Production of board-mounted modules

[avishorp]

Do PCB mounted modules (such as ESP-12) undergo any special process that allows them to withstand the reflow process twice?

[Berni]

Nope you just don't poke at any of the components during the reflow process and they stay in there place.

[ataradov]

Nope you just don't poke at any of the components during the reflow process and they stay in there place.

More often than not, a high temp solder is used as well.

[richardlawson1489]

Why you want to do reflow process twice?

[DTJ]

Why you want to do reflow process twice?

The modules are reflowed when manufactured and then reflowed when mounting to the final target  or product PCB.

Modules like this:
http://www.esp8266.com/wiki/lib/exe/fetch.php?cache=&media=esp-12-e2015-4-8_182428.jpg

[l0wside]

As the modules are usually populated only on one side and are typically placed on the top of the target PCB, the components see only two reflow cycles. Anything placed on the solder side of the target PCB sees the same number of cycles.

JEDEC seems to specify three reflow cycles per part, see for example http://www.nxp.com/documents/reflow_soldering/Reflow_Soldering_Profile.pdf

[HHaase]

You'd be surprised how many heat cycles a PCB can see,   particularly a PCB with dual-sided SMT components plus thru-hole.     It's routine to see a PCB that gets two reflow cycles plus another heat cycle over a wave.

-Hans