ESD Safe Handling of Boards and Assemblies Static damage is the defect that leaves no evidence behind. A device that has been exposed to a discharge may fail immediately, may drift slowly, or may pass every test and fail in the field after a month of use, and nothing about…

Assembly Drawing and Notes for PCB Production An assembly drawing is the document that tells the factory what the designer intends. When it is complete, the operator never has to guess; when it is thin, every guess becomes a defect that someone has to explain later. Most assembly problems that…

SMT Adhesive Dispensing And Dot Profile Control Adhesive dispensing is the operation that places a bead of surface mount adhesive to hold components to the underside of a board so that they survive wave soldering, and sometimes so that they survive a second reflow on the other side. It is…

Sheet Metal Chassis Grounding Guide Chassis grounding is the connection between the electrical reference of a board and the metal structure around it. The connection is made for two reasons: to give the return current a large, quiet path and to hold the enclosure at a defined potential. It is…

Chip Component Crack Causes in SMT Assembly A cracked chip component is one of the most common defects on a mature assembly line, and it is also one of the least visible. The body may look intact while a fracture runs through the ceramic, and the part passes final test…

ENIG Gold Thickness Control And Black Pad Risk Electroless nickel immersion gold is one of the most widely used finishes on a printed circuit board, and the part of it that draws the most argument is the thickness of the gold. The complaint is always that there is not enough…

Panelisation and Tab Routing for Board Assembly A panel exists so that the assembly line can handle many boards at once, and every decision about its size and its breakaway method has a cost somewhere. A panel that is too small wastes machine capacity, while a panel that is too…

PCB Reflow Profile Environment: What Matters on the Production Line Buyers and engineers often focus on the finished product and forget the production line behind it. In practice, most field failures can be traced back to process decisions made during assembly. Understanding PCB reflow profile environment gives you a practical…

PCB Reflow Profile Handover: What Matters on the Production Line Buyers and engineers often focus on the finished product and forget the production line behind it. In practice, most field failures can be traced back to process decisions made during assembly. Understanding PCB reflow profile handover gives you a practical…

Counterbore Hole: Design Rules and Process Limits A counterbore hole is a flat bottomed recess machined into a board so that a screw head sits below the surface. It is used where the head would otherwise touch a component, foul a mating part or stand proud of a panel. The…