Crazing in Solder Mask and Laminate: 6 Causes and Controls Crazing is a network of fine cracks that appears in a coating or in a laminate surface, usually with no single direction, so that the surface looks as though it has been shattered into small cells. Each crack is thin,…

Copper Nodules in Plating: Sources and Prevention Rules A copper nodule is a raised bump in an electroplated deposit, typically a tenth of a millimetre across and sometimes larger, that stands above the surrounding copper. It is created when a foreign particle sits on the surface and receives more current…

Solder Mask Orange Peel and Blooming: Causes and Fixes Orange peel is a fine, regular dimpling of the cured solder mask surface that resembles the skin of a citrus fruit. Blooming is a milky or hazy discolouration that appears after cure and often grows worse with time or with a…

Induction Soldering for Localised Heating: 7 Process Rules Induction soldering heats the metal itself rather than a tool that then touches the metal. An alternating current in a coil produces a changing magnetic field, the field induces eddy currents in the workpiece, and the resistance of the workpiece converts those…

Disturbed Joint: Movement While Solder Solidifies A disturbed joint is one that was mechanically moved while the alloy was still partly liquid, so the surface has frozen in a rippled, grainy or stepped condition instead of the smooth concave shape a good fillet should have. The defect is created in…

Refurbished Components: Risk Control in PCBA Manufacturing Refurbished components arrive on an assembly line with a history that no label records, and that history decides whether the part survives a lead-free reflow cycle. Parts pulled from scrapped boards, re-tinned and re-reeled can look identical to factory stock under a bench…

Drill Stack Clamping: 4 Checks That Protect Hole Quality Drill stack clamping is the force that holds the panel, the entry material and the backup board together while the drill passes through them. It is applied by a pressure foot, by clamps at the edges of the stack, or by…

Etchant Regeneration: 4 Checks for a Stable Etch Rate Etchant regeneration is the set of actions that keeps an etching bath doing the same thing hour after hour while copper continues to dissolve into it. Without it the bath loads, the etch rate falls, and the line has to be…

Solder Mask Ink Shelf Life: 4 Rules for Storage and Pot Life Ink shelf life is the time an unopened container can be stored before its chemistry changes, and it is not the same as pot life, which is the working time after the ink has been mixed or opened.…

Gold Plating Porosity: 4 Causes of Corrosion Under Gold Gold plating porosity is the network of tiny openings that runs through a gold deposit, and it is the reason a finish that looks perfect can corrode in service. Gold itself does not corrode, but the metal underneath it does, and…