Hand versus machine placement
Published on 6-Jan-2009
Veldhoven, April 25th
Hand placement may be the fastest option if you only have to place two or three components during 'final assembly'. For more components than that, though, and for high quality placement, nothing beats an AX-201.
Hand placement is only ever cost-effective if labour costs are low. Outsourcing is a possibility, but rework and repair levels are often unacceptable. The quality of hand and machine placements is on completely different levels, and a production line’s cycle time is as fast as the slowest step in the process. A Pick & Place machine will always deliver stable high quality, and won’t have a 'bad day' or a 'Monday morning problem'. Robotic cells can place odd-form components, but are not flexible enough to be changed frequently for a different job (product). They are normally used for large quantities of PCBs and often dedicated to a single product. Modern production lines often have to change frequently to new products, requiring more flexible solutions. The AX-201 offers this flexibility to bring high quality AND high output.
The AX-201 routinely achieves defect rates below 20 defects per million when placing standard SMTs with an accuracy of 20 microns at 3 sigma. Depending on the shape of component and the picking method, these figures are even possible with odd-form and through-hole components. Most ‘final assembly’ components are in fact through-hole components that require special attention when being placed manually. The AX-201 has a through-hole check that will verify if all leads are properly placed in the PCB’s holes. If the AX-201 encounters too high a resistance on insertion, the component is rejected and a new component will be picked and placed. Continuous checks on components using vacuum and vision can guarantee successful placement. Components can be fed in stick, tape or trays. And the machine configuration can be changed in less than a minute to a different combination of tray and/or feeding trolleys to give users flexible component packaging.
A versatile machine needs versatile component handling, particularly as the number of different component types is steadily increasing. Components are picked using vacuum nozzles or grippers. Vacuum nozzles can be standard or special (with different length and shape to match the components being picked), and the AX-201 can pick and place components with dimensions of 0.25 x 0.25 mm up to 63 x 45 mm and a height of 40 mm. If there is no available or reliable surface for a vacuum pad, a gripper can instead be used for components in tape or tray. Tape feeders are available in widths up to 88 mm, while tray components can be picked out of a standard JEDEC tray size or customized tray with dimensions up to 320 x 260 mm.
The AX-201 can place snap-in connectors and other components with a force of 40 Newtons, or right down to 0.9 N for delicate components. LEDs and capacitors can be packed in ‘ammo Pack’ and placed with a radial feeder and nozzle. With this combination we can cut, pick and place LEDs and capacitors at up to 7,200 components per hour.
The AX-201 can also be equipped with four dual-vision heads, which can pick four components up to 21 x 21 mm. For example, they can place 8500 shields per hour, from either tape or tray, depending on the packaging.
Whether for final assembly, for stand-alone use, or in-line with other equipment, the AX-201 offers total flexibility to handle SMD and non SMD devices with a quality and placement rate that is just not achievable with hand placement. More and more OEMs and subcontractors are looking to reduce hand placement to make the process more stable and more cost-effective. We have the equipment to help – just ask.
Tiely Hendrikx
Application & Sales
