This is a 6 high DEC KDJ processor board. It seems like it could be an 11/84 processor, which is Unibus, but the layout doesn't match. This board is Unibus as well, not QBUS like the 11/83
Attached are some shots of a document, and two pages of layout info from schematics.
Made in Japan with quite a bit of the document in Japanese.
Photo of board and scan of manual to follow.