System, devices and methods are presented that integrate stretchable or flexible circuitry, including arrays of active devices for enhanced sensing, diagnostic, and therapeutic capabilities. The invention enables conformal sensing contact with tissues of interest, such as the inner wall of a lumen, a the brain, or the surface of the heart. Such direct, conformal contact increases accuracy of measurement and delivery of therapy. Further, the invention enables the incorporation of both sensing and therapeutic devices on the same substrate allowing for faster treatment of diseased tissue and fewer devices to perform the same procedure.

Systems,methods, and devices having stretchable integrated circuitry for sensing and delivering therapy

A microelectronic package includes a microelectronic element having faces and contacts, the microelectronic element having an outer perimeter, and a substrate overlying and spaced from a first face of the microelectronic element, whereby an outer region of the substrate extends beyond the outer perimeter of the microelectronic element. The microelectronic package includes a plurality of etched conductive posts exposed at a surface of the substrate and being electrically interconnected with the microelectronic element, whereby at least one of the etched conductive posts is disposed in the outer region of the substrate. The package includes an encapsulating mold material in contact with the microelectronic element and overlying the outer region of the substrate, the encapsulating mold material extending outside of the etched conductive posts for defining an outermost edge of the microelectronic package.

Microelectronic packages and methods therefor

A ball grid array integrated circuit package is manufactured by mounting a semiconductor die, to a surface of a substrate such that bumps on the semiconductor die are electrically connected to conductive traces of the substrate. At least one collapsible spacer is mounted to at least one of a heat spreader, the semiconductor die and the substrate. The heat spreader is fixed to the at least one of the first surface of the substrate and the semiconductor die such that he at least one collapsible spacer is disposed therebetween. A ball grid array is formed on a second surface of the substrate, bumps of the ball grid array being electrically connected to the conductive traces and the integrated circuit package is singulated.

Ball grid array package and process for manufacturing same

The present invention provides a high-speed electrical interconnection system designed to overcome the drawbacks of conventional interconnection systems. That is, the present invention provides an electrical connector capable of handling high-speed signals effectively.

High-speed electrical connector

System, devices and methods are presented that integrate stretchable or flexible circuitry, including arrays of active devices for enhanced sensing, diagnostic, and therapeutic capabilities The invention enables conformal sensing contact with tissues of interest, such as the inner wall of a lumen, a nerve bundle, or the surface of the heart Such direct, conformal contact increases accuracy of measurement and delivery of therapy

Systems, methods, and devices using stretchable or flexible electronics for medical applications

Solder compositions are introduced to interface between an IC chip and its associated heat exchanger cover. The solder compositions have a solidus-liquidus temperature range that encompasses the IC chip operational temperature range. The solder composition has the desired property of absorbing and rejecting heat energy by changing state or phase with each temperature rise and decline that result from temperature fluctuations associated with the thermal cycles of the integrated circuit chips. A path for high thermal conduction (low thermal resistance) from the IC chip to the heat exchanger to the ambient air is provided by an electronic module cover, configured as a cap with a heat exchanger formed or attached as a single construction, and made of the same material as the substrate, or made with materials of compatible thermal coefficients of expansion to mitigate the effects of vertical displacement during thermal cycling. The cap-heat exchanger cover is constructed to be compliant, and to contact both the IC chip and substrate.

Thermal enhancement approach using solder compositions in the liquid state

An integrated circuit assembly has pads of a chip electrically connected to pads of a substrate with rolling metal balls. A pliable material bonds the balls in movable contact with pads of the chip and substrate. Because the balls are relatively free to move, thermal expansion differences that would ordinarily cause enormous stresses in the attached joints of the prior art, simply cause rolling of the balls of the present invention, avoiding thermal stress altogether. Reliability of the connections is substantially improved as compared with C4 solder bumps, and chips can be safely directly mounted to such substrates as PC boards, despite substantial thermal mismatch.

Rolling ball connector

High melting temperature Pb/Sn 95/5 solder balls are connected to copper pads on the bottom of a ceramic chip carrier substrate by low melting temperature eutectic Pb/Sn solder The connection is made by quick reflow to prevent dissolving Pb into the eutectic solder and raising its melting temperature Then the module is placed on a fiberglass-epoxy circuit board with the solder balls on eutectic Pb/Sn solder bumps on copper pads of the board The structure is reflowed to simultaneously melt the solder on both sides of the balls to allow each ball to center between the carrier pad and circuit board pad to form a more symmetric joint This process results in structure that are more reliable under high temperature cycling Also, to further improve reliability, the balls are made as large as the I/O spacing allows without bridging beam on balls; the two pads are about the same size with more solder on the smaller pad; the pads are at least 75% of the ball diameter; and the eutectic joints are made as large as possible without bridging between pads For reliability at even higher temperature cycles or larger substrate sizes columns are used instead of balls

Solder ball interconnected assembly

A heat sink in a heat transfer relationship with a substrate such as an integrated chip, chip carrier, or other electronic package. The heat sink is connected to a frame which is connected to a printed circuit board or other suitable support on which the substrate is positioned. The heat sink, which extends through an aperture in the frame is coupled to a surface of the substrate. The heat sink is mechanically decoupled from the substrate. Large heat sinks may be thermally connected to surface mount substrates mounted using technologies such as ceramic ball or column grid arrays, plastic ball or column grid arrays, or solder balls or columns. The heat sink is attached coaxially through the aperture to the substrate. After assembly and lead/tin or other metallic surface mount interconnects are relaxed such that the substrate and is completely supported by the frame and the heat sink imparts zero or nearly zero downward force. Because the heat sink moves freely within the aperture during assembly, the heat sink package is useful for a variety of different substrates. Preferably, the frame is a plate and a plurality of studs. The plate material are selected to match the thermal expansion of the underlying support, and the stud material matched the thermal expansion of the substrate. Thus, the frame construction allows matching expansion and contraction of the assembly to the underlying substrate and support.

Zero force heat sink

High melting temperature Pb/Sn 95/5 solder balls (18) are connected to copper pads on the bottom of a ceramic chip carrier substrate (10) by low melting temperature eutectic Pb/Sn solder. The connection is made by quick reflow to prevent dissolving Pb into the eutectic solder and raising its melting temperature. Then the module is placed on a fiberglass-epoxy circuit board with the solder balls on eutectic Pb/Sn solder bumps on copper pads of the board. The structure is reflowed to simultaneously melt the solder on both sides of the balls to allow each ball to center between the carrier pad and circuit board pad to form a more symmetric joint. This process results in structure that are more reliable under high temperature cycling. Also, to further improve reliability, the balls are made as large as the I/O spacing allows without bridging beam on balls; the two pads are about the same size with more solder on the smaller pad; the pads are at least 75% of the ball diameter; and the eutectic joints are made as large as possible without bridging between pads. For reliability at even higher temperature cycles or larger substrate sizes columns are used instead of balls.

Joseph A. Benenati

Papers

Thermal enhancement approach using solder compositions in the liquid state

Rolling ball connector

Solder ball interconnected assembly

Zero force heat sink

Solder ball connections and assembly process