X-Ray Inspection of SMT Solder Joints Most solder joints on a modern board can be inspected optically, but the ones that matter most usually cannot. A ball grid array hides its joints under the package body, a land grid array hides them under the component, and a bottom terminated component…

PCB Stencil Audit: Checking the Foil Electronics manufacturing has become a discipline of small details. Solder paste volumes, placement accuracy, temperature profiles and inspection limits all add up to the final result. This guide looks at PCB stencil audit from the perspective of a PCBA factory floor, covering auditing a…

PCB X Ray Inspection Limits: What the Picture Can Show Electronics manufacturing has become a discipline of small details. Solder paste volumes, placement accuracy, temperature profiles and inspection limits all add up to the final result. This guide looks at PCB X ray inspection limits from the perspective of a…

PCB ESD Audit: Checking the Protections Buyers and engineers often focus on the finished product and forget the production line behind it. In practice, most field failures can be traced back to process decisions made during assembly. Understanding PCB ESD audit gives you a practical advantage when you choose a…

PCB Cleanliness Audit: Looking for What Should Not Be There Electronics manufacturing has become a discipline of small details. Solder paste volumes, placement accuracy, temperature profiles and inspection limits all add up to the final result. This guide looks at PCB cleanliness audit from the perspective of a PCBA factory…

Selective Soldering: Design Rules and Process Limits When a board carries a mixture of surface mount and through-hole parts, and the through-hole joints are few enough that a wave is wasteful, selective soldering fills the gap. It applies solder to individual joints with a small nozzle, under program control. What…

Humidity Control in PCB Storage and SMT Production Humidity is the quiet variable on an SMT floor. It does not announce itself the way a machine fault does, yet it changes paste behaviour, laminate dimensions and component condition at the same time. A room that drifts from forty to seventy…

Mounting Holes and Standoffs: Fixing the Board to the Chassis The mounting holes are usually the last feature added to a layout and the first to cause a problem in the field. They carry the mechanical loads, they set the relationship between the board and the chassis, and they are…

Flexible Pcb: Flexible Multilayer PCB: Production and Testing A flexible pcb is built on a polymer film rather than on a rigid laminate, which allows it to bend, fold and conform to a shape. When several conductor layers are combined, the result is a flexible multilayer board that keeps the…

Photodiode Transimpedance Amplifier Layout A photodiode produces a current rather than a voltage, and that current is small: a few nanoamperes in a low light application and a few microamperes in a bright one. The transimpedance amplifier converts that current into a usable voltage, and because the signal is so…