Shunt Resistor Packages: Power and Thermal Limits A shunt resistor is the component that turns current into a voltage a circuit can measure, and it is chosen on the assumption that it will stay at the value printed on the reel. That assumption holds only if the part stays cool…

PCB Fabrication Drawing Notes: What the Shop Needs to Know Modern electronics depend on boards that are assembled correctly the first time. Every product – a phone, a charger, a medical instrument or an industrial controller – relies on thousands of solder joints that must conduct current for years. This…

PCB Skin Effect on A Trace: Current on the Outside 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 skin effect on a trace gives you…

PCB Via Stitching Rules: Holes With No Signal 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 via stitching rules gives you a practical advantage when…

Common Mode Choke: Preparation, Placement and Process Control A common mode choke is placed on a power input to block common mode noise, and at low frequency it does exactly that: the specified inductance is large and the impedance it presents to common mode current matches the datasheet curve. At…

Pin-In-Paste: Preparation, Placement and Process Control Through-hole connectors are mechanically robust and electrically reliable, and they are also the reason many assemblies need a second, slower soldering process. Pin-in-paste, sometimes called intrusive reflow, removes that step by printing enough solder paste into and around the holes so that the joints…

Laser Direct Imaging: Preparation, Placement and Process Control Imaging is where a circuit pattern is transferred from data into photoresist, and for decades that meant a film and a lamp. Laser direct imaging replaces the film with a scanned beam, removing a whole class of distortion problems and making fine-line…

Quasi-Peak Detector: Preparation, Placement and Process Control A pre-scan with a peak detector shows a point above the limit line, and the conclusion that the product has failed follows immediately. It is often the wrong conclusion. The peak detector is a fast and deliberately conservative screening tool, and the formal…

Aluminum Pcb Cost: Preparation, Placement and Process Control An aluminum board exists to move heat, and every cost decision on it follows from that purpose. The metal core is the heatsink, the dielectric layer is the thermal interface and the copper is the circuit, and the three have to be…

Under-Stencil Cleaning and Solder Paste Print Quality Print quality is decided in the few milliseconds when the stencil separates from the board, and the condition of the stencil underside decides a large part of it. Paste that sticks to the bottom of the stencil instead of transferring to the pad…