Immersion Tin Finish: Thickness, Whiskers and Shelf Life Immersion tin is a thin metallic coating deposited on copper by a displacement reaction. It provides a flat, solderable surface for fine pitch assembly and press-fit connectors, and it does so without the gold of an electroless nickel immersion gold finish and…

Pressure Foot and Drill Support: Fixturing for Hole Accuracy The pressure foot is the part of a drilling or routing spindle that presses down on the panel and holds it against the backup plate while the tool cuts. It looks like a simple clamp, but it sets the reference surface…

Drill Runout in PCB Drilling: What the Collet Adds Drill runout is the total indicated movement of the cutting edge as the drill turns, measured close to the tip rather than at the shank. It is the error that sits underneath every drilling parameter, because a bit that orbits cannot…

PCB Drill Bit Timing: A Factory-Floor Review 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…

Peck Drilling and Retract Rate Control for Deep PCB Holes Peck drilling breaks a deep hole into a series of short advances, retracting the bit between them so that chips leave the hole instead of packing around the flutes. It is the standard answer when the aspect ratio climbs past…

Print to Reflow Hold Time: How Long Printed Paste Can Wait Hold time is the interval between printing a board and reflowing it, and it is one of the least controlled variables in a surface mount line. It is invisible on the process sheet, it changes with the queue, and…

Feeder Calibration: Pick Position, Tape Lift and Pitch Feeders are the largest population of moving parts on a placement machine, and they are the ones most often excluded from the calibration schedule. A feeder that picks reliably is assumed to be correct, even when its pick position has drifted a…

Conformal Coating Cure: 6 Rules for a Full Cure Schedule A conformal coating cure schedule is the combination of temperature and time that turns a wet film into the protective layer the design assumed. It is written on the coating data sheet, and it is verified far less often than…

PCB Drill Bit Handover: A Practical Manufacturing Guide 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…

Solder Paste Shelf Life: Cold Chain, Thaw and Working Time Solder paste is a suspension of solder powder in flux, and it is chemically active from the moment it is manufactured. Its shelf life is the time over which that activity stays inside a usable range, and every step from…