ACT - Heat Pipes

ACT - Heat PipesACT - Heat PipesACT - Heat PipesACT - Heat Pipes
There are several types of heat pipes available, including:
  • Vapor chamber: These flat heat pipes are typically used when heat fluxes and high powers are applied to smaller evaporators, as well as for enabling heat flow through very thin devices.
  • Variable conductance: Adding a non-condensable gas (NGS) that mixes with working fluid vapor and a reservoir, creates a Variable Conductance Heat Pipe (VCHP), where the effective thermal conductivity varies with the input power and heat sink conditions.
  • Diode: Diode heat pipes are designed to transfer heat in one direction, and insulate it in the opposite direction.
  • Loop heat pipe (LHP): An LHP is a passive two-phase device that is capable of transferring higher power over longer distances.
Benefits of these devices include:
  • High Thermal Conductivity (10,000 to 100,000 W/m K)
  • Isothermal
  • Passive
  • Low Cost
  • Shock/Vibration tolerant
  • Freeze/thaw tolerant

More

ACT is one of leading manufacturers and suppliers of heat pipes in the United States. We produce a wide variety of heat pipes, heat sinks and heat pipe assemblies for thermal management of electronics and applications such as LEDs, card chassis, lasers, radar systems and medical systems. Our heat pipes offer a high thermal conductivity range of 10,000 to 100,000 W/m K and excellent shock/vibration and freeze/thaw tolerance. They also provide an extremely cost-effective thermal control system solution.

HOW ARE HEAT PIPES USED?

Heat Pipes which have also be termed heatpipes or even thermal pipes, are used across a wide range of markets and applications, and we’re known for producing high-quality copper heat pipes. In fact, ACT is the only US manufacturer that routinely delivers heat pipes for terrestrial electronics cooling (copper-water), on orbit satellite thermal management (aluminum-ammonia) and high temperature calibration equipment (liquid metal). Navigate through the products section below for more information on any of these highly reliable products.

AN OVERVIEW OF HEAT PIPE TECHNOLOGY

Figure 1. Illustration of Heat Pipe operation.

heat pipe is a two phase heat transfer device with a very high effective thermal conductivity.  It is a vacuum tight device consisting of an envelope, a working fluid, and a wick structure.  As shown in Figure 1, the heat input vaporizes the liquid working fluid inside the wick in the evaporator section. The saturated vapor, carrying the latent heat of vaporization, flows towards the colder condenser section.  In the condenser, the vapor condenses and gives up its latent heat.  The condensed liquid returns to the evaporator through the wick structure by capillary action.  The phase change processes and two- phase flow circulation continue as long as the temperature gradient between the evaporator and condenser are maintained.

MORE INFORMATION ABOUT HEAT PIPES

If you are designing a thermal system and simply want to learn more about heat pipes for cooling, use the links in the Operation Section. If you still have questions, contact us and an engineer will be in contact with you.

See a full video and transcription about the basics of heat pipes and their advantages.

More Product Information

Focus Microwaves - RF Test Fixtures

Focus’ modular microstrip, high power and ultra low loss coaxial  RF Test Fixtures are designed mainly for load pull testing of packaged transistors. All Focus test fixtures come with TRL calibration standards and support most transistor packages sized from less than 0.1″ and up to 1″.

Focus Microwaves - TRL Calibration Kits
Focus recommends TRL Calibration Kits for applications such  as load pull & noise parameters. Due to high reflection and low loss, tuner S-parameter measurements represent a challenge for VNA’s, because of error term determination and coupler directivity. Long experience has taught us not to rely on other calibration techniques than TRL (Thru-Reflect-Line). The popular SOLT technique is conditionally useable, but not guaranteed, up to 4GHz. The much convenient ECal method has provided questionable and inconsistent results. Our Customers are advised to be very careful with VNA calibrations, because the whole measured data depends on that.
 
Because of this, and to save our customers time and doubt, Focus has developed and offers a set of precise and reliable TRL calibration kits from 0.03 to 110 GHz with the following connector types: 7/16, N, APC-7, 3.5mm, 2.9mm, 2.4mm, 1.85mm, WR-15, WR-10. Our calibration kits are compatible with all commercial network analyzers. 
 
