Remove Old Chip: How to Desolder Without Damage

hello,
I have another basic question that I couldn't find the answer to using the search function.

I would like to replace the chips in the engine control unit for engine management and turbocharger with so-called 'tuning chips.'
Now the question is how I can best desolder the two chips without damaging them, so that I can potentially reuse them later.

Does anyone know of a trick or method to do this? I'm concerned that using the hot air method might damage the old chip.

Thank you in advance.
your Kalle

Hello,

If it's done correctly, it won't break. SMD components are also specified for a soldering process with 245 degrees Celsius for 60 seconds. I wouldn't be that worried about it.

Best regards,
Christian.

kalleblombquist wrote:

hello, Does anyone know of a trick or method to do this? I'm concerned that using the hot air method might damage the old chip. Thank you in advance. your Kalle

Hello,

'I had a standard manual vacuum pump available, the type you have to crank. Now, heat and remove the solder from each pin one by one. Be careful not to detach the traces. Work in a criss-cross pattern so that the chip doesn't get too hot locally. Let it cool down occasionally. Repeat this process on both the top and bottom of the circuit board. If you do this carefully, you should be able to remove the chip. Afterwards, it makes sense to solder in IC sockets. You should have some experience with soldering; otherwise, this won't work.'

Regards,
I'm sorry, I can't translate that word because it doesn't seem to be a real word in German. Could you please provide me with the correct spelling or context?

Hi Kalle,
When working with surface-mount devices (SMDs), you either use a hairdryer or a special tip that is suitable for the specific component.
The casing fits.
'With breadboard components, I use flush cutters to trim the legs close to the circuit board.'
(sharp, small wire cutters) and desoldering the remaining leg remnants.
I had the best experiences.
The original component (with the too-short protrusions) can then be placed on a base.
'Solder the pins to make contact and read/reuse the component.'

Best regards, Rudi.

Hi,

Without prior experience in this area, I would strongly advise against attempting this. These solder joints are critical for safety; a cold solder joint can have serious consequences if it disables the control unit during the overhaul process.

If you still want to try it... find a cheap computer circuit board (like a graphics card) with surface-mount components, and solder a comparable chip onto it and then remove it again. If the thing still works afterward, you'll have at least gained some experience, and the failed attempt will be cheaper than damaging the MSG.

Best regards,

January.

What kind of package are we talking about? Is it through-hole or surface mount (SMD)? And if it's SMD, what shape is it?

When wiring, you can either use solder or a soldering iron with flux. I personally prefer using the wire itself (litzendraht).

You can technically use a hot air gun for SMD soldering, but I strongly advise against it if you don't have experience! You wouldn't be the first person to accidentally desolder nearby components or completely ruin the entire circuit board.
With SOIC packages, you can use a suitably wide tip to heat all the pins on one side and gently bend the chip upwards, then do the same on the other side. This allows you to try again three times before damaging it (experience plays a role here). In my opinion, PLCC packages are not safely desoldered at home. The pads on the circuit board cannot withstand heat, and mechanical movement is even more problematic.

When soldering, as Jan already mentioned, achieving 100% perfect solder joints is absolutely essential.
With all due respect, someone who only occasionally solders is unlikely to achieve the same results with surface mount devices (SMDs) as someone who does it regularly. And a 30W DIY soldering iron is completely unsuitable for that purpose.

btw Chris: these parts are only specified for ONE soldering process .

Okay, regarding connectors, I'm very cautious in the automotive sector. Most connector variants aren't suitable for vibrations, and locking connectors that also provide electrical safety are hard to come by (if they exist at all).

/available
Here and here, some impressions of my daily life .
/offered from

CU Gremlin.

Sure, here is the translation of the text from German to English:

"Hi Gremlin,"

I like the idea of thinking in terms of pace or rhythm.

You should really create a smiley for the forum based on that.

Best regards,

January.

THAT was clear to me again .


I originally put up the quote for other reasons. But it fits perfectly with the surface mount device (SMD) soldering station, because haste and rushing around are completely out of place there. After all, we're also building prototypes, which are either very expensive or one-of-a-kind.
You can't afford to have damaged pads or broken pins.

CU Gremlin.

Hi

PLCC components can be removed quite well with a hot air gun, especially if you have a little (or maybe a lot!) of practice.
Surrounding components should be protected from heat, if necessary, using materials such as circuit board scraps.

Bosch used (or was using) AMP's PLCC socket for the STGs in the prototypes (which was previously available at Farnell).
unter der Best.Nr. 398-3468). Ich hatte mit den Teilen bislang keine Probleme bzgl. Vibration.
(also even in shaker tests far above passenger car specifications).

I remove the legs from DIP EEPROMs for the following reasons:
- I have already 'revived' several electronic control units where traces had been torn off.
and the connections were torn off because one of the legs wasn't fully...
It's usually not possible to achieve a loose fit with individual leg stumps.
- From both sides, a vacuum tool or desoldering wick is used to access the contact.
- No heat dissipation through the component itself, which means less heat is required and the board can be thinner.
suffers less.
- Over the years, the circuit boards absorb moisture. This recently had the effect of...
'that the circuit board, in the area of the holes, should be vacuumed using a Metcal suction tool.'
It had delaminated, but that wasn't a problem once I used desoldering braid and individual contacts.


Best regards, Rudi.

Thank you very much, everyone.

This is the second time I've received quick and friendly assistance.
Competent and helpful!

I'll let you know if I decide to go ahead with this risky procedure.

Regards, Kalle.