Stencil Cleaning and Paste Transfer Efficiency in SMT The stencil is the least expensive tool in the SMT line and the one that most directly determines whether the process works. Every paste deposit that ends up on a pad passed through an aperture, and every aperture that is partially blocked…

Placement Nozzle Selection, Wear and Management The nozzle is the last item in the placement chain before the component lands. It decides how the part is picked, how firmly it is held, and how it is released, and a worn nozzle produces placement defects that are usually blamed on the…

Fiducial Design and Placement for Pick and Place Alignment A pick and place machine has to know where the board actually is before it can put a component in the right place. Fiducials are the marks that give it that reference, and their design and placement decide how accurately the…

Through-Hole Lead Forming, Seating and Trimming Through-hole parts are still used where the mechanical strength, the current or the connector family requires them. Their leads have to be formed to fit the hole spacing and then trimmed, and the way those two steps are done decides whether the part sits…

PCB Test Data Storage: Keeping the Numbers 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 test data storage gives you a practical advantage when you…

Selective Soldering For Through Hole Components A board that is mostly surface mount often still carries a connector, a transformer or a large capacitor that has to be through hole. Those parts cannot be reflowed with the rest of the assembly, and passing the whole board through a wave exposes…

Solder Joint Voiding Causes And Acceptance Limits A void is a bubble of gas trapped inside a solder joint, and it is present in a large fraction of the joints on a production board. In most positions it is harmless, because the joint is still electrically continuous and mechanically adequate.…

PCB Magnification for Inspection: How Close to Look 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 magnification for inspection gives you a practical advantage when…

PCB Operator Fatigue Control: Eyes That Stay Sharp 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 operator fatigue control gives you a practical advantage when…

PCB Defect Photo Standard: Pictures Everyone Agrees On 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 explains…