Hello All,

 

 

I finally bit the bullet and went for it. I successfully de-lidded my i7 3770K using a razor blade, got rid of the old stuff and applied my Liquid Metal Pro. However, being such a thin layer when applied (regardless of how much is used) the die doesn't seem to reach high enough to make solid contact with the IHS. I took the IHS off to check the contact patch and the Liquid Metal has only been disturbed in a few remote places. ( Obviously doesn't need to be as close with thicker heat paste).

 

As if this wasn't bad enough, after carefully lapping both the IHS and the H100 plate they also appear to meet in some areas only. I don't know how to get them any flatter! I kept cleaning the Liquid Metal off and sanding the areas that were making contact to flatten them off, but after 4 attempts I had only improved the contact patch marginally before I ran out of Liquid Metal. (I now have to wait anther 2 weeks for more to reach Australia from Germany!

 

Am I being stupid puuling things apart again looking at the size and evenness of the contact patch? Does the Liquid Metal adhere to both faces and even leave a tell-tale mark?

 

Do I need to get them flatter and how?

 

Has anyone else found the die hardly touching the IHS?

 

Please help!

 

Regards,

 

Stephen.

You're definitely doing it right. The problem with the core and IHS is one I ran into as well, the solution is to also apply LMU to the underside of the IHS. As for the lapping, I found it to be a painfully slow process, took me hours and hours. Are you using a flat surface (like a piece of glass) to lap on? What motion are you using? What grit sand paper? I used a piece of glass with several grits from 400 up to 2500 in a small, circular motion, rotating the IHS/block by 45 or 90 degrees every minute or two. Also, I did not use any force or press down on the piece being sanded, I merely held it with my fingers. The center part of both the IHS and the block are convex, and this motion will often sand primarily in a single spot so you have to move the block all over the sand paper and even focus on the areas that seem to be sticking up. If you do a lap with a really fine grit and get it polished well, you will see the spots that are still not flat as they will still be rough. You can then move the piece so that these parts are the focus of your sanding.

 

Hope this helps!

Big thing here are your temps. I can't specifically address the LMP application (I've only used Ultra). Did you try searching Youtube for any related vids?

 

You are monitoring with something like RealTemp?

 

If it is like LMU (which seems similar) I would expect to see the H100 "stained" from where the LP made contact. As TechMax said... a very thin coat on the underneath side of the IHS should suffice.

 

Do I need to get them flatter and how?

 

For lapping... I had a local glass shop cut me a 4"x8" piece of 1/4" thick glass (beveled the edges). That was about the right size for paks of sandpaper like this : http://www.amazon.com/3M-03006-Wetordry-Automotive-Sandpaper/dp/B005JPGTNI/ref=pd_bxgy_auto_text_y Two excellent threads on this subject:

• http://forum.avsim.n...eds-de-lidding/
  
• http://forum.avsim.n...-ultra-results/
  

Note particularly what the BimmerCop has to say. One thing he mentioned was the grit(s) he used in this order:

• 180 - 220 - 320 - 400 - 600 - 800 - 1000 - 2000 - 3000
  

Only thing I might add would be to use 1500 & 2500 (since it came in the above pak... why not?). You finish with 3000 and it will be mirror-like (as he said). I spent a good number of hours too (like the Techmax)... this isn't an afternoon project...

 

I sand all in one direction, change grit, then rotate 90° and sand again until all the scratches from the previous sanding are removed (easy to tell as they are 90° from my current direction). Keep the sanding area wet (you are using Wetordry?) but not soaked. Sand a short bit, wipe off the surface of removed material, a couple drops of water on the metal, resume sanding. Firm but not too hard pressing... let the grit do the work.

 

One thing (as per manual) it's not a prerequisite to lap the cpu / cooler for LP - but the coating is a smidge thick more it says (we're talking thousandths of an inch)... hence why one laps - so there is less TIM.

 

@TechMax... very nice de-lid pictorial btw. :good: