Hello,
We are developing our handling documents, for that I need some information.
We get the PCBs assembled from the EMS supplier, but we are not having any guidelines on shelf life of the same.
Can you help me with the guideline for shelf life of Printed circuit board assemblies. (we are not using any battery /super cap in our assembly)
Is there any IPS standard stating the same?
Thanks for your support in advance.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of TechNet automatic digest system
Sent: Tuesday, January 24, 2017 11:30 AM
To: [log in to unmask]
Subject: TechNet Digest - 21 Jan 2017 to 23 Jan 2017 (#2017-12)
There are 20 messages totaling 1727 lines in this issue.
Topics of the day:
1. Element Quiz Question
2. Nitrogen Reflow and Warpage Issues on POPs (15)
3. Element Quiz Answer
4. Copper Thickness Tester, Coppertron SM6000 (2)
5. R: [TN] Nitrogen Reflow and Warpage Issues on POPs
----------------------------------------------------------------------
Date: Mon, 23 Jan 2017 16:02:04 +0000
From: "Stadem, Richard D." <[log in to unmask]>
Subject: Re: Element Quiz Question
Mama Carbone, mother of the pizza table.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Douglas Pauls
Sent: Friday, January 20, 2017 11:01 AM
To: [log in to unmask]
Subject: Re: [TN] Element Quiz Question
Robert Hydrogen. Father of the Periodic Table...
Doug Pauls
Principal Materials and Process Engineer Rockwell Collins
On Fri, Jan 20, 2017 at 10:43 AM, George Wenger <[log in to unmask]>
wrote:
> Hydrogen
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
> Sent: Friday, January 20, 2017 11:41 AM
> To: [log in to unmask]
> Subject: [TN] Element Quiz Question
>
> Here is the Element Quiz Question:
>
> The Question:
> This element is named after the "Father of the Periodic Table". Which
> element is being described?
>
>
> The winner of the quiz will get the services of Clumpy and Kloumpios
> for the week.
>
> So far Clumpy and Kloumpios have done the following:
>
> Past Quiz winners/tasks:
> Week 1 Ravinder Ajmani, Western Digital Week 1 Ron Feyereisen,
> SigmaTron Intl.
> Week 2 Louis Hart, Compunetics
> Week 3 Mark Kostinovsky, Schlumberger Ltd.
> Week 3 John Burke
> Week 4 Drew Meyer, Benchmark Electronics Week 5 No Winner - no correct
> responses!
> Week 6 Bhanu Sood, NASA
> Week 7 Keith Calhoun, Sopark Corp
>
> Week 7 Ian Fox, Rolls Royce
> - I have a bunch of jobs lined up commissioning our brand new lab in
> our new swanky factory. Who have I got so I can get security clearance?
>
> Week 8 Leland Woodall
> - Kloumpios assisted greatly with the clearing of my driveway on Monday.
> It was good to see the little guy again!
>
> Week 8 David Bealer, SMT
> - assisted with ???
>
> Week 9 Tom Carroll, Boeing
> - Tell Clumpy and Kloumpios to get on the first available flight to
> JFK, I live a mile from the JFK AirTrain station in Howard Beach, NY.
> Clumpy and Kloumpios can help me prepare some flammability burn test
> samples for an FAA project that I'm working on. After that they can go
> fishing in Jamaica Bay and catch some dinner.
>
> Week 10 ???
> - assisted with ???
>
> I hope everyone has a awesome week!
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
------------------------------
Date: Mon, 23 Jan 2017 11:29:11 -0600
From: Bob Wettermann <[log in to unmask]>
Subject: Nitrogen Reflow and Warpage Issues on POPs
Dear Technetters:
We have a Class 3 customer with very complex, high density placements
(think cell phone for the military). This board is laden w/0201s, 0.4mm
pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
The problems in this board assembly for some time have been isolated to
this OMAP part. We have lots of shorts and opens (randomly-spaced) as
confirmed by electrical testing, dye and pry and cross sectioning. The Omap
has been shown to warp 5-7 mils depending on the reflow profile.( It is a
no clean SAC305 process). We have profiled the reflow process by embedding
TCs in the corners of the balls of the device (ball interface with the
board where all of the problems are) , the die, neighboring components
etc. We dialed in the profile as low of a temp as possible.
We are running several DOEs to come up with a placement/rework process.
As part of the investigation the client is fixated on nitrogen reflow being
part of the solution to these warped BGAs. Nitrogen reflow IMHO is the
solution for joint aesthetics, wetting issues and enhanced reliability of
the interconnection.
? Does anyone have experience with hot air reflow using nitrogen where its
addition helped to mitigate warpage issues?
Thanks!
--
Bob Wettermann
BEST Inc
------------------------------
Date: Mon, 23 Jan 2017 17:40:19 +0000
From: Ed Popielarski <[log in to unmask]>
Subject: Re: Element Quiz Answer
Congratulations!
Ed Popielarski
Engineering Manager
970 NE 21st Ct.
Oak Harbor, Wa. 98277
Ph: 360-675-1322
Fx: 206-624-0695
Cl: 360-544-2289
“It's one kind of victory to slay a beast, move a mountain, and cross a chasm, but it's another kind altogether to realize that the beast, the mountain, and the chasm were of your own design.”
https://goo.gl/maps/mMjg43rXeFB2
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Douglas Pauls
Sent: Saturday, January 21, 2017 7:44 AM
To: [log in to unmask]
Subject: Re: [TN] Element Quiz Answer
Louis, I would have been the first to congratulate you and wish you well, but am sure the FEQAB would have disqualified me.
Doug Pauls
Principal Materials and Process Engineer Rockwell Collins
On Fri, Jan 20, 2017 at 6:42 PM, Bev Christian <[log in to unmask]>
wrote:
> Louis,
> I would like to be second in offering you congratulations on your
> forthcoming retirement. I wish you all the best.
>
> Regards,
> Bev
>
> Sent from my BlackBerry 10 smartphone on the Bell network.
> Original Message
> From: Louis Hart
> Sent: Friday, January 20, 2017 6:27 PM
> To: [log in to unmask]
> Reply To: TechNet E-Mail Forum
> Subject: Re: [TN] Element Quiz Answer
>
> Dave, this victory is the capstone, the gilding on my career...end of
> this month I'm officially retiring. Clumpy and Kloumpios help will be
> welcome in clearing out the office. Not sure if I will stick on
> TechNet or not...it's been a big part of my life for most of the past
> 20 years but I may go on to do something completely different... Louis
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
> Sent: Friday, January 20, 2017 2:44 PM
> To: [log in to unmask]
> Subject: [TN] Element Quiz Answer
>
> Here is the Element Quiz Question:
>
> The Question:
> This element is named after the "Father of the Periodic Table". Which
> element is being described?
>
> The Answer:
> The element is Mendelevium (Md)! Mendelevium was named after Russian
> chemist Dmitri Mendeleev who developed the Periodic table we use
> today. Md is one of the transuranic elements and was discovered by
> Albert Ghiorso and his team at Cal Berkeley in 1955 by bombarding
> einsteinium-253 with helium ions in the cyclotron. Ghiorso's team
> irradiated plutonium for one year to produce one billion atoms of
> einsteinium-253 target which had 3 week half life once purified -
> basically they had a one week window in their attempt to produce Md ( and we think we have ugly project deadlines).
>
> An interesting bit of trivia:
>
> "We thought it fitting that there be an element named for the Russian
> chemist Dmitri Mendeleev, who had developed the periodic table. In
> nearly all our experiments discovering transuranium elements, we'd
> depended on his method of predicting chemical properties based on the
> element's position in the table. But in the middle of the Cold War,
> naming an element for a Russian was a somewhat bold gesture that did
> not sit well with some American critics.[7]. Glenn T. Seaborg"
>
> [7] Mendelevium - Elementymology & Elements Multidict. Peter van der Krogt.
