Tag: laminar flow

EXAIR Products in the Semiconductor Industry

Published on by Jordan T ShouseLeave a comment

Manufacturers in semiconductor assembly and PCB production face strict cleanliness, throughput, and thermal-control requirements. EXAIRs compressed-air products, specifically our Air Knives and Vortex Tubes, and air amplifiers are proven, compact, and energy-efficient tools for precise blow-off, controlled cooling and heating for spot thermal conditioning and fume extraction. This Blog explains how EXAIR Super Air Knives and Vortex Tubes and Air Amplifiers address three common production needs: 

  1. Drying and particulate removal during lead frame processing with air knives. 
  1. Localized cooling/heating for functional PCB testing using Vortex Tubes. 
  1. Fume extraction during etching, cleaning and plating processes

I’ll cover technical fit, typical performance characteristics, and measurement/ROI considerations so engineers and plant managers can evaluate and implement these solutions. 

Intellistat Ion Air Nozzle in clean room, cleaning microchip parts before installation.

Super Air Knife and Success in the semiconductor lead frame manufacturing process.  

Typical use cases 

  • Removing rinse water or flux residues after cleaning 
  • Blowing off foreign matter, over spray, or machining debris prior to plating or die bonding. 
  • Drying prior to molding or coating operations. 
  • Static-assisted blow-off when combined with static eliminating product for electrostatically attracted particles. 

Why Super Air Knives? 

  • Uniform Laminar Sheet of air: delivers consistent, even blow-off across the width of a lead frame, reducing localized hot spots or mechanical damage. 
  • Adjustable force and flow: adjusting air pressure and shim size allow you to control force and volume so fragile wires or plated surfaces aren’t damaged. 
  • Entrainment & Efficiency: The knives are engineered so they entrain ambient air, increasing total developed flow and reducing compressed-air consumption compared to open pipes. 

Vortex Tubes for functional PCB testing / burn-in and thermal cycling

During in-line or bench functional testing, specific components or integrated circuits may overheat or require temperature conditioning to verify performance at the full range of the rated temperature specifications. Vortex Tubes give fast, localized cooling (or heating) without coolant loops, chillers, or plumbing intricacy. Subjecting devices to burn-in and thermal cycling stress helps products enter the field with confidence there will not be any preventable failures. Normally, environmental chambers are used for burn-in processes, but vortex tubes can help facilitate localized thermal ramps, corner stressing, or temporary additional cooling/heating when size, cost or availability of a full environmental chamber isn’t feasible.  

Why Vortex Tubes fit testing 

  • Instant cold/hot air from regular compressed air: no refrigeration system or refrigeration cycle; instantaneous on/off.  
  • No moving parts: high reliability and low maintenance for test fixtures. 
  • Local spot conditioning: focus cooling on integrated circuits or other small areas without cooling the entire board or fixture. 
  • Adjustable cold fraction: Vortex tubes can be tuned via the control valve to trade flow vs. temperature drop to meet testing conditions. 
Cooling or Heating with the Vortex Tube

Air Amplifiers for fume extraction and partial heat control during etching, cleaning and plating processes.

In semiconductor lead frame manufacturing, maintaining clean, particle-free environments is essential to ensure consistent product quality and process reliability. Processes such as flux cleaning, plating, molding, and soldering generate vapors, fumes, and fine particulates that can contaminate delicate components or compromise yields. EXAIR’s Super Air Amplifier provides an efficient, quiet, and maintenance-free solution for capturing and removing fumes, vapors, and airborne contaminants from sensitive production areas.

Why the Super Air Amplifier?
High-Volume Airflow Through Amplification

  • It uses a small amount of compressed air to entrain large volumes of ambient air multiplying total flow by up to 25 times.
  • Creates a strong, consistent vacuum draw ideal for capturing fumes and fine particulates at their source.

Energy Efficiency

  • Dramatically reduces compressed-air consumption compared to traditional vacuum or exhaust systems.
  • No electricity, motors, or moving parts, maintenance-free operation and long service life.

Compact and Versatile

  • Easy to integrate above process lines, in tool enclosures, or at conveyor transfer points.
  • Available in aluminum, stainless steel, and high-temperature materials for compatibility with cleanroom or chemical environments.
Model 120024 4″ Super Air Amplifiers are commonly used to exhaust smoke and fumes.

ROI and how to show value quantitatively  

  • Baseline metrics: scrap/rework rate, cycle time, compressed-air consumption, downtime for cleaning, and throughput. 
  • Pilot run: instrument a section of line with flow/force and temperature sensors for a 30 day trial. 
  • Key calculations: 
  • Reduced rework % × cost per part = direct savings. 
  • Throughput increase (parts/hr) × margin = additional revenue. 
  • Compressed-air energy reduction (compared to previous blow-offs) = kW savings (U.S. Department of Energy offers a benchmark of $0.25 per 1,000 SCF). 
  • Tangible benefits: throughput improvement, energy savings, reduced capital cost (vs. chillers/chambers), lower maintenance and smaller footprint. 

