Victor,
is the connector intended for socket instead of soldering?   did  
someone brought the wrong connector?  (have seen that before... buyer  
thought the dash number didn't make any difference, went ahead  
brought a cheap/faster delivery one...).  - if it is fine pitch  
connector, it could be used for ACF (like LCD ribbon connector  
type...).  your question didn't tell detail of connector in question,  
like pitch, etc.  just a guess, fyi only.  good luck.
jk
On Jul 31, 2018, at 1:38 PM, Stadem, Richard D wrote:

> So you want to solder just 30 uinches of a gullwing connector lead  
> frame to a number of OSP-coated bare copper PWB pads using lead  
> free solder. Why only 30 uinches?
> And the gull-wing SMT connector leads have 20 uinches of hard gold  
> electroplated on them?
> Why, sure you can! But it won't last very long. Sounds like a  
> recipe for a perfect storm of issues.
> You should pre-tin the connector lead-frame to remove the gold  
> first. Why were they plated with so much gold? What is the base  
> metal of the leadframe?
> I would use an immersion silver plated PWB, not OSP.
> I would also form the leads so you have more than 30 uinches of  
> solder wetting to the pads/leads.
> I would also qualify this process with some intensive reliability  
> testing, including shock, stress testing for connector insertion,  
> vibration and observe for fretting as well, and thermal cycling to  
> failure.
> All that may be overkill, but without a picture of the proposed  
> leadframe, the board layout, the use environment, etc., it is hard  
> to answer your question.
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of  
> [log in to unmask]
> Sent: Tuesday, July 31, 2018 10:45 AM
> To: [log in to unmask]
> Subject: Re: [TN] Solder joint integrity
>
> Dell - Internal Use - Confidential
>
> Fellow TechNetters:
>
>    I did not get very many relies to my original inquiry.    
> Therefore I post a second time.
>
>    Is it permissible to solder 30 micro inch of connector lead  
> frame to PWB copper pad with Lead Free Solder.   What are the Pros  
> & Cons.
>
> Clarification statement:
>    The PWB external copper pad finish is OSP.
>    The M2 connector gull wing leads are plated with 20 micro inch  
> of hard gold.
>    The process solder is Lead Free.
>
>    I have not seen a combination of this sort before.   SnPb and LF  
> solder will solder to ENIG, Will a reliable LF solder joint be form  
> with hard gold?
>
>    Is there a reliability concern?????????
>
> Victor,
>
> -----Original Message-----
> From: Giamis, Andy [mailto:[log in to unmask]]
> Sent: Friday, July 27, 2018 3:16 PM
> To: Hernandez, Victor G
> Subject: RE: Solder joint integrity
>
> Thanks for the clarification.  That's totally different from what I  
> was imagining.
>
> I have also never seen Au plating on a gull wing lead, let alone  
> hard Au.....
>
> I have seen mezzanine card PCBs with edge pin connections.  The  
> development products had full hard Au plating, eventually going to  
> ENiG with selective hard Au on the contact fingers.  The  
> development boards had regular SOICs, QFNs, BGAs and passive  
> parts.  Essentially a similar situation, just reversed:  Soldered  
> leaded components, one surface with thick hard Au.  This was  
> several years ago and I don't have the hard data available to me  
> anymore.  I remember that in reliability testing, leaded parts did  
> well.  I think we had Au embrittlement on QFNs and some fine-pitch  
> BGAs.
>
>
> How's your team down there in Austin?
> I hope you got somebody good for that open position.
>
> Best Regards,
> Andy
>
> Andrew C. Giamis
> Senior Failure Analysis Engineer
> CommScope
> 2601 Telecom Pkwy
> Richardson, TX, 75082, USA
> phone: 972-952-9847
>
> -----Original Message-----
> From: [log in to unmask] [mailto:[log in to unmask]]
> Sent: Friday, July 27, 2018 2:55 PM
> To: Giamis, Andy <[log in to unmask]>
> Cc: [log in to unmask]
> Subject: RE: Solder joint integrity
>
> Email Security Warning:
>
> The following message was sent from an external e-mail address.  
> Exercise caution when opening attachments, clicking links, or  
> exchanging information.
>
> Dell - Internal Use - Confidential
>
> Clarification statement:
>    The PWB external copper pad finish is OSP.
>    The connector gull wing leads are plated with 30 micro inch of  
> hard gold.
>    The process solder is Lead Free.
>
>    I have not seen a combination of this sort before.   SnPb and LF  
> solder will solder to ENIG, Will a reliable LF solder joint be form  
> with hard gold?
>
>    Is there a reliability concern?????????
>
> Victor,
>
> -----Original Message-----
> From: Giamis, Andy [mailto:[log in to unmask]]
> Sent: Friday, July 27, 2018 2:41 PM
> To: Hernandez, Victor G
> Subject: RE: Solder joint integrity
>
> I don't have any data to support a reliability assessment.
>
> The smallest I have ever seen for solder joints on connectors is in  
> an I-Phone 4 tear-down I keep in the lab (see attached).
>
> Maybe I don't understand you r intended application.
> Just to confirm, you are soldering to a lead or post that has a  
> solderable surface of 30 micro-inches?  That's about as thick as a  
> hard gold plating.
> On this scale any Sn-based solder would just saturate with the PCB  
> surface plating (ENiG, imAg or base Cu for OSP).  It would readily  
> and completely form intermetallic.  You wouldn't have any solder  
> left, just intermetallic.  I'd expect that this would crack on the  
> first sneeze.
>
> Best Regards,
> Andy
>
> Andrew C. Giamis
> Senior Failure Analysis Engineer
> CommScope
> 2601 Telecom Pkwy
> Richardson, TX, 75082, USA
> phone: 972-952-9847
>
> -----Original Message-----
> From: [log in to unmask] [mailto:[log in to unmask]]
> Sent: Friday, July 27, 2018 1:40 PM
> To: Giamis, Andy <[log in to unmask]>
> Cc: [log in to unmask]
> Subject: RE: Solder joint integrity
>
> Email Security Warning:
>
> The following message was sent from an external e-mail address.  
> Exercise caution when opening attachments, clicking links, or  
> exchanging information.
>
> Dell - Internal Use - Confidential
>
> Both, How Reliable is the solder joint given the working parameters.
>
> -----Original Message-----
> From: Giamis, Andy [mailto:[log in to unmask]]
> Sent: Friday, July 27, 2018 12:42 PM
> To: Hernandez, Victor G
> Subject: RE: Solder joint integrity
>
> Hi Victor,
>
> Is your primary concern soldering to 30 micro inches or soldering  
> with Pb-free solder?
>
> As long as the solder joints are well-formed, Pb-free solder  
> shouldn't be an issue (SAC alloys and related).
>
> 30 uin of solderable surface on a leadframe sounds frighteningly  
> small.    What kind of connector are you looking at?
>
>
>
>
>
> Best Regards,
> Andy
>
> Andrew C. Giamis
> Senior Failure Analysis Engineer
> CommScope
> 2601 Telecom Pkwy
> Richardson, TX, 75082, USA
> phone: 972-952-9847
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of  
> [log in to unmask]
> Sent: Friday, July 27, 2018 12:27 PM
> To: [log in to unmask]
> Subject: [TN] Solder joint integrity
>
> Email Security Warning:
>
> The following message was sent from an external e-mail address.  
> Exercise caution when opening attachments, clicking links, or  
> exchanging information.
>
> Fellow TechNetters:
>
>    Is it permissible to solder 30 micro inch of connector lead  
> frame to PWB copper pad with Lead Free Solder.   What are the Pros  
> & Cons.
>
> Victor,