Abstract: A method of characterizing an object includes determining a depth-wise composition of the object at a measurement site within the object. A property of the object within a region adjacent to the measurement site can, optionally, be estimated based on the determining. Another method of characterizing an object includes disposing at least a portion of an object within a measurement region of a metrology tool, aligning a feature of the object and a location of a designated measurement site within the measurement region relative to each other, and performing a performing a compositional analysis of a portion of the object occupying the measurement site. Various apparatus for performing these methods are also disclosed, as are methods of monitoring manufacturing processes based on these methods.

Abstract: A method for concentrating and isolating nucleated cells, such as a maternal and fetal nucleated red blood cells (NRBC's), in a maternal whole blood sample. The invention also provides methods and apparatus for preparing to analyze and analyzing the sample for identification of fetal genetic material as part of prenatal genetic testing. The invention also pertains to methods and apparatus for discriminating fetal nucleated red blood cells from maternal nucleated red blood cells obtained from a blood sample taken from a pregnant woman.

Abstract: A method for concentrating and isolating nucleated cells, such as a maternal and fetal nucleated red blood cells (NRBC's), in a maternal whole blood sample. The invention also provides methods and apparatus for preparing to analyze and analyzing the sample for identification of fetal genetic material as part of prenatal genetic testing. The invention also pertains to methods and apparatus for discriminating fetal nucleated red blood cells from maternal nucleated red blood cells obtained from a blood sample taken from a pregnant woman.

Abstract: Methods for determining genetic status of a fetus from a sample of maternal blood comprise enriching nucleated red blood cells in the sample, including both fetal and maternal nucleated red blood cells. The nucleated red blood cells are then differentiated from all other blood cells in the enriched sample, and the nucleated red blood cells genetically screened to determine the genetic status. The nucleated red blood cells may be differentiated by immobilizing all enriched blood cells on a solid phase and locating the nucleated red blood cells for interrogation. Optionally, the nucleated red blood cells may be sorted and separated from other enriched blood cells in a liquid phase.

Abstract: A method and an apparatus are provided for selectively depositing flux on a plurality of flip-chip bumps arranged on a semiconductor chip by jet printing a flux pattern, which is substantially identical to the arrangement pattern of the flip-chip bumps. The flux pattern is determined by measuring the chip configuration and converting the configuration to computer-recognizable data. The converted chip configuration is stored in data storage, and a jet printing head prints the flux pattern based on the computer-recognizable data. A conveyance plate is provided to transport the semiconductor chip to a flux-deposition area below the jet printing head.

Abstract: A package assembly is formed by applying flux to a substrate and inspecting the applied flux to determine whether the amount applied is adequate to form reliable interconnections between a device and the substrate. Embodiments include applying a rosin based flux on a laminate substrate and inspecting the coverage of the applied flux by fluorescent spectroscopy.

Abstract: Residue contaminates semiconductor devices during processing in a furnace. Residue contamination is prevented by removing the residue before it builds up to a point where it can contaminate semiconductor devices. Residue build-up is monitored using a residue build-up monitoring device mounted on the furnace exhaust stack. When residue build-up reaches a predetermined level a signal is generated by the residue build-up monitoring device notifying technicians that furnace cleaning is required.

Abstract: A method of cleaning residue on surfaces in a reflow furnace includes introducing a solvent into the furnace chamber; reacting the solvent with the residue to form a product; and, removing the product from the furnace chamber. The solvent is gaseous, such as an etch gas. Also, the product of the reaction between the residue and the solvent can is gaseous. The gaseous product can then be exhausted from the reflow furnace. A reflow furnace for practicing the method is also disclosed.

Abstract: This invention is directed to controlling the amount of flux dispensed onto the surface of an IC component. The component is continually weighed and data is fed back to a controller that controls the dispensing of flux onto the IC component. When the proper amount of flux is dispensed, the controller terminates the dispensing of the flux.

Abstract: An instrument and a method for measuring a duration at or above a predetermined temperature, such as a solder reflow temperature, are disclosed. The instrument includes a capillary tube and an indicator material that is solid at temperatures below the predetermined temperature and a liquid that will move into and through the capillary tube at and above the predetermined temperature. In the method according to the invention, an instrument according to the invention is heated, then cooled. The amount of indicator material in the capillary tube indicates how much time the instrument spent at temperatures at or above the predetermined temperature. The instrument and method are useful, for instance, for indicating the length of time an integrated circuit package is at or above a solder reflow temperature during manufacturing processes.

Abstract: A softened and compliant fillet portion of a cured polymeric underfill in a flip-chip arrangement reduces occurences of fillet crackings caused by thermal stresses. The softening of the fillet is achieved by chemically breaking cross-links in the cured polymeric underfill material using a chemical solvent. In another embodiment, the softening of the fillet is achieved by applying heat using a controllable beam of thermal energy to break up the cross-links to thereby soften the fillet.

Abstract: Detection of flux residue remaining the formation of a device/substrate assembly is carried out by contacting the assembly with a fixed amount of solvent adapted to remove residual flux from the assembly and measuring the conductivity or resistance of the contacted solvent to determine the presence of flux residue in the solvent obtained from the assembly. Embodiments include contacting the assembly with isopropanol by immersing and withdrawing the assembly in a fixed amount of the solvent and measuring the conductivity of the contacted solvent with a volt meter.

Abstract: A package assembly is formed by applying flux to a device and/or a substrate and inspecting the applied flux to determine whether the amount applied is within a predetermined range. Embodiments include applying a rosin based flux on a laminate substrate and measuring the thickness of the applied flux with an interferometer.

Abstract: An instrument and method for accurately measuring and displaying the length of time that the instrument spends at temperatures between a predetermined first temperature and a predetermined second temperature. The instrument includes a capillary tube, a plug and an indicator material that is liquid at temperatures below the predetermined second temperature and quickly solidifies at temperature equal to or above the predetermined second temperature. The plug melts at a temperature equal to the predetermined first temperature to allow the indicator material to move by capillary action into and through the capillary tube. When the indicator material reaches the predetermined second temperature, it solidifies.