ICE-Lok® Thermally Enhanced Wedgelock

Home  |  Products  |  ICE-Lok® Thermally Enhanced Wedgelock

ICE-Lok® Wedgelock

The patented Isothermal Card Edge ICE-Lok® is designed to enhance thermal performance for conduction-cooled embedded computing systems. Compared to conventional wedgelocks, the ICE-Lok® creates additional heat transfer paths from card to chassis, thereby reducing the thermal resistance.

The ICE-Lok thermally enhanced wedgelock, can be seamlessly integrated into standard VITA systems, enabling a longer lifetime and higher reliability for your critical components without costly board or chassis redesign.


ICE-Lok® Wedgelock Benefits for Embedded Computing

• 33%+ reduction in thermal resistance from equivalent size COTS wedgelocks, due to added heat transfer paths and surfacesACT's ICE-LOK System achieved a Platinum Honoree 2021 Innovator award from Military and Aerospace Electronics.
• Single screw access for easy board installation/removal
• Rugged design and construction as validated through shock/vibration testing and repeated installation cycles
• VITA 48.2 compliant
• Compatible with standard VITA 3U, 6U and 9U cards
• Superior clamping force
• Space VPX applicapable

Replacing COTS wedge locks with ACT’s 3/8” ICE-Lok™ for a 100W system lowers component temperatures by > 10°C.

Replacing COTS wedge locks with ACT’s 3/8” ICE-Lok® for a 100W system lowers component temperatures by > 10°C.

Everything you need to know about thermally enhanced wedgelocks


When are wedgelocks used?

Wedgelocks are used when electronics cards must be easily replaceable.  The wedgelock 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.

Wedgelock Comparison shown installed in chassis and conduction card frame


Can an ICE-Lok® wedgelock help with overheating components?

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

Standard wedgelock

How do wedgelocks work?

As shown in the photo on the right and Figure 1 below, a standard wedgelock 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.

Figure 1: Thermal and Mechanical comparison diagram of standard wedgelocks and ACT's ICE-Lok(TM)

Figure 1: Thermal and Mechanical comparison diagram


How does an ICE-Lok® wedgelock lower thermal resistance?

Thermally Enhanced Wedgelock- ACT's ICE-Lok(TM)

ICE-Lok® (375 Series)

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.



What is the nut driver size for the ICE-Lok® locking head of the 250 series?

The nut driver size is 1/8”.

Since the ICE-Lok® expands in two directions, do I need to be concerned with deforming the chassis or card?

Watch Now

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.

Wedge force application in standard wedgelock use cases

What is the mass of the 375 series ICE-Lok®?

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).

What tests were used to qualify the ICE-Lok® wedgelock?

The qualification tests included both thermal and mechanical tests.

  • ICE-Lok® Wedgelock 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.

Thermal Testing Timeline

    • 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.
  • ICE-Lok® Wedgelock Mechanical Qualification Testing: Mechanical testing consisted of retention testing and shock and vibration testing; see the figure below. Retention of the card under an applied for of 300 pounds is necessary for qualification.  Card retention was tested on a dedicated chassis, then shock and vibration testing was performed, followed by additional retention testing. The test conditions encompassed military aircraft, Delta IV, and Atlas V.  No problems were observed.

How do I know the ICE-Lok® thermally enhanced wedgelock will fit in my chassis?

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.

ACT’s ICE-Loks™ are designed to fit within chassis’ made to VITA standards.  The downloads below can be used to help size the thickness of the conduction card flange.  This way the card/ICE-Lok® assembly will be sure to fit within your chassis.  However, the ICE-Lok won’t expand indefinitely.  Maximum limitations for each model can be found on the product data sheets and on each .STEP file below.

ICE-Lok’s® are available in standard in 1/4″ (250 series) with 7, 9, and 11 wedge configurations and 3/8″ (375 series) diameters with 5, 7, or 9 wedge configurations.


Contact ACT engineers for solid models of custom variants using 3, 5, 11, 13 wedge sizes.

Get your quote today

Now that you’ve learned what a wedgelock is and how they are used, it’s time to contact ACT for more information and a quote for improving your equipment’s thermal conductivity and efficiency. We will help you decide how best to meet your needs. We will provide you with everything you need to understand the cost of the ICE-Lok®solution as well as the options that will replace your current wedgelock.

Reduce your costs and improve the life and reliability of your equipment with a simple conversation designed to make your operations easier and affordable.


Sealed Enclosure Cooling Selection ToolUse our ICE-Lok SKU configuration tool to select the best choices for your project; this makes ordering online a breeze, or you can easily use the complete SKU for quick processing!




Have a Question or Project to Discuss?