|AYLESBURY, Buckinghamshire, UK —
Nordson DAGE announces that Dr. Evstatin Krastev, International Applications Engineering Manager, will present a paper titled “3D board level X-Ray inspection via Limited Angle Computer Tomography” at the upcoming SMTA International Conference & Exhibition, scheduled to take place October 16-17, 2012 at the Walt Disney World Dolphin Hotel in Orlando, FL. The presentation will be held during session MFX5, titled “Advanced Inspection Techniques for Printed Circuit Board Assembly,” which will take place Wednesday, October 17, 2012 from 10:30 a.m. – 12 p.m. in room Asia 4. Dr. Krastev co-authored the paper with his Nordson DAGE colleagues Dragos Golubovic and Dr David Bernard.
Computer Tomography (CT) is a powerful Inspection technique used widely in the electronic industry, especially for multi-layered devices and interconnects. The CT technique permits different layers of the device to be isolated and examined practically performing an electronic or virtual cross sectioning. The benefits of the electronic cross section compared to the traditional mechanical cross sectioning are many. These include that the electronic cross sectioning is reversible, the cutting plane can be positioned in any direction of the 3D space, and no additional defects are introduced or existing defects concealed in the process of mechanically cutting the device of interest.
One of the limitations of the traditional CT is that there is a restriction to the maximum sample size in order to produce CT models with reasonable quality and analytical value. Typically the practical size for a regular CT is less than 2 x 2". Thus in order to use the CT on a large PCB, there is a need to cut around the device to be examined and thus destroying the board. In order to overcome the size limitation, a limited angle or partial CT technique has been developed and used in some X-ray systems. This permits a 3D model to be created of the devices placed on large boards without destroying the board. This paper will explain the mechanism and differences between full CT and limited angle CT, and compare different applications where one or the other technique is applicable, backed by real life cases and examples.
This paper will be available to download at www.nordsondage.com after the event.