Lsi Logic Corporation

Edwin M Fulcher

Leah Miller

Michael D Rostoker

Aritharan Thurairajaratnam

Farshad Ghahghahi

Mark R Schneider

James S Koford

Qwai Hoong Low

Carlos Dangelo

Kumar Nagarajan

Anwar Ali

Ramaswamy Ranganathan

Stan Mihelcic

Thomas Evans

A system and method are provided for forming a multi-chip package. The multi-chip package includes a multi-layer substrate and a heat spreader of single, unibody construction. At least two integrated circuits are coupled between the multi-layer substrate and the heat spreader. The integrated circuits are spaced from one another to allow airflow between those circuits and a portion of the underside surface of the heat spreader. Depending on the layout of the package, a passive device can also be placed in the space between integrated circuits. The passive device extends upward a spaced distance from the underneath surface of the heat spreader so as not to block the airflow therebetween. The multi-chip package can accommodate integrated circuits that are either all packaged, all unpackaged, or a combination of each. If packaged and unpackaged integrated circuits are placed on the multi-layer substrate, the heat spreader can extend in two separate planes to accommodate the different thicknesses of those packaged and unpackaged integrated circuits. Alternatively, a second heat spreader can be placed on a relatively thin integrated circuit so that the upper surface of the second heat spreader is coplanar with an upper surface of a relatively thick integrated circuit. This will allow a planar heat spreader to be arranged across the thick integrated circuit and the second heat spreader. In all instances, however, the heat spreader extends as a single, contiguous unibody element across the entire multi-chip package.

Multi-chip package having a contiguous heat spreader assembly

An integrated circuit having signal traces, power traces, and ground traces. The signal traces are disposed on at least one signal distribution layer, and the signal traces on the at least one signal distribution layer are formed at no more than a first thickness. The power traces and ground traces are formed on at least one power ground distribution layer, where the at least one power ground distribution layer is an overlying layer of the integrated circuit relative to the at least one signal distribution layer. The power traces and ground traces on the at least one power ground distribution layer are formed at no less than a second thickness that is greater than the first thickness of the signal traces. In this manner, the signal traces, which can be formed with a relatively thin thickness, can be placed very close together on the signal distribution layers, and have sufficient conductivity for the signals transmitted thereon. At the same time, the power and ground traces, which are typically required to carry a greater current, can be formed with a relatively thick thickness and with wider widths, without taking up precious space on the signal distribution layers. In this manner, the signal traces can be placed closed together, both because they are thinner and because space is not taken by power and ground traces on the same layer, and thus they require less space, and the integrated circuit can be made smaller.

Thick metal top layer

An integrated circuit having functional circuitry within a core portion of the integrated circuit. Input circuits are disposed on a first layer within a peripheral portion of the integrated circuit, where the input circuits are electrically connected to the functional circuitry. Power and ground buss lines are disposed on a second layer within the peripheral portion of the integrated circuit, where the second layer overlies the first layer. The power and ground buss lines overlie the input circuits, and are electrically connected to the input circuits. Bonding pads are disposed on a third layer within the peripheral portion of the integrated circuit, where the third layer overlies the second layer. The bonding pads overlie the power and ground buss lines and the input circuits, and are electrically connected to the input circuits.

Bonding pads over input circuits

A bonding pad structure having an electrically conductive capping layer. An electrically conductive first supporting layer is disposed immediately under the electrically conductive capping layer, without any intervening layers between the electrically conductive capping layer and the electrically conductive first supporting layer. The electrically conductive first supporting layer is configured as one of a sheet having no voids and a sheet having slotted voids in a first direction. An electrically conductive second supporting layer is disposed under the electrically conductive first supporting layer. The electrically conductive second supporting layer is configured as one of a sheet having slotted voids in the first direction, a sheet having slotted voids in a second direction, and a sheet having checkerboard voids.

Bonding pad for low k dielectric

A package substrate is contemplated herein for reducing cross-talk for noise-sensitive signals. The package substrate includes noise-sensitive conductors adapted to receive the noise-sensitive signals. In one embodiment, the cross-sectional width of the noise-sensitive conductors is increased to reduce certain parasitic effects such as resistance and/or inductance. The package substrate also includes guard conductors which are arranged co-planar with and substantially parallel to the noise-sensitive conductors. A plurality of vias spaced equidistant from one another extends from a ground conductor to the guard conductors, providing a substantially uniform voltage across the guard conductors. The overall effect will reduce the inductive and capacitive cross-talk from neighboring signals and increase the signal integrity of noise-sensitive signals.

Integrated circuit packaging that uses guard conductors to isolate noise-sensitive signals within the package substrate

A printed circuit board having contacts in a contact array of rows and columns. Groups of n columns of the contacts are electrically connected to n&minus;1 columns of vias disposed interstitially in a via array between the n columns of the contacts. A major vertical routing channel is formed between adjacent groups of n columns of the contacts and the n&minus;1 columns of vias. First electrical traces are electrically connected to a first number of the vias. The first electrical traces are routed to an outside edge of the via array through the major vertical routing channel.

Ball assignment for ball grid array package

A package substrate having separate routing layers for transmitter signals and receiver signals, which signals are routed in differential pairs. The differential pairs of signal routing lines are isolated between a separate ground plane for transmitter and receiver traces and dedicated power planes, where a single power plane is dedicated to a single differential pair of signal routing lines. In this manner, a high degree of electrical isolation exists not only between the transmitter signal traces and the receiver signal traces, which are on different layers, but also between different differential pairs of signal routing lines on the same layer, each of which has its own dedicated power plane. Thus, a very high speed core routing system can be designed in a package substrate that can then be adapted as necessary to support a broad range of different integrated circuit designs.

