Hello are there any specs from ST on reflow temperatures for a TSSOP 20 chip?

[mike louaillier]

Posted on July 15, 2017 at 21:58

can't find one word on their site about temperatures for soldering.

[Tesla DeLorean]

Posted on July 15, 2017 at 22:22

Definitely an area where the documentation you'd expect to find such detail has it missing.

Google AN2639 Soldering Recommendations, couldn't find a linkable copy on ST's site. Have attached

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Attachments :

en.CD00173820.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HyZG&d=%2Fa%2F0X0000000b9Z%2FBgvxm1e710Ve1Nedl369SD8V4mVqOZqq.YxMmDzMZV4&asPdf=false

[mike louaillier]

Posted on July 15, 2017 at 23:01

thanx Clive One, yes and they don't have any references to AN2639. and no hope searching it out around here, either. maybe if i put in a few keywords it might help.

reflow temperature profile hot air soldering specs specifications method limits heat

AN2639 Soldering recommendations and package information for Lead-free ECOPACK microcontrollers

[T J]

Posted on July 17, 2017 at 01:12

Starting out, I wasn't sure what temperature to use;

almost 10 years ago, I built a toaster oven to re-flow my PCBs.

but I wasn't sure what temperature to use.

Some datasheets suggest 160C-180C and other datasheets suggest upto 260C for reflow.

I built the unit with Fibro-insulation, it gets to 275C

I carefully put my loaded PCB and ran it up to 250C

it worked, but I had to adjust some parts. I put that board through 7 times at over 200C

it still worked at 25MHz, albeit scorched with a tinge of burnt.

the moral of the story is that the temp is not critical for prototypes.

Lead free you need over 200C

Leaded solder needs over 190C to flow well.  ( 2 minutes duration)

Capacitors don't like the high temp, the capacity will degrade with excessive temperature.

I use through-hole caps for that reason.