Quad Flat No-lead (QFN) presents an excellent example of a complex substrate composed of both ductile (copper) and brittle (plastic molding compound) materials, showing clear trends of reduction in package size and the combination ductile and brittle materials in the same sawing process which creates real challenges in term of sawing quality, blade life and throughput. This paper discussed on t...

At present, there is little fundamental guidance available to assist contractors in choosing when to schedule saw cuts on joints. To conduct pavement finishing and sawing activities effectively, however, contractors need to know when a concrete mixture is going to reach initial set, or when the sawing window will open. Previous research investigated the use of the ultrasonic pulse velocity (UPV...

Semiconductor wafer post-sawing requires full inspection to assure defect-free outgoing dies. A defect problem is usually identified through visual judgment by the aid of a scanning electron microscope. By this means, potential misjudgment may be introduced into the inspection process due to human fatigue. In addition, the full inspection process can incur significant personnel costs. This rese...

The objective of this work was to study maritime pine (Pinus pinaster Ait.) wood characteristics and their impact on the sawing yield using virtual stem models and sawing simulation procedures. In the first part of the work, a characterisation of maritime pine as raw material for the wood industry was performed. The stem shape, distribution of knots, and heartwood/sapwood contents were studied....

With rising timber costs and a decreasing supply of high-grade timber resources, manufacturers of solid wood products need to adopt more efficient processing methods that better utilize existing timber resources. To address this need, this study explores the potential of converting hardwood logs directly into dimension parts. The specific objective of this study was to estimate the potential cu...

Curve sawing is a technique used more and more widely in lumber mills in order to obtain more commercially valuable pieces from a given log. It is important to understand and know this technique in order for it to be used optimally. This article deals with the mathematical modeling of curve sawing, so that a module pertaining to curve sawing can be incorporated into the Optitek software, which ...

In this paper we investigate the behavior of mutation-based evolutionary algorithms on highly symmetric binary constraint satisfaction problems. With empirical methods we study why and when these algorithms perform better under the stepwise adaptive weighting of penalties (SAWing) than under the standard penalty function. We observe that SAWing has little effect when the local optima of the sym...