Hello there!
I’m trying to find out some manufacturability info for the Tadiran TL-4920/T lithium batteries. Specifically, whether they can survive a trip through a selective solder process. The datasheet does not mention anything about this specification, and it is not found within the plethora of information gleaned from SiliconExpert. I tried contacting Tadiran directly by email and phone. I have received no response to my email, and nobody is answering the phone.
Basically, what I’m looking for is the max temp these can be subjected to before the insides become the outsides. If anybody can provide this info, I would be greatly appreciative.
Thanks!
Unfortunately the blunt answer to that question is “it depends, and it’s your responsibility to answer it for yourself.”
Assembly processes are beyond a component manufacturer’s control, so while they may from time to time offer suggestions or guidance in such matters it’s ultimately the user’s responsibility to determine whether the end result is acceptable for their purposes.
The point at which heat from a selective solder process will travel along the spot-welded leads and cause things to become unhappy will vary, depending on factors such as point of application, process temperature, dwell time, etc. If those strips are nickel /nickel plated, the question can become further complicated due to potential solderability issues/flux selection/wash requirements, etc.
Your assembly service provider may have some insights on the question to offer.
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Yeah, I was kind of expecting this answer. We have reached out to multiple sources to try to obtain this information, but considering the replies we have (or haven’t, as the case may be) received, we are leaning toward not wanting to risk putting these through the auto-solder process.
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I finally was able to contact Tadiran Batteries, and I now have the official answer to my question. I wanted to post it in case anybody has this same question in the future. In regards to putting the Tadiran TL-4920/T lithium batteries through the wave/selective process, Tadiran recommends against it. Per their Lithium Technical Notice dated March 2008:
"Tadiran flat cells are provided with nickel pins and may be wave soldered.
Tadiran bobbin type cells can be provided with axial wire leads or with nickel solder tags. The small cells may be wave soldered. The big cells (C, D, DD), HLC and TLM cells should be hand soldered in order to prevent any short circuit current during soldering. "
As the TL-4920/T batteries are size C batteries, this means no wave/selective solder for them.
Additionally, there was a caution note on the publication that warned against wave soldering batteries with more than 2.4 Ah. My batteries in question are 8.5Ah, so once again, so wave/selective for them! Hand solder all the way!
TL;DR version - No, don’t put the batteries through the wave/selective solder process. Hand solder them.
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