PCB设计博客

How UL recognition works for flex circuits: UL 796F, UL 94 V-0 versus VTM-0, why materials are recognized rather than finished boards, and the documents to request before you accept a flame-rating claim.

Hommer Zhao

阅读更多

Design sculptured flex with thin bend zones and thick integral contacts: copper transitions, etch allowance, current-loss calculations, contact finishes, and supplier RFQ requirements.

Hommer Zhao

阅读更多

How to design and source an etched-copper flexible heater on polyimide: size the trace from voltage and power, allow for copper's temperature coefficient, choose adhesive and coverlay, add sensing and protection, and write the drawing so the fab builds the resistance you need.

Hommer Zhao

阅读更多

A hatched ground plane trades some shielding and impedance stability for flexibility. This guide gives the geometry math (line width, pitch, copper fill), the impedance and return-path risks, and the routing and drawing rules that keep a hatched reference plane predictable on a flex or rigid-flex board.

Hommer Zhao

阅读更多

The copper foil type decides whether a flex circuit survives repeated bending. Rolled annealed (RA) copper has an elongated grain that flexes without cracking; electrodeposited (ED) copper has a columnar grain that fatigues under dynamic flex. Here is how each is made, why the grain structure changes flex life, and when to specify which for your flex or rigid-flex board.

Hommer Zhao

阅读更多

A flex PCB fabrication drawing has to say things a rigid drawing never does — bend lines and bend zones, coverlay openings, stiffeners, and the IPC callouts that fix the acceptance class. Here is exactly what to put on the drawing so a fab house can build it without a round of engineering questions.

Hommer Zhao

阅读更多

How to attach an FPC to a board or display: direct solder, ZIF connector, ACF bonding, and hot-bar soldering compared by pitch, permanence, rework, cost, and reliability — with a clear method-selection rule.

Hommer Zhao

阅读更多

A supplier audit verifies that a flex PCB maker can build to your class before you commit; incoming IQC verifies that the boards which actually arrived meet it. Here is how to run both — what to audit, what to inspect on the dock, and how to right-size sampling to board risk.

Hommer Zhao

阅读更多

When to choose an FPC cable assembly over a discrete wire harness: space, dynamic flex life, current, length, branching, serviceability, and cost, compared.

Hommer Zhao

阅读更多