Brian P Welch

James E Jasmin

Robert Charles Cusimano

Haitian Hu

Ze Gui Pang

Gustina B Collins

Rory D Loughran

David Toub

The invention generally relates to systems and methods for modeling I/O simultaneous switching noise, and, more particularly, to systems and methods for modeling I/O simultaneous switching noise in a selected chip window area while accounting for the effect of current sharing among neighbors. A method includes determining a current sharing factor of areas of an integrated circuit (IC) chip package, and determining an offload scaling factor of the IC chip package based upon the current sharing factor and numbers of I/O devices in neighboring areas of the IC chip package.

System and method for modeling I/O simultaneous switching noise

Methods, systems, computer programs, etc., determine the required number of decoupling capacitors, and approximate locations for the decoupling capacitors, for a region of an integrated circuit. Switching elements of the region are entered into a simulation program running on a computerized device. Also, a power distribution model of the region is entered into the simulation program, and a power-supply voltage compression target is entered into the simulation program. These methods, systems, etc., generate an upper number of decoupling capacitors required to satisfy the compression target when all the switching elements concurrently switch. For each switching element, the methods, systems, etc., generate a specific number of decoupling capacitors required to satisfy the compression when only the element switches, calculate a fraction of the specific number to the upper number, assign the fraction of the total number of decoupling capacitors to each switching circuit element, and place the fraction of the total number of decoupling capacitors in electrical proximity to the element.

Early decoupling capacitor optimization method for hierarchical circuit design

A method for modeling bond wires in an IC package for predicting noise effects generated by electromagnetic coupling in complex bond wire configurations. A look-up table of equivalent LC circuit models for the bond wires is generated that accurately predicts the effects of the bond wire circuitry of a signal transmission system. Switch and mirror techniques are applied to reduce the bond wire configurations necessary to simulate. The method includes: setting parameters related to the IC package layout of groups of bond wires; sub-dividing each group of bond wires into regions, each including a portion of the bond wire or its corresponding pad, and generating dissection planes for the regions consisting of the bond wires; performing a 3D simulation on the regions consisting of the corresponding pads, and a 2D simulation for each dissection plane; constructing equivalent circuit models for groups of bond wires and corresponding pads based on the 3D and 2D simulations results; inputting the equivalent circuit models into a circuit simulator to measure the noise effects; and modifying the layout geometry to meet noise targets.

Multi-segments modeling bond wire interconnects with 2D simulations in high speed, high density wire bond packages

A method, apparatus, and computer program product for creating a model representing an electrical network residing in an integrated circuit package.

Method, apparatus and computer program product for electrical package modeling

The invention relates generally to a method of power supply noise and signal integrity analysis for creating frequency-dependent electrical models particularly related to microelectronic packages. The method discloses creation of equivalent circuits for geometries encountered in a typical chip package, including how to partition the geometry into cells which are less then 1/20 the minimum wavelength (&#x3bb;) in size, and how to handle signal and power supply vias, signal wires, and power planes. The method also instructs how to assign values to each of the inductors, capacitors, resistors, and transmission lines in each equivalent circuit. The method further provides modeling of only those interactions which occur between adjacent cells.

Hierarchical method of power supply noise and signal integrity analysis

A method, system and program product for creating a simplified equivalent model for an IC that can be used for detailed analysis. The equivalent model takes into consideration the effects of all the I/O placement regardless of the non-uniformity of I/O placement. The equivalent model is generated, in part, by partitioning the IC into simulation windows and converting I/Os within each simulation window to a current source having the same current change rate, and then running a simulation on this intermediate model. A current change rate observed for a simulation window is then used to convert back to actual I/Os to create the equivalent model. The equivalent model can be simulated using conventional software, e.g., SPICE, for more detailed analysis such as signal integrity, timing of I/Os and noise.

