Fab Chemical Shelf Life: Labels, Dates and Stock Shelf life is the period a chemical can be kept before its performance is no longer guaranteed, and in a PCB fabrication shop it is quoted on the label, in the certificate and in the process specification. The dates matter because plating,…

Cooling Tower Control for Plating and Etch Lines A cooling tower removes heat from the water circuits that serve rectifiers, heat exchangers, chillers and etch lines, and it does so by evaporating a small part of the water it circulates. That evaporation is the whole mechanism, and it also explains…

Release Film in PCB Lamination: Reuse and Handling Release film sits between the press plate and the board stack, and its job is to let the two part cleanly after the cycle. It also carries the surface texture that the press plate would otherwise print onto the laminate, and it…

Plating Bath Chemical Addition: Sequence and Make-Up Chemical addition is the routine of topping up a plating bath, and it is one of the few operations where the order of the steps changes the result. The same chemicals added in a different sequence can produce a cloudy bath, a precipitated…

Stencil Frame Tension: Mesh, Glue and Print Quality Frame tension is the force holding the mesh taut inside a stencil frame, and it is the property that keeps the stencil flat against the board through a print stroke. A frame that has lost tension still looks correct on a bench,…

Laser Depaneling: Heat, Char and Edge Quality Laser depaneling cuts a panel into single boards with a focused beam instead of a router bit, and it does so without mechanical stress on the edge. That is its main advantage for thin boards, for dense assemblies and for shapes that a…

Differential Pressure: Plating Filter Cartridge Life Differential pressure is the most useful number on a plating filter, because it describes the condition of the media rather than the condition of the pump. A gauge across the housing shows the pressure the pump must overcome to push solution through the cartridge.…

Electroless Accelerator: Strength, Rinse and Control The accelerator is the step that follows the palladium catalyst in an electroless plating line, and its job is to remove the tin that surrounds the palladium so that the catalyst can actually work. Without it, the surface carries palladium that is buried inside…

Solder Paste Waste: Expiry, Return and Disposal Solder paste waste is the material that cannot be printed again, and it is produced on every shift: expired jars, paste left on the stencil, paste returned from the squeegee and paste contaminated by the board. It is a small fraction of consumption…

Effluent Filter Press: Dewatering and Cake Quality A filter press is the equipment that turns the sludge from a PCB waste treatment plant into a handleable cake. The plates are closed, the conditioned sludge is pumped in, and the water is squeezed out through a filter cloth until only the…