Knocking Down the Bone Pile: Interposer Rework and Precision Solder Ball Attachment
Standard of Excellence: AI Makes It Possible, and Engineers Make It Happen
The Fearless Connector: Why I Chose the Hard Road
The demands on volume delivery and positioning accuracy for solder paste deposits are increasing as the size and complexity of circuits continue to develop in the electronics industry. Board designs that include advanced BGAs, CSPs with 0.4 mm and 0.3 mm pitch, as well as simpler 01005 and 008006 components, raise the bar for positioning demands and volume delivery for solder paste deposits.
According to the iNEMI 2013 Roadmap, placement accuracy for these kinds of components will reach 6 sigma placement accuracy in X and Y of 30 μm by 2023. This level of placement accuracy for components must be accompanied by a related accuracy for the deposit of solder paste and related fluids.
Among the alternatives for the deposition of solder paste and other fluids on a PCB is jetting, which offers advantages concerning precise volume repeatability, software control and local volume control. The ejection of fluid from a jetting head has been studied extensively for low-viscosity fluids.
This research has naturally been driven by work related to inkjet printing. The jetting of more complex fluids is challenging and the amount of research is limited. An interesting theoretical study on jetting in general was carried out by Clasen.
The goal of this study is to examine the effect of piezo actuation profile on deposit quality with respect to positioning, shape and satellite levels in order to achieve adequate deposition quality for applications such as 0.4 mm BGA.
Editor's Note: This article originally appeared in the April issue of SMT Magazine.
