Effects of moisture on CPLD

I have twenty Xilinx XC9572XL VQFP64. Their sealed package has been open two
months, and stored in an office with no temperature/humidity control. Now I
want to get these devices soldered in for a pre-production run.

If I put these in without carrying out a baking cycle am I asking for
trouble? What are the likely effects due to moisture, and what are people's
real-life experiences?

Many thanks,

Dave

Dave,

The packages may have absorbed moisture, and if you put them through a 
normal solder wave machine, you will have popcorn.

The devices are prone to crack, and shatter due to the moisture turning 
to steam, and having no where to go.

Parts may be baked before assembly to remove the water.
http://www.xilinx.com/bvdocs/whitepapers/wp192.pdf
details some of the procedures.

Austin

Dave Marsh wrote:
> I have twenty Xilinx XC9572XL VQFP64. Their sealed package has been open two
> months, and stored in an office with no temperature/humidity control. Now I
> want to get these devices soldered in for a pre-production run.
> 
> If I put these in without carrying out a baking cycle am I asking for
> trouble? What are the likely effects due to moisture, and what are people's
> real-life experiences?
> 
> Many thanks,
> 
> Dave
> 
> 
> 

"Austin Lesea" <austin@xilinx.com> wrote in message
news:c7qnr5$n103@cliff.xsj.xilinx.com...
> Dave Marsh wrote:
> > I have twenty Xilinx XC9572XL VQFP64. Their sealed package has been open
two
> > months, and stored in an office with no temperature/humidity control.
Now I
> > want to get these devices soldered in for a pre-production run.
> >
> > If I put these in without carrying out a baking cycle am I asking for
> > trouble? What are the likely effects due to moisture, and what are
people's
> > real-life experiences?
> >
> > Many thanks,
> >
> > Dave
>
> Dave,
>
> The packages may have absorbed moisture, and if you put them through a
> normal solder wave machine, you will have popcorn.
>
> The devices are prone to crack, and shatter due to the moisture turning
> to steam, and having no where to go.
>
> Parts may be baked before assembly to remove the water.
> http://www.xilinx.com/bvdocs/whitepapers/wp192.pdf
> details some of the procedures.
>
> Austin
>

Thanks Austin - It sounds like we we would definitely notice if there was a
problem then?! From the white paper it suggests a minimum of a 12 hour cycle
at 125degC is needed.

Dave

"Dave Marsh" <me@privacy.net> wrote in message
news:40a0dd9d$0$15249$fa0fcedb@lovejoy.zen.co.uk...
> I have twenty Xilinx XC9572XL VQFP64. Their sealed package has been open
two
> months, and stored in an office with no temperature/humidity control. Now
I
> want to get these devices soldered in for a pre-production run.
>
> If I put these in without carrying out a baking cycle am I asking for
> trouble? What are the likely effects due to moisture, and what are
people's
> real-life experiences?

Reflow soldering without baking them (probably 120 C for 24 hours) might
give problems. Hand soldering should be OK: I never have problems, anyway.

Leon
-- 
Leon Heller, G1HSM
http://www.geocities.com/leon_heller

"Leon Heller" <leon_heller@hotmail.com> wrote in message
news:40a0ebc8$0$25328$cc9e4d1f@news-text.dial.pipex.com...
> "Dave Marsh" <me@privacy.net> wrote in message
> news:40a0dd9d$0$15249$fa0fcedb@lovejoy.zen.co.uk...
> > I have twenty Xilinx XC9572XL VQFP64. Their sealed package has been open
> two
> > months, and stored in an office with no temperature/humidity control.
Now
> I
> > want to get these devices soldered in for a pre-production run.
> >
> > If I put these in without carrying out a baking cycle am I asking for
> > trouble? What are the likely effects due to moisture, and what are
> people's
> > real-life experiences?
>
> Reflow soldering without baking them (probably 120 C for 24 hours) might
> give problems. Hand soldering should be OK: I never have problems, anyway.
>
> Leon
> --
> Leon Heller, G1HSM
> http://www.geocities.com/leon_heller
>

Thanks Leon. That's interesting, as the first few are going to be hand
soldered (and I don't have a proper oven at the moment).

Dave

Dave,

Yes, you would notice a difference!  Not all parts will pop, and those 
that do, may not even be noticed initially.  Later they will fail as 
they will now absorb water like crazy from all of the cracks.

Austin

Dave Marsh wrote:

> "Austin Lesea" <austin@xilinx.com> wrote in message
> news:c7qnr5$n103@cliff.xsj.xilinx.com...
> 
>>Dave Marsh wrote:
>>
>>>I have twenty Xilinx XC9572XL VQFP64. Their sealed package has been open
> 
> two
> 
>>>months, and stored in an office with no temperature/humidity control.
> 
> Now I
> 
>>>want to get these devices soldered in for a pre-production run.
>>>
>>>If I put these in without carrying out a baking cycle am I asking for
>>>trouble? What are the likely effects due to moisture, and what are
> 
> people's
> 
>>>real-life experiences?
>>>
>>>Many thanks,
>>>
>>>Dave
>>
>>Dave,
>>
>>The packages may have absorbed moisture, and if you put them through a
>>normal solder wave machine, you will have popcorn.
>>
>>The devices are prone to crack, and shatter due to the moisture turning
>>to steam, and having no where to go.
>>
>>Parts may be baked before assembly to remove the water.
>>http://www.xilinx.com/bvdocs/whitepapers/wp192.pdf
>>details some of the procedures.
>>
>>Austin
>>
> 
> 
> Thanks Austin - It sounds like we we would definitely notice if there was a
> problem then?! From the white paper it suggests a minimum of a 12 hour cycle
> at 125degC is needed.
> 
> Dave
> 
> 
> 

