Avoiding soldering by using double-sided conductive tape + shrink tubes

Factual Questions
1

Title sort of says it all.

I just have to connect some long-ish leads to a few battery posts (stubs, really) to a PCB.

I’m really tired of soldering.

Why not use an aluminum, say, conductive tape, with double-sided conductivity, to create the “join,” slip a heat shrink tube (2:1) over the connection, and call it a day?

This is for installing a CR2032 battery with a case, with the longer leads allowing me to mount the battery holder someplace convenient, away from the PCB.

If this were just for me, I wouldn’t sweat it so much, but the device is to be shipped to a buyer across the country, so I want durability as wlell as fast, fast, fast quality joint.

This should be just fine, especially with shrink tube applied to provide extra mechanical stability.

I know I should have more confidence in my ability to create a simple solder joint, but, well, I just don’t, especially when it’s somebody else’s money and hopes and dreams on the line.

Yes, for a vertical joint, I could use all kinds of temporary fasteners to get the joint perfect…anything from alligator clips to a dab of hot glue, to even some cyanoacrylate glue about the insulated portion of the wire, but I’m at my wits end spending sleepless nights and just want this piece of equipment to survive cross-country shipment and for me to spend as little time soldering as possible, which I absolutely despise and am just not that good at.

If it were for my own use, yeah, I’d just slap it together with solder, but I really want this to be both robust and as fast as possible, since this poor woman who’s waiting for the product has been waiting for a week for me to prepare for shipment.

2

What you may want is a crimped connection. Done right these are arguably better than a soldered join anyway. But you really need a proper crimp tool, not the stupid dime store crimping pliers. These are not cheap. But they are a buy once thing. Not sure exactly what the requirement here is, so there may not be fit.

Anything that depends upon tacky adhesives or heat shrink for mechanical stability is a no-go. It certainly isn’t going to be reasonable for a paying customer. You don’t want to be inventing connection technology when there is is well over a century of engineering experience to call upon.

If you don’t have confidence in your own ability here, I’m not sure you should be offering services. You would be much better served spending time practising soldering than wasting time worrying about inventing alternatives.

3

I agree with the above. Soldering is the simplest and most secure means of connection. What exactly are you joining? Is it wire connected to a battery case? Wire connected to a PCB?

4

That’s fair enough.

I can certainly make a solid join between the battery posts, and apply shrink tube (not depending on that alone for structural stability, but it seems to me the proper way to do things…including when soldering leads onto the CR2032 battery holder…why not, you know?)

I think it’s probably best to create a solid join with solder, after tinning the leads…by the book, you know, traditional, apply heat shrink tube for whatever extra benefit it may have (may be none, but it looks nicer).

Clarification, I didn’t sell my services as a master craftsman: this is an older digital-analog hybrid “vintage” synth and I just want to use the CR2032 as a replacement for the Br-2/3 battery which is, to my revised thinking, prone to break loose during shipping and the buyer is a connoisseur of sorts and would rather have me spend the extra time to make sure everything is 100%.

Yes, I know the Br-2/3 is at 1200mAh and the CR2032 is only at just above 200mAh, but this is a common mod/improvement. Yes, I soldered leads onto the terminals of a new Br-2/3, but it’s not the most robust connection, although the multimeter reads correct from the leads. It’s a really awkward battery to deal with.

No, I wouldn’t depend on adhesives alone for mechanical stability.

Well, I think I’ll just do a nice clean joint on the uprights, and either use the helping hands tool to keep the joint steady plus, at most, a pair of vise grips to act as a heat sink near where the stubby battery posts encounter the PCB.

The battery area is relatively free of traces to ICs or other components, so even a mediocre solderer like me should have a pretty easy go of it.

/* And thank you, BTW. That gives me something to ponder about doing things the right way, It’s still not clear to me why conductive tape wouldn’t work, but it’s most welcome advice on your part. */

5

Wires to be connected to the remaining stubs of battery posts on a PCB, give the wires a long-ish leash, to a battery case to be mounted pretty far away from the PCB. Mostly for convenience and easy of replacing the battery for the future owner. Both my convenience and that of the future owner.

I know there are battery cases for the Panasonic Br-2/3, but I couldn’t find any that could be had or delivered in the somewhat speedy desires of the buyer. Anyway, the CR2032 is, by all accounts I’ve read, including by owners of this exact instrument, more than adequate.

6

I’m 72 and here’s the opinion of a Grumpy Old Man.
Soldering ALWAYS makes THE BEST electrical connections.
Thank you.