>
>
> The winner of the quiz is Louis Hart, Compunetics and will get the
> services of Clumpy and Kloumpios for the week.
>
> So far Clumpy and Kloumpios have done the following:
>
> Past Quiz winners/tasks:
> Week 1 Ravinder Ajmani, Western Digital Week 1 Ron Feyereisen,
> SigmaTron Intl.
> Week 2 Louis Hart, Compunetics
> Week 3 Mark Kostinovsky, Schlumberger Ltd.
> Week 3 John Burke
> Week 4 Drew Meyer, Benchmark Electronics Week 5 No Winner - no correct
> responses!
> Week 6 Bhanu Sood, NASA
> Week 7 Keith Calhoun, Sopark Corp
>
> Week 7 Ian Fox, Rolls Royce
> - I have a bunch of jobs lined up commissioning our brand new lab in
> our new swanky factory. Who have I got so I can get security clearance?
>
> Week 8 Leland Woodall
> - Kloumpios assisted greatly with the clearing of my driveway on Monday.
> It was good to see the little guy again!
>
> Week 8 David Bealer, SMT
> - assisted with ???
>
> Week 9 Tom Carroll, Boeing
> - Tell Clumpy and Kloumpios to get on the first available flight to
> JFK, I live a mile from the JFK AirTrain station in Howard Beach, NY.
> Clumpy and Kloumpios can help me prepare some flammability burn test
> samples for an FAA project that I'm working on. After that they can go
> fishing in Jamaica Bay and catch some dinner.
>
> Week 10 Louis Hart, Compunetics
> - assisted with ???
>
> I hope everyone has a awesome week!
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
------------------------------
Date: Mon, 23 Jan 2017 18:13:09 +0000
From: "Stadem, Richard D." <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
I have never heard of using nitrogen to mitigate warpage, only oxidation.
I do not see how it would affect warpage, but I could be very wrong.
However, nitrogen could help the solder joints flow out a little better by reducing oxidation, and as an indirect benefit, help reduce issues caused by warpage.
But because solder wetting is improved in a nitrogen atmosphere, it could likewise exacerbate solder shorting.
But the presence of the nitrogen (or lack thereof) would not directly affect the amount of warpage. Warpage is related to the heat exposure, more precisely, the ramp rate and the effect is has on the various parts of the TI Omap component itself. If the topside surface is expanding faster than the bottom, the chip will curl down in the corners. If the bottom is expanding faster, the chip will curl upwards in the corners. This may be caused not only by a difference in the CTE between the top and bottom of the part, but also by the core (heatspreaders, etc.)
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
Sent: Monday, January 23, 2017 11:29 AM
To: [log in to unmask]
Subject: [TN] Nitrogen Reflow and Warpage Issues on POPs
Dear Technetters:
We have a Class 3 customer with very complex, high density placements (think cell phone for the military). This board is laden w/0201s, 0.4mm pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
The problems in this board assembly for some time have been isolated to this OMAP part. We have lots of shorts and opens (randomly-spaced) as confirmed by electrical testing, dye and pry and cross sectioning. The Omap has been shown to warp 5-7 mils depending on the reflow profile.( It is a no clean SAC305 process). We have profiled the reflow process by embedding TCs in the corners of the balls of the device (ball interface with the board where all of the problems are) , the die, neighboring components etc. We dialed in the profile as low of a temp as possible.
We are running several DOEs to come up with a placement/rework process.
As part of the investigation the client is fixated on nitrogen reflow being part of the solution to these warped BGAs. Nitrogen reflow IMHO is the solution for joint aesthetics, wetting issues and enhanced reliability of the interconnection.
? Does anyone have experience with hot air reflow using nitrogen where its addition helped to mitigate warpage issues?
Thanks!
--
Bob Wettermann
BEST Inc
------------------------------
Date: Mon, 23 Jan 2017 18:19:29 +0000
From: "Stadem, Richard D." <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
Bob,
Did you see this? Lots of good process information.
http://www.ti.com/lit/an/swpa182c/swpa182c.pdf
Hope it helps.
dean
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
Sent: Monday, January 23, 2017 11:29 AM
To: [log in to unmask]
Subject: [TN] Nitrogen Reflow and Warpage Issues on POPs
Dear Technetters:
We have a Class 3 customer with very complex, high density placements (think cell phone for the military). This board is laden w/0201s, 0.4mm pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
The problems in this board assembly for some time have been isolated to this OMAP part. We have lots of shorts and opens (randomly-spaced) as confirmed by electrical testing, dye and pry and cross sectioning. The Omap has been shown to warp 5-7 mils depending on the reflow profile.( It is a no clean SAC305 process). We have profiled the reflow process by embedding TCs in the corners of the balls of the device (ball interface with the board where all of the problems are) , the die, neighboring components etc. We dialed in the profile as low of a temp as possible.
We are running several DOEs to come up with a placement/rework process.
As part of the investigation the client is fixated on nitrogen reflow being part of the solution to these warped BGAs. Nitrogen reflow IMHO is the solution for joint aesthetics, wetting issues and enhanced reliability of the interconnection.
? Does anyone have experience with hot air reflow using nitrogen where its addition helped to mitigate warpage issues?
Thanks!
--
Bob Wettermann
BEST Inc
------------------------------
Date: Mon, 23 Jan 2017 13:36:09 -0500
From: Joyce Koo <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
IMHO, nitrogen will allow you to lower the Tp 3-5 degree and change reflow
profile to shorter. it does have an impact on the bridging, and warpage.
the solder ball claps (reflow) of corner and center under nitrogen showed
little difference, but not in air... your HOP or bridge will tell you the
device might be tilt to one side or warped. nitrogen will help, but not
cure all. my 1.5 cents.
jk
> Bob,
> Did you see this? Lots of good process information.
> http://www.ti.com/lit/an/swpa182c/swpa182c.pdf
> Hope it helps.
> dean
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
> Sent: Monday, January 23, 2017 11:29 AM
> To: [log in to unmask]
> Subject: [TN] Nitrogen Reflow and Warpage Issues on POPs
>
> Dear Technetters:
>
>
>
> We have a Class 3 customer with very complex, high density placements
> (think cell phone for the military). This board is laden w/0201s, 0.4mm
> pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
>
>
> The problems in this board assembly for some time have been isolated to
> this OMAP part. We have lots of shorts and opens (randomly-spaced) as
> confirmed by electrical testing, dye and pry and cross sectioning. The
> Omap has been shown to warp 5-7 mils depending on the reflow profile.( It
> is a no clean SAC305 process). We have profiled the reflow process by
> embedding TCs in the corners of the balls of the device (ball interface
> with the board where all of the problems are) , the die, neighboring
> components etc. We dialed in the profile as low of a temp as possible.
>
>
> We are running several DOEs to come up with a placement/rework process.
>
> As part of the investigation the client is fixated on nitrogen reflow
> being part of the solution to these warped BGAs. Nitrogen reflow IMHO is
> the solution for joint aesthetics, wetting issues and enhanced reliability
> of the interconnection.
>
>
> ? Does anyone have experience with hot air reflow using nitrogen where its
> addition helped to mitigate warpage issues?
>
>
> Thanks!
>
>
> --
> Bob Wettermann
> BEST Inc
>
------------------------------
Date: Mon, 23 Jan 2017 18:57:55 +0000
From: [log in to unmask]
Subject: Copper Thickness Tester, Coppertron SM6000
Fellow TechNetters:
Has anyone out there have experience measuring copper thickness on PWB, either foil copper and/or plated copper thickness.
