International Business Machines Corporation

Alan L Jones

Keith A Snyder

Paul E Winkler

Joseph P Pawletko

Jerry Wesley Raider

Robert Melroy Kellogg

Keith A Synder

An improved circuit board structure and method of forming the same are provided. The circuit board includes an insulating core and has plated through holes connecting the circuitry on both sides and intermediate layers of the core. A permanent dielectric material is applied on at least one surface of the board covering the circuitry and plated through holes. Vias are formed through the dielectric material and signal lines are formed on the top of the dielectric material connected to the circuitry onto the board through the vias. Additional layers of dielectric material with additional wiring and vias can also be formed for multi-level wiring.

Method of forming a hybrid printed circuit board

An electronic package including a first circuitized substrate (e.g., printed circuit board) a second, flexible circuitized substrate (e.g., polyimide), an electronic device (semiconductor chip) and a metallic (e.g., aluminum) heat sink member joined to the first substrate to provide a cover for the package's internal components. A predetermined quantity of liquid material (e.g. wax or oil) is located between a defined surface of the chip and a corresponding internal surface of the heat sink member during assembly of the package, this material possessing a surface tension sufficient to create a suction force between the device and heat sink so as to elevate the device in a spaced position from (e.g., above) the first circuitized substrate during said assembly. Should a liquid material such as oil be utilized, this material remains in the liquid state during package operation to continuously provide the defined suction force sufficient to maintain the device at the elevated position. If a material such as wax is used, this material becomes solidified and remains so during package operation to thus maintain the device in elevated position by adhesion. Improved heat dissipation for the package and ease of assembly thereof is thus possible.

Electronic package with a device positioned above a substrate by suction

Circuit board

Magnetoresistive displacement transducer arrangement for toothed magnetic members in which each transducer is formed by a pair of interconnected sections spaced from each other by the width of a tooth to provide greater change and improved symmetry in the output signal at the tooth edges. Multiple transducers can be positioned interdigitally for compact packaging for vernier type detection of motion. Transducer embodiments for both linear and rotary motion are disclosed.

Interleaved magnetoresistive displacement transducers

A fluid container particularly useful in a centrifuge system for separating the various fractions in blood. The container comprises two circular sheets of flexible material, having central openings therein. The outer peripheral edges are sealed together, as well as an annular portion extending outwardly from the central opening. A radial arcuate portion is sealed off, thereby providing an interrupted or discontinuous annular chamber. At one end of the interrupted annular chamber, an inlet tube is provided, extending outwardly from the central opening and communicating with one end of the interrupted annular chamber. At the other end of the interrupted annular chamber, there is provided a radially enlarged portion, which acts as a collection chamber for the various portions of the fluid separated by centrifugal force. The various portions, or fractions, will exist at different radial distances from the center of the bag. A plurality of outlet tubes extend radially outward from the center of the bag to open within the collection chamber at different radial distances. Through these outlet tubes, selected separated portions of the fluid are withdrawn from the bag.

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Endwell, NY, United States of America

Alan L Jones