Can a soldering iron damage a CMOS?

[MrJack 0]

Hi Forum,

 

I just got this new toy, the Velleman VTS09 (http://www.velleman.eu/products/view/?id=375228).

 

But is it safe to use it in a CMOS setting?

 

I have read that soldering irons are better than soldering guns, because the 'guns' work by shorting a current, which can damage the CMOS chip....is this true?

 

Unfortunately, I cant see how the VTS09 works, other than it uses three AA batteries and is ready pretty quick.

 

Thanks.

[Soundy 1]

CMOS chips tend to be static sensitive - use a grounded iron and follow proper handling procedures, be sure not to apply too much heat to your semiconductors, and you should be fine.

[mike_va 0]

Hi Forum,

 

I just got this new toy, the Velleman VTS09 (http://www.velleman.eu/products/view/?id=375228).

 

But is it safe to use it in a CMOS setting?

 

I have read that soldering irons are better than soldering guns, because the 'guns' work by shorting a current, which can damage the CMOS chip....is this true?

 

Unfortunately, I cant see how the VTS09 works, other than it uses three AA batteries and is ready pretty quick.

 

Thanks.

 

A battery powered iron is not going to be grounded, I would not use that for CMOS.

 

CMOS (complementary MOS) work with a really thin oxide layer for the gate, doesn't take much to break that down. While the inputs usually have protection diodes I would not risk it (i.e. they need something to conduct to, which if your installing is not there).

 

The problem with ESD is that it can cause latent damage which only becomes apparent later. Also good practice to use a wrist strap and dissipative mat.

 

Also get a temp controlled iron or gun, irons are a lot easier to use on tiny parts. Get a weller. Guns are usually for bigger things that suck up heat.

[camera-newbie 0]

Take what Mike and Soundy say as they're spot on.. I was reminded of these facts when I took my ESD refresher course (an annual requirement) last Friday..

 

Also make sure it's not too dry (low humidity) which can increase the possibility of static shock.

[survtech 0]

I know many are freaky about ESD damaging solid state circuits but I can tell you from over 40 years of experience that it is less of an issue than is generally believed. All it takes is reasonable care, such as touching a ground before touching a PC board or device. In all of my time as a bench tech, I never bothered wearing a grounding device or strap and I never blew a circuit or device due to static.

[mike_va 0]

Yes, I did not wear a wrist strap thirty years ago but things have changed. Further, damage can go undetected initially and show up later. The real problem today is that they have gotten so small - very little leakage inductance and die features have gotten incredibly small.

 

IC's already installed are less susceptible.

 

A quick search on google images shows some examples for the curious...

 

Sure you can get away with it, however try installing a MOSFET sometime without any ESD protection as an experiment...

[survtech 0]

however try installing a MOSFET sometime without any ESD protection as an experiment...

I have. No sweat, unless it takes up to 10 years for the damage to appear.

 

I'm not advocating taking no precautions, I just never relished being hooked up like a machine just to solder parts to a PC board. Anti-static mats, grounded and controlled temperature soldering irons and accounting for low humidity is one thing; being handcuffed like a criminal is quite another.

 

Besides, I doubt anyone on this forum is contemplating complex soldering of surface mount ICs or MOSFETs to extremely dense circuit boards. And if they were, a basic soldering iron, even controlled temperature, is not the device of choice.

 

This is CCTV, not circuit manufacturing or rework.

[MrJack 0]

Thank you for all the good advise. I certainly got both opinions explained, which is very good