JLCPCB Blog

Components & Sourcing

SMD Inductor Code: How to Read Inductor Markings and Values

Key Takeaways Three digits are read in µH: 100 is 10 µH and 101 is 100 µH. The third digit is the number of zeros, not part of the value. R and N are decimal points: R in microhenries (4R7 = 4.7 µH), N in nanohenries (2N2 = 2.2 nH). A trailing letter is a tolerance: K is ±10% and M is ±20%. On RF inductors below about 10 nH, C and D mean ±0.2 nH and ±0.5 nH. Most small chip inductors are unmarked: identify them from the BOM or reel label first, then with an LCR meter at the right test frequency. The m......

Oct 31, 2026

Heating Technology & Trends

How Graphene and MXene Inks Enable Stretchable Circuits

Stretchable circuits must maintain electrical performance while bending, stretching, or twisting. Graphene and MXene inks offer a promising approach by combining electrical conductivity, mechanical flexibility, and printability. But how do these materials actually enable circuits to stretch without losing their electrical function? Graphene and MXene inks enable stretchable circuits by forming interconnected conductive networks that can rearrange as the substrate deforms. Their overlapping 2D platelet......

Oct 31, 2026

Hand Soldering & Stencils

How to Solder a JST Connector: Through-Hole, SMT, and Board-to-Board Guide

Key Takeaways Soldering a connector is electrical and mechanical at once: Seat the header flush and square, tack one corner pin, verify alignment, then solder the remaining pins and every mechanical anchor tab, because plugging and cable forces travel through the housing and hold-downs rather than the signal pins. Match the method to the mount type: Through-hole headers need full barrel fill with a larger tip and flux for heat-sinking power pins, SMT headers need tack-and-align with hold-down tabs ful......

Oct 30, 2026

SMT Repair & Rework

How to Replace an Electrolytic Capacitor Step by Step

Key Takeaways Match the spec, respect the polarity: Replace with the same capacitance, an equal-or-higher voltage rating, a 105 °C rating, and an equal-or-lower ESR — and remember that an aluminum electrolytic stripe marks the NEGATIVE terminal while a tantalum stripe marks the POSITIVE terminal. Diagnose before you desolder: Visual signs such as a domed top, opened vent, or leakage combine with electrical checks like rising ESR, low capacitance, or a dead short to confirm the fault, and one failed ca......

Oct 30, 2026

Design for Manufacturing

Implications of border lines and 3D footprint lines on Mechanical Layer 1

Key Takeaways Mastering Mechanical Layer 1 is essential for accurate PCB manufacturing. Always place the complete board outline, mounting holes, and irregular slots on Mechanical Layer 1 (GM1), as JLCPCB prioritizes the lowest-numbered Mechanical Layer while ignoring KEEP-OUT and higher Mechanical Layers. 3D footprint lines serve only as design references and will not be fabricated. Following these layer priority rules and best practices ensures correct board dimensions, proper slot formation, and avo......

Oct 30, 2026

Design Tools & Best Practices

From Concept to Production: PCB DFM Guidelines and Analysis

Key Takeaways PCB DFM (Design for Manufacturing) is the bridge between design intent and manufacturing reality, ensuring a board can actually be fabricated and assembled with high yield. Essential DFM guidelines cover trace width and spacing, annular rings, via placement and drill sizes, soldermask and silkscreen, surface finish, and panelization. Modern DFM analysis is data-driven and automated, and many manufacturers now offer free DFM tools that check Gerber and drill files against fabrication and ......

Oct 30, 2026