Conclusion  

EXAIR Super Air Knives, Vortex Tubes and air amplifiers are compact, reliable, and flexible products that can improve cleanliness, thermal testing, and throughput in semiconductor processes.  

  1. Select a process you think could be helped with an air knife, Vortex Tube or an air amplifier and take advantage of our 30-day money-back guarantee.  
  1. Validate throughput and quality improvements and calculate ROI. 
  1. Rollout with appropriate controls, filtration, and operator training.  

If you think any of our products can help you in your process, please reach out. We have a team of application engineers here M-F to answer your questions!

Jordan Shouse, CCASS

Application Engineer

Send me an email
Find us on the Web 

Application Spotlight! – Super Air Knife

Published on by Jordan T ShouseLeave a comment

I haven’t done a spotlight in a while, so I figured it was time.  In these, I pull from the dozens of phone calls or emails and walk you through how we on the Application Engineering team select a product for a specific application!

In this week’s spotlight, we focus on a common application we see here at EXAIR. Customers have a product that is too wet, and they need to reduce the excess liquid in or on their product.

For this, the customer makes candied cranberries. As they processed down the line, the excess liquid was creating a large mess, and they were spending too much time cleaning. And on top of that, the liquid is valuable to the customer, so the more they can reclaim and sell, the more profit they are making. Currently, the cranberries are moving on a 22″ slotted stainless steel belt. They were just letting the liquid fall off as they moved down the belt and that wasn’t working.

We had a conversation about the Super Air Knives and their ability to provide a forceful blast of air that was adjustable. We settled on a quote for a 22″ custom length 316 stainless steel super air knife to provide the force to get as much excess liquid off the cranberries as possible without blowing them all over the place. This will allow them to have less mess upstream and collect more of the liquid to be sold. Both will increase productivity and profits.

Why custom length? EXAIR produces our products right here in Cincinnati, Ohio, while we carry all of our stock knives on the shelf ready to ship the same day with an order by 2PM EST. The width of this belt was 4″ larger than our closest stock size. But we custom-make knives all the time, so we quoted just that.

Why 316 ST.ST? This is a food operation that requires wash-downs with fairly caustic chemicals. The 316 ST.ST will hold up to those products.

Why the Super Air Knife? Well, the Super Air Knife is the most efficient, quietest knife we offer. The Standard and Full flow are great options for some applications, but the Super Air Knife is the king of them all when it comes to the most efficient way to produce the laminar flow our air knives offer.

With lengths from 3” to 108” and (4) four different materials all available from stock, EXAIR has the right Super Air Knife for your application. In addition to shipping from stock, it’ll also come with our unconditional 30-day guarantee. Test one out for yourself to see just how effective the Super Air Knife is in a wide variety of cooling, cleaning, or drying applications.

EXAIR Super Air Knives are the most efficient compressed air knife on the market. Please reach out if you have an application we can help with!

Jordan Shouse, CCASS

Application Engineer

Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_JS

Laminar Curtain of Air For Cleaning, Drying, Cooling, and Blowoff: EXAIR’s Super Air Knife

Published on by Tyler DanielLeave a comment

When a wide, even, laminar flow is necessary, there isn’t a better option available on the market than EXAIR’s Super Air Knife. We’ve been manufacturing Air Knives for 35 years now, with the Super Air Knife making its first appearance back in 1997. Since then, the Super Air Knife has undergone a few enhancements over the years as we’re constantly trying to not only introduce new products but also improve on the ones we have. We’ve added new materials, longer single piece knives, as well as additional accessories. But, by and large, the basic design has remained the same. As the saying goes “If it ain’t broke, don’t fix it!”.

What sets EXAIR’s Super Air Knife above the competition is the ability to maintain a consistent laminar flow across the full length of the knife, particularly when compared against blower-operated knives or even fans. A fan “slaps” the air, resulting in a turbulent airflow where the airflow particles are irregular and will interfere with each other. A laminar airflow, by contrast, will maintain smooth paths that will never interfere with one another.

The effectiveness of a laminar airflow vs turbulent airflow is particularly evident in the case of a cooling application. The chart below shows the time to cool computers to ambient temperatures for an automotive electronics manufacturer. They used a total of (32) 6” axial fans, (16) across the top and (16) across the bottom as the computers traveled along a conveyor. The computers needed to be cooled down before they could begin the testing process. By replacing the fans with just (3) Model 110012 Super Air Knives at a pressure of just 40 psig, the fans were cooled from 194 °F down to 81°F in just 90 seconds. The fans, even after 300 seconds, still couldn’t remove enough heat to allow the customer to test them.

