https://blog.pcbrfq.com/tags/stackup/Recent content in Stackup on PCB RFQ BlogHugo -- gohugo.ioen© 2026Sat, 06 Jun 2026 00:00:00 +0000https://blog.pcbrfq.com/posts/fr4-core-and-prepreg-thicknesses/Sat, 06 Jun 2026 00:00:00 +0000https://blog.pcbrfq.com/posts/fr4-core-and-prepreg-thicknesses/<p>When engineers search for standard FR4 thicknesses, they usually expect a simple answer. Instead, they often encounter conflicting information.</p> <p>One source lists a 0.10 mm core. Another shows 0.136 mm. A third refers to a 1080 prepreg with a thickness of 0.075 mm, while a supplier datasheet lists an entirely different value.</p> <p>The confusion arises because several different concepts are being mixed together:</p> <ul> <li>Core thickness</li> <li>Finished core thickness</li> <li>Prepreg thickness</li> <li>Pressed dielectric thickness</li> <li>Glass style</li> <li>Resin content</li> <li>Lamination behaviour</li> </ul> <p>All of these values are related, but they are not the same thing.</p>