0603 Ceramic Capacitors and Soldering Damage during Repair

[mikkkejickles]

Hey Folks,

As I was soldering some (good quality) ceramic 0603 capacitors from mouser, a couple ended up sticking to the iron for 4 or 5 seconds @ 350 degrees Celsius. After this they look darker than the others (obviously).

My question is if those capacitors are actually destroyed?

Sorry if this is a stupid question. This was my bad technique at the time.

[T3sl4co1l]

Not in my experience.

if you're suspicious, do an electrical test when you're done: verify that the capacitors are the correct value and not shorted.  This may not be possible for all capacitors in a finished circuit, or maybe you can test as you go, I don't know.

Hmm, I wonder if the flex-contact type capacitors degrade with heat.  AFAIK, they use an epoxy undercoat, which would be prone to decomposition at that temperature.  (If the parts you bought don't specify flex type, then they're not flex, just plain old solid ceramic and metal.)

Tim

[KaneTW]

I recommend reading https://nepp.nasa.gov/files/16346/08_002_01%20GSFC%20Teverovsky.pdf --- cracks are relatively easy to cause, and while they don't impact capacitance too much, they cause an increase in avalanche breakdown failures and leakage current.

[DC1MC]

Hey Folks,

As I was soldering some (good quality) ceramic 0603 capacitors from mouser, a couple ended up sticking to the iron for 4 or 5 seconds @ 350 degrees Celsius. After this they look darker than the others (obviously).

My question is if those capacitors are actually destroyed?

Sorry if this is a stupid question. This was my bad technique at the time.

If the 350 degrees are really Celsius, then they are gone now, what kind of solder do you use for 350C ? If there are 350F then they degraded a bit but survived most likely.

 Cheers,
 DC1MC

[langwadt]

Hey Folks,

As I was soldering some (good quality) ceramic 0603 capacitors from mouser, a couple ended up sticking to the iron for 4 or 5 seconds @ 350 degrees Celsius. After this they look darker than the others (obviously).

My question is if those capacitors are actually destroyed?

Sorry if this is a stupid question. This was my bad technique at the time.

350'C is normal soldering iron temperature for leaded solder, unleaded around 380'C



If the 350 degrees are really Celsius, then they are gone now, what kind of solder do you use for 350C ? If there are 350F then they degraded a bit but survived most likely.

 Cheers,
 DC1MC

[DC1MC]

[
350'C is normal soldering iron temperature for leaded solder, unleaded around 380'C

 Hääää ?

[Howardlong]

There can be problems with ceramic caps due to the the package cracking with repeated or uneven temperature cycling. The cracks are frequently not visible under inspection. This can lead to intermittent problems which become worse over time due to small mechanical stresses, for example board stress when cycling connectors.

I learned this the hard way, but in general if you need to rework with an iron rather than reflow, consider replacing the caps that you thermally cycle.

Edit: the darkening might just be dead flux, so consider cleaning your board.

[tooki]

Hey Folks,

As I was soldering some (good quality) ceramic 0603 capacitors from mouser, a couple ended up sticking to the iron for 4 or 5 seconds @ 350 degrees Celsius. After this they look darker than the others (obviously).

My question is if those capacitors are actually destroyed?

Sorry if this is a stupid question. This was my bad technique at the time.

If the 350 degrees are really Celsius, then they are gone now, what kind of solder do you use for 350C ? If there are 350F then they degraded a bit but survived most likely.

 Cheers,
 DC1MC

350'C is normal soldering iron temperature for leaded solder, unleaded around 380'C

Say what now?!?

I use 290-310 for leaded solder and 300-350 for lead-free — for through-hole! For small SMD parts like an 0603 I could probably get away with even less. (The only time I've had to really crank up the heat on SMD was to replace a quite large (~12mm square) ferrite choke.)

[T3sl4co1l]

You are either a much more patient person than most of us... or you're using a beefy JBC.

(Or your iron's cal is off )

Tim

[KaneTW]

I usually solder leadless SMD at 350C. Should be able to lower it quite a bit if I had a preheater, but alas.

[tooki]

You are either a much more patient person than most of us... or you're using a beefy JBC.

(Or your iron's cal is off )

It's an Ersa i-Con nano. Probably not out of cal given how new it is — but it is a powerful iron that can heat fast.

[amyk]

You can test them if you want to be sure but I doubt they'll be much affected --- the normal manufacturing process of those capacitors involves baking them at much higher temperatures --- they are ceramic after all...

https://en.wikipedia.org/wiki/File:MLCC-Manufacturing-Process.png

[Howardlong]

You can test them if you want to be sure but I doubt they'll be much affected --- the normal manufacturing process of those capacitors involves baking them at much higher temperatures --- they are ceramic after all...

https://en.wikipedia.org/wiki/File:MLCC-Manufacturing-Process.png

Under reflow, yes, but if you’re hand soldering with an iron, there is much more thermal stress as the package is unevenly heated, see my comment above.

[mikkkejickles]

Really appreciate all the replies folks. I'll test them at the end! There are 64 of them.

They're automotive capacitors but I'm using them for a video up-scaling device.

Here is the datasheet.

https://www.mouser.com/ProductDetail/81-GCM188R71C104KA7J