Replacement backplate for Sandy Bridge / Ivy Bridge motherboards. The CPU retention mechanism (AKA Independent Loading Mechanism) screws into this part.
The ILM is the arm & plate assembly which forces the processor evenly into the socket, ensuring reliable connectivity. Note that backplates for CPU heat sinks are designed to fit over the ILM backplate, providing either holes to allow longer ILM screws to poke through, or avoiding the fastener areas completely.
Why would you need this? Mainly, to use an aftermarket heat sink on an OEM system which has a non-reference backplate - in this example, one from a Dell workstation that integrates mounting arms for the stock cooler. Without this print, one would need to either source UNC #6-32 screws to fit their cooler, which may not be possible, or saw off the mounting arms (which destroys the ability to use the stock cooler again, hurting resale value.)
0.15LH / 0.25 LW / 0.4mm nozzle / 55mm/sec
The screw threads are modelled, but at this size one might as well just use undersized round holes for filament printers. Either way, this is intended as an install-once part - don't over-tighten or you risk stripping the threads.
In the STL file, the text box on the part has been much reduced in height compared to my print.. At only 0.05mm most slicers should just ignore it.
- Although Intel's specs call for metal construction with a plastic insulation shim, the rigidity of this part should be acceptable. However, there is some risk of the plastic overheating. For the hottest 1155 processors, coolers meeting the design recommendations should allow a maximum temperature of ~73C, while PLA starts to soften at ~60C. I did a quick test on my system under full load with the case off, and the surface of the motherboard beneath the socket was about 18C below the highest core temperature. The backplate is open in the area beneath the CPU die, but problems could occur due to a closed case, warm climate, or overclocking.
If your situation invites temperature issues, it is probably worth the time to anneal the print if you use PLA. Then again, if the cooler is properly mounted, some of the tension on the ILM will be removed due to the pressure of the heat sink, which should mitigate the risk of outright failure.
No post-processing should be required. Annealing recommended if temperatures under your motherboard surpass 55C.
This model is based entirely on the mechanical drawing provided in Intel's
Thermal Mechanical Specifications and Design Guidelines for Socket LGA1155
(Document number 326767-005, drawing E20847, page 132)
Not all measurements are provided in that document, especially around the area of the shoulder screw, so there is some guesswork involved. Most cooler backplates should be compatible unless they are made to fit flush around the edges of the ILM backplate, but this is uncommon with aftermarket designs.