Mass imaging process enhances singulated package assembly
May 21, 2004
DEK has introduced new techniques for performing mass imaging processes on singulated substrates directly from the process carrier. This streamlines assembly of singulated packages, and allows the advantages of mass imaging to be gained without having to move substrates into a special carrier. These include high throughput, enhanced control over deposit shape and thickness, and low-voiding.
Electronic materials such as conductive adhesives, solder pastes, fluxes, underfills and also solder balls can now be applied to singulated substrates lifted from the carrier one at a time. Substrates enter the printer in the customerís chosen process carrier, such as an Auer boat. Upon reaching the board stop, the carrier is held in place by the machineís snugger rail system as the first substrate is aligned. The machineís camera system verifies correct alignment before the substrate is raised into contact with the stencil by standard vacuum tooling. After mass imaging the substrate is lowered into the carrier. The board stop then allows the carrier to move to the next position, where the second substrate is aligned and the cycle repeated.
After each substrate has been processed and returned to the carrier, the carrier is able to move directly to the next downstream process.
DEKís new singulated packaging process gives package assemblers greater flexibility than can be achieved using dispensing techniques. Mass imaging inherently provides greater control over the shape of deposits, as well as higher throughput. This is important when depositing conductive adhesives, for example. The deposited material also has uniform thickness and a flat surface, enhancing component placement and allowing lower placement forces. This reduces the potential for component damage. Instances of voiding beneath the component are also reduced. Voids give rise to hotspots in the end product, leading to early failures in the field.
The new singulation process can be performed on any DEK machine configured for semiconductor packaging applications, including the Micron-class Galaxy, and the new Europa machine.
For more information go to www.dek.com/singulationpr