Abstract:
A method of fabricating a microelectronic package comprising an expandable structure includes the steps of providing first and second microelectronic elements having electrically conductive parts, providing the expandable structure between the microelectronic elements, connecting the electrically conductive parts together so that the microelectronic elements are electrically interconnected, and expanding the expandable structure after the connecting step so that the microelectronic elements move away from one another. The expandable structure is more rigid before the expanding step and less rigid after the expanding step. During the expanding step, the expandable structure remains in contact with the microelectronic elements and the microelectronic elements remain electrically interconnected. A microelectronic package including an expandable structure is also disclosed.
Abstract:
A method of providing a substantially void free layer for one or more flip chip assemblies, or one or more microelectronic components, utilizing a curable encapsulant. Also disclosed is a method of injecting an encapsulant into an assembly and a method of treating a microelectronic component to form a void free layer.
Abstract:
A method of making a contact having a wear resistant edge by forming a photoresist layer on a copper clad polyimide composite structure, patterning the photoresist layer to expose a portion of the copper; etching the copper to form a contact and/or contact tabs having etched edges, and plating a wear resistant material on the etched edges. After the photoresist layer is stripped, the top portion of the contact and/or contact tabs are etched to height that is below the height of the wear resistant edge.
Abstract:
A method of making a compliant microelectronic assembly includes providing a microelectronic element having a first surface, the first surface having a central region and a peripheral region surrounding the central region, the microelectronic element including a plurality of contacts disposed in the central region and providing a compliant layer over the peripheral region of the first surface, the compliant layer having a bottom surface facing toward the first surface of the microelectronic element, a top surface facing upwardly away from the microelectronic element and one or more edge surfaces extending between the top and bottom surfaces. Next, flexible bond ribbons are selectively formed over the compliant layer so that the bond ribbons extend over the top surface and one or more of the edge surfaces and the bond ribbons electrically connect the contacts to conductive terminals overlying the top surface of the compliant layer.
Abstract:
An interposer for interconnection between microelectronic circuit panels has contacts at its surfaces. Each contact has a central axis normal to the surface and a peripheral portion adapted to expand radially outwardly from the central axis responsive to a force applied by a pad on the engaged circuit panel. Thus, when the circuit panels are compressed with the interposers, the contacts expand radially and wipe across the pads. The wiping action facilitates bonding of the contacts to the pads, as by conductive bonding material carried on the contacts themselves.
Abstract:
A connector for microelectronic elements includes electrically conductive, elongated leads having contact portions underlying a compliant layer. The contact portion of each lead overlies a pedestal portion of the compliant layer. The pedestal portion is at least partially isolated from the remaining portion of the compliant layer by gaps in the compliant layer. The pedestals may thus deflect horizontally, compensating for relative movement between the connector and the microelectronic element. Portions of the leads spanning the gaps may be curved to facilitate deflection. The pedestals may be attached to a substrate having terminals. A terminal end of each lead is then electrically connected to the terminal in the substrate, either through a plated through-hole, or by bending downward and bonding. The pedestals may support a plurality of leads along their length. Alternatively, the pedestals may support only a single respective lead, in which case the pedestal is isolated from neighboring pedestals and may deflect in a plurality of horizontal directions.
Abstract:
A testing fixture for microelectronic elements is in the nature of an interposer which is operative for receiving a plurality of test probes. The interposer enables the simultaneous testing of contacts on the microelectronic element which are arranged in both high contact pitch density areas and normal contact pitch density areas. The contacts on the microelectronic element within the high contact pitch density areas are accessed by conductive leads on the interposer having rigid portions arranged in a corresponding high contact pitch density.
Abstract:
Microelectronic contacts, such as flexible, tab-like, cantilever contacts, are provided with asperities disposed in a regular pattern. Each asperity has a sharp feature at its tip remote from the surface of the contact. As mating microelectronic elements are engaged with the contacts, a wiping action causes the sharp features of the asperities to scrape the mating element, so as to provide effective electrical interconnection and, optionally, effective metallurgical bonding between the contact and the mating element upon activation of a bonding material.
Abstract:
A method of encapsulating a microelectronic assembly includes providing one or more microelectronic assemblies having one or more elements defining exterior surfaces and an array of terminals exposed at the exterior surfaces, the one or more elements defining one or more apertures through the exterior surfaces. A layer of a curable barrier material is then provided on a supporting element. The barrier layer has openings therein in a pattern corresponding to the array of terminals on the one or more microelectronic assemblies. The supporting element and the one or more microelectronic elements are then assembled together so that the layer of barrier material contacts the exterior surfaces and covers the apertures and so that the openings in the layer of barrier material are aligned with the terminals. The barrier material is then cured while in contact with the exterior surfaces to thereby form a barrier layer covering the apertures. Next, a curable liquid encapsulant is applied to the microelectronic assemblies, whereby the barrier layer prevents the curable liquid encapsulant from flowing through the apertures, and the encapsulant is cured. The barrier layer and the supporting element cooperatively surround the terminals exposed at the exterior surfaces to protect the terminals from contaminants.
Abstract:
A method of encapsulating a microelectronic assembly includes providing one or more microelectronic assemblies having one or more elements defining exterior surfaces and an array of terminals exposed at the exterior surfaces, the one or more elements defining one or more apertures through the exterior surfaces. A layer of a curable barrier material is then provided on a supporting element. The barrier layer has openings therein in a pattern corresponding to the array of terminals on the one or more microelectronic assemblies. The supporting element and the one or more microelectronic elements are then assembled together so that the layer of barrier material contacts the exterior surfaces and covers the apertures and so that the openings in the layer of barrier material are aligned with the terminals. The barrier material is then cured while in contact with the exterior surfaces to thereby form a barrier layer covering the apertures. Next, a curable liquid encapsulant is applied to the microelectronic assemblies, whereby the barrier layer prevents the curable liquid encapsulant from flowing through the apertures, and the encapsulant is cured. The barrier layer and the supporting element cooperatively surround the terminals exposed at the exterior surfaces to protect the terminals from contaminants.