"Dave Marsh" <me@privacy.net> wrote in message
news:40a0f66b$0$15245$fa0fcedb@lovejoy.zen.co.uk...
> "Leon Heller" <leon_heller@hotmail.com> wrote in message
> news:40a0ebc8$0$25328$cc9e4d1f@news-text.dial.pipex.com...
> > "Dave Marsh" <me@privacy.net> wrote in message
> > news:40a0dd9d$0$15249$fa0fcedb@lovejoy.zen.co.uk...
> > > I have twenty Xilinx XC9572XL VQFP64. Their sealed package has been
open
> > two
> > > months, and stored in an office with no temperature/humidity control.
> Now
> > I
> > > want to get these devices soldered in for a pre-production run.
> > >
> > > If I put these in without carrying out a baking cycle am I asking for
> > > trouble? What are the likely effects due to moisture, and what are
> > people's
> > > real-life experiences?
> >
> > Reflow soldering without baking them (probably 120 C for 24 hours) might
> > give problems. Hand soldering should be OK: I never have problems,
anyway.
> >
> > Leon
> > --
> > Leon Heller, G1HSM
> > http://www.geocities.com/leon_heller
> >
>
> Thanks Leon. That's interesting, as the first few are going to be hand
> soldered (and I don't have a proper oven at the moment).

If you get a PCB assembly company to do the others, they should be able to
do the baking for you. They probably do it all the time.

Leon

"Leon Heller" <leon_heller@hotmail.com> wrote in message news:<40a0ebc8$0$25328$cc9e4d1f@news-text.dial.pipex.com>...
> "Dave Marsh" <me@privacy.net> wrote in message
> news:40a0dd9d$0$15249$fa0fcedb@lovejoy.zen.co.uk...
> > I have twenty Xilinx XC9572XL VQFP64. Their sealed package has been open
>  two
> > months, and stored in an office with no temperature/humidity control. Now
>  I
> > want to get these devices soldered in for a pre-production run.
> >
> > If I put these in without carrying out a baking cycle am I asking for
> > trouble? What are the likely effects due to moisture, and what are
>  people's
> > real-life experiences?
> 
> Reflow soldering without baking them (probably 120 C for 24 hours) might
> give problems. Hand soldering should be OK: I never have problems, anyway.

I'm not so sure about that.  I bought a handful of microcontrollers
about a year ago and stuffed boards, and all was fine.  I never
resealed the bag (I don't have the facility) so they sat until I used
them a month ago.  I handsoldered one prototype and it failed in a
particular way.  After much gnashing of teeth (I hate shotgunning
parts), I removed the micro and replaced it with another from the same
bag, which worked.  I have since hand-built three more prototypes and
I've had a 50% fallout.  I guess I should've baked the parts...

-a

"Andy Peters" <Bassman59a@yahoo.com> wrote in message
news:9a2c3a75.0405131635.25f8ea90@posting.google.com...
> "Leon Heller" <leon_heller@hotmail.com> wrote in message
news:<40a0ebc8$0$25328$cc9e4d1f@news-text.dial.pipex.com>...
> >
> > Reflow soldering without baking them (probably 120 C for 24 hours) might
> > give problems. Hand soldering should be OK: I never have problems,
anyway.
>
> I'm not so sure about that.  I bought a handful of microcontrollers
> about a year ago and stuffed boards, and all was fine.  I never
> resealed the bag (I don't have the facility) so they sat until I used
> them a month ago.  I handsoldered one prototype and it failed in a
> particular way.  After much gnashing of teeth (I hate shotgunning
> parts), I removed the micro and replaced it with another from the same
> bag, which worked.  I have since hand-built three more prototypes and
> I've had a 50% fallout.  I guess I should've baked the parts...
>
> -a

Thanks Andy. That's interesting - One of the assembly houses I've come
across on the web says the parts would need baking before they will hand
solder them . This seems to concur with your experiences.

Dave

"Dave Marsh" <me@privacy.net> wrote in message news:<40a4ce89$0$4587$db0fefd9@news.zen.co.uk>...
> "Andy Peters" <Bassman59a@yahoo.com> wrote in message
> news:9a2c3a75.0405131635.25f8ea90@posting.google.com...
> > "Leon Heller" <leon_heller@hotmail.com> wrote in message
>  news:<40a0ebc8$0$25328$cc9e4d1f@news-text.dial.pipex.com>...
> > >
> > > Reflow soldering without baking them (probably 120 C for 24 hours) might
> > > give problems. Hand soldering should be OK: I never have problems,
>  anyway.
> >
> > I'm not so sure about that.  I bought a handful of microcontrollers
> > about a year ago and stuffed boards, and all was fine.  I never
> > resealed the bag (I don't have the facility) so they sat until I used
> > them a month ago.  I handsoldered one prototype and it failed in a
> > particular way.  After much gnashing of teeth (I hate shotgunning
> > parts), I removed the micro and replaced it with another from the same
> > bag, which worked.  I have since hand-built three more prototypes and
> > I've had a 50% fallout.  I guess I should've baked the parts...
> >
> > -a
> 
> Thanks Andy. That's interesting - One of the assembly houses I've come
> across on the web says the parts would need baking before they will hand
> solder them . This seems to concur with your experiences.
> 
> Dave

Perhaps one of those BlackNdecker toaster ovens will do the job since
they were mentioned awhile back as being useable for home based reflow
ovens in another thread on BGA pcb work.

regards

johnjakson_usa_com