7

Not at all, I thank you!

Then again, you haven’t seen my soldering!

I do tin the wires and the soldering tip, though…when I remember to!

So, got that going for me, which is nice.

However if I may add a recently learned experience: one can glob on a bunch of solder onto battery terminals, ideally after roughing up the smooth ends with a screwdriver or whatever…and insert some wire leads into blobs of solder…meh, it sort of works…but I’m thinking an actual battery holder is far better.

I could have just hot-glued the Br-2/3 to the PCB and called it a day after soldering the leads to the battery posts…but nah.

I’m going this guy’s method, just because it’s easy enough for me to do and I can ship the synth without making this poor woman wait any further. But this guy makes it look easy! I mean, it is, but…he’s probably not nearly as lazy as I am.

https:// www.youtube.com/watch?v=I3LJTsILbOo

8

No :heart: for wire-wrap? :slight_smile:

9

“They” say that wire wrap can be a bit of an investment!

10

It’s got to be solder.
From that video, i can see there’s just not enough stub left for anything else
to be strong enough. (maybe liquid solder, but that’s expensive).
I see that guy’s also being lazy by not removing the pcb and unsoldering the Br-2/3 !!

11

Yes.

I think of soldering as fairly easy to learn. I’ve brought (interested) 12-year-olds to basic competence in 30 minutes. It really is the both the quickest and best technique in most cases.

Note that crappy soldering equipment (which abounds) will make the job much harder - another case of “Anyone skilled enough to succeed with it should be smart enough not to try.”

12

I agree that soldered connections are best, but only if they are soldered correctly. Wire wrap was invented at Bell Labs in part because it was easier to train people to make reliable connections. At least, that was the story I heard back in the 1970s when wire wrap was popular.

13

While I think soldering is the best solution for the OP, your statement is factually incorrect. As explained by @Francis_Vaughan, a proper crimp is often better than solder in certain applications
for a variety of reasons. And in some applications, crimping is the only thing that is allowed; soldering is forbidden.

At any rate, it would behoove the OP to learn the Fine Art of Soldering™ if is he to do repairs on electronics equipment. There are a lot of nuances to it that the YT videos don’t cover. My advice is to get with someone who has been soldering for many decades and have them show you the basics. (I wouldn’t say I’m an expert per say, but I’ve been hand-soldering since 1974. If you’re in the Ohio area, send me a PM.)

14

The described setup seems to have terrible mechanical strenght. If I understand the arrangement, you’re connecting leads to the surfaces of a coin cell, which means that forces along the wire will pull the connection in shear, along the surface of the cell and not away from the surface. Tape adhesion is probably terrible against shear, espeically for such a small contact surface (the diameter of the conductor).

The shrink tube won’t help much because most of its compressive forces will be at the edges of the cells; the surfaces of the cell may actually wind up covered with slack shrink-wrap, contributing no strength whatsoever.

OTOH, I’m still nervous about soldering directly onto a cell; they don’t like heat very much.

If there are solder tabs on the cell, it’s best to use them, and to solder. Usually, the tabs are soft nickle alloy so not very good for crimping. Solder is what they’re designed for.

15

You would not be soldering anything directly to the battery, though. This common battery case has little pins designed to be soldered to a PCB:

16

Exactly.

Otherwise, you’d end up with something like this,

Which is not ideal! (And probably not great for the battery either). It does read 3V from the wire leads, though. So at least technically I can solder…but perhaps only stupid things!

17

What size wire are you using? What kind of soldering iron do you have and what wattage? What kind of solder are you using and what size?

18

Don’t solder directly onto the cell. You can put a lot of thermal energy into a very small cell unless you are very carefull with tip temperatures and contact times. Damage may not show up as a drop in voltage, but you may kill the cell life overall, also open circuit voltage doesn’t always tell you much about a battery, may want to see its voltage under load. I doubt you can do enough to cause it to pop with drama unless you fall asleep with the iron on it.

You can buy tabbed CR cells that have the tab attached to the case prior to cell construction if you don’t have a carrier , they are not that expensive in the scheme of things .

19

That’s the punchline with all soldering.

Done unskillfully you’ll pump way too much heat into everything and damage wire insulation, PCB traces and mounted components, batteries, etc. Done skillfully none of that stuff gets overheated.

The only way to get from unskilled to skilled is to do a lot of it using sacrificial components. You sure don’t want to be learning on an irreplaceable antique. And doubly so on somebody else’s irreplaceable antique.

20

@Bob_Blaylock, any thoughts on this one?