Abstract:
A method of forming solder bumps on a wafer. The wafer includes at least one substrate, a plurality of solder-wettable pads and a solder wettable retention ring about the periphery of the wafer. The method of forming solder bumps includes forming a non-solder-wettable mask on the wafer which includes a plurality of apertures which align with the solder-wettable pads, and the solder wettable retention ring surrounds the mask. The mask and wafer are positioned within an aperture of a stencil so that the solder wettable retention ring aligns with a gap between the periphery edge of the mask and an inside edge of the aperture of the stencil. Solder paste is applied to the mask so that the solder paste fills the apertures of the mask and the gap. The solder paste is reflowed forming solder bumps on the pads and a solder ring on the solder wettable retention ring. The mask is removed after formation of the solder bumps.
Abstract:
An apparatus for producing magnetically-permeable cores for use in electromechanical machines, such as electric motors. The apparatus includes a plurality of welding arbors adapted to support a stack of core laminations. A storage structure defines a plurality of arbor storage locations at which respective welding arbors are maintained. A transporter device is operative to individually move the welding arbors to and from a respective arbor storage location. A welding device is operative to weld the stack of core laminations together. A conveyor assembly is also provided for moving the welding arbors between the welding device and the transporter device.
Abstract:
A system to find wirebonded leads by obtaining an image of the crescent formed on a lead after wire bonding, or a difference image (taken from an image of the lead before bonding and the crescent and wire formed after bonding) to create an intermediate image having the desired rotation and registration characteristics. Using a caliper or other wire-finding tool, the invention locates the wire and generates a threshold value for a boundary tracker that will make the located wire the expected width. An alternative preferred embodiment uses the gray value of an edge of the wire as the threshold. An optional artificial boundary is created as a limit for a boundary tracker. The invention then applies a boundary tracker to the intermediate image using the threshold value generated and any artificial boundary created. It then applies a corner finder that restricts starting corner orientations and analyzes the boundary and its features to find crescent tips and extrema to obtain measurements for inspection.
Abstract:
A method and apparatus is disclosed for applying solder to a substrate which has a predetermined pattern of receiving pads thereon and forming solder balls from the applied solder. A conveyor is provided having a support member and a continuous metering member. The metering member has openings thereon arranged in the same preselected pattern as the solder receiving pads on the substrate. The substrate is moved into contact with the support member and the metering member, the openings in the metering member being in alignment with the solder receiving pads of the substrate. A container of solder is provided which supplies solder to the openings. The solder may be in liquid form, or in paste form, or in the form of solid solder balls. The applied solder, if in the form of paste or solid balls is melted. Thereafter, the solder is solidified on the pads to form solder balls, and the substrate is discharged from the conveyor with the solidified solder balls thereon.
Abstract:
This invention relates to a method of embedding electric components or optical components, such as sensors, in a high-temperature metal and the embedded products produced by the method. In the preferred embodiment the components are embedded on a substrate of the high-temperature metal by being placed on a first insulating layer. A second electrically insulating layer, a low thermal conductivity layer, a high thermal conductivity layer, and a primer layer are then deposited in order. The high thermal conductivity layer is in good thermal contact with the substrate. The high-temperature metal is deposited, preferably as molten drops, on the primer layer and the heat from the drops is conducted by high thermal conductivity layer to the substrate while the components are protected by the low thermal conductivity layer.
Abstract:
New solder compositions having enhanced mechanical properties are disclosed. Relatively inert particles having a diameter of 2000 nm or less are dispersed in a solder material having an average grain size of 500 nm or less to produce such solder compositions. The dispersed particles act as physical barriers substantially impeding the motion of grain boundaries and inhibiting grain growth during thermal and stress cycling which substantially inhibits coarsening. As a consequence, the solder composition exhibits an advantageous level of superplasticity that is substantially resistant to joint failure. Methods for forming articles using such solder compositions is also disclosed.
Abstract:
A seam welder for sealing a cover of a surface mount package to its carrier includes a table for receiving a fixture which itself carried surface mount packages to be welded for sealing an electronic component therein. Electrical current to welding electrodes is controlled for resistance welding the cover to the carrier. Electrode temperature and table temperature and monitored. Heat exchangers including a reservoir and heat transfer fluid interface with the electrodes and the table for controlling their respective temperatures and thus the temperature of the fixture and package during the welding of the cover to the carrier. Factors affecting the quality of the weld, including temperature, time/temperature profile, the temperature of the electrode just before current starts to flow, the temperature of the package/cover and carrier combination just before current starts to flow, the difference between the package/cover and carrier combination temperature and the electrode temperature just before current starts to flow, are monitored and controlled. As a result of such monitoring and control, induced stresses typically resulting in a package because of the differing coefficients of thermal expansion for the materials used in the package are reduced during and after sealing the cover to the carrier. Seal quality and integrity is improved and the range of seal parameter tolerances tightened.
Abstract:
An apparatus for spreading a fluid substance, includes a container containing the fluid substance and a supporting unit. A lower holding unit, connected to the supporting unit, holds a lower end of the container. An upper holding unit, connected to the supporting unit, holds an upper end of the container. A driving unit, connected to the supporting unit, drives the container up or down. A rotating unit, connected to the supporting unit, rotates the container around a vertical axis. Finally, a needle, connected to the lower holding unit, spreads the fluid substance