Posts on PCB RFQ Blog

PCB Etching Reality — Why Copper Thickness Defines Minimum Track and Spacing

Tue, 26 May 2026 00:00:00 +0000

Etching defines what your PCB layout can and cannot achieve. Understanding the relationship between copper thickness, trace width, and spacing is not optional — it directly affects what your board costs and who can make it.

How Etching Works — Downward and Sideways
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The etchant does not only remove copper downward. It simultaneously attacks laterally — inward beneath the etch resist at the edges of every copper structure. This lateral attack is called undercut. The etch medium itself can be alkaline or acidic depending on the process — both attack copper selectively through the use of photo and metal resists as protective layers.

How to Write a PCB RFQ That Gets Accurate Quotes

Mon, 25 May 2026 00:00:00 +0000

A complete guide to writing a PCB Request for Quotation that suppliers can price accurately — saving you time and avoiding costly surprises.

PCB Material Selection for Environmental Conditions — Temperature, Humidity, and Beyond

Wed, 20 May 2026 00:00:00 +0000

Material selection for a PCB is rarely driven by electrical requirements alone. The operating environment — temperature, humidity, chemical exposure, thermal cycling — defines the boundary conditions within which the laminate must perform reliably over its service life. Choosing a material adequate for the bench but wrong for the field is one of the most consistent sources of premature failure in electronic assemblies.

The Four Laminate Families
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For the purposes of environmental selection, the relevant laminate families are:

Polyimide Flex PCBs — Chemistry, Coverlay, and Why Flexible Solder Mask Is Not the Same Thing

Wed, 20 May 2026 00:00:00 +0000

Flex PCB specifications are among the most frequently underspecified documents in electronics procurement. Buyers write “flex PCB, polyimide base” and assume the supplier will fill in the rest correctly. Sometimes they do. Often they do not — and the failure mode is a board that cracks, delaminates, or develops intermittent opens after a few thousand flex cycles.

Understanding why polyimide behaves the way it does, and why the protective layer choices matter as much as the base material, is the foundation of a correct flex PCB specification.

PTFE Is Not a Flex Material — Physical Form, Elasticity, and What You Cannot Do With It

Wed, 20 May 2026 00:00:00 +0000

One of the most persistent misconceptions about PTFE-based PCB laminates comes from handling the material. Pick up a sheet of Rogers RO4350B or RT/duroid 5880 and compare it to a sheet of standard FR4. The PTFE laminate feels different — slightly softer, with a quality that engineers sometimes describe as rubbery or compliant. Bend it gently and it flexes slightly before springing back.

This tactile impression leads directly to a dangerous assumption: that PTFE can be used in flexible PCB applications, or treated with more mechanical freedom than a rigid board.

PTFE PCB Laminates — Why RF and Microwave Designs Need a Different Material Entirely

Wed, 20 May 2026 00:00:00 +0000

Every laminate material discussed in this series so far — standard FR4, High-Tg FR4, polyimide — shares a common selection logic. You choose among them based on thermal performance, mechanical requirements, and environmental resistance. Electrical properties rarely drive the decision because at the frequencies where these materials are used, the differences are manageable.

PTFE-based laminates exist in a different category entirely. They are selected primarily for their electrical properties — specifically their ability to transmit high-frequency signals with minimal loss and maximum dimensional consistency.

Why FR4 High-Tg Behaves Differently — The Chemistry Behind Cross-Linking

Tue, 19 May 2026 00:00:00 +0000

When buyers specify FR4 High-Tg on an RFQ, they often do so because a datasheet or engineer told them to. Fewer understand why it behaves differently from standard FR4 — and why that difference matters when a board heats up under load, goes through lead-free soldering, or operates in a demanding environment.

The answer lies not in the glass fibres or mineral fillers, but in the epoxy resin chemistry itself.

Posts on PCB RFQ Blog

PCB Etching Reality — Why Copper Thickness Defines Minimum Track and Spacing

How Etching Works — Downward and Sideways #

How to Write a PCB RFQ That Gets Accurate Quotes

PCB Material Selection for Environmental Conditions — Temperature, Humidity, and Beyond

The Four Laminate Families #

Polyimide Flex PCBs — Chemistry, Coverlay, and Why Flexible Solder Mask Is Not the Same Thing

PTFE Is Not a Flex Material — Physical Form, Elasticity, and What You Cannot Do With It

PTFE PCB Laminates — Why RF and Microwave Designs Need a Different Material Entirely

Why FR4 High-Tg Behaves Differently — The Chemistry Behind Cross-Linking

How Etching Works — Downward and Sideways
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The Four Laminate Families
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