Moisture Sensitivity Levels and Baking Before Assembly Plastic packages absorb water from the air, and that water turns to steam the moment the part enters a reflow oven. What follows can be a crack, a delaminated die attach, or a bond wire that breaks months later in the field. Moisture…

Active Crystal Oscillator Selection for Industrial Boards An oscillator is one of the few components whose error budget cannot be corrected elsewhere in the system. A voltage reference can be calibrated, a sensor can be linearised, but the clock that drives a converter, a radio or a serial link defines…

Integrated EMI and ESD Protection at the I/O Connector A product fails its emissions test because a camera data bus is radiating, or fails an ESD test because a plug is discharged through an exposed connector. Both problems arrive at the same place: the interface between the board and the…

Gold Plated PCB Manufacturing: Process, Benefits and Cost Gold on a circuit board is a reliability decision rather than a decoration. It resists oxidation, keeps contact resistance stable and survives repeated insertion, which is why it appears on connectors, test pads and any surface that has to remain solderable or…

First Article Bring-Up: Mistakes That Cost Days The first article of a new design is where every assumption in the database meets physics for the first time. Most of the time lost during bring-up is not spent on the design itself but on the small omissions that make a board…

Microstrip Impedance Matching for RF Signal Integrity A microstrip line is the simplest RF structure on a PCB and the easiest one to get subtly wrong. Its impedance depends on the trace width, the dielectric thickness beneath it and the properties of the material, and every one of those is…

Mezzanine Connector: Preparation, Placement and Process Control Two boards stacked on a mezzanine connector look simple from the outside, and they are one of the harder interfaces to design. The connector defines the stack height, the pin assignment, and the impedance of every signal that crosses it, and a mistake…

Custom PCB Production: From Layout to Volume Delivery Custom PCB production is a process rather than a purchase. Between a finished layout and a delivered volume order there are reviews, tooling, a first article and a ramp, and each stage either confirms the design or exposes a question that was…

PCB Desmear and Hole Wall Preparation Process Guide Before a plated through hole can carry current, the resin that drilling melted onto its walls has to be removed. That is the job of desmear, a wet chemistry or plasma step that sits between drilling and <a href="https://www.gopcba.com/pcb-plating-thickness-guide/” title=”electroless copper”>electroless copper…

Ionic Contamination and Cleanliness Control in PCB Assembly Most assembly residues are harmless at the moment of test and dangerous a year later. Ionic contamination left on a board by flux, plating chemistry, or handling provides the electrolyte that lets metal migrate between conductors, and the failure it produces is…