Abstract:
The present invention provides a number of interrelated methods for the production of random and ordered arrays of particles and recesses, as well as films containing such arrays and recesses. The present invention also relates to the random and ordered arrays of particles and films prepared therefrom. The ordered arrays are obtained by the use of ferrofluid compositions which may be curable, solidifiable or non-curing/non-solidifiable. The arrays and films may contain electrically-conductive particles useful in electronic applications for effecting contact between leads or pads.
Abstract:
Disclosed is an anisotropic conductive adhesive (10) having an adhesive layer (12) and conductive particles (16) individually adhered to the adhesive layer, the conductive particles being arranged in an ordered array. The size of the conductive particles is at least somewhat smaller than the thickness of the adhesive layer. Also disclosed is an anisotropic conductive adhesive having an adhesive layer, conductive particles individually adhered to the adhesive layer, and a release liner (28) having an ordered array of dimples (24). The conductive particles reside in a single layer in the dimples. The anisotropic conductive adhesive is made by placing the conductive particles in an ordered array of dimples on a low adhesion surface. An adhesive layer is then laminated on top such that the conductive particles individually adhere to the adhesive layer. The anisotropic conductive adhesive may be used to electrically connect fine pitch electrodes on opposing circuit layers.
Abstract:
The invention relates to a method of making a multi-layer circuit assembly. Said method comprises the steps of providing a first circuit panel (544) having a dielectric body with oppositely directed top and bottom surfaces, contacts (538) on its top surface at locations of a first pattern, terminals (530) on its bottom surface, and through-conductors (527) electrically connected to said terminals and extending to the top surface of the panel, and a second circuit panel (562) having a dielectric body with a bottom surface and terminals (530) at locations of said first pattern on the bottom surface of such panel, said providing step including the step of customizing said first circuit panel by selectively treating the top surface of such panel so that less than all of the through conductors of such panel are connected to contacts of such panel; stacking said circuit panels in superposed, top-surface to bottom surface relation so that the top surface of said first circuit panel faces the bottom surface of said second circuit panel at a first interface and said first patterns on said facing surfaces are in registration with one another, with said contacts of said first panel being aligned with said terminals of said second panel at least some locations of said inregistration patterns; and non-selectively connecting all of said aligned contacts and terminals at said interface, whereby less than all of said through conductors of said customized panel are connected to terminals of said adjacent panel. The invention also relates to a multi-layer circuit assembly.
Abstract:
Electronic devices having at least two components (53,55) with mating contact pads (52,54) are provided with high-aspect-ratio solder joints between the mating pads. These joints are formed by placing a composite solder medium (51) containing solder wires (56) in an electrically insulating matrix (57) such that at least two solder wires (56) are in contact with the mating pads (52,54), and fusing the wires (56) to the pads. The insulating matrix (57) with remainder of solder wires (56) is then optionally removed from between the said at least two components (53,55). The composite solder medium (51) is formed by preparing an elongated body of solder wires in an insulating matrix and cutting off slices of the composite solder medium, the solder wires having a high-aspect-ratio of length to their diameter. Alternatively sheets of the composite solder medium are prepared by magnetically aligning solder coated magnetic particles into columns arranged transverse of an insulating matrix and heating sufficiently to fuse the solder in each column into a continuously conducting solder path.
Abstract:
In accordance with the invention, a high density z-direction interconnection medium is made by the steps of providing a non-conductive membrane having z-direction channels, filling the channels with liquid precursor of conductive material, converting the trapped precursor into conductive material within the channels, and, advantageously, forming solder bumps in contact with the conductive material in the channels. The method is particularly useful for forming hollow tubular or porous conductive pathways having enhanced resistance to thermal and mechanical stress. The channels can be conveniently filled by vacuum suction,
Abstract:
The present invention provides a method for providing an array of metal microbeads on a substrate, preferably in a regular pattern of very fine, uniform size microspheres or microbeads at precise spacing or scale previously unachievable. The method of the present invention comprises the steps of providing a metal layer (14) on a substrate (12) that is partitioned into metal regions (20); heating the metal layer to a temperature sufficient to melt the metal and to permit beading of the layer into discrete microbeads (22).
Abstract:
The process for producing subsequently contactable contact points between two conductive track planes on a circuit substrate separated by an electrically insulating layer makes it possible to produce, for example, a basic conductor pattern which can subsequently be easily adapted to requirements. By laying windows in the conductive track planes out in such a way that, when the electrically insulating layer is subsequently through-etched due to under-etching, rod-like parts connected to the aperture periphery are revealed between or in the apertures which can be brought into contact with electrically conductive parts of the other conductive track plane, these conductive tracks can be electrically interconnected by mechanical bending.