Abstract: A method and apparatus is provided for transporting circuit boards in a screen printer. In embodiments of the present invention, a transportation system is provided for a printer that prints material on a substrate. The transportation system has the ability to independently move substrates from one position to another within the printer without moving other substrates contained within the transportation system. In one embodiment, the transportation system includes a conveyor system and a plurality of lifters that lift substrates off of the conveyor system to prevent at least one substrate from moving when other substrates are moved by the conveyor system. In another embodiment, the transportation system includes a conveyor system and a plurality of retractable pins, that are individually controllable to be raised above the conveyor system to contact at least one substrate on the conveyor system and prevent the substrate from moving when other substrates are moved by the conveyor system.

Abstract: An apparatus for dispensing a fluid includes a dispensing chamber coupled to a dispensing orifice and a fluid reservoir. The dispensing chamber is coupled to a transducer which is adapted to change the volume of the dispensing chamber in response to a signal applied to the transducer. The signal is characterized by 1) an initial rise time RT1 during which an increasing amplitude signal is applied to the transducer to gradually expand the dispensing chamber from a first volume at a first amplitude to a second volume at a second amplitude; 2) a fall time FT during which a decreasing amplitude signal is applied to the transducer to contract or compress the dispensing chamber rapidly (relative to the initial rise time RT1) to a third volume at third amplitude; 3) a final rise time RT2 during which an increasing amplitude signal is applied to the transducer to gradually expand the dispensing chamber to a fourth volume at a fourth amplitude.

Abstract: Providing encapsulated electronic components on a circuit board by providing dams on a circuit board around areas on which respective electronic components will be mounted, mounting the respective electronic components within the dams on the circuit board, and printing encapsulating material through a stencil in order to provide deposits of encapsulating material over the electronic components and within the dams.

Abstract: A method and apparatus is provided for transporting circuit boards in a screen printer. In embodiments of the present invention, a transportation system is provided for a printer that prints material on a substrate. The transportation system has the ability to independently move substrates from one position to another within the printer without moving other substrates contained within the transportation system. In one embodiment, the transportation system includes a conveyor system and a plurality of lifters that lift substrates off of the conveyor system to prevent at least one substrate from moving when other substrates are moved by the conveyor system. In another embodiment, the transportation system includes a conveyor system and a plurality of retractable pins, that are individually controllable to be raised above the conveyor system to contact at least one substrate on the conveyor system and prevent the substrate from moving when other substrates are moved by the conveyor system.

Abstract: Web displacing apparatus selectively displaces a web between a first position engaging a fluid source and a second position spaced from the fluid source. A web drive is constructed and arranged to move the web in a direction from the fluid source toward a surface for engagement with the web for receiving fluid carried by the web from the fluid source. Web moving structure is constructed and arranged to selectively move the web between the first and second positions.

Abstract: Automatically monitoring pads of material deposited on a surface of a workpiece using an inspection system that senses a deposited pad of material and determines pad height values at a plurality of locations across the pad, and a shape classifier that receives the pad height values as inputs and outputs a plurality of three-dimensional shape attributes related to pad deposit conditions.

Abstract: An apparatus for depositing a selected pattern of solder onto a substrate comprising a substrate support, a solder ejector, and a gas-delivery system associated with the solder ejector. The substrate support has structure for bearing a substrate on which one or more electronic components are to be mounted. The solder ejector has a housing that defines an orifice for producing a stream of molten solder droplets along a selected trajectory relative to the substrate support to deposit molten solder onto the substrate in a selected pattern. The gas delivery system has an input for receiving pressurized inert gas and an output aligned with the directed stream of molten droplets for discharging from the orifice of the solder ejector a flow of inert gas aligned with the ejected molten solder droplets. A method for depositing a selected pattern of solder onto a substrate is also described.

Abstract: Applying adhesive in a desired pattern on a substrate by determining one or more inspection sites for monitoring adhesive deposition, applying adhesive to a substrate with a stencil or screen printer, viewing the inspection sites with a camera that generates image signals, and processing the image signals to determine if adhesive has been properly applied at the inspection sites.

Abstract: Pin placement and support apparatus for a circuit board that has a rigid support table, a supply of pins, a pin placement head, and an X-Y transporter that moves the pin placement head relative to the table so as to place the pins at desired and variable locations on the table. To facilitate defining pin locations, the apparatus includes a computer that is programmed to display a board area of the table and pins at user-selected locations within the board area.

Abstract: A stencil for applying solder paste in a desired pattern for mounting electronic components on a surface of a circuit board, said stencil including a sheet having holes therethrough in a pattern corresponding to the desired pattern, a smooth upper surface for receiving the solder paste thereon, and a smooth lower surface for contacting the surface of the circuit board, the upper surface having relieved portions so as to increase the friction between the upper surface and the solder paste being squeegeed thereover.

Abstract: An illuminated video probe in an aligning system for similtaneously viewing an object and a device acting on the object while illuminating the object and the device acting on the object directly along their respective viewing axes. A first optical beamsplitter and adjacent mirror surface act to simultaneously translate the object and device images to the video probe optical axis. A second optical beamsplitter, adjacent light source, and opaque surface act to illuminate the object along the viewing axis without causing light to project back toward the video probe.

Abstract: An aligning system includes an object to be acted upon at predetermined locations, such as a circuit board to receive solder paste. There is a device, such as a stencil, characterized by the pattern for acting upon the object. A video probe is arranged to look at both the device and the object for providing image signals representative of both. A comparator compares the image signals to provide an error signal representative of misalignment between the device and object. A positioner responsive to the error signal relatively positions the device and object to reduce the error. An operator causes the device to operate upon the object at the predetermined locations.

Abstract: An aligning system includes an object to be acted upon at predetermined locations, such as a circuit board to receive solder paste. There is a device, such as a stencil, characterized by the pattern for acting upon the object. A video probe is arranged to look at both the device and the object for providing image signals representative of both. A comparator compares the image signals to provide an error signal representative of misalignment between the device and object. A positioner responsive to the error signal relatively positions the device and object to reduce the error. An operator causes the device to operate upon the object at the predetermined locations.