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I have to solder a chip in a TSSOP-20 package on a board but unfortunately I have no "pcb oven". During the design I had access to a such oven but it's no longer possible. After some search on internet, I found many post about DIY pcb oven. As far as I understood, the heat is monitored to fit the soldering curve on the datasheet. enter image description here

I don't have time to make this kind of oven or spare money to buy one. So, I wonder if it's possible to solder the TSSOP-20 chip thanks to an "unmonitored" oven?

Note that I'm jus a hobbyist, I do not need a very high quality weld.

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    \$\begingroup\$ You do NOT "weld" a tssop. You solder them. And, yes, they can be hand soldered with a soldering iron and fine solder. I do it all the time. \$\endgroup\$ – JRE Jul 4 '17 at 11:24
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    \$\begingroup\$ I'm just an amateur and I can drag solder TSSOP-20 fine. It would be a good chance to develop the technique, just make sure to use plenty of flux. \$\endgroup\$ – Roger Rowland Jul 4 '17 at 11:50
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    \$\begingroup\$ @M.Ferru: Use solder wick if your pins get shorted while soldering. Even consider using lots of flux. That'll make your joints solder cleanly. \$\endgroup\$ – Sachin Jul 4 '17 at 12:38
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    \$\begingroup\$ My hands are shaking like hell all the time and still TSSOP-20 is a piece of cake. I use 0.4mm conical tip and 0.25mm solder and some flux. Trust me, if I can do this, you certainly can do this too. Just a little bit of practice and you'll be fine. \$\endgroup\$ – GAttuso Jul 4 '17 at 14:07
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    \$\begingroup\$ @RogerRowland I answered my own question. I hope you the best for your surgery \$\endgroup\$ – M.Ferru Jul 6 '17 at 19:25
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I finally soldered the chip on my own without a reflow oven. It was way easier than I was expecting, thanks to many comments and some videos found on YouTube.

Materials:

  • Soldering iron, 2mm head
  • Solder wire with incorporated flux
  • Flux in a syringe

I first tinned the top-left pin footprint in order to be able to place the chip for further solder. I then melted the tin again and placed the chip with a little clamp with accuracy to make sure that all the pins were on the corresponding pin footprint. I then soldered the opposite pin. After that, I was sure that the chip would not move during the rest of the process.

I started to solder each pin one by one until two pins got linked due to my lack of soldering skill. To correct my mistake, I put a drop of flux on and then I heated both pins with the soldering iron. With much surprise, it appears that it perfectly corrected the mistake. For the other side, I linked half the pins together on purpose and then use some flux. It's way easier, faster, and produced a cleaner soldering result.

Here is the result of the process:

enter image description here


I did some research about the oven part of the post. It appears that it's possible to use an unmonitored heat control oven (like a kitchen oven) to solder an entire board at once. Since it's non-monitored, it is not advisable to solder sensitive chips. However, it's pretty safe to solder every resistor and capacitor with the oven and then solder chips like this with a soldering iron. (Now I know how to do it properly so it's no big deal.)

But please, DO NOT use the oven you are using to bake food!

Solder wire/paste releases toxic fumes when it melts, so use a dedicated oven that you are sure to not use again.


I made this answer with the help of comments left by other users.

This post might seem useless for experienced people but I think it can help other people like me who have no real experience in soldering.

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You don't have to use a temperature profile, and the chips you solder (not weld) to the board don't have to work either. If you don't follow the temperature profile, your not guaranteed that the chip will work. I've seen some chips fail.

Skillets work in a pinch, so do toaster ovens, but these don't follow a profile and have uneven heating. There are two bad things that can happen:

1) The uneven heating causes parts to be misaligned (which is easily fixable if a soldering iron is accessible)

2) You get too much heat, and burn up parts, some chips are some sensitive then others, for example: mems parts are extremely sensitive to thermal stress or humidity. It may be worth it to invest in a cheap oven if working with expensive parts or if time is valuable to you.

That being said, almost all chips are solderable as a hobbyist with only a soldering iron. As long as the pins are on the outside of the chip an iron can melt the solder and get the job done. The main idea is you have enough flux to help the solder to only stick to the metal and run a blob of solder past the pins, it will only stick to the pins.

QFN's with pins underneath are solderable especially when the pads are extended beyond the part. Even exposed pads (the kind used for thermal sinking) that are underneath TSOPS or DFN's are solderable if you create a via for heating underneath the chip.

If you want to remove chips, however a heat gun may be required (or you could just clip it off if your careful and solder on a new one)

BGA's and LGA's need a hot air gun minimum.

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Yes it's possible. I have soldered 7x7mm QFN-48 package successfully using only heatgun. I did this by pre-soldering the pins on pcb with iron. Then place the chip. And last carefully descent the tip of the gun towards target. When the solder flows the chip should find it's place. Just take your time as the soldering curve shows.

You can also use solderpaste but be careful about the amount of paste.

Check before that your heat gun is hot enough.

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  • \$\begingroup\$ I'd just use the iron for a QFN. As long as it doesn't have a bottom pad, it'll hand solder no problem. \$\endgroup\$ – JRE Jul 4 '17 at 14:55
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I've never soldered surface mount devices, but I know that I can because of YouTube. I could type lots regarding how it's done, but I suggest that the best advice you'll get is to YouTube "Soldering SMD". There are lots of videos.

There are also videos of people who have used simple skillets on cooker tops to solder SMD. It doesn't seem to damage the PCB, so if something this crude works, a basic oven would probably work. Just keep an eye on it and stop when all the paste has flowed. The important thing is that it's just one chip, so unless your oven is extremely uneven, visual temperature control should be possible.

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  • \$\begingroup\$ I solder the chip by hand finally. I watch lot of video about soldering electronic board with reflow oven. This is why my question came in. And there is still not answer to it \$\endgroup\$ – M.Ferru Jul 4 '17 at 20:50
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    \$\begingroup\$ @M.Ferru If you found a particular comment to be so helpful that you would accept it as an answer - perhaps Roger Rowland's comment on drag soldering, perhaps a different one - you can ask them to write it as an answer. \$\endgroup\$ – Andrew Morton Jul 4 '17 at 20:56
  • \$\begingroup\$ Yes I'm thinking about it but none of each comment really answer the question either. I'll wait a bit to see if some answer shows up. If not, I'll ask someone to rewrite a comment as an answer and then accept it as you suggest \$\endgroup\$ – M.Ferru Jul 4 '17 at 20:58
  • \$\begingroup\$ @M.Ferru Have you sought an answer in the list of Related questions that appear alongside yours? You might find some joy there. \$\endgroup\$ – Paul Uszak Jul 4 '17 at 21:01
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    \$\begingroup\$ @M.Ferru You can write your own answer if you want to: self-answered questions are entirely acceptable. Good photos (in focus, well-lit, and well-framed) and some comments on what worked and what went wrong would go a long way to being appreciated by others. \$\endgroup\$ – Andrew Morton Jul 4 '17 at 21:11

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