As the SMT industry continues to demand the placement of smaller chips with higher placement speeds, Manncorp has entered into the prototype to mid-volume market with its MC-392 pick and place machine (Figure 5-1).

Building on the solid performance of the MC-391 pick and place, the servo system (the critical assembly for fast and accurate placement of the components) has been redesigned by mounting AC servo motors and encoders directly to the lead screws. With the resulting improved accuracy, the MC-392 can now repeatably place the smallest components on the market (the 01005) measuring 0.01 inch by 0.005 inch. Placing a part this small is no trivial accomplishment. This accuracy improvement allows for easier placement of the larger 0201, 0402, or other components at placement rates approaching 5,500 components per hour (cph).

In recent years, the size of many production runs has been trending downward and the importance of quickly changing from one job to another has taken increased significance. Quick job processing requires a pick and place system with user friendly software for fast set-up and the machine must be both fast and accurate in the actual placement of components assembled on the board.

To keep the set-up times short, all the component placement information can be downloaded into the MC-392 from a computer aided design (CAD) file that contains the coordinates for every chip being placed on the circuit board. With circuit boards containing hundreds of chips, having this placement information accurately transferred from a network drive or memory stick to the MC-392 is a requirement for fast set-up. Manual set-up is also available for special applications.

A Cognex vision system provides the image processing required to accurately locate, pick, and place the components. High performance systems like the MC-392 have two cameras; a downward looking camera is mounted on the pick-up head which moves the components from the feeder reels to the circuit board. The image of the component is used to align the component so that it can be placed accurately on the circuit board. A bottom vision camera (looking up to the component) is used to locate large and fine pitch components like ball grid arrays (BGA) and quad flat pack (QFP).

If time is not available to use a stencil printer to apply the solder paste, the MC-392 is available with a solder paste dispenser option. This Martin solder paste dispenser is attached to the head of the MC-392 and is under machine control. The dispenser indexes through the circuit board, dispensing precisely measured amounts of solder paste accurately on the pads of the circuit board. After solder paste is dispensed, the MC-392 can place the components on the circuit board to finish the job.

Prototype circuit boards are an important business for many contract manufacturers and OEMs. The combination of both solder paste dispense and component placement in one machine means prototype boards can be built in hours instead of days.

To summarize, when assessing the performance of a pick and place system, some of the key measures are placement speed, range of component size, vision system employed, and efficiency of set-up and programming tools. In the prototype to mid-range volume market segment where this machine competes, the 5500 cph speed, Cognix vision system, 01005 component capability, and reasonable price makes the MC-392 Pick and Place from Manncorp an excellent choice. For more information or for a demonstration of this machine at the EMPF, contact Mike Prestoy at 610.362.1200, extension 241 or via email at mprestoy@aciusa.org.