Dave:
We use 17 different part numbers (lucky us) and after looking at our defect data and comparing it to component date codes, I could not draw any correlations based on the age of the parts. Date codes were from late 2014 to early 2017.
The pad layouts are per the manufacturer’s recommendations, so I’ll likely try tweaking my reflow profile per your recommendations below and I’ll also keep beating on my customer to move toward a 63/37 finish (or even SAC305) – wishful thinking………..
Thanks again for your insight.
Regards,
Steve Vargas
If you don't have time to do it right, when will you have time to do it over?
John Wooden
Polaris Contract Mfg Inc
15 Barnabas Rd
Marion, MA 02738
774-553-6192
[log in to unmask]<mailto:[log in to unmask]>
P Please consider the environment before printing this e-mail
From: David Hillman [mailto:[log in to unmask]]
Sent: Tuesday, August 29, 2017 8:59 AM
To: TechNet E-Mail Forum <[log in to unmask]>; Vargas, Stephen M (US) <[log in to unmask]>
Subject: EXTERNAL: Re: [TN] EXTERNAL: RE: [TN] EXTERNAL: RE: [TN] Odd Finish Soldering
Hi Steve - yes, if you bump up the reflow temperature to the 220C-225C it will help but also watch your TAL because the Ag/Pd/Pt termination finish can completely diffuse into the solder resulting in a weak mechanical connection instead of a metallurgical connection. We have had better luck wit the Ramp to Spike profile than the Ramp Soak Spike profile but we moved to the Ramp to Spike profile for other reasons than just the Ag/Pd/Pt surface finish. The SMQ92J paste is active enough in terms of flux strength so you are good on that count. Do you know how old the inductors are?
Dave
On Mon, Aug 28, 2017 at 10:40 AM, Vargas, Stephen M <[log in to unmask]<mailto:[log in to unmask]>> wrote:
Bev:
We solder these parts using Indium SMQ92J paste. It is advertised as no-clean (although we do clean) and the flux classification is ROLO. We also use a Ramp-Soak-Spike profile (I'm not sure if a Ramp to Spike profile might help....). I'll also add that our peak temperatures are running around 218 degrees C, I'm wondering if we bump this up to closer to 220-225 degrees C if there would be any benefit?
Regards,
Steve Vargas
If you don't have time to do it right, when will you have time to do it over?
John Wooden
Polaris Contract Mfg Inc
15 Barnabas Rd
Marion, MA 02738
774-553-6192<tel:774-553-6192>
[log in to unmask]<mailto:[log in to unmask]>
• Please consider the environment before printing this e-mail
-----Original Message-----
From: Bev Christian [mailto:[log in to unmask]<mailto:[log in to unmask]>]
Sent: Monday, August 28, 2017 11:32 AM
To: 'TechNet E-Mail Forum' <[log in to unmask]<mailto:[log in to unmask]>>; Vargas, Stephen M (US) <[log in to unmask]<mailto:[log in to unmask]>>
Subject: EXTERNAL: RE: [TN] EXTERNAL: RE: [TN] Odd Finish Soldering
Steve,
I forgot to ask, what type of flux are you using? I remember discussing in the IPC J-002 committee that some no-clean fluxes are better than others for soldering application with a palladium finish. I wonder if that is in play here? I expect Dave Hillman to have more to say about this.
Bev
-----Original Message-----
From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of Vargas, Stephen M
Sent: Monday, August 28, 2017 11:25 AM
To: [log in to unmask]<mailto:[log in to unmask]>
Subject: Re: [TN] EXTERNAL: RE: [TN] Odd Finish Soldering
Bev:
Yes, the end of the copper winding is embedded in the bottom termination and does not appear to be covered by the finish. It actually looks like the copper wire has been compressed to produce a more flattened surface. I suspect oxidation of this wire is contributing to our problem, but I've also read (back from 2008) that this finish will dissolve into solder causing non-optimized soldering angles which can cause premature failure during shock and vibe testing. I'm trying to determine if this theory still holds true today. Thanks again.
Regards,
Steve Vargas
If you don't have time to do it right, when will you have time to do it over?
John Wooden
Polaris Contract Mfg Inc
15 Barnabas Rd
Marion, MA 02738
774-553-6192<tel:774-553-6192>
[log in to unmask]<mailto:[log in to unmask]>
• Please consider the environment before printing this e-mail
-----Original Message-----
From: Bev Christian [mailto:[log in to unmask]<mailto:[log in to unmask]>]
Sent: Monday, August 28, 2017 11:04 AM
To: 'TechNet E-Mail Forum' <[log in to unmask]<mailto:[log in to unmask]>>; Vargas, Stephen M (US) <[log in to unmask]<mailto:[log in to unmask]>>
Subject: EXTERNAL: RE: [TN] Odd Finish Soldering
Steve,
Is the problem the finish or does the inductor have the end of the copper winding embedded in the bottom termination finish but it is not totally covered by that finish? If so, then the oxidized copper wiring is your problem, not the termination finish. I have run into this before. Why the manufacturers insist on terminating the wire on the bottom rather than the top is beyond me.
Bev
-----Original Message-----
From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of Vargas, Stephen M
Sent: Monday, August 28, 2017 10:38 AM
To: [log in to unmask]<mailto:[log in to unmask]>
Subject: [TN] Odd Finish Soldering
Good morning:
We've experienced some soldering difficulties with small 0402 inductors using a silver palladium platinum glass plating. Our application is a 63/37 process and we find that these parts shift randomly through our reflow oven and the overall soldering is less than optimum. The part is available in a more robust plating, but the cost impact is absurd. I'm wondering if others have run into similar problems with this finish and why the difficulty in soldering these parts. Thanks in advance.
Regards,
Steve Vargas
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