HDMI Interface ESD Protection Layout An HDMI interface carries several gigabit pairs, a set of control lines and a power pin through a connector that the user plugs and unplugs by hand. That combination of speed and human contact makes it one of the hardest interfaces to protect without degrading,…

Underfill for Board Level Reliability: When It Pays Off Underfill is a filled epoxy that is dispensed alongside a package and drawn under it by capillary action. It exists for one reason: to spread the stress that thermal expansion puts on solder joints across a larger volume of material. Used…

Trace Width Selection: Current, Rise and Impedance Trace width is one of the first decisions made in a layout and one of the least examined afterwards. Too narrow and the trace runs hot, drops voltage and may fail over time; too wide and routing space is wasted that dense areas…

Cleaning Equipment and Bath Control for PCB Production Cleaning equipment is bought to remove what the soldering process leaves behind, and it only does that job when the chemistry, the mechanical action, the rinse quality and the drying step are all controlled together. A machine that is correctly sized and…

Gyroscope Sensor PCB Design Guide A MEMS gyroscope measures how fast something is rotating, and the number it reports is the difference between a real rotation and a set of error terms that are produced by the board it is mounted on. Temperature, vibration and mechanical stress all enter the…

PCB Prototype Cost Factors You Can Control Prototype orders are priced differently from production because the fixed costs are spread over very few boards. Understanding which parts of the price are fixed, which scale with the board and which are optional is what allows a design team to reduce cost…

Solder Paste Volume: Stencil Aperture and Print Parameters Most solder defects that appear at reflow were decided at the printer, and most printing problems are decided by the aperture in the stencil. The paste volume deposited on a pad is the single variable that predicts bridging, insufficient solder and voiding…

Low Loss Materials for Millimetre Wave PCB Stack-Ups Above roughly thirty gigahertz the wavelength on a printed circuit board is measured in millimetres, and low loss material stops being an optimisation and becomes the starting point of the design. Every stub, pad and connector launch that was invisible at lower…

Panel Mounting and Soldering of Coaxial Connectors A coaxial connector that passes through an enclosure wall carries two joints at once. Inside the box it is soldered to the board, and at the wall it is mechanically fastened to the panel. Both have to work, and the electrical performance of…

Pick and Place Nozzle Selection, Wear and Maintenance Placement accuracy is usually credited to the machine, yet many placement faults trace back to the small consumable on the end of the head. The pick and place nozzle decides how firmly a component is held, how squarely it sits after release,…