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This manuscript presents an adaptive high order discretization technique for elliptic boundary value problems. The technique is applied to an updated version of the Hierarchical Poincar\'e-Steklov (HPS) method. Roughly speaking, the HPS method is based on local pseudospectral discretizations glued together with Poincar\'e-Steklov operators. The new version uses a modified tensor product basis which is more efficient and stable than previous versions. The adaptive technique exploits the tensor product nature of the basis functions to create a criterion for determining which parts of the domain require additional refinement. The resulting discretization achieves the user prescribed accuracy and comes with an efficient direct solver. The direct solver increases the range of applicability to time dependent problems where the cost of solving elliptic problems previously limited the use of implicit time stepping schemes.

A process has been developed for the fabrication of high density arrays of miniaturized pluggable connectors for interconnections in high performance computers using Josephson devices. Electrical contacts are made by inserting (at room temperature) arrays of metal pins, each about 200 µm long and 75 µm in diameter with a center-to-center spacing of 300 µm, into corresponding Si microsockets containing a liquid metal. Such pins and sockets have been successfully batch fabricated with high positional accuracy, using electrodischarge machining (EDM) and anisotropic etching techniques, respectively. The fabrication process is described here.

This letter describes the first system level test vehicle in Josephson technology. The experiment consists of four circuit chips assembled on two cards in a high density, 3-dimensional, card-on-board package. A data path, which is representative of a critical path of a future prototype processor, was successfully operated with a minimum cycle time of 3.7ns. The path simulates a jump control sequence and a cache access in each machine cycle. This experiment incorporates the essential components of the logic, power and package portions of a Josephson technology prototype.

Packaging technology used to build the first system crosssection test vehicle in Josephson technology is described. A threedimensional modular card-on-board packaging approach has been selected to fabricate the test vehicle which incorporates all the essential features of the technology required to build a high performance processor prototype. Potential viability of the described packaging technology for the fabrication of such a prototype has been demonstrated by an experiment in which a critical data path has been successfully operated with a minimum cycle time of 3.7 ns.

This paper reports results of a detailed performance evaluation of the chain magnetic film storage element. The chains are made from copper strips which have been plated with Ni-Fe film and are used to carry word current. The bit/sense signals are carried in wires which pass through the holes in the "links" of the chain. The memory elementth us formed will operate in a rotational switching mode and can be used for a word-organized memory. The results indicate both the advantages and the shortcomings of the device. Because of the complete flux closure, comparatively high output signal flux (200 mV-nsec) can be obtained from small, densely packaged devices which require less than 200 mA of word current and less than 100 mA of bit current. The chain shows high magnetic stability and can be operated in both a destructive and a nondestructive mode. The main problem is the difficulty in handling the delicate self-supporting magnetic devices, for testing, packaging, and wiring; this difficulty determines the limit of miniaturization. Experimental results, including a large-scale reproducibility study, verify theoretical expectations.

We have measured ‘‘in situ’’ the stresses generated in polyimide films produced from the ethyl ester of benzophenone tetracarbolic acid and methylene dianiline during the curing cycle. The room temperature stress in a fully cured film (to 400 °C) is approximately 70 MPa. The stresses at room temperature vary with the cure temperature and are due to coefficient of thermal expansion mismatch between film and substrate. The in situ measurements show that the glass transition temperature is the same as the maximum cure temperature that the film experiences. The stress measurements were made using an x‐ray double crystal lattice curvature technique.