Abstract: A plurality of semiconductor devices are provided on a carrier for testing or burning-in. The carrier is then cut up to provide single chip-on-carrier components or multi-chip-on-carrier components. The carrier is used as a first level package for each chip. Thus, the carrier serves a dual purpose for test and burn-in and for packaging. A lead reduction mechanism, such as a built-in self-test engine, can be provided on each chip or on the carrier and is connected to contacts of the carrier for the testing and burn-in steps. The final package after cutting includes at least one known good die and may include an array of chips on the carrier, such as a SIMM or a DIMM. The final package can also be a stack of chips each mounted on a separate carrier. The carriers of the stack are connected to each other through a substrate mounted along a side face of the stack that is electrically connected to a line of pads along an edge of each carrier.

Abstract: A screen printing fixture holds a flexible circuit board having components attached to one side, to allow screening a pattern of solder paste onto the second side for subsequent attachment of components to that side. In an electronic package assembly a flexible circuit board with components is wound about a heat spreader assembly having a cavity so that at least one component on the flexible circuit board is positioned within the cavity and in thermal connection to the heat spreader.

Abstract: A multi-layer flexible circuit board has thicker regions to which surface-mount-technology (SMT) components (such as flip chips and QFPs) and pin-in-hole (PIH) components are mounted on both sides and which contains conductive through vias between wiring layers. After the SMT components have been mounted to the first side, a screening fixture with a support surface that has cavities conforming the components on the first side, is used to screen solder paste to the other side of the board. The thicker regions are surrounded by thinner regions of the board with fewer wiring layers and preferably fewer or thinner dielectric layers, and which can be bent along a line without bending the thicker regions. A common heat spreader plate with cavities or holes for multiple components is laminated to the thicker regions on one side of the board. The thicker regions have windows in which wire-bond chips are mounted to the heat spreader and the chips are wirebonded to the other side of the board.

Abstract: A screen printing machine comprising a backing plate with holes conforming to components attached to the surface of a flexible circuit board. The machine includes a screen which patterns solder paste on the surface of the circuit board while the circuit board is on the backing plate. Also included is a spring loaded element disposed adjacent to the backing plate which applies a predetermined continuous force to the four corners of the circuit board. This force is applied in a diagonal direction to the corners to stretch the circuit board so that the circuit board is parallel to the backing plate during screening.

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.

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.

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 bonding agent injection head which includes a wiping guide, a blade which cooperates with the wiping guide to form an elongate nozzle slit, and an evacuation path ahead of the nozzle slit in a direction of movement of the 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 evacuation path ahead of the nozzle slit lets air out of the cavity openings as the cavity openings are filled with bonding agent. The injection head is then removed from the surface of the mask.