Wedge locks are used when electronics cards must be easily replaceable.  The wedge lock is a mechanical clamp that allows a card to be swapped quickly but has the drawback of being a relatively poor thermal conductor.  As power per card continues to increase, a lower thermal resistance device is needed.

Yes.  By lowering the thermal resistance by more than one-third, replacing a standard wedge lock with a 3/8” ICE-Lok^®, component temperatures are lowered by 10°C at 100 W power input.

As shown in the photo on the right and Figure 1 below, a standard wedge lock has a series of trapezoidal-shaped wedges, with an internal screw.  As the screw is tightened, the wedges are forced up and down, exerting pressure to clamp the card into the chassis.

As shown in the photo to the right and described in the video below, the ICE-Lok^® improves performance by increasing the surface area for heat transfer and maximizing contact pressure.  The wedges are cut at a bias, so that the wedge can expand in two directions, allowing the ICE-Lok to contact all four sides of the thermal interface.  An integral bracket also reduces thermal resistance.

The nut driver size is 1/8”.

Chassis and/or card deformation is not a problem, since the wedges are designed to “Friction Lock”.  The wedges do not apply forces on the chassis or card until the wedges fully contact all four faces. When considering a horizontal conduction card, the bias angle of the wedges is designed so that the friction forces of the vertical load is greater than horizontally.  This generates a friction force greater than the horizontal force and prevents the ICE-Lok^® from further movement in the horizontal direction. This results in no external deflection of the chassis or conduction card.

The mass of a single, 9 wedge 375 ICE-Lok^® is approximately 47.5 grams.  For each increment in length, the mass changes by approximately 11 grams (i.e. 11 wedge – 58.5 grams; 7 wedge – 36.5 grams).

The qualification tests included both thermal and mechanical tests.

• ICE-Lok^® Wedge lock Thermal Qualification Testing: The thermal testing procedure is shown in the figure below.  In one set of tests, the thermal resistance was measured initially, and after each 20 card withdrawals/insertions.  No appreciable change was measured.

• In the other set of tests, the thermal resistance of the card was measured before and aftershock and vibration tests. The test conditions encompassed military aircraft, Delta IV, and Atlas V.  No problems were observed.

In order to get the thermal benefits of the ICE-Lok^®,  both the Card Guides and Conductance Card need to make physical contact with the ICE-Lok^® , and by extension with each other.