Print Head Technology in SMT Printing The print head is the part of a stencil printer that turns paste into a deposit. It carries the squeegee, applies the force and moves across the stencil, and the way it does those three things sets the fill of the aperture and the…

Backdrilling And Stub Removal In High Speed Boards A plated through hole that only needs to connect the outer layers still passes through the whole board, and the unused portion below the last connected layer is called a stub. At high frequencies the stub behaves as a resonant transmission line…

PCB Soldermask Data: What Matters on the Production Line 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 article…

PCB Soldermask Plan: What Matters on the Production Line 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 soldermask plan gives you a practical advantage when…

Ionic Contamination: Preparation, Placement and Process Control Ionic contamination is the residue of the soldering process that remains on the board in the form of dissolved salts and flux activators. It is conductive once it absorbs moisture, and it is the raw material for leakage currents and for electrochemical migration…

Surface Insulation Resistance Test On Assemblies Surface insulation resistance is a measure of how well a surface resists the flow of leakage current between two conductors. On an assembled board it is affected by the flux residue left behind, by the cleanliness of the process and by the humidity of…

PCB Soldermask Standards: Agreeing the Rules Soldermask looks like a cosmetic layer until a defect reaches the assembly line. A mask that lifts, cracks or traps flux can block a pad, shift a joint or fail a cleanliness check. The rules that govern mask quality are rarely argued at the…

Solder Paste Inspection Guide Solder paste inspection measures the deposit on every pad before a component is placed. It measures a process that has no other in line check, and it does so at the point where a correction is still cheap, which is why the data is more valuable…

Stencil Cleaning Methods Compared A stencil collects paste on both faces during a print run. The underside picks up paste that is squeezed under the foil and the apertures collect paste on their walls, and both of them change the deposit. Stencil cleaning is therefore a continuous process rather than…

PCB Soldermask Limits: Where the Edges Are Soldermask is not a coating that simply covers a board. It defines where solder may land, where copper stays protected and where the circuit must stay clear. The limits around those edges decide whether a design builds cleanly at volume. This review sets…