Blitz, from the looks of the photo you provided (good job with the shots, btw; I don't have that talent), the TIM coverage looks okay. The dispersal pattern appears to indicate that the core die area in the middle has enough coverage.
On the other hand, even if the TIM coverage is good, does this actually mean that the contacting surfaces (the bottom of the HSF and the top of the IHS) have optimal contact? In other words, are the IHS and the HSF base flat, especially in their middle sections? (Please forgive me if I've asked you this before.)
The Spirit of OCN: To give is far better than to receive.The best advice to follow: Read your product's user's manual.
“Give a man a fish; you have fed him for a day. Teach a man to fish, and you have fed him for a lifetime.”—Lao Tzu (thanks to Blitz6804)
Today's "thlnk3r's thoughts": "You may fire when ready."