bmdo technologies for biomedical applications - MDA Technology

CHIP-STACKING TECHNOLOGYFROM IRVINE SENSORS & JPLBMDO HISTORYTo fit ever more circuitry into computers, manufacturers and designers havedemanded narrow line widths and novel chip architectures. Chip stackingis one approach to both increase the speed and decrease the size of multichipmodules (MCMs). This 3-D architecture would shorten chip interconnections,thus producing smaller, faster MCMs. BMDO has funded researchinto this technology at Irvine SensorsCorporation (ISC; Costa Mesa, CA) and theVisual processing takes upJet Propulsion Laboratory (JPL; Pasadena,CA) for a number of programs, includinga little more than half theVIGILANTE, an Innovative Science andbrain’s workload. Humans Technology project that has as its goal thedevelopment of a neural-network moduleare so pictorially oriented that can perform image recognition.• 3-D neural networks can quicklyprocess and analyze images.that the blind can interprettouch as a visual signal.Neural activity in areas ofthe brain that subservevision can be stimulatedby tracing outlines ofsimple objects on theskin of a blind subject.HOW IT WORKSISC creates its MCMs by thinning eachwafer layer to less than 100 micrometers,patterning it, and dicing it to form separateintegrated circuits. After surface metallization,the chips are stacked together, aligned,and bonded with a thermally compatibleepoxy. Raised metallic leads on the surfaceof each chip provide electrical contactbetween adjacent chip elements. Thesethrough-thickness electrical connectionsreduce circuit path lengths and therebyincrease the module’s operating speed. Theshorter current paths also reduce overallpower consumption.16Using this technology, ISC and JPL are working on a 3-D neural-networkmicroprocessor. Artificial neural networks are designed to behave approximatelyas human brains are thought to function; they enable patternrecognition and learning behaviors that are difficult for conventional computersto handle. Thus, a neural-network processor involves large numbersof data and processing nodes that continuously interact with each other.The ISC chip-stacking techniques can achieve the high interconnectiondensities necessary to construct an efficient and fast neural network.JPL and ISC jointly developed and designed a 3-D neural-network microprocessingmodule called 3DANN, as well as a new device called theNeural Processing Module (NPM). The 3DANN module is three-quartersthe size of two stacked sugar cubes; 64 of them will be integrated into acube to form the NPM. Mounted on the cube will be a column loadingChapter 1 - Information TechnologiesSection A - PresentationBMDO Technologies for Biomedical Applications