Producing more boards per hour within the same line footprint is the ambition of every high-volume electronics assembly company. The more high-yield boards that can be squeezed out of the SMT line, the more profitability can be squeezed out of the bottom line.
This reality, of course, was the driver of dual-lane placement systems many years ago. Once an astute placement company developed the first gantry system – to move the placement heads and not the boards – dual-lane processing became a reality. With some slick engineering, the addition of a second conveyor and the ability to use a single work nest to effectively place components on two different products (or two different sides of one product), dual-lane placement was born and has continued to advance over the years.
In most cases, dual-lane lines are set up to process a single product, with one lane utilized for the A side of the assembly, and the other lane used to assemble the B side of the board. Some manufacturers use dual-lane capability a bit more radically, however. In such cases, either two different products are produced on a single line, or one lane is used for a complete product (A side and B side), while the second lane accommodates NPI work. Speaking from experience having worked at an OEM once myself, getting time on the line to do necessary NPI activities can be challenging at best. So, utilizing a dual-lane system in this way can be very beneficial.
While dual-lane certainly isn’t a new concept in electronics assembly, there have been limitations, particularly with the printing process. It’s not that current printing platforms can’t accommodate dual-lane; they can. When you put two printers side-by-side to feed a dual-lane placement system, they do just that. The challenge, however, is with the footprint and equipment utilization. Two standard-sized printers take up a fair amount of floor space. Efforts to reduce the footprint of side-by-side or back-to-back printer configurations have resulted in equipment that is either not capable of managing standard stencil sizes, or not a complete package for advanced processes. To shrink the floor space requirement, many dual-lane printers also shrink the available print area. This means that manufacturers can’t use standard stencil frame sizes (29" x 29") for typical print areas. Retooling PCB panel configurations and ordering a completely new inventory of stencils isn’t an inexpensive proposition.
Second, sacrifices made on the print platform’s relative size many not only affect print area, but also printer capability. Just because the platform is more compact doesn’t mean it shouldn’t be just as robust in terms of its process aptitude. Two printers packaged together should each be as capable as a single printer. Each printer should be a solid machine on its own and able to manage the most advanced technologies, such as high-speed understencil cleaning, enclosed head printing, closed-loop SPI, process alignment and more. This isn’t often the case, however, and in high-volume manufacturing environments where miniaturized mobile assemblies are going down the line, a less-capable dual-lane print platform may result in less-desirable yield levels. So, dual-lane-ready printers that are just as robust as their single printer cousins are what’s required for today’s complex assemblies. Process capability should not have to be sacrificed for speed.
Furthermore, in today’s world of changing requirements, new product builds and geographical production shifts, having the ability to redeploy equipment resource is a huge advantage. Dual-lane printers that can be controlled independently so that, as mentioned, one printer can manage other tasks such as product changeover or NPI while the other printer feeds the line improve equipment utilization tremendously so as to fully capitalize on the investment. Even better are two printers that operate as a dual-lane platform when required, but can be split apart to manage the most complex assemblies individually.
New dual-lane printer platforms address some of the shortcomings of previous solutions and offer fully capable, advanced printing technology, either as a dual solution or as single printers. Has dual-lane processing finally come of age? I do believe it has.
Clive Ashmore is global applied process engineering manager at DEK International (dek.com); firstname.lastname@example.org. His column appears bimonthly.