Routing Signals Between PCB Layers

Part 1: An ESD Example Signal Current Flow in a Layer Transition Abstract: Printed circuit board, PCB, signal paths must often change layers in a board stackup. Under some conditions this can cause problems. An ESD example is used to …
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Voltage testing equipment

An Introduction to Controlled Impedance for PCBs

What is Controlled Impedance? Electrical impedance is the measure of the opposition (resistance) that a circuit presents to the passage of a current when a voltage is applied in an alternating current circuit.   It is represented by Zo:   Electrical …
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Introduction to IPC Inspection Guidelines

Acceptable Quality Level Before discussing IPC Inspection Guidelines, it’s important to understand the meaning of the term Acceptable Quality Level (AQL), also referred to as Acceptance Quality Limit. It is an inspection standard that prescribes the range of the number …
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Bare Printed Circuit Board Electrical Test

Visual inspections are performed following the manufacturing process of a printed circuit board to identify any potential problems. While that may work fine for a two-layer PCB, for multi-layer PCBs, it is almost impossible to visually inspect the internal layers …
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