Laminography: 3D X-Ray Imaging for Solder Joints Laminography, also called computed laminography or tomosynthesis, produces an X-ray image of one plane inside an assembly while the material above and below that plane is blurred out. The result is a view of a single solder joint layer without the superposition that…

Lead Tinning: 6 Rules for Component Solderability Lead tinning is the operation that replaces a component lead finish with fresh solder so that the part can be soldered reliably in a later assembly step. It is common on parts with aged, oxidised or incompatible finishes, and on hardware and connectors…

Tin Pest in PCB Finishes: 6 Rules for Cold Storage and Alloys Tin pest is the transformation of white tin, the familiar ductile metal, into grey tin, a brittle phase that crumbles to powder. The change becomes possible below about thirteen degrees Celsius, it is slow at first and then…

Dye Penetrant Testing for BGA Joint Cracks and Voids Dye penetrant testing is a destructive method in which a coloured fluid is drawn into every crack in a solder joint before the package is separated from the board. When the joint is opened, the stained area is the crack, and…

Trace Repair and Jumper Wires on PCB Assemblies: 7 Rules A trace repair is the last resort before a board is scrapped. A conductor that has been cut by a probe, torn during rework or cracked by repeated flexing can often be restored, but the repair has to carry the…

Hole Cleaning After Drilling: 4 Steps Before PTH Hole cleaning after drilling is the step that removes what the bit leaves behind, and it sits between the drilling machine and the PTH line. Dust, resin particles and copper slivers are pushed into the barrel as the drill cuts, and if…

Tin Plating Bath: 4 Checks for a Uniform Etch Resist A tin plating bath deposits the metal that protects the copper while the panel is etched, so the deposit acts as a resist rather than as a finish. Its quality decides whether the tracks leave the etcher with clean edges…

Spray Rinse Design: 4 Ways to Cut Drag-Out on a Plating Line A spray rinse sits between two process tanks and has one job: to remove the chemistry that the panel carries out of the first tank before it reaches the second. It is the cheapest control on a plating…

Rectifier Calibration: 4 Checks for True Plating Current Rectifier calibration is the check that connects the number on the control panel with the current actually flowing through the tank. Every thickness calculation on the line rests on that connection, and when it drifts the error is invisible until the copper…

Plating Tank Filtration: 6 Rules for Clean Copper Baths Plating tank filtration is the continuous removal of particles, organic material and debris from a plating solution while the bath is in use. It sits quietly in the background of a PCB plating line, and when it stops working the symptoms…