Rework vs Scrap Decision Every assembly line eventually produces a board that does not pass. The question is not whether to rework or to scrap it, but how that decision is made, by whom, and on what evidence. A line that answers those questions in advance saves money on both…

Layer Registration Tolerance Every layer in a multilayer board has to line up with every other layer, and the tolerance that governs the alignment is built up from a chain of steps rather than set at one operation. Registration is therefore a capability that has to be understood from the…

Selective Soldering: Nozzle Design and Care Selective soldering exists because a wave solder machine is a blunt instrument for a board that mixes surface mount and through-hole parts. The wave treats the whole panel at once, which is fine when everything on the secondary side can take the same thermal…

Nitrogen Reflow: Cost, Wetting and Oxide Control in Practice Nitrogen reflow replaces the air in the oven with an atmosphere that is almost free of oxygen, and the change is visible in wetting, in solder ball counts and in the operating cost of the line. Whether it pays depends on…

ESD Floor and Wrist Strap Testing An ESD protected area depends on a chain of controls, and a chain is only as strong as the test that proves each link is intact. Floors, wrist straps, footwear, benches and ionisers all have a resistance or a decay time that can be…

Drilling Entry Material and Burr Drilling a printed board is a machining operation, and like any machining operation the result depends on the tool, the material being cut and what is on either side of the workpiece. Entry and backup material sits on the top and bottom of the stack,…

Reflow Oven Zone Settings: Temperature, Time and Limits Reflow zone settings decide whether a joint forms cleanly or becomes one of the slow, intermittent defects that are hardest to diagnose. The oven is not a single temperature but a series of zones, each doing a different job, and the profile…

PCB Shop Humidity Risks: What Could Go Wrong 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 shop humidity risks gives you a practical advantage when…

PCB Shop Humidity Sample: Checking a Small Piece 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…

PCB Shop Humidity Review: A Second Look 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 shop humidity review from the perspective of a PCBA factory floor, covering…