Victor,
------------------------------
Date: Mon, 23 Jan 2017 12:58:06 -0600
From: Bob Wettermann <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
Thanks Joyce (and others).
We believe that there will be less thermal stress and hence less warping in
vapor phase reflow.
If you were a betting person (so far I have gambled 25 cents in my life in
Las Vegas but gamble every single day on our business) would you bet on
vapor phase or nitrogen reflow?
Bob
On Mon, Jan 23, 2017 at 12:36 PM, Joyce Koo <[log in to unmask]> wrote:
> IMHO, nitrogen will allow you to lower the Tp 3-5 degree and change reflow
> profile to shorter. it does have an impact on the bridging, and warpage.
> the solder ball claps (reflow) of corner and center under nitrogen showed
> little difference, but not in air... your HOP or bridge will tell you the
> device might be tilt to one side or warped. nitrogen will help, but not
> cure all. my 1.5 cents.
> jk
> > Bob,
> > Did you see this? Lots of good process information.
> > http://www.ti.com/lit/an/swpa182c/swpa182c.pdf
> > Hope it helps.
> > dean
> >
> > -----Original Message-----
> > From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
> > Sent: Monday, January 23, 2017 11:29 AM
> > To: [log in to unmask]
> > Subject: [TN] Nitrogen Reflow and Warpage Issues on POPs
> >
> > Dear Technetters:
> >
> >
> >
> > We have a Class 3 customer with very complex, high density placements
> > (think cell phone for the military). This board is laden w/0201s, 0.4mm
> > pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
> >
> >
> > The problems in this board assembly for some time have been isolated to
> > this OMAP part. We have lots of shorts and opens (randomly-spaced) as
> > confirmed by electrical testing, dye and pry and cross sectioning. The
> > Omap has been shown to warp 5-7 mils depending on the reflow profile.( It
> > is a no clean SAC305 process). We have profiled the reflow process by
> > embedding TCs in the corners of the balls of the device (ball interface
> > with the board where all of the problems are) , the die, neighboring
> > components etc. We dialed in the profile as low of a temp as possible.
> >
> >
> > We are running several DOEs to come up with a placement/rework process.
> >
> > As part of the investigation the client is fixated on nitrogen reflow
> > being part of the solution to these warped BGAs. Nitrogen reflow IMHO is
> > the solution for joint aesthetics, wetting issues and enhanced
> reliability
> > of the interconnection.
> >
> >
> > ? Does anyone have experience with hot air reflow using nitrogen where
> its
> > addition helped to mitigate warpage issues?
> >
> >
> > Thanks!
> >
> >
> > --
> > Bob Wettermann
> > BEST Inc
> >
>
--
Bob Wettermann
BEST Inc
[log in to unmask]
Cell: 847-767-5745
------------------------------
Date: Mon, 23 Jan 2017 13:29:50 -0600
From: David Hillman <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
Hi Bob - I have done process compatibility testing with the TI OMAP BGA and
the use of a inert atmosphere has no impact on the warpage characteristics
of the package (been there, done that, have the Tshirt). Are you using a
tin/lead soldering process or a lead-free soldering process? POP technology
was "born" in the lead-free era and as such, that package isn't a fan of a
tin/lead soldering profile.
Dave Hillman
Rockwell Collins
[log in to unmask]
On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann <[log in to unmask]> wrote:
> Dear Technetters:
>
>
>
> We have a Class 3 customer with very complex, high density placements
> (think cell phone for the military). This board is laden w/0201s, 0.4mm
> pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
>
>
> The problems in this board assembly for some time have been isolated to
> this OMAP part. We have lots of shorts and opens (randomly-spaced) as
> confirmed by electrical testing, dye and pry and cross sectioning. The Omap
> has been shown to warp 5-7 mils depending on the reflow profile.( It is a
> no clean SAC305 process). We have profiled the reflow process by embedding
> TCs in the corners of the balls of the device (ball interface with the
> board where all of the problems are) , the die, neighboring components
> etc. We dialed in the profile as low of a temp as possible.
>
>
> We are running several DOEs to come up with a placement/rework process.
>
> As part of the investigation the client is fixated on nitrogen reflow being
> part of the solution to these warped BGAs. Nitrogen reflow IMHO is the
> solution for joint aesthetics, wetting issues and enhanced reliability of
> the interconnection.
>
>
> ? Does anyone have experience with hot air reflow using nitrogen where its
> addition helped to mitigate warpage issues?
>
>
> Thanks!
>
>
> --
> Bob Wettermann
> BEST Inc
>
------------------------------
Date: Mon, 23 Jan 2017 13:48:04 -0600
From: Bob Wettermann <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
Hi Dave:
This is SAC process.
For rework we have tried to go "backwards" to Sn63 to reduce max temp. The
results were better. Customer did not want to go throiugh the rel testing
reqts of a bismuth-based alloy.
Any thoughts on using a vapor phase reflow instead?
BWET
On Mon, Jan 23, 2017 at 1:29 PM, David Hillman <
[log in to unmask]> wrote:
> Hi Bob - I have done process compatibility testing with the TI OMAP BGA
> and the use of a inert atmosphere has no impact on the warpage
> characteristics of the package (been there, done that, have the Tshirt).
> Are you using a tin/lead soldering process or a lead-free soldering
> process? POP technology was "born" in the lead-free era and as such, that
> package isn't a fan of a tin/lead soldering profile.
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
> On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann <[log in to unmask]>
> wrote:
>
>> Dear Technetters:
>>
>>
>>
>> We have a Class 3 customer with very complex, high density placements
>> (think cell phone for the military). This board is laden w/0201s, 0.4mm
>> pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
>>
>>
>> The problems in this board assembly for some time have been isolated to
>> this OMAP part. We have lots of shorts and opens (randomly-spaced) as
>> confirmed by electrical testing, dye and pry and cross sectioning. The
>> Omap
>> has been shown to warp 5-7 mils depending on the reflow profile.( It is a
>> no clean SAC305 process). We have profiled the reflow process by embedding
>> TCs in the corners of the balls of the device (ball interface with the
>> board where all of the problems are) , the die, neighboring components
>> etc. We dialed in the profile as low of a temp as possible.
>>
>>
>> We are running several DOEs to come up with a placement/rework process.
>>
>> As part of the investigation the client is fixated on nitrogen reflow
>> being
>> part of the solution to these warped BGAs. Nitrogen reflow IMHO is the
>> solution for joint aesthetics, wetting issues and enhanced reliability of
>> the interconnection.
>>
>>
>> ? Does anyone have experience with hot air reflow using nitrogen where its
>> addition helped to mitigate warpage issues?
>>
>>
>> Thanks!
>>
>>
>> --
>> Bob Wettermann
>> BEST Inc
>>
>
>
--
Bob Wettermann
BEST Inc
[log in to unmask]
Cell: 847-767-5745
------------------------------
Date: Mon, 23 Jan 2017 13:54:04 -0600
From: David Hillman <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
Hi Bob - in our testing, the package preformed better using a lead-free
temperature reflow profile - we had much less warpage and other associated
temperature impacts which we attributed to the package designers optimizing
their package construction characteristics for a lead-free reflow
temperature profile (its a lead-free part, so most frequent use would be in
a lead-free process). We were using a 12 zone oven so lots of room to
profile creation - how many zones in your oven?
As for VP - I have never put a BGA in a VP process yet. It should work
provided the condensing VP fluid doesn't cause the BGA to physically move.
