Abstract: A preformed planar structure is interposed between the chip(s) and the substrate in a flip-chip structure, and establishes a minimum gap between the chip(s) and the substrate. Liquid flux may be applied to the preformed planar structure in order that flux is selectively applied to the solder balls (pads) on the chip and the substrate. The preformed planar structure may be provided with through holes in registration with the solder balls on the chip(s) and the substrate. In this case, liquid flux selectively fills the through holes for delivery to the solder balls during soldering. The through holes also aid in maintaining registration of the chip(s) and the substrate. The through holes may be sized to establish a predetermined mechanical structure of solder joints formed by the solder balls when fused together. The preformed planar structure has a planar core and opposing planar faces.

Abstract: A preformed planar structure is interposed between the chip(s) and the substrate in a flip-chip structure, and establishes a minimum gap between the chip(s) and the substrate. Liquid flux may be applied to the preformed planar structure in order that flux is selectively applied to the solder balls (pads) on the chip and the substrate. The preformed planar structure may be provided with through holes in registration with the solder balls on the chip(s) and the substrate. In this case, liquid flux selectively fills the through holes for delivery to the solder balls during soldering. The through holes also aid in maintaining registration of the chip(s) and the substrate. The through holes may be sized to establish a predetermined mechanical structure of solder joints formed by the solder balls when fused together. The preformed planar structure has a planar core and opposing planar faces.

Abstract: A preformed planar structure is interposed between the chip(s) and the substrate in a flip-chip structure, and establishes a minimum gap between the chip(s) and the substrate. Liquid flux may be applied to the preformed planar structure in order that flux is selectively applied to the solder balls (pads) on the chip and the substrate. The preformed planar structure may be provided with through holes in registration with the solder balls on the chip(s) and the substrate. In this case, liquid flux selectively fills the through holes for delivery to the solder balls during soldering. The through holes also aid in maintaining registration of the chip(s) and the substrate. The through holes may be sized to establish a predetermined mechanical structure of solder joints formed by the solder balls when fused together. The preformed planar structure has a planar core and opposing planar faces.

Abstract: A preformed planar structure is interposed between the chip(s) and the substrate in a flip-chip structure, and establishes a minimum gap between the chip(s) and the substrate. Liquid flux may be applied to the preformed planar structure in order that flux is selectively applied to the solder balls (pads) on the chip and the substrate. The preformed planar structure may be provided with through holes in registration with the solder balls on the chip(s) and the substrate. In this case, liquid flux selectively fills the through holes for delivery to the solder balls during soldering. The through holes also aid in maintaining registration of the chip(s) and the substrate. The through holes may be sized to establish a predetermined mechanical structure of solder joints formed by the solder balls when fused together. The preformed planar structure has a planar core and opposing planar faces.

Abstract: A gate array is provided in which active areas within the substrate are arranged in alternating columns of opposite conductivity type and symmetrical about the center lines through each column so that CMOS devices can be advantageously formed by allocating only small increments of active area to metal routing. The substrate and well taps are also symmetrical about the column center line. The active area symmetry allows p-channel and n-channel transistors to be combined where the p-channel transistor is on either the right or left, thus increasing the flexibility in placing the elements within the integrated circuit chip.