This paper describes a reliable emission spectrographic method capable of quantitatively determining boron in the 0.5 to 50 ppm range. The detection limit for the method is 0.1 ppm. Previous to this report no reliable method was available for the accurate determination of boron in reagent 40% ammonium fluoride solution in the ppm range; consequently, no incoming inspection or manufacturer's certification was available for boron content. Analysis of representative ammonium fluoride samples shows that the boron level is less than 0.1 ppm, suggesting that this element may not be a major problem in ammonium fluoride reagent.

This paper describes a method to "non-destructively" inspect the bump side of an assembled flip-chip test die. The method is used in conjunction with a simple metal-connecting "modified daisy chain" die and makes use of the fact that polished silicon is transparent to infra-red (IR) light. The paper describes the technique, scope of detection and examples of failure mechanisms successfully identified. It includes an example of a shorting anomaly that was not detectable with the state of the art X-ray equipment, but was detected by an IR emission microscope. The anomalies, in many cases, have shown to be the cause of failure. Once this has been accomplished, then a reasonable deprocessing plan can be instituted to proceed with the failure analysis.