JLCPCB Blog

Layout for Manufacturing

Rigid Flex PCB Stackup Design: The Complete Guide 2026

Key Takeaways Adhesiveless Polyimide Cores: Cores should be made from adhesiveless polyimide laminates to eliminate inner-layer separation and plated through-hole (PTH) barrel cracking caused by the high Z-axis coefficient of thermal expansion (CTE) of acrylic adhesives. Rolled-Annealed Copper: Use rolled-annealed (RA) copper anywhere the board is designed to bend. Unlike electrodeposited (ED) copper, RA copper features a lamellar grain structure that withstands approximately 20–40% elongation without......

Jul 13, 2026

PCB Fabrication Case

From Membrane Frustration to Custom Mechanical Mastery: Taifur's V3 Full Keyboard Project

In the world of electronics hobbyists and DIY communities, custom mechanical keyboards stand out as one of the most rewarding projects. They combine personalized typing experiences with PCB design, firmware development, and mechanical engineering. Taifur's "Mechanical Keyboard V3 Full" project on OSHWLab is a shining example: a Tenkeyless (TKL) mechanical keyboard featuring a Raspberry Pi Pico (RP2040) controller, full QMK firmware support, per-key RGB lighting, an OLED display, and a rotary encoder. ......

Jul 13, 2026

PCB Materials Science

Understanding the Materials Used in PCBs: Selection, Types, and Importance

Key Takeaways FR-4 is the go-to material for most cost-effective and reliable PCBs. Use Rogers for high-frequency and RF applications to reduce signal loss. Higher copper weight (2oz) improves current and heat handling. Choose High-Tg substrates for better thermal stability in multilayer boards. Green LPI soldermask offers the best balance of performance and inspection. Printed circuit boards (PCBs) are an essential component of modern electronics. These boards connect and support electronic component......

Jul 13, 2026

Stencil Design

Solder Paste Printing Machine Guide: Selection, Settings & Stencil Optimization

Key Takeaways at a Glance A solder paste printing machine forces paste through stencil apertures onto PCB pads, setting the volume and registration that every later stage depends on. Printing is where most SMT defects begin — industry studies commonly attribute more than half of assembly defects to the paste-print stage. Manual printers fit prototypes and low volume, semi-automatic suits mid-volume EMS work, and fully automatic inline systems handle continuous, high-throughput production. Typical indu......

Jul 11, 2026

PCB Materials Science

How to Select Tg of PCB ？

What is the Tg of PCB? In PCB manufacturing, "Tg" stands for Glass Transition Temperature. It is the temperature at which the PCB substrate material transitions from a rigid, glassy state to a soft, rubbery state. PCBs are flame-retardant (UL94 V-0) and do not burn easily; instead, they soften above Tg. The Critical Correlation Between Tg and Z-Axis CTE (Coefficient of Thermal Expansion) When the temperature exceeds the Tg point, the PCB substrate material (such as standard FR-4) undergoes a physical ......

Jul 11, 2026

Layout Guide

Mastering PCB Design: A Step-by-Step PCB Layout Process Guide

Key Takeaways Process over improvisation: A repeatable, standardized PCB layout process—not luck—is what turns a working schematic into a board that succeeds on the first spin. Placement drives everything: Component layout and functional block partitioning are the most impactful steps; good placement makes routing easy, poor placement makes it impossible. Route critical signals manually first: Clocks, differential pairs, sensitive analog nets, and power switching loops must be hand-routed before auto-......

Jul 11, 2026