Suited heatgun.

[Oldschool297]

What is the most suited heatgun for removing U12? I have a big one on 1600w and i guess it is to big? Does a one on 300w the job?

[data-medics]

What you want is NOT a heat gun at all. You want to get yourself a proper hot air rework station with controllable airflow and temperature. Even if it's just something cheap like this, it's 100x better than a hot air gun:
https://www.aliexpress.com/item/1005003798289394.html

[Amarbir[CDR-Labs]]

What is the most suited heatgun for removing U12? I have a big one on 1600w and i guess it is to big? Does a one on 300w the job?

Hi,
What are your plans are you wanting to join the data recovery industry or some other plans

[michael chiklis]

Many PROs that do smd soldering are promoting the ATTEN ST-862D hot air station.
https://aliexpress.com/item/1005003428182509.html

That's one of the most cheap for professional working and it has a lot of good reviews on the web.
I personally use the Quick 861DW (original version) which is about double the price.

ATTEN ST-862D vs Quick 861DW review
https://youtu.be/wYCmU6jMLo8

If you need to use hot air only for hobbies, then go with the 858D

I've found on youtube a review of the ATTEN 858D+
https://youtu.be/vva2t21sOAs

Last edited by michael chiklis on May 21st, 2022, 16:12, edited 1 time in total.

[michael chiklis]

What you want is NOT a heat gun at all. You want to get yourself a proper hot air rework station with controllable airflow and temperature. Even if it's just something cheap like this, it's 100x better than a hot air gun:
https://www.aliexpress.com/item/1005003798289394.html

Jared, i think the one you linked is a chinese clone of the ATTEN 858+

[data-medics]

Jared, i think the one you linked is a chinese clone of the ATTEN 858+

Or possibly the exact same thing just sold as a no-name brand for cheap. I was just trying to point to anything cheap that had both temperature and airflow controls, so did a quick AliExpress search and clicked one that looked sufficient.

[Oldschool297]

Thanks i guess a little like this don't do the job? https://www.tradera.com/item/302429/541 ... r-heat-gun

A Air flow station how many W should it be on?

[Oldschool297]

How many W needs to get it done? And how long should i heat it up without damaging?

[Arch Stanton]

How many W needs to get it done? And how long should i heat it up without damaging?

What tool did you get then? You don't set wattage, you aim for a temperature that melts the solder. Now what best temperature is, seems to be topic of debate in some places and depends how fragile the chip is you're trying to remove. Basically debate is either high temps and short heating times vs. moderate temps but potentially longer heating times.

Assume around 220 Celsius melting temp for leaded solder, some of the heat you apply will dissipate into the board so you need more than that, ideally you preheat the board using a pre-heater I suppose. TBH I don't do hard drives so I have no idea how fragile this chip is. I'd say use somewhere between 350-400 degrees Celsius, low-moderate airflow so you do not blow away nearby components.

You might want to practice on some piece of crap board first.

Someone more experienced with this, PLEASE correct me if I'm wrong!

https://youtu.be/slpSo4fND98

[LarrySabo]

Unleaded solder (most likely to have been used these days) melts at 217C. Leaded solder melts at 183C. Use flux when unsoldering/soldering to make the solder flow better, or use a soldering iron and low-melt solder (Bismuth) to lower the melting temperature (safer).

Personally, I use a preheater to slowly raise the temp of the PCB to 210C then use hot air at ~400C to quickly liquify the solder and remove the chip. Be very careful not to dislodge small components nearby.

I put both PCBs on the preheater and mark the location of pin 1 on both ICs before starting, using a line on one and a dot on the other to keep track of which is the patient ROM. Orienting the PCBs so pin 1 is in the same relative position on each PCB helps.

[pepe]

Some words on heating it up:

Humidity trapped within the IC casing can blow the whole thing up, so it is useful to keep the chip at an elevated temp like 70-80C for 20-60 minutes ( before heating it to solder temps with hot air or infrared). These values worked for me albeit most sites say the temp should be above 100 C (which i consider bs coz we do not need to boil the water, just get it out of the IC case by providing an environment with lower rel. hum.) and the time should be 4-48 hours or even more, but i would not do that for memory components to prevent corruption of the content.
Also, it depends on the environment's relative humidity, there's mostly lower % of rel. hum. (30-40% here)in rooms the winter coz the absolute humidity of the outside air is lower, while in the summer you get 60%+ rel. humidity in the house easily.

pepe

[fzabkar]

"Popcorn cracking" or "popcorning" is the commonly used term to describe what happens when an IC with trapped moisture is heated inappropriately.

https://www.pcbonline.com/blog/what-is-popcorn-effect-in-pcb-assembly.html

[pepe]

yep. The point is to be aware of the phenomenon.

[Oldschool297]

I can take a photo of mine. But it is to big. But i used it without blowing other parts away. I guess pin 1 is the same on the same models?

[Arch Stanton]

I can take a photo of mine. But it is to big. But i used it without blowing other parts away.

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