Yup. Been there, done that. It is simply not fun.
From: Steve Gregory [mailto:[log in to unmask]]
Sent: Thursday, September 20, 2018 12:21 PM
To: [log in to unmask]; Stadem, Richard D
Subject: Re: [TN] High Temp SnPb solder
Hi Richard,
Did some work for Schlumberger back when I was in Tulsa. We had a dual pot Technical devices wave machine with one of the pots filled with HMP solder. I didn't know how the boards were able to withstand going across a wave of 300 C. liquidus solder but they did. I got to see one of the tools and how these boards are mounted in the tools, they're all potted with a 1-inch thick layer of potting material around the assembly inside a cavity machined into the tool. Like you said, you don't even want to think about failure. With all the horizontal drilling that they do nowadays there can be thousands and thousands of feet of pipe in the well that will need to be pulled to get to the tool at the end of the pipe if you need to fix something.
Steve
On Thu, Sep 20, 2018 at 11:00 AM Stadem, Richard D <[log in to unmask]<mailto:[log in to unmask]>> wrote:
Yeah, and no MEMs or BTCs would ever be allowed, either!
Hmm.....maybe we should go back to those old rules, LOL!
-----Original Message-----
From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of David Hillman
Sent: Thursday, September 20, 2018 9:17 AM
To: [log in to unmask]<mailto:[log in to unmask]>
Subject: Re: [TN] High Temp SnPb solder
LOL - if we were following the old rules then there would not be a
component called a BGA.............. :-)
Dave
On Thu, Sep 20, 2018 at 9:07 AM, Yuan-chia Joyce Koo <[log in to unmask]<mailto:[log in to unmask]>>
wrote:
> according to my book (old), you should NOT count on solder as
> mechanical support of ANY kind. solder is intended to provide electrical
> connect, use solder, especially high temp solder (assume you are going to
> use it at elevated temp for service, or assembly sequence - such as
> multiple reflows... it is difficult to count on microstructure to be the
> same as you initially put down).
> as for FEM purpose, I would use 50% book value that tell you - if i
> were you...
> my 1.5 cents.
> jk
> On Sep 20, 2018, at 9:54 AM, Stadem, Richard D wrote:
>
> Adding to what Dave said; you don't get something for nothing! Different
>> alloys have different physical characteristics and are used for
>> correspondingly different purposes and applications. Don't attempt to use
>> something not AABUS and fully documented on the applicable BOM.
>>
>> -----Original Message-----
>> From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of David Hillman
>> Sent: Thursday, September 20, 2018 6:57 AM
>> To: [log in to unmask]<mailto:[log in to unmask]>
>> Subject: Re: [TN] High Temp SnPb solder
>>
>> Hi Ben - yes, there are differences in the mechanical properties and the
>> solder joint microstructures for the "high temp" alloys. Most of those
>> alloys have applications in component construction, specifically in
>> component die attachment. One very common alloy used frequently in a
>> number
>> of applications is the 10Sn88Pb2Ag alloy.
>>
>> Dave Hillman
>> Rockwell Collins
>> [log in to unmask]<mailto:[log in to unmask]>
>>
>> On Thu, Sep 20, 2018 at 6:40 AM, Gumpert, Ben <[log in to unmask]<mailto:[log in to unmask]>>
>> wrote:
>>
>> TechNetters,
>>>
>>> J-STD-006 has a series of 'high temp' SnPb alloys (some with Ag) that are
>>> close in SOL/LIQ temps. I'm familiar with Sn10Pb90 as a common high-temp
>>> ball on ceramic BGAs, but I haven't seen the others used. Are there any
>>> differences (e.g. mechanical properties) among these that would drive
>>> selection, other than the SOL/LIQ?
>>> Are some alloys more readily available than others?
>>>
>>> Ben
>>>
>>>
--
Steve Gregory
Kimco Design and Manufacturing
Process Engineer
(208) 322-0500 Ext. -3133
[http://fileserver1.kimco.net/PublicDocs/KDMsig200.png]
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