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…

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,…

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,…

PCB Aluminum Metal Core Board: A Board That Sheds Heat 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…

Stencil Aperture Design for Fine Pitch Why Aperture Design Decides Print Quality The stencil aperture is the mould that gives each solder paste deposit its shape and volume, and almost every print defect can be traced to it. An aperture that is too small releases paste poorly; one that is…

Solder Paste Storage, Expiry and Handling Why Solder Paste Is Perishable Solder paste is a suspension of fine alloy powder in a flux vehicle, and that mixture changes from the moment it is made. The flux slowly reacts with the powder, the solvent evaporates, and the rheology drifts. A paste…