--- title: What is a Wafer Chuck? description: A wafer chuck is often used to hold wafers in place while they are being probed (tested). Check out the SemiProbe website for more information on wafer chucks. image: https://blog.semiprobe.com/hubfs/wafer%20chuck/wafer%20chuck%202.jpg --- # What is a Wafer Chuck? December 12, 2017 By [Doug Merrill](https://blog.semiprobe.com/author/doug-merrill) ![wafer chuck ](https://blog.semiprobe.com/hs-fs/hubfs/wafer%20chuck/wafer%20chuck%202.jpg?width=320&name=wafer%20chuck%202.jpg "wafer chuck ")   **What is a Wafer Chuck?** A wafer chuck is often used to hold wafers in place while they are being probed (tested). Most wafers are held in place by applying a small amount of vacuum to the backside of the wafer. The majority of [analytical probing systems](https://blog.semiprobe.com/probe-system) are provided with a a wafer chuck. Wafer chucks are available in a variety of shapes, sizes and materials. They are typically round and are slightly larger then the wafer size. Common sizes range from 50 mm to over 300 mm in diameter. Most chucks have a circular (concentric) ring vacuum design and will often hold small die, partial wafers and whole wafers. For example, a 150 mm (6”) chuck will have  vacuum ring patterns that will allow your to hold individual die, 50 mm, 75 mm, 100 mm and 150 mm wafers. Most chucks are made of aluminum and have a nickel or gold plating. Sometimes chucks are made of steel, could be square and have a vacuum hole pattern instead of a vacuum ring pattern. Most chucks will have flatness specifications that range from +/- 4 um to +/- 8 um.  Chucks are often manufactured for specific applications. There are ambient chucks, high frequency/microwave chucks, high power (high voltage or high current) chucks, double-sided chucks and thermal chucks.  It is not uncommon to make customized chucks. ![wafer chuck ](https://blog.semiprobe.com/hs-fs/hubfs/wafer%20chuck/wafer%20chuck%201.jpg?width=320&name=wafer%20chuck%201.jpg "wafer chuck ")![wafer chuck ](https://blog.semiprobe.com/hs-fs/hubfs/wafer%20chuck/wafer%20chuck%203.jpg?width=320&name=wafer%20chuck%203.jpg "wafer chuck ")   **[![Request a Discovery Call](https://no-cache.hubspot.com/cta/default/3442595/d8c1879a-b359-425a-9bbd-6041453ba0ae.png)](https://cta-redirect.hubspot.com/cta/redirect/3442595/d8c1879a-b359-425a-9bbd-6041453ba0ae)**   **[![New Call-to-action](https://no-cache.hubspot.com/cta/default/3442595/e935e060-6612-4c59-8d4a-87cb942514bc.png)](https://cta-redirect.hubspot.com/cta/redirect/3442595/e935e060-6612-4c59-8d4a-87cb942514bc)**   Topics: [Accessories](https://blog.semiprobe.com/tag/accessories), [Educational Topics](https://blog.semiprobe.com/tag/educational-topics) - [Facebook ](http://www.facebook.com/sharer.php?u=https://blog.semiprobe.com/wafer-chucks) - [Twitter ](https://twitter.com/share?url=https://blog.semiprobe.com/wafer-chucks&text=Simple%20Share%20Buttons&hashtags=simplesharebuttons) - Pinterest - [Linkedin ](http://www.linkedin.com/shareArticle?mini=true&url=https://blog.semiprobe.com/wafer-chucks) - [Email ](mailto:?Subject=Simple%20Share%20Buttons&Body=I%20saw%20this%20and%20thought%20of%20you!%20%20https://blog.semiprobe.com/wafer-chucks) ### Author: [Doug Merrill](https://blog.semiprobe.com/author/doug-merrill) Doug Merrill, CEO, joined Semiprobe in 2016 and brings 25 years of operations, quality, and financial experience to the team. He has degrees in Engineering Physics and an MBA from Cornell University. He began his career with 14 years at General Electric, graduating from the Manufacturing Management Program and rising through the ranks of GE Energy. He has worked in executive roles for Husky Injection Molding and Dynapower Company, and sits on the board of directors of Orbit/FR, a microwave test equipment firm. Doug lives in Shelburne, Vermont with his wife and two sons. When not in the office, he can often be found sailing on nearby Lake Champlain. Find me on: [LinkedIn](https://www.linkedin.com/in/doug-merrill-718b245/) [![Semiconductor Wafer Testing Discovery Call](https://no-cache.hubspot.com/cta/default/3442595/bf2f5ff3-0eb4-48b2-a96e-633e18b75f31.png)](https://cta-redirect.hubspot.com/cta/redirect/3442595/bf2f5ff3-0eb4-48b2-a96e-633e18b75f31) ### Subscribe to our email list. [![SemiProbe Capabilities & Applications Guide for Wafer Characterization & Testing](https://no-cache.hubspot.com/cta/default/3442595/781fdf49-c19f-45ca-b599-d90ec8671f56.png)](https://cta-redirect.hubspot.com/cta/redirect/3442595/781fdf49-c19f-45ca-b599-d90ec8671f56) ![](https://segment.prod.bidr.io/associate-segment?buzz_key=brandgen&segment_key=brandgen-5457&value=) ![](https://segment.prod.bidr.io/associate-segment?buzz_key=brandgen&segment_key=brandgen-5457&value=)