Isolated stripline structure

An input/output array of an integrated circuit comprises concentric rings of input/output tiles. The peripheral input/output tiles are adjacently arranged along the periphery of the integrated circuit to form a peripheral ring. Each of the peripheral input/output tiles is associated with a corresponding peripheral input/output device group having x number of input/output devices. Each peripheral input/output tile includes x number of signal contacts for coupling signals to corresponding ones of the x number of input/output devices, y number of input/output driver voltage contacts for coupling a source voltage to drivers of the x number of input/output devices, and z number of ground contacts. The interior input/output tiles are adjacently arranged within the interior of the integrated circuit to form n number of substantially concentric interior rings, where n is greater than or equal to one.

High density input output

A structure for receiving electrical signals near a central portion of the structure and distributing the electrical signals to a peripheral portion of the structure. The structure has a first set of contacts arranged in an array near the central portion of the structure. Electrically conductive traces connect the first set of contacts to a second set of contacts, where each of the electrically conductive traces has at least a first segment, a second segment, and a third segment. The first segment of each of the electrically conductive traces has relatively narrow width and spacing. The first segment of each of the electrically conductive traces is connected on a first end of the first segment to one of the first set of contacts and on a second end of the first segment to the second segment of each of the electrically conductive traces. The second segment of each of the electrically conductive traces has relatively intermediate width and spacing. The second segment of each of the electrically conductive traces is connected on a first end of the second segment to the second end of the first segment and on a second end of the second segment to the third segment of each of the electrically conductive traces. The third segment of each of the electrically conductive traces has relatively wide width and spacing. The third segment of each of the electrically conductive traces is connected on a first end of the third segment to the second end of the second segment and on a second end of the third segment to one of the second set of contacts.

High density signal routing

A semiconductor device package is presented having signal traces interposed between power and ground conductors in order to form stripline transmission lines. The semiconductor device package includes a substrate having a die area defined upon an upper surface. The die area is dimensioned to receive the integrated circuit. A first planar conductive layer formed upon the upper surface includes a first set of bonding pads and a set of conductive traces. Members of the first set of bonding pads are arranged upon the upper surface proximate the die area, and are used to make electrical connections to the integrated circuit. Members of the set of conductive traces are connected between one of two polarities of a power supply and corresponding members of the first set of bonding pads, and function as reference planes for underlying signal traces. A second planar conductive layer is positioned between the first planar conductive layer and an underside surface of the substrate. The second conductive layer is connected to the other of the two polarities of the power supply, and also functions as a reference plane for signal traces within the substrate. A planar conductive signal layer is interposed between the first and second conductive layers and patterned to form a set of signal traces. The signal traces form stripline transmission lines which are highly desirable in high frequency applications as their impedances are highly predictable and controllable.

Integrated circuit package having signal traces interposed between power

A ball bump grid array package includes dies on one surface of a printed wiring board (PWB) and an array of ball bumps on the other surface of the PWB. The die is interconnected with the ball bumps by bond wires, traces on the one surface of the PWB, vias through the PWB and traces on the other surface of the PWB. Various die encapsulation schemes are discussed. The PWB is formed of FR4, BT, teflon or polyimide, or ceramic materials. The die may be connected to the traces on the one surface of the PWB with solder balls, rather than with bond wires. Two or more dies may be disposed on the one surface of the PWB, within the plastic molded body. The ball bumps on the other surface of the PWB may be arranged in a multiple grid pitch array--ball bumps within a central area being on a first pitch, and ball bumps without the central area being on a second pitch which is a multiple of the first pitch.

Method of assembling ball bump grid array semiconductor packages

A flip chip substrate includes first and second conductive layers, and a dielectric layer interposed therebetween. Each conductive layer includes a repeating pattern of a group of I/O signal traces such as two I/O signal traces, followed by a wider power or ground trace. The I/O traces on one conductive layer lie atop or below power or ground traces on the other conductive layer. The wider power and ground traces provide shielding on either side of the I/O trace group, as well as above or below.

Flip chip package with reduced number of package layers

Unsingulated dies on a wafer may be individually electronically selected using various 'electronic mechanisms' on the wafer. Conductive lines extend on the wafer from the electronic mechanism to the individual dies. The conductive lines may be provided in sets of two or more, such as for providing discrete power and ground connections from the external equipment to the individual dies. Redundant conductive lines may be provided to ensure against 'open' faults. Diode and/or fuses may also be provided in conjunction with the conductive lines to ensure against leakages and shorts. Redundant electronic selection mechanisms may also be provided.

Integrated circuit wafer comprising unsingulated dies, and decoder

A first, lower heat sink disposed immediately below and closely adjacent a semiconductor chip (die) in a semiconductor chip assembly is disclosed. The lower heat sink is a flat metallic or ceramic shim. A second, upper heat sink disposed immediately above and closely adjacent the top surface of the semiconductor device is disclosed. The upper heat sink may have a portion in contact with a passivation layer over the top surface of the semiconductor die (device). The second heat sink preferably has a flat surface forming an exterior surface of the semiconductor device assembly. In one embodiment, the second heat sink has pedestals resting atop a plastic layer in a tape-like structure within the semiconductor chip assembly. In a second embodiment, the second heat sink includes an add-on portion that is external to the semiconductor chip assembly. The first heat sink is particularly well-suited to applications wherein the semiconductor chip assembly is mounted to a thermal mass. The second heat sink is particularly well-suited to applications wherein air cooling is available. Each of the first and second heat sinks provide effective cooling, and when used together provide even more effective cooling. Alternatively, the die may be mounted to the top surface of a printed circuit board support structure, the bottom surface of which is provided with a plurality of solder bumps.

Growing community of inventors

Palo Alto, CA, United States of America

Edwin M Fulcher