Soldering Pallet Care: 5 Rules for Selective Solder A soldering pallet is the fixture that carries a board through a selective or wave soldering machine, and it does more than hold the board still. It masks the areas that must stay solder free, it keeps the board flat under the…

Skipped Deposits: 7 Causes in Stencil Printing Skipped deposits are apertures that receive no paste at all, leaving a bare pad after the print. The defect is different from a deposit that is short or thin, because the failure is complete rather than partial, and the cause is usually a…

SMT Line Changeover: 6 Steps That Cut Setup Time Safely Line changeover is the interval between the last good board of one product and the first good board of the next, and it is one of the largest hidden costs on an SMT line. It is not only the machine…

Emulsion Thickness: 5 Rules for Printing Screens Emulsion thickness is the depth of the light sensitive layer that sits above the mesh on a printing screen, and it is the single biggest control over how much ink is deposited. The ink fills the opening, and the volume of that opening…

Anode Bag Care: 5 Rules for Copper Plating Baths An anode bag is a porous sleeve that wraps a copper anode in a plating bath, and its job is to hold the anode sludge where it is produced. As the anode dissolves, the insoluble material that was inside the metal…

Core Baking: Preparation, Placement and Process Control Core baking is the drying step that removes absorbed moisture from inner layer cores and, where the process requires it, from prepreg before the stack goes into the press. It is a short operation with an outsized effect, because water trapped inside a…

PCB First Pass Yield Sample: Process Details and Inspection Points 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 first pass yield sample from the perspective of a…

Iron Contamination: 5 Signs a Solder Bath Needs Alloy Iron contamination is the gradual build up of iron in a molten solder bath, and it comes from the pot itself rather than from the alloy that was delivered. Iron dissolves slowly in molten tin, and once it is in solution…

Permanganate Desmear Control: 6 Steps That Protect the Hole Wall Permanganate desmear is the wet chemical sequence that removes resin smear from a drilled hole so that copper can be plated onto a clean, bondable surface. Smear forms when the drill heats the resin beyond its softening point, and the…

Solder Mask Viscosity: 5 Rules Before Printing Solder mask viscosity is the property that decides how the ink leaves the screen, how it levels on the panel and how much of it stays where it was printed. It is measured in the ink kitchen, it changes with temperature and shear,…