HOMEWhat is an electrostatic chuck?
Electrostatic chuck (ESC) is a specialized type of clamp used to hold down or pick up objects by electrical force, by attraction forces from static electricity.
Invisible to the naked eye, every matter has an intrinsic positive and negative charge. When the object is placed on an ESC and a bipolar voltage is applied to its internal electrodes, a directional electric field is created, and positive and negative charges drifts within the material to match the polarity of the chuck’s internal electrode. This attracting force between the ESC and the material is what is called the electrostatic force, and is the basic mechanism behind our chucks.
Speaking of “static electricity”, there are many people who remember the painful experience that comes when you touch the door of a car in winter. This mild electric shock is generated when static electricity stored in a person flows to the doorknob due to friction of clothing via electric current.
On the other hand, the ESC moves only the intrinsic charge within the chuck as shown in the figure, hence the generated current is minimal and does not harm the material and people nearby. You can use it safely as it does not create any electric shocks (However, precautions shall be followed when use).
To sum it up in a nutshell, ESC sticks things together by artificially creating static electricity. So where is it used?
For example, many electrical products today, including personal computers, smartphones, and automobiles, use components called IC chips, that is, the computing brain of electronic components. These components are commonly referred to as “semiconductors”, and ESC have played an important role in the process of manufacturing semiconductors as equipment to reliably grip silicon wafers as substrate materials in atmospheric air and vacuum environments.
In recent years, electrostatic technology has been adopted as robot hands in automating production. In addition, we have developed new consumer applications, such as an electrostatic bulletin board eliminating pushpins and magnets to post notes and wallpaper. Electrostatic technology has been the foundation of technological advancements in electronics you see and use today.
Even though there are a variety of ways to pick and place materials such as mechanical clamps and vacuum chucks, why is the ESC chosen?
This is because the electrostatic force is a material-friendly chucking technology. For example, if you try to lift delicate objects such as thin metal foil or polymer film, the smallest uneven physical force can create unintended nicks, scratches, and warping to the material and become defective. On the contrary, the ESC uniformly attracts the entire workpiece, so it creates less physical wear on the material.
In addition, we have recently received strong interest from the garment industry due to increased demands for reducing manual labor and accelerating production automation. ESCs are adopted in gripping and transporting relatively thick, sturdy materials like cloth fabric in a flat manner, regardless of the material’s air permeability, perforation or material indentations.
ESCs are often compared to vacuum chucks, so let’s take a look at a side-by-side comparison of the key features.
|Electrostatic Chuck||Vacuum Chuck|
|Use in Atmospheric Environments||Good||Good|
|Use in Vacuum Environments||Excellent||Not good|
|Use with Perforated Materials||Good||Fair|
|Noise Performance||Excellent||Not good|
|Power Consumption||Excellent||Not good|
|Residual Suction Marks||Do not remain||Easy to remain|
|Material Compatibility||Influenced by shape and surface||Not influenced by shape and surface|
|Material Size Compatibility||Tuning not required for each size||Process tuning required for each size|
|External Power Source||ESC Power supply||Air Compressor|
There is a distinct difference among the same chucking equipment.
If you are struggling with your existing pick-and-place equipment, consider the ESC once by all means.
We are a pioneer in the field of ESC for more than 25 years. In addition to our in-house manufacturing of the chucks, we are the leading innovators in ESC refurbishments, which had been disposable until then.
Our main objective is to offer products to “grip all kinds of materials.”
We have studied and researched ESC materials and its internal electrode patterns to enable the chucking of glass and cloth previously considered difficult to chuck. And now our research extends to the chucking of three-dimensional objects.
Not only chucking, detaching the material is also important. We offer solutions to improve the responsiveness of the ESC from various criteria while also addressing its peripheral processes and its impact, and ultimately focusing on the end customers’ objective.
Based on our extensive experience, we offer specialized engineering solutions to solve your multifaceted issues in material chucking, transport and de-chucking processes. Feel free to contact Creative Technology.
Q1I would like to check whether my Proof of Concept with the ESC is feasible.
We offer trial demonstrations according to your request with your material samples to check your Proof of Concept. You can visit us directly or send us your material samples for the trial. Feel free to contact us for more information.
Q2I want to use an ESC, but I lack experience in using these chucks. Can you help me?
We have a wealth of development and installation experience with major clients in the manufacturing industry. We offer a one-stop solution for ESC and its related peripheral technologies (power supply, vacuum method, electrical connection methods, clamping monitor, etc.).
Q3At the bare minimum, what do I need to use an ESC?
An ESC and a power supply are required to operate. Our power supply can be powered by any typical household outlet. *Depending on the ESC, it can be also powered by household batteries, similar to our electrostatic display board “ESCLIP”
Q4Does static electricity adversely affect my workpiece?
Electrostatic chucking basically does not damage the workpiece since the chucking force is created solely by the movement of the charge internal of the workpiece. However, depending on the material of the workpiece, the concentrated charge may not quickly dissipate after chucking and de-chucking. For concerns, please contact us to conduct a chucking trial.
Q5Are there any environments where ESCs are not suitable?
ESCs are not suitable for outdoor use or clamping of wet workpieces, as static electricity and its attraction force dissipate faster in high moisture. In the same manner, caution shall be exercised with use in oily environment.
Q6Can I combine use of ESC and automated robots?
No problem. We offer custom-made design of ESCs tailored to your automation strategy. In addition, we provide dedicated customizable power supplies of which can be triggered by external signal inputs.
Q7Is it possible to export overseas?
Depending on its delivery method and country, it may be subject to restrictions on Japan’s Export Trade Control Order. Consult with us directly for more information.
Q1What kind of care is necessary?
Because the chucking power decreases when dust is attached to its adhering surface, we recommend wiping the ESC surface with a clean cloth containing industrial alcohol (IPA) on a regular basis. Always turn the power OFF when cleaning.
*The electrostatic display board “ESCLIP” is recommended to be cleaned with a dry cloth.
Q2Is there any problem touching the adhering surface?
Although it is designed for safe operation, we recommend that you wear rubber gloves for safety when handling. *Electrostatic display board “ESCLIP” is designed to touch with bare hands.
Q3What are the causes of ESC failure?
The chucking function is lost when there is a void (via hole, scratch, etc) of the top surface and the internal electrode is exposed. Also, do not use it in this state because it may cause electric shock. If you think there is ESC failure, please contact us first.
Q1When the power supply is turned off, the material does not detach from the ESC.
We offer customized ESC and optimized power supplies to optimally detach materials. In addition, we offer additional mechanical removal systems as necessary.
Q2Can I correct warping and curling of workpieces?
Large warping and curling may not be corrected even with an ESC. However, it may be possible to alleviate minor warping and curling by optimizing operating conditions of the ESC and power supply. Feel free to contact us for your chucking trials with your material today.
Q3When compared to vacuum chucks, how long does the ESC take to chuck and de-chuck?
Although it varies depending on its material, the ESC typically takes longer to chuck and de-chuck compared to a vacuum chuck. We can offer solutions to shorten this time by optimizing the conditions of chucking and de-chucking.
Q4Do you have numerical data for the chucking force?
Unfortunately, we do not offer general data as it varies greatly on the material and its surface condition of the workpiece. Conductors such as metal tend to be chucked easier, whereas insulators such as glass and cloth typically exhibit less chucking force. The ESC is strong in both the direction parallel and normal to the adhesion surface, but weak to peeling moments. Please contact us for conducting chucking trials with your materials today.