Component Height and Clearance Verification Component height is a mechanical parameter that decides whether an assembly can be built at all, and it is usually verified with a drawing rather than with a measurement. A part that is 0.3 mm taller than its nominal value can collide with a placement…

Lead Trimming and Clinch Control After Wave Soldering Lead trimming and clinching look like finishing operations, but they apply mechanical loads to joints that have just been soldered. A blade that shears instead of cutting, or a clinch that is bent too tightly, can crack a fillet or lift a…

Flux Density and Specific Gravity Control in Wave Soldering Flux density is the parameter that decides how much active chemistry reaches the joint, and it is also the parameter most often checked with a single hydrometer reading taken at the start of a shift. A wave soldering machine running on…

Auto-Insertion Process Control for Through-Hole Assembly Auto-insertion is the mechanised placement of through-hole parts, and it succeeds or fails on mechanical tolerances rather than on electrical ones. The machine pushes a lead into a hole with a defined force, and if the lead span, the hole position and the clinch…

Solder Paste Hot Slump and Reflow Preheat Control Hot slump is the movement of a solder paste deposit after printing but before the alloy melts, and it is caused by the paste softening as it warms rather than by anything mechanical. A deposit that was well formed at the printer…

Micro-Hardness Testing of Plated Copper in PCB Fabrication Micro-hardness is one of the few measurements that describes the quality of plated copper rather than its quantity. Thickness tells you how much metal was deposited, while hardness tells you how the deposit will behave when the board is drilled, routed, thermally…

PCB Drill Bit Sample: Checking a Small Piece 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 drill bit sample from the perspective of a PCBA factory floor,…

Direct Metallization Control for PCB Plated Through Holes: 6 Rules Direct metallization is a family of processes that make a drilled hole conductive without the electroless copper step that traditionally followed desmear. The hole wall is treated with a conductive material, usually a carbon or graphite dispersion or a conductive…

Megasonic Cleaning Control for PCB Assemblies: 6 Rules Megasonic cleaning uses sound in the range of several hundred kilohertz to several megahertz to remove particles from a surface. It is a different mechanism from the ultrasonic baths used for heavier soils: where ultrasound relies on the violent collapse of cavitation…

PCB Drill Bit Risks: What Could Go Wrong 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…