Abstract:
The present invention stacks packaged integrated circuits into modules that conserve PWB or other board surface area. The present invention can be used to advantage with packages of a variety of sizes and configurations ranging from larger packaged base elements having many dozens of contacts to smaller packages such as, for example, die-sized packages such as DSBGA. In a preferred embodiment devised in accordance with the present invention, a base element CSP integrated circuit and a support element CSP integrated circuit are aggregated through a flex circuit having at least two conductive layers that are patterned to selectively connect the two CSP elements. A portion of the flex circuit connected to the support element is folded over the base element to dispose the support element above the base element while reducing the overall footprint. The flex circuit provides a thermal and electrical connection path between the module and an application environment such as a printed wiring board (PWB).
Abstract:
The present invention stacks chip scale-packaged integrated circuits (CSPs) into modules that conserve PWB or other board surface area. Multiple numbers of CSPs may be stacked in accordance with the present invention. The CSPs employed in stacked modules devised in accordance with the present invention are connected with flex circuitry. A form standard is disposed along a planar surface of a CSP. The form standard provides a physical form that allows many of the varying package sizes found in the broad family of CSP packages to be used to advantage while employing a standard connective flex circuitry design. The form standard achieves a reduced profile after the CSP has been attached to the form standard. In addition, in constructing modules in accordance with some preferred modes of the invention, CSP contacts are reduced in height to create lower profile modules. Thus, low profile embodiments of the modules of the present invention are devised.
Abstract:
Flexible circuitry is populated with integrated circuitry disposed along one or both of its major sides. Contacts distributed along the flexible circuitry provide connection between the module and an application environment. The circuit-populated flexible circuitry is disposed about an edge of a rigid substrate thus placing the integrated circuitry on one or both sides of the substrate with one or two layers of integrated circuitry on one or both sides of the substrate. The substrate form is preferably devised from thermally conductive materials and includes a high thermal conductivity core or area that is disposed proximal to higher thermal energy devices such as an AMB when the flex circuit is brought about the substrate. Other variations include thermally-conductive clips that grasp respective ICs on opposite sides of the module to further shunt heat from the ICs. Preferred extensions from the substrate body or substrate core encourage reduced thermal variations amongst the integrated circuits of the module.
Abstract:
The present invention stacks integrated circuits into modules that conserve board surface area. In a precursor assembly devised as a component for a stacked circuit module in accordance with a preferred embodiment of the present invention, one or more stiffeners are disposed at least partially between a flex circuit and an integrated circuit. In a two-high stacked circuit module devised in accordance with a preferred embodiment of the present invention, an integrated circuit is stacked above a precursor assembly. The two integrated circuits are connected with the flex circuit of the precursor assembly. The present invention may be employed to advantage in numerous configurations and combinations of integrated circuits in modules.
Abstract:
The present invention stacks integrated circuits into modules that conserve board surface area. In a precursor assembly devised as a component for a stacked circuit module in accordance with a preferred embodiment of the present invention, one or more stiffeners are disposed at least partially between a flex circuit and an integrated circuit. In a two-high stacked circuit module devised in accordance with a preferred embodiment of the present invention, an integrated circuit is stacked above a precursor assembly. The two integrated circuits are connected with the flex circuit of the precursor assembly. The present invention may be employed to advantage in numerous configurations and combinations of integrated circuits in modules.
Abstract:
An IC die and a flexible circuit structure are integrated into a lower stack element that can be stacked with either further integrated lower stack element iterations or with pre-packaged ICs in any of a variety of package types. A die is positioned above the surface of portions of a pair of flex circuits. Connection is made between the die and the flex circuitry. A protective layer is formed to protect the flex-connected die and its connection to the flex. Connective elements are placed along the flex circuitry to create an array of module contacts along the second side of the flex circuitry. The flex circuitry is positioned above the body-protected die to create an integrated lower stack element. The integrated lower stack element may be stacked either with iterations of the integrated lower stack element or with a pre-packaged IC to create a multi-element stacked circuit module.
Abstract:
A circuit module that includes a system for reducing thermal variation and cooling the circuit module. In preferred embodiments, the module includes a thermally-conductive rigid substrate having first and second lateral sides, an edge, and an integrated cooling component. The integrated cooling component reduces thermal variation and cools the circuit module. Flex circuitry populated with a plurality of ICs and exhibiting a connective facility that comprises plural contacts for use with an edge connector is wrapped about the edge of the thermally-conductive substrate. Heat from the plurality of ICs is thermally-conducted by the thermally-conductive substrate to the integrated cooling component.
Abstract:
The present invention provides a system and method for employing leaded packaged memory devices in memory cards. Leaded packaged ICs are disposed on one or both sides of a flex circuitry structure to create an IC-populated structure. In a preferred embodiment, leads of constituent leaded IC packages are configured to allowed the lower surface of the leaded IC packages to contact respective surfaces of the flex circuitry structure. Contacts for typical embodiments are supported by a rigid portion of the flex circuitry structure and the IC-populated structure is disposed in a casing to provide card structure for the module.
Abstract:
The present invention provides a system and method that amounts integrated circuit devices onto substrates and a system and method for employing the method in stacked modules. The contact pads of a packaged integrated circuit device are substantially exposed. A solder paste that includes higher temperature solder paste alloy is applied to a substrate or to the integrated circuit device to be mounted. The integrated circuit device is positioned to contact the contacts of the substrate. Heat is applied to create high temperature joints between the contacts of the substrate and the integrated circuit device resulting in a device-substrate assembly with high temperature joints. The formed joints are less subject to re-melting in subsequent processing steps. The method may be employed in devising stacked module constructions such as those disclosed herein as preferred embodiments in accordance with the invention. Typically, the created joints are low in profile.
Abstract:
A combination composed from a form standard and a CSP is attached to flex circuitry. Solder paste is applied to first selected locations on the flex circuitry and adhesive is applied to second selected locations on the flex circuitry. The flex circuitry and the combination of the form standard and CSP are brought into proximity with each other. During solder reflow operation, a force is applied that tends to bring the combination and flex circuitry closer together. As the heat of solder reflow melts the contacts of the CSP, the combination collapses toward the flex circuitry displacing the adhesive as the solder paste and contacts merge into solder joints. In a preferred embodiment, the form standard will be devised of heat transference material, a metal, for example, such as copper would be preferred, to improve thermal performance. In other embodiments, the methods of the invention may be used to attach a CSP without a form standard to flex circuitry.