Cray Research, Inc.

Control Data Corporation

Carl D Breske

Nicholas J Krajewski

William T Moore, Jr

David J Johnson

Kent T McDaniel

Bricky A Stephenson

David R Kiefer

Jeffrey M Borning

Michael R Edwards

Anthony A Vacca

The invention comprises a plurality of stacked planar processing circuit boards surrounded on at least one side by a plurality of memory boards located substantially perpendicular to the planar processing boards, the processing and memory boards connected by orthogonal interconnect modules. The orthogonal interconnect modules allow closely-spaced orthogonal connection of the processing boards to the memory boards. The memory boards are of a densely packed design having a plurality of removeable memory chip stacks located on the memory boards.

High density interconnect apparatus

A solder/desolder tool has a heater block supporting a handle at its upper end and a heating plate at its lower end. The heating plate is thermally engaged by heating elements housed in the heater block. An array of pin relief apertures are formed in the heating plate. Retractable clamps are pivoted to the heater block for clamping a leadless chip against the heating plate. The leadless chip has an array of input/output sockets corresponding to the array of pin relief apertures. A method is disclosed for soldering the chip sockets to a corresponding array of pins supported by a PC board. According to the method, solder balls are loaded in the chip sockets, and the chip is then secured in the tool to reflow the solder balls to form solder plugs. The solder plugs are then set upon the upper ends of the pins and melted by the heating plate so that solder joints are formed between the pins and sockets. The chip is released from the tool to allow the solder joints to cool. A desoldering method is disclosed wherein the tool is secured to a chip which is in a soldered condition (i.e., the chip sockets are soldered to the pins). The heating plate applies heat to the solder joints about the individual circumferences of the pins. Once the solder joints reach reflow temperature, the chip can be removed from the pins.

Process for soldering and desoldering apertured leadless packages

Device for soldering/desoldering apertured lendless packages

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Scandia, MN, United States of America

Carl D Breske