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Eqipment Advances
Juki’s high-speed modular chipshooter, the FX-3, features two placement stations, each with two head beams. In each placement station, the two heads are arranged in front and behind each other, alternately carrying out component picking and placement. The four high-speed assembly heads each support six nozzles, for a total of 24 nozzles.
The component placement range is from 01005 (0402 metric) through 33.5 mm sq. Each head is driven by an overhead x-y dual gantry positioning system with closed-loop independent linear servomotors and magnetic linear encoders. The y beam has dual synchronized linear motors for each station, both left and right. Each nozzle is controlled with independent z and u AC servomotors featuring new encoders with a resolution of 260,000 pulses per revolution, for reliability and accuracy. Control of each nozzle is possible without affecting other nozzles. This reportedly aids machine uptime, as well as time between repairs. The design results in a placement rate of 60,000 cph (0.06 sec./chip), according to IPC-9850.
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The head unit is equipped with a new precision laser alignment and control system for both upper and lower rotary axes to improve efficiency. Placement is done via exclusive laser centering using the new CyberOptics LNC60 system. The LNC60 laser uses novel Tangent Line Centering, which takes multiple views of the component by rotating it 360° through the laser to achieve a full outline of the component. The LNC60 measures the component’s center, dimensions and angular correction in a single sweep. The machine features 1 µm linear encoders on the x and y axes. Combined, these enhancements improve placement accuracy to ±50 µm (Cpk >/= 1).
Other important features of the LNC60 laser include the exact height of the nozzle tip, bent nozzle detection, and a tombstone pick. Additionally, it ensures a component is present before placement, and that the component has been placed successfully. The LNC60 laser measures components while they move from the pick to the placement site and never requires moving to a stationary camera or Line Scan Camera because it is built into the head, creating an efficient method of component measurement. The optical design of this laser has been simplified to provide higher reliability in a thinner and lighter package.
The head unit is designed for easy maintenance. Vacuum filters have been moved for better access and reportedly require no adjustments or calibrations after replacement. Laser centering measures the components on the side. It is not affected by variations of component color or width/length; unlike vision centering, there is no need to edit component data for different component vendors. Component data can be completed by entering approximate dimensions, type and packaging information. The exact dimensions and lead count/pitch are measured by the machine and automatically entered into the component data. A vacuum self-calibration function eliminates the need for a vacuum “blowing-off” during placement, which can disturb neighboring components or solder paste.
Standard features include:
- Pick position auto teach, for 8 mm components, to reduce changeover time and mis-picks.
- OCC lighting system/fiducial recognition systems, which support a variety of board materials including flexible PCBs. Programmable brightness and directional lighting improves fiducial recognition.
- Height measurement system, for quick, accurate measurement of component pick height. A laser sensor measures the distance instantly without physical contact.
- Bad mark detection, which is performed using the machine’s standard downward-looking camera (also used for fiducials and teaching) and detects a range of marks on various substrates, including flex circuits.
- Cast iron frame: A high-rigidity frame made by cast metal molding has excellent anti-vibration characteristics that support high-speed operation.
- Operations can be carried out easily using the touch panel while referring to camera-recognized images.
- Screens can be switched between real-time display in Japanese, English and Chinese.
Available from Juki Automation Systems, jas-smt.com.