Plated Through Hole, Blind Via and Buried Via Compared A via looks like a hole and behaves like a very short piece of wire, but its real cost is space. Every via drilled through the whole board consumes a cylinder of routing area on every layer it passes through, and…

Crosstalk Control in Mixed-Signal PCB Design A digital net can tolerate a surprising amount of interference. A three volt logic input that receives a few hundred millivolts of coupled noise still reads the correct state, and the design works. An analogue net in the same product may be carrying a…

Buried Via, Blind Via and Through Via: Choosing PCB Via Types Every via makes a hole in a board, but not every hole is made the same way or costs the same amount. A through via passes from the top face to the bottom and is drilled after lamination, while…

PCB Gold Plating Types: ENIG, Hard Gold and Thickness Gold appears on a printed circuit board for two reasons, and they rarely coexist. One is chemistry: a thin, dense gold layer over nickel keeps copper from oxidising and preserves a solderable or wire bondable surface for months. The other is…

PCB Cable Assembly: Crimp, Strain Relief and Routing Practice Most products do not end at the edge of the board. A PCB cable assembly joins the circuit to the outside world, and it usually carries the signals that are least forgiving: the power feed, the differential pair that runs to…

High Temperature PCB Manufacturing: Materials and Process Building a board that has to work at 200 degrees Celsius is not simply a matter of buying a better laminate. It changes the lamination cycle, the drilling parameters, the plating chemistry, the solder mask, the surface finish and the amount of testing…

Laser Sensor PCB Design for LiDAR and Precision Measurement A laser sensor measures distance, speed or presence by emitting light and detecting what returns. The electronics that make that measurement have to resolve a pulse that may be a few nanoseconds wide and a few photons strong, and they have…

Rigid-Flex PCB for Wearables: Bend Radius and Stackup Rules A wearable device folds electronics into a shape that the human body dictates. The display, the sensor package, the battery and the radio rarely sit on one plane, and the space between them is measured in millimetres that also have to…

EMI Immunity in Mixed-Signal and Power Boards An interference problem always has the same three parts: something that generates noise, something that is sensitive to it, and a path between the two. Fixing a board that misbehaves means deciding which of the three can be changed most cheaply, and that…

Managing PCB Design Rules Across Projects Every layout is driven by a set of design rules, whether or not anyone has written them down. If the rule set is well built, the tool catches the mistakes as they are made and the layout proceeds without rework. If it is left…