Production Yield Improvement in PCB Manufacturing Production yield improvement is the discipline of raising the share of boards that pass without rework, and it is the most direct lever a board shop has on both cost and delivery. The work is unglamorous: measure the real first pass yield, find where…

Squeegee Blade Wear and Solder Paste Print Quality The squeegee is the simplest part of a solder paste printer and the one that wears fastest. It is a strip of metal or polyurethane that is dragged across the stencil, and its job is to roll the paste ahead of the…

ESD Control In The Assembly Area An assembly area is a controlled environment in which every surface, every tool and every person is held at the same potential, so that a static discharge cannot pass through a component. Control is not a single product but a system of grounding, materials…

X-Ray Slice And CT Inspection For PCB Quality An X-ray slice is a cross-sectional image of a board taken from a rotational scan, and it is the only non-destructive way to look inside a plated hole, a via or a solder joint. Where a two-dimensional image collapses the whole thickness…

PCB Scrap Analysis: Tracking Real Yield Loss Scrap analysis is the work of finding out what a board shop is really throwing away, why it happens, and what the loss costs. Many shops record a scrap rate and stop there, which turns a number into a mood rather than a…

Electroless Copper Coverage and Hole Wall Control on PCBs Before a hole in a printed circuit board can be electroplated it has to be made conductive. The resin surface left by drilling is an insulator, and the thin layer of electroless copper that is deposited on it is what carries…

Tombstoning Causes and Prevention in Reflow Soldering Tombstoning is the defect in which a two terminal chip component stands up on one end after reflow instead of lying flat on its pads. The joint on one side forms and pulls the part upright, while the other termination is left in…

Electroless Copper Bath Control And Deposit Quality Before a hole can be electroplated, its wall has to be made conductive. That is the job of the electroless copper bath, which deposits a thin layer of copper on the laminate, on the glass fibres and on the inner layer copper without…

Squeegee Pressure And Solder Paste Printing The squeegee is the moving blade that rolls the solder paste across the stencil and presses it into the apertures. Three settings describe it: the pressure that holds it against the stencil, the speed at which it travels and the angle at which the…

Statistical Process Control PCB Guide Statistical process control is the practice of measuring a process while it runs and reacting to the result before the product is out of specification. It is not a report, and it is not a one off study, both of which are common misunderstandings. The…