Integrated circuit and package modeling

A semiconductor chip package with reduced cross-talk between adjacent signals in a layer of a carrier is disclosed. A first pair of conductors for carrying a first signal is provided in a layer of the carrier. A second pair of conductors for carrying a second signal is provided adjacent to the first pair of conductors in the layer, where the first and second pairs of conductors are configured such that cross-talk between the first and second pairs of conductors is substantially minimized, without increasing the size of the package. The height of the first pair of conductors is shorter than the second pair of conductors. Alternatively, the first and second pairs of conductors are configured so that they evenly affect each other. The chip package thus reduces the cross-talk without compromising the density of the interconnections in the package or resulting in an increase in the size of the package.

Apparatus and method to reduce signal cross-talk

Disclosed is an improved method of determining mutual inductance of wires in an electronic design. First, the invention selects a pair of wires. Then, the invention adds concentric ring lines to the design. The invention then adds straight line segments representing each wire between points where each corresponding wire crosses the adjacent ring lines. Each of the straight lines run from a point where a corresponding wire crosses an outer concentric ring line to a point where the corresponding wire crosses an inner concentric ring line. The invention can then very simply calculate the mutual inductance between the straight line segments (not the actual potentially non-linear wires themselves). The mutual inductance of the straight line segments only comprises an approximate mutual inductance of the wires because the actual mutual inductance of the wires may be slightly different if the wires are non-linear.

Efficient and comprehensive method to calculate IC package or PCB trace mutual inductance using circular segments and lookup tables

A method for enhancing power bus for I/O libraries in ASIC designs is disclosed. An I/O assignment for I/O circuits to be utilized in an ASIC design is initially generated. Each I/O circuit may obtain power from either a primary I/O power bus or a secondary I/O power bus. A determination is then made as to whether or not the I/O assignment meets certain predetermined power distribution requirements. In a determination that the I/O assignment does not meet the predetermined power bus distribution requirements, a power enhancement cell is added. The power enhancement circuit includes at least one metal line for connecting the primary I/O power bus to the secondary I/O power bus in order for the I/O assignment to meet the power bus distribution requirements.

Method for enhancing a power bus in I/O regions of an ASIC device

A method of analyzing I/O cell layouts for integrated circuits, such as ASICs, includes defining a proposed I/O cell layout on a selected chip image, providing a set of limit rules for electromigration, IR voltage drop and di/dt noise for the selected chip image, providing characteristics for each I/O cell type used in the proposed I/O cell layout, checking the proposed I/O cell layout by applying the limit rules to the proposed I/O cell layout and reporting all I/O cells used in the proposed I/O cell layout that do not meet the limit rules for the selected chip image.

Fast method of I/O circuit placement and electrical rule checking

Disclosed is a method of designing voltage partitions in a solder bump package for a chip, comprising: determining the current requirements of a chip voltage island, the chip voltage island including chip power and signal pads, and creating an equivalent circuit model of the chip voltage island; defining a package voltage island, the package voltage island including power and signal package pins, and creating an equivalent circuit model of the package voltage island; analyzing electrical attributes of a combination of the chip voltage island model and the package voltage island model; and modifying the package voltage island until the electrical attributes are acceptable.

Method of designing a voltage partitioned solder-bump package

Disclosed is a method of designing voltage partitions in a package for a chip, comprising: determining the current requirements of a chip voltage island comprising a voltage island and power and signal chip pads; computing the voltage drop across power buses in the chip voltage island; assigning additional chip pads to the chip voltage island for use as power pads if the voltage drop is not acceptable; defining a package voltage island, the package voltage island including power and signal package pads; analyzing electrical attributes of a combination of the chip voltage island, the package voltage island and conductive interconnects connecting chip voltage island pads to package voltage island pads; and assigning additional chip pads to the chip voltage island and additional package pads to the package voltage island for use as power pads until the electrical attributes are acceptable.

Growing community of inventors

Essex Junction, VT, United States of America

Charles S Chiu