Dave
On Mon, Jan 23, 2017 at 1:48 PM, Bob Wettermann <[log in to unmask]> wrote:
> Hi Dave:
>
> This is SAC process.
>
> For rework we have tried to go "backwards" to Sn63 to reduce max temp. The
> results were better. Customer did not want to go throiugh the rel testing
> reqts of a bismuth-based alloy.
>
> Any thoughts on using a vapor phase reflow instead?
>
> BWET
>
> On Mon, Jan 23, 2017 at 1:29 PM, David Hillman <david.hillman@
> rockwellcollins.com> wrote:
>
>> Hi Bob - I have done process compatibility testing with the TI OMAP BGA
>> and the use of a inert atmosphere has no impact on the warpage
>> characteristics of the package (been there, done that, have the Tshirt).
>> Are you using a tin/lead soldering process or a lead-free soldering
>> process? POP technology was "born" in the lead-free era and as such, that
>> package isn't a fan of a tin/lead soldering profile.
>>
>> Dave Hillman
>> Rockwell Collins
>> [log in to unmask]
>>
>> On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann <[log in to unmask]>
>> wrote:
>>
>>> Dear Technetters:
>>>
>>>
>>>
>>> We have a Class 3 customer with very complex, high density placements
>>> (think cell phone for the military). This board is laden w/0201s, 0.4mm
>>> pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
>>>
>>>
>>> The problems in this board assembly for some time have been isolated to
>>> this OMAP part. We have lots of shorts and opens (randomly-spaced) as
>>> confirmed by electrical testing, dye and pry and cross sectioning. The
>>> Omap
>>> has been shown to warp 5-7 mils depending on the reflow profile.( It is a
>>> no clean SAC305 process). We have profiled the reflow process by
>>> embedding
>>> TCs in the corners of the balls of the device (ball interface with the
>>> board where all of the problems are) , the die, neighboring components
>>> etc. We dialed in the profile as low of a temp as possible.
>>>
>>>
>>> We are running several DOEs to come up with a placement/rework process.
>>>
>>> As part of the investigation the client is fixated on nitrogen reflow
>>> being
>>> part of the solution to these warped BGAs. Nitrogen reflow IMHO is the
>>> solution for joint aesthetics, wetting issues and enhanced reliability of
>>> the interconnection.
>>>
>>>
>>> ? Does anyone have experience with hot air reflow using nitrogen where
>>> its
>>> addition helped to mitigate warpage issues?
>>>
>>>
>>> Thanks!
>>>
>>>
>>> --
>>> Bob Wettermann
>>> BEST Inc
>>>
>>
>>
>
>
> --
> Bob Wettermann
> BEST Inc
> [log in to unmask]
> Cell: 847-767-5745 <(847)%20767-5745>
>
------------------------------
Date: Mon, 23 Jan 2017 14:44:29 -0600
From: Bob Wettermann <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
We have a 5 zone oven.....and a BGA rework station (tried with some boards
with the OMAP missing and all other parts populated) w/multi zone bottom
heater.
BWET
On Mon, Jan 23, 2017 at 1:54 PM, David Hillman <
[log in to unmask]> wrote:
> Hi Bob - in our testing, the package preformed better using a lead-free
> temperature reflow profile - we had much less warpage and other associated
> temperature impacts which we attributed to the package designers optimizing
> their package construction characteristics for a lead-free reflow
> temperature profile (its a lead-free part, so most frequent use would be in
> a lead-free process). We were using a 12 zone oven so lots of room to
> profile creation - how many zones in your oven?
>
> As for VP - I have never put a BGA in a VP process yet. It should work
> provided the condensing VP fluid doesn't cause the BGA to physically move.
>
> Dave
>
> On Mon, Jan 23, 2017 at 1:48 PM, Bob Wettermann <[log in to unmask]> wrote:
>
>> Hi Dave:
>>
>> This is SAC process.
>>
>> For rework we have tried to go "backwards" to Sn63 to reduce max temp.
>> The results were better. Customer did not want to go throiugh the rel
>> testing reqts of a bismuth-based alloy.
>>
>> Any thoughts on using a vapor phase reflow instead?
>>
>> BWET
>>
>> On Mon, Jan 23, 2017 at 1:29 PM, David Hillman <
>> [log in to unmask]> wrote:
>>
>>> Hi Bob - I have done process compatibility testing with the TI OMAP BGA
>>> and the use of a inert atmosphere has no impact on the warpage
>>> characteristics of the package (been there, done that, have the Tshirt).
>>> Are you using a tin/lead soldering process or a lead-free soldering
>>> process? POP technology was "born" in the lead-free era and as such, that
>>> package isn't a fan of a tin/lead soldering profile.
>>>
>>> Dave Hillman
>>> Rockwell Collins
>>> [log in to unmask]
>>>
>>> On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann <[log in to unmask]>
>>> wrote:
>>>
>>>> Dear Technetters:
>>>>
>>>>
>>>>
>>>> We have a Class 3 customer with very complex, high density placements
>>>> (think cell phone for the military). This board is laden w/0201s, 0.4mm
>>>> pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm
>>>> pitch).
>>>>
>>>>
>>>> The problems in this board assembly for some time have been isolated to
>>>> this OMAP part. We have lots of shorts and opens (randomly-spaced) as
>>>> confirmed by electrical testing, dye and pry and cross sectioning. The
>>>> Omap
>>>> has been shown to warp 5-7 mils depending on the reflow profile.( It is
>>>> a
>>>> no clean SAC305 process). We have profiled the reflow process by
>>>> embedding
>>>> TCs in the corners of the balls of the device (ball interface with the
>>>> board where all of the problems are) , the die, neighboring components
>>>> etc. We dialed in the profile as low of a temp as possible.
>>>>
>>>>
>>>> We are running several DOEs to come up with a placement/rework process.
>>>>
>>>> As part of the investigation the client is fixated on nitrogen reflow
>>>> being
>>>> part of the solution to these warped BGAs. Nitrogen reflow IMHO is the
>>>> solution for joint aesthetics, wetting issues and enhanced reliability
>>>> of
>>>> the interconnection.
>>>>
>>>>
>>>> ? Does anyone have experience with hot air reflow using nitrogen where
>>>> its
>>>> addition helped to mitigate warpage issues?
>>>>
>>>>
>>>> Thanks!
>>>>
>>>>
>>>> --
>>>> Bob Wettermann
>>>> BEST Inc
>>>>
>>>
>>>
>>
>>
>> --
>> Bob Wettermann
>> BEST Inc
>> [log in to unmask]
>> Cell: 847-767-5745 <(847)%20767-5745>
>>
>
>
--
Bob Wettermann
BEST Inc
[log in to unmask]
Cell: 847-767-5745
------------------------------
Date: Mon, 23 Jan 2017 15:50:15 -0500
From: Joyce Koo <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
what is your PWB material (Tg) and how many layers? many decouple cap on
the other side or not? (hopefully, you don't have other side big chip in
near by area... ). it is not just the device, also the pwb layout.
> Hi Dave:
>
> This is SAC process.
>
> For rework we have tried to go "backwards" to Sn63 to reduce max temp. The
> results were better. Customer did not want to go throiugh the rel testing
> reqts of a bismuth-based alloy.
>
> Any thoughts on using a vapor phase reflow instead?
>
> BWET
>
> On Mon, Jan 23, 2017 at 1:29 PM, David Hillman <
> [log in to unmask]> wrote:
>
>> Hi Bob - I have done process compatibility testing with the TI OMAP BGA
>> and the use of a inert atmosphere has no impact on the warpage
>> characteristics of the package (been there, done that, have the Tshirt).
