Abstract:
A structure that adhesively couples a chip to an organic chip carrier. The chip is attached to a top surface of the organic chip carrier by interfacing a solder bump between a C4 solder structure on the chip and a pad on a top surface of the chip carrier. The melting temperature of the solder bump is less than the melting temperature of the C4 solder structure. A block of ferrous material is on a top surface of the chip. A temporary or permanent stiffener of ferrous material is on the top surface of the chip carrier. A permanent magnet is coupled to a bottom surface of the chip carrier. Alternatively, an electromagnetic could be utilized instead of the electromagnet. Due to the permanent magnet or the electromagnet, a magnetic force on the stiffener is directed toward the magnet and substantially flattens the first surface of the chip carrier. Similarly, a magnetic force on the block is directed toward the magnet such that the electronic component and the chip carrier are held in alignment. After the solder bump has been reflowed at a temperature between the melting temperature of the solder bump and the melting temperature of the C4 solder structure, the solder bump is reconfigured. The magnetic force on the block frictionally clamps the reflowed solder between the C4 solder structure and the pad. After the chip and carrier are cooled, the C4 solder structure is adhesively and conductively coupled to the pad.
Abstract:
A method and device for testing and burning-in semiconductor circuits. The method and device permit the entire wafer to be tested by temporarily attaching the wafer to a test substrate using electrically conductive adhesive (ECA). The ECA conforms to deviations from co-planarity of the contact points of both the wafer and test substrate while providing a quality electrical connection at each point. ECA material can be deposited on either the wafer contacts or the substrate pads. In addition, the ECA may be deposited on C4 bumps or tin-capped lead bases. Variations in the method and device include filling vias of a non-conductive interposer with ECA. The electrical connection may be enhanced by forming conductive dendrites on test pads while the ECA is deposited on the wafer contacts. To further enhance the electrical connection, the ECA material can be plasma etched to remove some of its polymer matrix and to expose the electrically conductive particles on one side and then plating with palladium. After the palladium-plated ECA is brought into contact with aluminum pads, palladium-coated aluminum pads, or even C4 solder bumps, conductive dendrites are formed on the palladium-treated ECA bumps.
Abstract:
A system for aligning and attaching together a plurality of thin film transistor tiles for constructing a flat panel display. A coverplate loading station where a coverplate that the tiles are to be attached to is arranged on a coverplate support. A coverplate bonding material dispensing station where a bonding material for bonding the tiles to the coverplate is applied to a surface of the coverplate. A tile placement station where the tiles are arranged on the coverplate. A tile aligning and securing station where the tiles are aligned relative to each other and the coverplate by the tile aligner and where the tiles are at least partially bonded to the coverplate. A tile assembly bonding material dispensing station where a bonding material is applied to a surface of the tiles opposite the side that the coverplate is bonded to. A backplate placement station where a backplate is arranged on the tiles. A backplate aligning and securing station where the backplate is aligned with the tiles and the coverplate and at least partially secured to the tiles A full bonding station where the tiles are fully bonded to the coverplate and the backplate.
Abstract:
A multi-layer flexible circuit board has multiple thicker regions to which components are mounted and thinner, more flexible regions with fewer wiring layers through which the board can be bent about a line without bending thicker regions. Surface mount components such as QFP's and flip-chips are mounted on the front side, and surface mount and pin-in-hole components are mounted on the back side of the circuit board at the thick regions. Heat spreaders are laminated to the back sides of thicker regions. The thicker regions have windows in which wire bond chips are mounted on the heat spreader and wire bonded to the front side of the board. A thermally conductive adhesive or grease connects between the tops of the back side components and the bottoms of the cavities. The heat sinks are bolted together and/or to an enclosure frame to improve thermal performance.
Abstract:
A method of applying bonding agents, such as solder pastes and conductive adhesives, to pad sites in the manufacture of electronic circuits uses a paste injection head. A permanent mask with cavity openings is applied around conductive pads on a carrier. The conductive pads correspond to chip attachment sites. The injection head is brought into contact with a surface of the mask, and pressure is applied to a bonding agent in the injection head. The injection head is then moved over the surface of the mask, filling cavity openings with the bonding agent. The injection head is then removed from the surface of the mask. If a solder paste is used, infrared radiation is applied to filled cavity openings to evaporate a paste flux and reflow solder to form solder balls within the cavity openings projecting above the mask. If a conductive adhesive is used, a stencil is applied to the surface of the mask prior to contacting the mask with said injection head. When the cavity openings are filled, stencil is removed from the mask and the conductive adhesive filling the cavity openings is dried.
Abstract:
A method and apparatus for testing semi-conductor chips is disclosed. The individual semiconductor chips have I/O contacts. The apparatus is provided with an interposer that has contacts corresponding to the contacts on the semiconductor chip. Both the chip and the interposer contacts can be any known type including metal ball, bumps, or tabs or may be provided with dendritic surfaces. The chip contacts are first brought into relative loose temporary contact with the contacts on the interposer and then a compressive force greater that 5 grams per chip contact is applied to the chip to force the chip contacts into good electrical contact with the interposer contacts. Testing of the chip is then performed. The tests may include heating of the chip as well as the application of signals to the chip contacts. After testing the chip is removed from the substrate.
Abstract:
A method of testing semi-conductor chips is disclosed. The individual semiconductor chips have I/O, power, and ground contacts. In the method of the invention a chip test fixture system is provided. The chip test fixture system has contacts corresponding to the contacts on the semiconductor chip. The carrier contacts have dendritic surfaces. The chip contacts are brought into electrically conductive contact with the conductor pads on the chip test fixture system. Test signal input vectors are applied to the inputs of the semiconductor chip, and output signal vectors are recovered from the semiconductor chip. After testing the chip is removed from the substrate.
Abstract:
Disclosed is a transfer container for carrying circuit panels in and between substantially contaminant free environments. The walls of the transfer container are fabricated out of substantially particulate free, unfilled polymers, such as polycarbonate. One of the end walls is an access wall. The access wall has an opening surrounded by a ferromagnetic gasket. This gasketed opening is adapted to receive a ferromagnetic door panel. The side walls, and the top and bottom walls may extend beyond the access wall, with the ends of said walls defining a plane, so that the access wall is recessed with respect to the plane defined by the said extensions. Each of the side walls have co-planar bracket pairs for holding circuit panels. Either one of, or preferably both brackets of a bracket pair have pyramidal or conical positioning pins. These pins extend upwardly from the brackets and are adapted to receive and hold a workpiece in place.
Abstract:
An electronic component insertion apparatus having an inserter assembly rotatable from a drive position to a feed position where a feeding subassembly feeds a component along the longitudinal axis of the inserter assembly into the inserter and subsequently the inserter assembly is rotated back to the drive position where it is driven along its longitudinal axis to insert the component into a circuit board.