Utilizing a laminar airflow is also critical when the airflow is being used to carry static eliminating ions further to the surface. Static charges can be both positive or negative. In order to eliminate them, we need to deliver an ion of the opposite charge to neutralize it. Since opposite charges attract, having a product that produces a laminar airflow to carry the ions makes the static reduction dramatically more effective. As you can see from the graphic above showing a turbulent airflow pattern vs a laminar one, a turbulent airflow is going to cause these ions to come into contact with one another. This neutralizes them before they’re even delivered to the surface needing to be treated. With a product such as the Super Ion Air Knife, we’re using a laminar airflow pattern to deliver the positive and negative ions. Since the flow is laminar, the total quantity of ions that we’re able to deliver to the surface of the material remains greater. This allows the charge to be neutralized more quickly, rather than having to sit and “dwell” under the ionized airflow.

With lengths from 3” to 108” and (4) four different materials all available from stock, EXAIR has the right Super Air Knife for your application. In addition to shipping from stock, it’ll also come with our unconditional 30-day guarantee. Test one out for yourself to see just how effective the Super Air Knife is in a wide variety of cooling, cleaning, or drying applications.

EXAIR Super Air Knives are the most efficient compressed air knife on the market, and for a limited time, you will receive a FREE Safety Air Gun when you purchase any EXAIR Super Air Knife! Learn more over on our site.

Tyler Daniel, CCASS

Application Engineer

E-mail: TylerDaniel@exair.com

Twitter: @EXAIR_TD

Fluid Mechanics – Boundary Layer

Published on by John BallLeave a comment

Fluid mechanics is the field that studies the properties of fluids in various states.  Fluid dynamics studies the forces on a liquid or a gas during motion.  Osborne Reynolds, an Irish innovator, popularized this dynamic with a dimensionless number, Re.  This number determines the state in which the fluid is moving; laminar, transitional, or turbulent.  For compressed air, a value of Re < 2300 will indicate a laminar air flow while the value of Re > 4000 will be in the range of turbulent flow.  Equation 1 below shows the relationship between the inertial forces of the fluid as compared to the viscous forces.

Equation 1:

Re = V * Dh / u

Re – Reynolds Number (no dimensions)

V – Velocity (feet/sec or meters/sec)

Dh – hydraulic diameter (feet or meters)

u – Kinematic Viscosity (feet^2/sec or meter^2/sec)

To dive deeper into the fluid dynamics, we can examine the layer which is next to the surface; the boundary layer.  This could refer to a wing on an airplane, a blade in a turbine, or inside compressed air lines.  In this blog, I will target the boundary layer inside pipes, tubes, and hoses that are used to transport compressed air.  The profile across the area (reference diagram below) is a velocity gradient.  The boundary layer is the distance from the wall or surface to 99% of the maximum velocity of the fluid stream.  At the surface, the velocity of the fluid is zero because the fluid is in a “no slip” condition.  As you move away from the wall, the velocity starts to increase.  The boundary layer thickness measures that area where the velocity is not uniform.  If you reach 99% of the maximum velocity very close to the wall of the pipe, the air flow is turbulent.  If the boundary layer reaches the radius of the pipe, then the velocity is fully developed, or laminar.  Mathematically, laminar flow can be calculated, but turbulent flow requires theories and experimental data to determine. 

As an analogy, imagine an expressway as the velocity profile, and the on-ramp as the boundary layer.  If the on-ramp is long and smooth, a car can reach the speed of traffic and merge without disrupting the flow.  This would be considered Laminar Flow.  Now imagine an on-ramp to be perpendicular to the expressway. As the car goes to merge into traffic, it will cause chaos and accidents.  This is what I would consider to be turbulent flow.     

In a compressed air system, similar things happen within the piping scheme.  Valves, tees, elbows, pipe reducers, filters, etc. are common items that will disrupt the flow.  Let’s look at a scenario with the EXAIR Digital Flowmeters.  In the instruction manual, we require the meter to be placed 30 pipe diameters from any disruptions.  The reason is to get a laminar air flow for accurate flow measurements.  In order to get laminar flow, we need the boundary layer thickness to reach the radius of the pipe where 99% of the air speed is represented at the center. 

Why is this important to know?  In many compressed air applications, the laminar region is the best flow to generate a strong force; efficiently and quietly.  Allowing the compressed air to have a more uniform boundary layer will optimize your compressed air system.  And for the Digital Flowmeter, it helps to measure the flow accurately and consistently.  If you would like to discuss further how to reduce “traffic jams” in your process, an EXAIR Application Engineer will be happy to help you.

John Ball
Application Engineer
Email: johnball@exair.com

Twitter: @EXAIR_jb

Photo: Smoke by Skitterphoto.  Pixabay license