>> Are you using a tin/lead soldering process or a lead-free soldering
>> process? POP technology was "born" in the lead-free era and as such,
>> that
>> package isn't a fan of a tin/lead soldering profile.
>>
>> Dave Hillman
>> Rockwell Collins
>> [log in to unmask]
>>
>> On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann <[log in to unmask]>
>> wrote:
>>
>>> Dear Technetters:
>>>
>>>
>>>
>>> We have a Class 3 customer with very complex, high density placements
>>> (think cell phone for the military). This board is laden w/0201s, 0.4mm
>>> pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm
>>> pitch).
>>>
>>>
>>> The problems in this board assembly for some time have been isolated to
>>> this OMAP part. We have lots of shorts and opens (randomly-spaced) as
>>> confirmed by electrical testing, dye and pry and cross sectioning. The
>>> Omap
>>> has been shown to warp 5-7 mils depending on the reflow profile.( It is
>>> a
>>> no clean SAC305 process). We have profiled the reflow process by
>>> embedding
>>> TCs in the corners of the balls of the device (ball interface with the
>>> board where all of the problems are) , the die, neighboring components
>>> etc. We dialed in the profile as low of a temp as possible.
>>>
>>>
>>> We are running several DOEs to come up with a placement/rework process.
>>>
>>> As part of the investigation the client is fixated on nitrogen reflow
>>> being
>>> part of the solution to these warped BGAs. Nitrogen reflow IMHO is the
>>> solution for joint aesthetics, wetting issues and enhanced reliability
>>> of
>>> the interconnection.
>>>
>>>
>>> ? Does anyone have experience with hot air reflow using nitrogen where
>>> its
>>> addition helped to mitigate warpage issues?
>>>
>>>
>>> Thanks!
>>>
>>>
>>> --
>>> Bob Wettermann
>>> BEST Inc
>>>
>>
>>
>
>
> --
> Bob Wettermann
> BEST Inc
> [log in to unmask]
> Cell: 847-767-5745
>
------------------------------
Date: Mon, 23 Jan 2017 22:01:24 +0100
From: SALA GABRIELE <[log in to unmask]>
Subject: R: [TN] Nitrogen Reflow and Warpage Issues on POPs
Any moisture entrapped in the PoP before reflow ?
MSL ?
GS
-----Messaggio originale-----
Da: TechNet [mailto:[log in to unmask]] Per conto di Bob Wettermann
Inviato: lunedì 23 gennaio 2017 19:58
A: [log in to unmask]
Oggetto: Re: [TN] Nitrogen Reflow and Warpage Issues on POPs
Thanks Joyce (and others).
We believe that there will be less thermal stress and hence less warping in vapor phase reflow.
If you were a betting person (so far I have gambled 25 cents in my life in Las Vegas but gamble every single day on our business) would you bet on vapor phase or nitrogen reflow?
Bob
On Mon, Jan 23, 2017 at 12:36 PM, Joyce Koo <[log in to unmask]> wrote:
> IMHO, nitrogen will allow you to lower the Tp 3-5 degree and change
> reflow profile to shorter. it does have an impact on the bridging, and warpage.
> the solder ball claps (reflow) of corner and center under nitrogen
> showed little difference, but not in air... your HOP or bridge will
> tell you the device might be tilt to one side or warped. nitrogen
> will help, but not cure all. my 1.5 cents.
> jk
> > Bob,
> > Did you see this? Lots of good process information.
> > http://www.ti.com/lit/an/swpa182c/swpa182c.pdf
> > Hope it helps.
> > dean
> >
> > -----Original Message-----
> > From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
> > Sent: Monday, January 23, 2017 11:29 AM
> > To: [log in to unmask]
> > Subject: [TN] Nitrogen Reflow and Warpage Issues on POPs
> >
> > Dear Technetters:
> >
> >
> >
> > We have a Class 3 customer with very complex, high density
> > placements (think cell phone for the military). This board is laden
> > w/0201s, 0.4mm pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
> >
> >
> > The problems in this board assembly for some time have been isolated
> > to this OMAP part. We have lots of shorts and opens
> > (randomly-spaced) as confirmed by electrical testing, dye and pry
> > and cross sectioning. The Omap has been shown to warp 5-7 mils
> > depending on the reflow profile.( It is a no clean SAC305 process).
> > We have profiled the reflow process by embedding TCs in the corners
> > of the balls of the device (ball interface with the board where all
> > of the problems are) , the die, neighboring components etc. We dialed in the profile as low of a temp as possible.
> >
> >
> > We are running several DOEs to come up with a placement/rework process.
> >
> > As part of the investigation the client is fixated on nitrogen
> > reflow being part of the solution to these warped BGAs. Nitrogen
> > reflow IMHO is the solution for joint aesthetics, wetting issues and
> > enhanced
> reliability
> > of the interconnection.
> >
> >
> > ? Does anyone have experience with hot air reflow using nitrogen
> > where
> its
> > addition helped to mitigate warpage issues?
> >
> >
> > Thanks!
> >
> >
> > --
> > Bob Wettermann
> > BEST Inc
> >
>
--
Bob Wettermann
BEST Inc
[log in to unmask]
Cell: 847-767-5745
---
Questa e-mail è stata controllata per individuare virus con Avast antivirus.
https://www.avast.com/antivirus
------------------------------
Date: Mon, 23 Jan 2017 15:02:25 -0600
From: David Hillman <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
Hi Bob - your oven is a part of the issue equation. With a 5 zone oven you
are pushing a bunch of heat into the POP in contrast to a larger oven with
7-12 zones. You might be able to minimize the warp effects by going thru
the oven slower but make sure you also don't burn up the flux by the
extended temperature exposure. Using short ovens with minimum heat zones
can make profiling difficult.
Dave
On Mon, Jan 23, 2017 at 2:44 PM, Bob Wettermann <[log in to unmask]> wrote:
> We have a 5 zone oven.....and a BGA rework station (tried with some boards
> with the OMAP missing and all other parts populated) w/multi zone bottom
> heater.
>
> BWET
>
> On Mon, Jan 23, 2017 at 1:54 PM, David Hillman <david.hillman@
> rockwellcollins.com> wrote:
>
>> Hi Bob - in our testing, the package preformed better using a lead-free
>> temperature reflow profile - we had much less warpage and other associated
>> temperature impacts which we attributed to the package designers optimizing
>> their package construction characteristics for a lead-free reflow
>> temperature profile (its a lead-free part, so most frequent use would be in
>> a lead-free process). We were using a 12 zone oven so lots of room to
>> profile creation - how many zones in your oven?
>>
>> As for VP - I have never put a BGA in a VP process yet. It should work
>> provided the condensing VP fluid doesn't cause the BGA to physically move.
>>
>> Dave
>>
>> On Mon, Jan 23, 2017 at 1:48 PM, Bob Wettermann <[log in to unmask]>
>> wrote:
>>
>>> Hi Dave:
>>>
>>> This is SAC process.
>>>
>>> For rework we have tried to go "backwards" to Sn63 to reduce max temp.
>>> The results were better. Customer did not want to go throiugh the rel
>>> testing reqts of a bismuth-based alloy.
>>>
>>> Any thoughts on using a vapor phase reflow instead?
>>>
>>> BWET
>>>
>>> On Mon, Jan 23, 2017 at 1:29 PM, David Hillman <
>>> [log in to unmask]> wrote:
>>>
>>>> Hi Bob - I have done process compatibility testing with the TI OMAP BGA
>>>> and the use of a inert atmosphere has no impact on the warpage
>>>> characteristics of the package (been there, done that, have the Tshirt).
