TABLE OF CONTENTS After the adhesive has been dispensed onto the PCBs or other interconnect substrate, bare die and other electronic components must be precisely placed. Of course, pick and place can be done manually using vacuum pick-up tools or tweezers, but this approach is useful only for small quantities, prototypes, or for rework. The risk of human error is high and accuracy is exacerbated as more and more very fine pitch devices are used. Even placing the device in the correct location, but in the wrong orientation can result in electrical failure. Manual placement is impractical for production quantities.
Fortunately, advanced robotic equipment has been developed and is commercially available for accurate, high-speed placement of components. Entry-level automated placement machines can place 3,000 5,000 parts per hour while mid-range equipment, that can hold more feeders, can place 8,000 10,000 parts per hour. On the high-end, placement speeds of 30,000 and higher are being achieved.[67] In fact, speeds of the new equipment are so great (chipshooters can place up to 80,000 components per hour) that they often must be slowed in order for adhesive dispensing to catch up; alternatively extra adhesive dispensers must be added to the production line.
A wide variety of fully automatic machines exist. Generally, feeders, which may consist of tape-and-reel, stick, or tray, deliver the parts individually so they can be picked up and automatically inspected. Machines are equipped with vacuum nozzles to pick up the components and carry them through inspection, alignment, and placement.
