I'm trying to mount an RF module that has 33 edge castellation pins. The data sheet says that the peak temperature is 250°C. I'm using 60/40 lead solder for a lower melting point but the solder will only melt at 315°C and I suspect that I'm burning the gates on these expensive modules.

Is reflow soldering the only way to mount components like these?

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    \$\begingroup\$ I would recommend posting a link to the actual RF module, if possible. Regardless, I believe you are mistaking the 315C \$\endgroup\$
    – scld
    Jan 8, 2014 at 20:15
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    \$\begingroup\$ According to wikipedia Alloys commonly used for electrical soldering are 60/40 Tin/lead (Sn/Pb) which melts at 370 °F or 188 °C \$\endgroup\$
    – alexan_e
    Jan 8, 2014 at 20:18
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    \$\begingroup\$ I'm using the Hakko FX-888D with the 60/40 tin/lead. I'm quite sure the programming is in Fahrenheit and when I place the tinned tip up to the solder, it will only melt if I the programmable temp says 600F(315C). Could it be my tip? \$\endgroup\$ Jan 8, 2014 at 20:25
  • \$\begingroup\$ cel.com/pdf/datasheets/MeshConnect_EM357_Mini_Modules_DS.pdf \$\endgroup\$ Jan 8, 2014 at 20:27
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    \$\begingroup\$ Well, the big problem, as Kaz said, is that the tip temp is not going to be equal to the melting temp when you first touch the solder. I like to solder stuff with my tip at 800F. Better irons will self adjust and keep a steady temperature more reliably. \$\endgroup\$
    – scld
    Jan 8, 2014 at 21:13

1 Answer 1


60/40 solder melts at somewhere around 180 to 190 degrees Celsius, not 300-something.

Use a temperature-controlled soldering station.

In any case, the temperature in the device itself is not necessarily as high as it is at the joint being soldered. If you work quickly, you can create a fast, local temperature rise at the joint.

Also, depending on the size and geometry of the part being soldered, sometimes it is feasible to introduce a sink which removes heat somewhere along the pin between the joint and the part itself.

  • \$\begingroup\$ Maybe he got confused with Fahrenheit? But that is only 157C, so equally, maybe not... \$\endgroup\$
    – gbmhunter
    Jan 8, 2014 at 20:22
  • \$\begingroup\$ @gbmhunter I remember having seen the same confusion months ago in another question. Someone also had the idea that Sn/Pb melted at 300-something C but the figure did not exactly correspond to the correct F either. \$\endgroup\$
    – Kaz
    Jan 8, 2014 at 20:24

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