>>>> Are you using a tin/lead soldering process or a lead-free soldering
>>>> process? POP technology was "born" in the lead-free era and as such, that
>>>> package isn't a fan of a tin/lead soldering profile.
>>>>
>>>> Dave Hillman
>>>> Rockwell Collins
>>>> [log in to unmask]
>>>>
>>>> On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann <[log in to unmask]>
>>>> wrote:
>>>>
>>>>> Dear Technetters:
>>>>>
>>>>>
>>>>>
>>>>> We have a Class 3 customer with very complex, high density placements
>>>>> (think cell phone for the military). This board is laden w/0201s, 0.4mm
>>>>> pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm
>>>>> pitch).
>>>>>
>>>>>
>>>>> The problems in this board assembly for some time have been isolated to
>>>>> this OMAP part. We have lots of shorts and opens (randomly-spaced) as
>>>>> confirmed by electrical testing, dye and pry and cross sectioning. The
>>>>> Omap
>>>>> has been shown to warp 5-7 mils depending on the reflow profile.( It
>>>>> is a
>>>>> no clean SAC305 process). We have profiled the reflow process by
>>>>> embedding
>>>>> TCs in the corners of the balls of the device (ball interface with the
>>>>> board where all of the problems are) , the die, neighboring components
>>>>> etc. We dialed in the profile as low of a temp as possible.
>>>>>
>>>>>
>>>>> We are running several DOEs to come up with a placement/rework process.
>>>>>
>>>>> As part of the investigation the client is fixated on nitrogen reflow
>>>>> being
>>>>> part of the solution to these warped BGAs. Nitrogen reflow IMHO is the
>>>>> solution for joint aesthetics, wetting issues and enhanced reliability
>>>>> of
>>>>> the interconnection.
>>>>>
>>>>>
>>>>> ? Does anyone have experience with hot air reflow using nitrogen where
>>>>> its
>>>>> addition helped to mitigate warpage issues?
>>>>>
>>>>>
>>>>> Thanks!
>>>>>
>>>>>
>>>>> --
>>>>> Bob Wettermann
>>>>> BEST Inc
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Bob Wettermann
>>> BEST Inc
>>> [log in to unmask]
>>> Cell: 847-767-5745 <(847)%20767-5745>
>>>
>>
>>
>
>
> --
> Bob Wettermann
> BEST Inc
> [log in to unmask]
> Cell: 847-767-5745 <(847)%20767-5745>
>
------------------------------
Date: Mon, 23 Jan 2017 21:11:59 +0000
From: Wayne Thayer <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
Hi Bob-
What diagnostic tools have you used to conclude this is a warpage problem and not some other problem, such as flux distribution, solder deposition, substrate overall flatness, etc.?
I'm worried you could have our TechNet brain trust barking up the wrong tree!
I put down a few of those parts around 4 years ago, and I recall it being a bit of process development, but I was able to make it happen without a large furnace (we had a 5 zone, but I can't even remember whether I ended up doing it on a rework machine or even a set of hot plates! I do recall that getting the fluxing right was one of the issues.
Wayne
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
Sent: Monday, January 23, 2017 1:02 PM
To: [log in to unmask]
Subject: Re: [TN] Nitrogen Reflow and Warpage Issues on POPs
Hi Bob - your oven is a part of the issue equation. With a 5 zone oven you are pushing a bunch of heat into the POP in contrast to a larger oven with
7-12 zones. You might be able to minimize the warp effects by going thru the oven slower but make sure you also don't burn up the flux by the extended temperature exposure. Using short ovens with minimum heat zones can make profiling difficult.
Dave
On Mon, Jan 23, 2017 at 2:44 PM, Bob Wettermann <[log in to unmask]> wrote:
> We have a 5 zone oven.....and a BGA rework station (tried with some
> boards with the OMAP missing and all other parts populated) w/multi
> zone bottom heater.
>
> BWET
>
> On Mon, Jan 23, 2017 at 1:54 PM, David Hillman <david.hillman@
> rockwellcollins.com> wrote:
>
>> Hi Bob - in our testing, the package preformed better using a
>> lead-free temperature reflow profile - we had much less warpage and
>> other associated temperature impacts which we attributed to the
>> package designers optimizing their package construction
>> characteristics for a lead-free reflow temperature profile (its a
>> lead-free part, so most frequent use would be in a lead-free
>> process). We were using a 12 zone oven so lots of room to profile creation - how many zones in your oven?
>>
>> As for VP - I have never put a BGA in a VP process yet. It should
>> work provided the condensing VP fluid doesn't cause the BGA to physically move.
>>
>> Dave
>>
>> On Mon, Jan 23, 2017 at 1:48 PM, Bob Wettermann <[log in to unmask]>
>> wrote:
>>
>>> Hi Dave:
>>>
>>> This is SAC process.
>>>
>>> For rework we have tried to go "backwards" to Sn63 to reduce max temp.
>>> The results were better. Customer did not want to go throiugh the
>>> rel testing reqts of a bismuth-based alloy.
>>>
>>> Any thoughts on using a vapor phase reflow instead?
>>>
>>> BWET
>>>
>>> On Mon, Jan 23, 2017 at 1:29 PM, David Hillman <
>>> [log in to unmask]> wrote:
>>>
>>>> Hi Bob - I have done process compatibility testing with the TI OMAP
>>>> BGA and the use of a inert atmosphere has no impact on the warpage
>>>> characteristics of the package (been there, done that, have the Tshirt).
>>>> Are you using a tin/lead soldering process or a lead-free soldering
>>>> process? POP technology was "born" in the lead-free era and as
>>>> such, that package isn't a fan of a tin/lead soldering profile.
>>>>
>>>> Dave Hillman
>>>> Rockwell Collins
>>>> [log in to unmask]
>>>>
>>>> On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann
>>>> <[log in to unmask]>
>>>> wrote:
>>>>
>>>>> Dear Technetters:
>>>>>
>>>>>
>>>>>
>>>>> We have a Class 3 customer with very complex, high density
>>>>> placements (think cell phone for the military). This board is
>>>>> laden w/0201s, 0.4mm pitch BGAs, shields, mirrored BGAs and the TI
>>>>> Omap POP (0.4/0.5mm pitch).
>>>>>
>>>>>
>>>>> The problems in this board assembly for some time have been
>>>>> isolated to this OMAP part. We have lots of shorts and opens
>>>>> (randomly-spaced) as confirmed by electrical testing, dye and pry
>>>>> and cross sectioning. The Omap has been shown to warp 5-7 mils
>>>>> depending on the reflow profile.( It is a no clean SAC305
>>>>> process). We have profiled the reflow process by embedding TCs in
>>>>> the corners of the balls of the device (ball interface with the
>>>>> board where all of the problems are) , the die, neighboring
>>>>> components etc. We dialed in the profile as low of a temp as possible.
>>>>>
>>>>>
>>>>> We are running several DOEs to come up with a placement/rework process.
>>>>>
>>>>> As part of the investigation the client is fixated on nitrogen
>>>>> reflow being part of the solution to these warped BGAs. Nitrogen
>>>>> reflow IMHO is the solution for joint aesthetics, wetting issues
>>>>> and enhanced reliability of the interconnection.
>>>>>
>>>>>
>>>>> ? Does anyone have experience with hot air reflow using nitrogen
>>>>> where its addition helped to mitigate warpage issues?
>>>>>
>>>>>
>>>>> Thanks!