For more information on TRL Calibration Kits, please read the following paper on TRL Versus SOLT

Focus Microwaves - Noise Parameter Characterization Test Software

Noise measurements allow the determination of the four Noise Parameters of a device (transistor).  There are four Noise Parameters which fully describe the noise behaviour of an active or passive device at a given frequency.

Focus Microwaves - Vector Load Pull Test Software
An impedance tuner is an apparatus, which generates controllable reflection factor (Impedance) over a certain frequency range. Focus uses two basic technologies:
a) For frequencies from 100MHz to 110GHz (and above) we use the slide screw technique (models Multi Harmonic MPT, wideband (fundamental) CCMT, harmonic rejection PHT), in which a reflective probe (slug) is inserted into the slot of a low loss slotted transmission line (slabline or waveguide).
b) For frequencies from below 10MHz to 170MHz  we use a lumped element technology (models LFT), whereby variable capacitors are connected with optimized lengths of coaxial cable.

Focus Microwaves - Scalar Load Pull Test Software
An impedance tuner is an apparatus, which generates controllable reflection factor (Impedance) over a certain frequency range. Focus uses two basic technologies:
a) For frequencies from 100MHz to 110GHz (and above) we use the slide screw technique (models Multi Harmonic MPT, wideband (fundamental) CCMT, harmonic rejection PHT), in which a reflective probe (slug) is inserted into the slot of a low loss slotted transmission line (slabline or waveguide).
b) For frequencies from below 10MHz to 170MHz  we use a lumped element technology (models LFT), whereby variable capacitors are connected with optimized lengths of coaxial cable.

Focus Microwaves - Cardiff Behavioral Model Software
Non-linear measurement data is often used to create a behavioral model for high frequency components. Formulations of these models have been defined in terms of traveling waves, with a desire to represent nonlinear behavior of high frequency transistors through a direct extension from linear s-parameters.
The Mesuro model portfolio is comprised of two variations of a behavioral model  – each targeted at a particular end use – Cardiff Model Lite (CML), where the desired output is a local model, and Cardiff Model+ (CM+), which incorporates higher order mixing terms allowing a single model to fit over a range of impedance space.

Focus Microwaves - Focus Compact Modeling Software
The Focus Compact Model (FCM) utility is a streamlined software package designed to be used with Focus’ AURIGA high-end Pulsed-IV system, that is used to generate Compact Models for transistors from their Pulsed-IV and wideband pulsed s-parameter data. 
This is achieved by generating a network of lumped circuit elements that represent accurately the fundamental linear & non-linear behavior of the device over a broad range of bias and power range. 
The result of the modeling is a netlist and compatible with- the most common CAD tools used in RF Design; such as AWR Microwave office (MWO) and Keysight PathWave Advanced Design System (ADS).

Focus Microwaves - MPIV - Modular Pulsed IV
  • High power capability: +/- 200V, 17A.
  • Minimum pulse width: 200ns.
  • Modular design which enables multiple configurations.
  • Shared library. The MPIV can be used as a standalone instrument using an ActiveX library, which easily integrates into existing test software.
  • Flexible Input/Output. Choose between high power and high precision pulse modules to create a customized setup for your specific application.
  • Compatible with Focus Microwaves’ device characterization software (Load Pull Explorer, LPEx)

Focus Microwaves - TRI-STATE Pulsed IV System
  • 3 Measurement States; Quiescent (OFF-State), Non Quiescent (ON-State), and Pre-State
      • The Pre State is a short high voltage state used to activate
        the traps in the semiconductor.
  • Adjustable delay (Δt) between the Pre state and Non Quiescent state down to 0s.
  • Independently adjustable timing settings for the Three-state gate pulser and drain pulser
  • Easy Integration into existing mainframes

Advanced Cooling Technologies, Inc.

Advanced Cooling Technologies, Inc. (ACT) is a premier thermal management solutions company. Started in 2003 as an R&D company, ACT has grown into a leading manufacturer of thermal management products for diverse industries and applications. Our thermal management designs and products are now deployed in numerous commercial satellites, military vehicles, medical devices, Primary Calibration equipment, and HVAC systems. Read more on how we partner with our customers, and how we can assist you.


Contact Details

Corporate Headquarters

Advanced Cooling Technologies, Inc.

1046 New Holland Avenue, Lancaster, PA 17601-5688

Phone: 717-295-6061

Fax: 717-295-6064

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