PCB Back-drill Via Stub Removal: Cutting the Stub Away 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…

Bend Radius in Flexible Circuits Why Bend Radius Matters A flexible circuit earns its place by bending, and the radius of that bend determines how much strain the copper sees. Bend the flex too tightly and the copper, which is the least ductile of the materials in the stackup, will…

Stiffeners for Rigid-Flex Assemblies Why Stiffeners Are Used A flexible circuit bends, and that is usually the point. But there are places on the same circuit where bending is a problem: under a connector that must be plugged and unplugged, around a component that must stay flat, or at an…

SMT Solder Dendrite Growth: Metal That Grows a Branch 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 SMT solder dendrite growth from the perspective of a PCBA factory…

Thermal Interface Materials and Gap Fillers What a Thermal Interface Material Does Two surfaces that look flat are not, at the microscopic scale. When a heat sink is placed on a component, the contact is made at a few high points, and the air in the gaps between them is…

Masking for Conformal Coating Why Masking Is Needed Conformal coating protects a board by covering it, and there are places where coverage is not wanted. Connectors need metal-to-metal contact, test points need to be probeable, and some components cannot tolerate a coating on their surfaces. Masking keeps the coating off…

PCB Halogen-free Laminate: A Board Without the Bad Chemistry 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 halogen-free laminate from the perspective of a PCBA factory floor,…

Hand Soldering Quality and Operator Skill Where Hand Soldering Still Matters Hand soldering has not disappeared with the growth of surface mount assembly, because there are joints that machines cannot reach. Rework on a populated board, wire attachments, connectors added after reflow, and prototypes built without stencils all depend on…

PCB Polyimide Flexible Material: A Board That Bends 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 polyimide flexible material from the perspective of a PCBA factory floor,…

Component Shift and Mid-Reflow Movement What Component Shift Looks Like Component shift is a displacement of a part from its placed position during reflow. The part may slide slightly along its pads, rotate a few degrees, or lift at one end. Unlike tombstoning, where the part stands on one end,…