>>>>>
>>>>>
>>>>> --
>>>>> Bob Wettermann
>>>>> BEST Inc
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Bob Wettermann
>>> BEST Inc
>>> [log in to unmask]
>>> Cell: 847-767-5745 <(847)%20767-5745>
>>>
>>
>>
>
>
> --
> Bob Wettermann
> BEST Inc
> [log in to unmask]
> Cell: 847-767-5745 <(847)%20767-5745>
>
------------------------------
Date: Mon, 23 Jan 2017 21:12:36 +0000
From: "Stadem, Richard D." <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
VPS, provided everything else on the CCA can be soldered that way.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
Sent: Monday, January 23, 2017 12:58 PM
To: [log in to unmask]
Subject: Re: [TN] Nitrogen Reflow and Warpage Issues on POPs
Thanks Joyce (and others).
We believe that there will be less thermal stress and hence less warping in vapor phase reflow.
If you were a betting person (so far I have gambled 25 cents in my life in Las Vegas but gamble every single day on our business) would you bet on vapor phase or nitrogen reflow?
Bob
On Mon, Jan 23, 2017 at 12:36 PM, Joyce Koo <[log in to unmask]> wrote:
> IMHO, nitrogen will allow you to lower the Tp 3-5 degree and change
> reflow profile to shorter. it does have an impact on the bridging, and warpage.
> the solder ball claps (reflow) of corner and center under nitrogen
> showed little difference, but not in air... your HOP or bridge will
> tell you the device might be tilt to one side or warped. nitrogen
> will help, but not cure all. my 1.5 cents.
> jk
> > Bob,
> > Did you see this? Lots of good process information.
> > http://www.ti.com/lit/an/swpa182c/swpa182c.pdf
> > Hope it helps.
> > dean
> >
> > -----Original Message-----
> > From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
> > Sent: Monday, January 23, 2017 11:29 AM
> > To: [log in to unmask]
> > Subject: [TN] Nitrogen Reflow and Warpage Issues on POPs
> >
> > Dear Technetters:
> >
> >
> >
> > We have a Class 3 customer with very complex, high density
> > placements (think cell phone for the military). This board is laden
> > w/0201s, 0.4mm pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
> >
> >
> > The problems in this board assembly for some time have been isolated
> > to this OMAP part. We have lots of shorts and opens
> > (randomly-spaced) as confirmed by electrical testing, dye and pry
> > and cross sectioning. The Omap has been shown to warp 5-7 mils
> > depending on the reflow profile.( It is a no clean SAC305 process).
> > We have profiled the reflow process by embedding TCs in the corners
> > of the balls of the device (ball interface with the board where all
> > of the problems are) , the die, neighboring components etc. We dialed in the profile as low of a temp as possible.
> >
> >
> > We are running several DOEs to come up with a placement/rework process.
> >
> > As part of the investigation the client is fixated on nitrogen
> > reflow being part of the solution to these warped BGAs. Nitrogen
> > reflow IMHO is the solution for joint aesthetics, wetting issues and
> > enhanced
> reliability
> > of the interconnection.
> >
> >
> > ? Does anyone have experience with hot air reflow using nitrogen
> > where
> its
> > addition helped to mitigate warpage issues?
> >
> >
> > Thanks!
> >
> >
> > --
> > Bob Wettermann
> > BEST Inc
> >
>
--
Bob Wettermann
BEST Inc
[log in to unmask]
Cell: 847-767-5745
------------------------------
Date: Mon, 23 Jan 2017 16:13:47 -0500
From: George Wenger <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
We as usual I have to agree with Dave Hillman and Richard Stadem. The point that Joyce made about nitrogen allowing you to lower the Tp a couple of degrees an make minor changes to the reflow profile are correct and they may have a very minor impact on warpage but to the best of my knowledge the impact wouldn't be large enough to measure much less make a difference. All of my experience with condensation reflow soldering (i.e., vapor phase) was before BGAs so I don't have any direct data but vapor phase is a much more uniform heating process and would therefore have an impact on board and part warpage and might be helpful but I don't think you would have to run a trial to see if it would be helpful enough.
George
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
Sent: Monday, January 23, 2017 2:54 PM
To: [log in to unmask]
Subject: Re: [TN] Nitrogen Reflow and Warpage Issues on POPs
Hi Bob - in our testing, the package preformed better using a lead-free temperature reflow profile - we had much less warpage and other associated temperature impacts which we attributed to the package designers optimizing their package construction characteristics for a lead-free reflow temperature profile (its a lead-free part, so most frequent use would be in a lead-free process). We were using a 12 zone oven so lots of room to profile creation - how many zones in your oven?
As for VP - I have never put a BGA in a VP process yet. It should work provided the condensing VP fluid doesn't cause the BGA to physically move.
Dave
On Mon, Jan 23, 2017 at 1:48 PM, Bob Wettermann <[log in to unmask]> wrote:
> Hi Dave:
>
> This is SAC process.
>
> For rework we have tried to go "backwards" to Sn63 to reduce max temp.
> The results were better. Customer did not want to go throiugh the rel
> testing reqts of a bismuth-based alloy.
>
> Any thoughts on using a vapor phase reflow instead?
>
> BWET
>
> On Mon, Jan 23, 2017 at 1:29 PM, David Hillman <david.hillman@
> rockwellcollins.com> wrote:
>
>> Hi Bob - I have done process compatibility testing with the TI OMAP
>> BGA and the use of a inert atmosphere has no impact on the warpage
>> characteristics of the package (been there, done that, have the Tshirt).
>> Are you using a tin/lead soldering process or a lead-free soldering
>> process? POP technology was "born" in the lead-free era and as such,
>> that package isn't a fan of a tin/lead soldering profile.
>>
>> Dave Hillman
>> Rockwell Collins
>> [log in to unmask]
>>
>> On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann <[log in to unmask]>
>> wrote:
>>
>>> Dear Technetters:
>>>
>>>
>>>
>>> We have a Class 3 customer with very complex, high density
>>> placements (think cell phone for the military). This board is laden
>>> w/0201s, 0.4mm pitch BGAs, shields, mirrored BGAs and the TI Omap POP (0.4/0.5mm pitch).
>>>
>>>
>>> The problems in this board assembly for some time have been isolated
>>> to this OMAP part. We have lots of shorts and opens
>>> (randomly-spaced) as confirmed by electrical testing, dye and pry
>>> and cross sectioning. The Omap has been shown to warp 5-7 mils
>>> depending on the reflow profile.( It is a no clean SAC305 process).
>>> We have profiled the reflow process by embedding TCs in the corners
>>> of the balls of the device (ball interface with the board where all
>>> of the problems are) , the die, neighboring components etc. We
>>> dialed in the profile as low of a temp as possible.
>>>
>>>
>>> We are running several DOEs to come up with a placement/rework process.
>>>
>>> As part of the investigation the client is fixated on nitrogen
>>> reflow being part of the solution to these warped BGAs. Nitrogen
>>> reflow IMHO is the solution for joint aesthetics, wetting issues and
>>> enhanced reliability of the interconnection.
>>>
>>>
>>> ? Does anyone have experience with hot air reflow using nitrogen
>>> where its addition helped to mitigate warpage issues?
>>>
>>>
>>> Thanks!
>>>
>>>
>>> --
>>> Bob Wettermann
>>> BEST Inc
>>>
>>
>>
>
>
> --
> Bob Wettermann
> BEST Inc
> [log in to unmask]
> Cell: 847-767-5745 <(847)%20767-5745>
>
------------------------------
Date: Mon, 23 Jan 2017 21:29:41 +0000
From: Jose A Rios <[log in to unmask]>
Subject: Re: Copper Thickness Tester, Coppertron SM6000
I’ve seen these types of tools used during incoming inspection of cores (for example to verify that a 1 oz / 1 oz core is indeed that, for example). Also to verify a mixed weight core as well to not get the sides mixed up before imaging (like the 1/2 oz side vs the 1 oz side of mixed weight core). But I would not recommend using these for in process quality control of plated thickness, much less for lot acceptance. Actually for lot acceptance (per the 6012, 60134, 6018 series), it is not an accepted method.
