Joyce, 

Most of the SMTs in modern electronics have solder as their ONLY means of mechanical support.
(but I have also been in the industry since the 1980's, so I remember books like that!)

I always enjoy reading about your experience,
Jack

On Thu, 20 Sep 2018 10:07:18 -0400, Yuan-chia Joyce Koo <[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