Design for long term reliability?
NASA has a lot to say about long term reliability of electronics. Here's one example ->
https://nepp.nasa.gov/files/20223/09_109_1%20JPL_Spence%20Longterm%20Reliability%20of%20Hand%20Soldering%20M55365%20Ta%20Capacitors%2009_30%2011_09%203_2_10.pdf one example (references are at the end). 

I can't give you good link to everything related (NASA web site is quite messy), however, googling 'nasa long term reliability electronics' gives a lot of links to papers on the topic.