José (Joey) Ríos, Sr QA Engineer
Mission Assurance
Kavli Institute for Astrophysics & Space Research
Massachusetts Institute of Technology
[log in to unmask] <mailto:[log in to unmask]>
(617)324-6272
> On Jan 23, 2017, at 1:57 PM, [log in to unmask] wrote:
>
> Fellow TechNetters:
>
> Has anyone out there have experience measuring copper thickness on PWB, either foil copper and/or plated copper thickness.
>
> Victor,
------------------------------
Date: Mon, 23 Jan 2017 16:16:52 -0600
From: David Hillman <[log in to unmask]>
Subject: Re: Nitrogen Reflow and Warpage Issues on POPs
Hi team - and yes, I would echo Wayne's point. I have a 12 zone oven so I
was able to very easily change my reflow profile to minimize the POP
warpage and produce acceptable solder joints (aka I was able to be lazy).
That doesn't mean you couldn't accomplish the same result using other
methods, it just may take a bunch of extra effort. We have used our BGA
rework systems to accomplish the same thing, the overall profile was quite
long and we had to change fluxes so we didn't "burn up" the flux but in the
end, we did make acceptable joints.
Dave
On Mon, Jan 23, 2017 at 3:11 PM, Wayne Thayer <[log in to unmask]>
wrote:
> Hi Bob-
>
> What diagnostic tools have you used to conclude this is a warpage problem
> and not some other problem, such as flux distribution, solder deposition,
> substrate overall flatness, etc.?
>
> I'm worried you could have our TechNet brain trust barking up the wrong
> tree!
>
> I put down a few of those parts around 4 years ago, and I recall it being
> a bit of process development, but I was able to make it happen without a
> large furnace (we had a 5 zone, but I can't even remember whether I ended
> up doing it on a rework machine or even a set of hot plates! I do recall
> that getting the fluxing right was one of the issues.
>
> Wayne
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
> Sent: Monday, January 23, 2017 1:02 PM
> To: [log in to unmask]
> Subject: Re: [TN] Nitrogen Reflow and Warpage Issues on POPs
>
> Hi Bob - your oven is a part of the issue equation. With a 5 zone oven you
> are pushing a bunch of heat into the POP in contrast to a larger oven with
> 7-12 zones. You might be able to minimize the warp effects by going thru
> the oven slower but make sure you also don't burn up the flux by the
> extended temperature exposure. Using short ovens with minimum heat zones
> can make profiling difficult.
>
> Dave
>
> On Mon, Jan 23, 2017 at 2:44 PM, Bob Wettermann <[log in to unmask]> wrote:
>
> > We have a 5 zone oven.....and a BGA rework station (tried with some
> > boards with the OMAP missing and all other parts populated) w/multi
> > zone bottom heater.
> >
> > BWET
> >
> > On Mon, Jan 23, 2017 at 1:54 PM, David Hillman <david.hillman@
> > rockwellcollins.com> wrote:
> >
> >> Hi Bob - in our testing, the package preformed better using a
> >> lead-free temperature reflow profile - we had much less warpage and
> >> other associated temperature impacts which we attributed to the
> >> package designers optimizing their package construction
> >> characteristics for a lead-free reflow temperature profile (its a
> >> lead-free part, so most frequent use would be in a lead-free
> >> process). We were using a 12 zone oven so lots of room to profile
> creation - how many zones in your oven?
> >>
> >> As for VP - I have never put a BGA in a VP process yet. It should
> >> work provided the condensing VP fluid doesn't cause the BGA to
> physically move.
> >>
> >> Dave
> >>
> >> On Mon, Jan 23, 2017 at 1:48 PM, Bob Wettermann <[log in to unmask]>
> >> wrote:
> >>
> >>> Hi Dave:
> >>>
> >>> This is SAC process.
> >>>
> >>> For rework we have tried to go "backwards" to Sn63 to reduce max temp.
> >>> The results were better. Customer did not want to go throiugh the
> >>> rel testing reqts of a bismuth-based alloy.
> >>>
> >>> Any thoughts on using a vapor phase reflow instead?
> >>>
> >>> BWET
> >>>
> >>> On Mon, Jan 23, 2017 at 1:29 PM, David Hillman <
> >>> [log in to unmask]> wrote:
> >>>
> >>>> Hi Bob - I have done process compatibility testing with the TI OMAP
> >>>> BGA and the use of a inert atmosphere has no impact on the warpage
> >>>> characteristics of the package (been there, done that, have the
> Tshirt).
> >>>> Are you using a tin/lead soldering process or a lead-free soldering
> >>>> process? POP technology was "born" in the lead-free era and as
> >>>> such, that package isn't a fan of a tin/lead soldering profile.
> >>>>
> >>>> Dave Hillman
> >>>> Rockwell Collins
> >>>> [log in to unmask]
> >>>>
> >>>> On Mon, Jan 23, 2017 at 11:29 AM, Bob Wettermann
> >>>> <[log in to unmask]>
> >>>> wrote:
> >>>>
> >>>>> Dear Technetters:
> >>>>>
> >>>>>
> >>>>>
> >>>>> We have a Class 3 customer with very complex, high density
> >>>>> placements (think cell phone for the military). This board is
> >>>>> laden w/0201s, 0.4mm pitch BGAs, shields, mirrored BGAs and the TI
> >>>>> Omap POP (0.4/0.5mm pitch).
> >>>>>
> >>>>>
> >>>>> The problems in this board assembly for some time have been
> >>>>> isolated to this OMAP part. We have lots of shorts and opens
> >>>>> (randomly-spaced) as confirmed by electrical testing, dye and pry
> >>>>> and cross sectioning. The Omap has been shown to warp 5-7 mils
> >>>>> depending on the reflow profile.( It is a no clean SAC305
> >>>>> process). We have profiled the reflow process by embedding TCs in
> >>>>> the corners of the balls of the device (ball interface with the
> >>>>> board where all of the problems are) , the die, neighboring
> >>>>> components etc. We dialed in the profile as low of a temp as
> possible.
> >>>>>
> >>>>>
> >>>>> We are running several DOEs to come up with a placement/rework
> process.
> >>>>>
> >>>>> As part of the investigation the client is fixated on nitrogen
> >>>>> reflow being part of the solution to these warped BGAs. Nitrogen
> >>>>> reflow IMHO is the solution for joint aesthetics, wetting issues
> >>>>> and enhanced reliability of the interconnection.
> >>>>>
> >>>>>
> >>>>> ? Does anyone have experience with hot air reflow using nitrogen
> >>>>> where its addition helped to mitigate warpage issues?
> >>>>>
> >>>>>
> >>>>> Thanks!
> >>>>>
> >>>>>
> >>>>> --
> >>>>> Bob Wettermann
> >>>>> BEST Inc
> >>>>>
> >>>>
> >>>>
> >>>
> >>>
> >>> --
> >>> Bob Wettermann
> >>> BEST Inc
> >>> [log in to unmask]
> >>> Cell: 847-767-5745 <(847)%20767-5745>
> >>>
> >>
> >>
> >
> >
> > --
> > Bob Wettermann
> > BEST Inc
> > [log in to unmask]
> > Cell: 847-767-5745 <(847)%20767-5745>
> >
>
------------------------------
End of TechNet Digest - 21 Jan 2017 to 23 Jan 2017 (#2017-12)
*************************************************************