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Background

I tested some Bourns PEC11L encoders before soldering - they were working fine. Once soldered to my PCB at 300C using Sn99.3,Cu0.7 solder, they stopped working. Looking at the datasheet, I see that I did it all wrong...

PEC11L datasheet excerpt

(In case you're interested, the encoders now almost always skip some of the states in the cycle 00-01-11-10-00.)

So now I'm considering Cui's ACZ11, TT Electronics' EN11. Neither of the datasheets for these mention soldering considerations.

Wurth's mentions wave soldering in the datasheet, but not hand soldering. I don't have a wave soldering machine.

CTS's 11CE gives manual soldering advice, but has a plastic shaft, so I can't use it.

Question(s)

Should I try the Bourns again at 250C, use no-clean flux, and make sure the iron's only applied for a short time? (How short?) Should I get some SnAgCu solder? In the absence of information on the Cui and TT datasheets, can I assume anything?

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    \$\begingroup\$ When soldering by hand, what matters way more than your temp is your dwell time. If these are pins that go into a plastic housing, man it's super easy to melt the plastic. But it can definitely be done. The trick is to not even touch the pin. You get a flat chisel tip, clean it, put a small drop of solder on it (like the amount a fly would expell if he sneezed), and touch that little blob to the PCB's copper ring but NOT THE PIN. Let it dwell for one second, heats up your PCB. Then touch the solder directly between the soldering tip and the pin. Be quick to feed it in, and pull away. \$\endgroup\$
    – Kyle B
    Dec 29, 2021 at 7:50
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    \$\begingroup\$ Practice on scrap parts, and magnification is your friend --- Even some cheap reading glasses from the drug store if you can't afford a good loupe. \$\endgroup\$
    – Kyle B
    Dec 29, 2021 at 7:56
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    \$\begingroup\$ @OutstandingBill: Try it, verify it, write an answer, profit. \$\endgroup\$
    – JRE
    Dec 29, 2021 at 8:33
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    \$\begingroup\$ BTW - we're neighbors! I see you're in Rochester. I'm just west of you on the 90. Go Bills! (Rite?) \$\endgroup\$
    – Kyle B
    Oct 10, 2022 at 18:44
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    \$\begingroup\$ ... and this may be the Bill's big year! \$\endgroup\$ Oct 10, 2022 at 20:39

2 Answers 2

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I found soldering was destroying too many of my encoders, and messing up the whole PCB as a result. Instead I designed a little daughter board (pictured below) which connects to the main board via four blue wires. The sockets are SSW-103-01-T-S from DigiKey.

rotary daughter board

daughter board with encoder

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Problems like this should alleviate with experience, but I really recommend prototyping delicate parts with lead solder.

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