Abstract:
An electronic device comprising a semiconductor chip which is fixed to the mounting face of a wiring board through an adhesive and in which external terminals are electrically connected with electrode pads of the wiring board through bump electrodes. Recesses are formed in the electrode pads, and in the recesses the electrode pads and the bump electrodes are connected. The electrode pads are formed over the surface of a soft layer, and the recesses are formed by elastic deformation of the electrode pads and the soft layer.
Abstract:
A semiconductor chip package structure for providing a reliable interface between a semiconductor chip and a PWB to accommodate for the thermal coefficient of expansion mismatch therebetween. The interface between a chip and a PWB is comprised of a package substrate having a plurality of compliant pads defining channels therebetween. The package substrate is typically comprised of a flexible dielectric sheet that has leads and terminals on at least one surface thereof. The pads have a first coefficient of thermal expansion (“CTE”) and are comprised of a material having a fairly low modulus of elasticity. An encapsulant having a second CTE lower than the CTE of the compliant pads is disposed within the channels to form a uniform encapsulation layer. The pads are in rough alignment with the conductive terminals on the package substrate thereby allowing independent movement of the terminals during thermal cycling of the chip. The encapsulant encases the conductive leads electrically connecting the terminals to chip contacts on a face surface of the chip. The lower CTE of the encapsulant controls the flexing of the conductive leads so that the leads do not prematurely fatigue and become unreliable while the lower modulus compliant pads relieve the stress on the solder balls induced by the CTE mismatch of the chip and the PWB.
Abstract:
A microelectronic connection component includes a dielectric sheet having an area array of elongated, strip-like leads. Each lead has a terminal end fastened to the sheet and a tip end detachable from the sheet. Each lead extends horizontally parallel to the sheet, from its terminal end to its tip end. The tip ends are attached to a second element, such as another dielectric sheet or a semiconductor wafer. The first and second elements are then moved relative to one another to advance the tip end of each lead vertically away from the dielectric sheet and deform the leads into a bent, vertically extensive configuration. The preferred structures provide semiconductor chip assemblies with a planar area array of contacts on the chip, an array of terminals on the sheet positioned so that each terminal is substantially over the corresponding contact, and an array of metal S-shaped ribbons connected between the terminals and contacts. A compliant dielectric material may be provided between the sheet and chip, substantially surrounding the S-shaped ribbons.
Abstract:
A printed circuit board has a plastic carrier plate and a one-piece pressed screen forming interconnects of the electrical circuit that are firmly mechanically connected to one another via preferably hot-stamped or ultrasound-deformed plastic webs. The interconnects have connector tabs bent off at a right angle and contact tabs for contacting the plug-in base and the relays to be accepted and also have stamped-out contact profiles for the connection to electrical components. The plugged-on relays and components are preferably connected to the interconnects welding. A two-sided access to parting locations in the pressed screen is made for tools on the basis of recesses in the carrier plate.
Abstract:
The present invention provides an interconnection scheme having compliant contacts arranged in an array to connect conductive surfaces on a microelectronic device and a supporting substrate, such as a printed circuit board. This invention accommodates for the difference in thermal coefficients of expansion between the device and the supporting substrate. Typically, an area array of conductive contact pads are connected into rows by conductive leads on a flexible, intermediate substrate. Each of the conductive leads bridges a bonding hole in the intermediate substrate which is situated between successive contact pads. Each of the conductive leads further has a frangible portion within or near each bonding hole. A stand-off between the intermediate substrate and the device is create by compliant dielectric pads, typically composed of an elastomer material, positioned under each contact pad. The frangible portions allow the leads to be cleanly broken, bent and secured into electrical contact with mating contact pads on the device. Each of these connections may be supported by a compliant layer, typically an uncured elastomer which fills the area around the dielectric pads and is then cured.
Abstract:
A method of making a multiple part compliant interface for a microelectronic package including the steps of providing a first microelectronic element having electrically conductive parts, providing an array of curable elastomer support pads in contact with the first microelectronic element, curing the curable elastomer support pads while the support pads remain in contact with the first microelectronic element and providing an array of adhesive pads in contact with the support pads, whereby each adhesive pad is disposed over and in substantial alignment with one of the support pads. A second microelectronic element having electrically conductive parts is then assembled in contact with the array of adhesive pads by abutting the second microelectronic element against the array of adhesive pads and compressing the adhesive pads and support pads between the first and second microelectronic elements. The array of adhesive pads are then cured and the electrically conductive parts of the first and second microelectronic elements are interconnected. The array of support pads define channels running between any two adjacent support pads. A flowable curable elastomer encapsulant may be disposed within the channels after the electrically connecting step. Preferably, the support pads, adhesive pads and the encapsulant comprise substantially similar materials, such as silicone, in order to avoid problems associated with thermal cycling, such as air entrapment and/or voiding.
Abstract:
In a method for mounting a sheet-like multi-layer element for producing a microelectronic component, the sheet-like element is first bonded to an expansion ring. The expansion ring is then heated to stretch the sheet-like element. A frame ring, having an external diameter smaller than the internal diameter of the expansion ring, is then bonded to the sheet-like element. The assembly is then cooled, and the expansion ring is cut away. In another embodiment, a method is provided for bonding bond pads on a sheet-like microelectronic element to terminal pads on a microelectronic component. The microelectronic element is first placed on a rigid plate and the sheet-like element, which has been bonded to a frame ring, is placed over the microelectronic component. A disk is then placed on the sheet-like element, and force is applied to the disk, bringing the bond pads on the sheet-like element into contact with the terminal pads on the microelectronic element. Heat is then applied, forming the bonds.
Abstract:
A branch junction box containing a flexible printed circuit sheet includes circuit terminals and other parts which are easily mounted. A first insulation plate is provided on one of its faces, with a plurality of printed circuit terminals vertically fixed therethrough. On its other face, the first insulation plate carries a flexible printed circuit sheet, the printed circuit of which is electrically connected to the circuit terminals. The surface of the insulating plate facing the circuit terminals may be provided with bus bar wiring patterns and corresponding bus bar terminals. These circuit terminals and bus bar terminals are branch-connected to wiring harnesses in a proper and reliable way through connectors formed in the casing of the box.
Abstract:
In the case of the conductor film (4) resting on a base the contact conductor tracks are arranged on a tab attachment (5) so as to run parallel to each other. Furthermore, in the base an open shaft (6) which runs obliquely downward is provided, on whose obliquely sloping bottom surface the tab attachment (5) with the contact conductor tracks which are free at the top comes to rest. For making contact, a plug socket, together with its contact spring element (8) passed outward and facing the bottom surface of the shaft (6), is inserted into the shaft (6) in the direction of the free tab end and is fastened in the end position in a locking manner.
Abstract:
A bus bar of a branch joint box, which is formed by punching a metal sheet into a preset pattern of a circuit and is formed, at a predetermined location of the circuit, with a tab to be plated with metal having excellent electrical conductivity such that a connector of a wiring harness is connected to the tab through plug-in, including a separate bus bar portion which is formed by punching a separate metal sheet and includes the tab; wherein after the tab of the separate bus bar portion has been plated with the metal, the separate bus bar portion is inserted into a predetermined portion of the bus bar so as to be mounted on the bus bar.