https://www.google.co.uk/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=alpha+assembly+Comprehensive+Report+on+Low+Temp+Solder+Alloys+for+Portable+Electronics
---
Regards
Mike
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Mike Fenner
Sent: Wednesday, February 15, 2017 10:20 PM
To: [log in to unmask]
Subject: Re: [TN] New Solder Alloy
Quite right, but something only has to be good enough to work for its design life and use conditions and these days (low end) laptops are definitely a short life consumer item.
Bi/Sn has better thermal fatigue properties than it should have for its MP, and I imagine that the inclusions of Ag/Cu and NI are to improve the ductility so making it superior to classic types evaluated in the past. How well this has been achieved will become clearer when test data is published. It’s an interesting idea anyway.
---
Regards
Mike
www.chrisfennerfund.org
www.facebook.com/chrisfennerfund/
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Thayer
Sent: Wednesday, February 15, 2017 12:29 AM
To: [log in to unmask]
Subject: Re: [TN] New Solder Alloy
Another concern with an alloy with a designed reflow oven temperature of 180C is that the melting point is going to be around 145C. As devices run hotter and hotter, being so close to the melting point may decrease fatigue life significantly. Maybe Lenovo has defined the parameters for the attachment process and told the designers what the new boundary conditions are--for example, if fatigue life goes down due to the new alloy, bring it back up to acceptable by decreasing max operating temperature, reducing max component size, etc. Or maybe they figured out their products are lasting too long anyway!
Wayne
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
Sent: Tuesday, February 14, 2017 4:02 PM
To: [log in to unmask]
Subject: Re: [TN] New Solder Alloy
Hi TechNet - I will echo Andy's comments, the SnBi solder alloy system may have some application in some products but a number of solder alloys in the SnBi alloy family have been extensively investigated and found to not be applicable for a large segment of high performance product types/use environments.
Dave
On Tue, Feb 14, 2017 at 2:06 PM, Giamis, Andy <[log in to unmask]>
wrote:
> Interesting.
> I tore apart a certain smart phone a few years back and saw that they
> attach heat shields/heat spreaders to the PCB edge with Sn-Bi. The PCBA
> was amazing but I thought the Sn-Bi solder joints had wetting issues
> and many of the solder joints were cracked. Sn-Bi seems to be rather brittle.
> It would be interesting to see how this particular alloy performs.
>
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Mike Buetow
> Sent: Tuesday, February 14, 2017 11:38 AM
> To: [log in to unmask]
> Subject: Re: [TN] New Solder Alloy
>
> I have been in touch with Lenovo about the alloy, which is a
> tin-bismuth alloy developed in concert with Alpha and Senju. There's
> some info in the link below based on what I've learned.
> http://circuitsassembly.com/ca/editorial/menu-news/27004-
> new-lenovo-lts-lowers-melting-temp-cuts-co2-emissions.html
> Best,
> Mike
> -------- Original message --------From: "Vargas, Stephen M" <
> [log in to unmask]> Date: 2/14/17 9:19 AM (GMT-08:00) To:
> [log in to unmask] Subject: [TN] New Solder Alloy Got news of this from a
> colleague. Interesting... would love to hear comments from the TechNet
> group.
>
> http://news.lenovo.com/news-releases/lenovo-announces-
> breakthrough-innovative-pc-manufacturing-process.htm
>
> Regards,
> Steve Vargas
>
|
