Although initially fairly reclusive, Boards of Canada has, in recent years, opened up, and there are now quite a few interviews to read.
"The Age of Aquarius" by the Cosmic Crofter
EHX online interview [1] of canada/bocehx.html [2] [3]
"A Bunker Full of Memories" by René Passet
Forcefield online interview [4] [5] of canada/bocforcefield0498.html [6] [7]
Republished in Pop Is Dead fanzane (aka pissdead) issue #7 (February, 1999) [8] [9]
"Two Aesthetes of Electronic Music" (in French) by Ariel Kyrou