A formal study will be coming, it should be completed by year end. The size of the aluminum tape was about 1/4″ square. Kapton was not used with the aluminum tape.

Brian

Thanks, Miriam

Great question. Several years ago we (KIC) took a look at Saunder probes which I now believe are called Temprobes from ECD. Now this was many many years ago and at the time we found the attachment method to be too unstable to warrant further investigation. I came across these probes again at a customer about a year ago and do not know how old they were, but I still observed real difficulty keeping them in place. You could see them bounce around when running a live RF profile since the TC reading looked like a saw-tooth. Also I had a few contact points that were not perpendicular to the probe which made attachment nearly impossible. In the end, the operator gave up in frustration and went for aluminum tape. The idea of external probes seems like a good one, but getting everything to line up just right I am not sure how practical it is. What is your experience? How complex are your boards? I am also told if you have low clearance in your oven you can’t use them, but not sure about this. Frankly they were not considered for the RIT study since they are not widely used despite being on the market I believe for more than 10 years. Kapton tape is still king as the mostly widely used attachment method, perhaps more than ¾ of the time and what this study showed is aluminum tape performed better thermally while also having the convenience of tape that it can be “sized/cut” to the attachment area and used in just about any situation. With ever more denser boards there is not a whole lot or real estate to work with so having the ability to conform your tape to a tight spot is pretty important. Of course the downside to Kapton is it doesn’t want to stay in place also giving you that similar saw-tooth reading. If you do not have issues keeping the probes in place, I suggest you conduct your own mini-study. Compare the same contact points with more than one attachment method. For example run a TC using aluminum tape to the same contact point as the probe, of course if you connect them at the same time don’t let them touch. This is not exactly scientific but it will at least give you an idea if both attachment methods give you the same reading.

Also, I have no idea if all the mass of the temp probes comes into play with the overall thermodynamics of the board? The arm of the probe looks beefer than the wire of a TC and the hinging mechanism I wonder if it has a thermal impact? ECD, I am sure has considered this and I would assume it doesn’t have an impact, but I don’t know. Keep in mind though, the whole point is to measure your PCB with the least amount of foreign material attached, since whatever you are introducing into your production environment from TCs to even the profiler doesn’t belong there. For example, most users will trail a profiler a foot or longer behind the board as to not introduce the mass of the profiler to the production board being measured. Dick, I will be exploring further how mass plays into profiling. My gut tells me that my industry is getting a little carried away with all these tools we are introducing to make your life easier. Their mass could perhaps be causing their own problems in interfering with accurate data collection,……but I ramble…. Thanks for the question.
Brian