Copper Oxide Treatment for Inner Layer Bonding Inner layer copper is bonded to the resin through a treatment that grows a controlled oxide on the surface. Without it the copper and the resin do not adhere, and with the wrong one the bond is either weak or the oxide is…

Through Hole Soldering Method Comparison for Mixed Assemblies A board that carries both surface mount and through hole parts has to be soldered twice, and the second operation determines the quality of the through hole joints. Three methods are in common use: wave soldering with a masking pallet, selective soldering…

Solder Paste Viscosity and Printing Window Control Guide Solder paste is a suspension of solder powder in a flux vehicle, and its viscosity is the property that decides how well it prints, how long it stays on the stencil and how much it slumps before reflow. Because the paste is…

Acceptance Class Selection for Electronics Manufacturing Every board is inspected against something. If the criteria are not written down, the inspector applies personal judgement, and the result varies between shifts, sites and customers. An acceptance class is a way to state in advance how much deviation is tolerable, so that…

Pin in Paste Reflow for Through-Hole Components Pin in paste places the solder for a through hole joint as paste in the stencil, so that the joint is formed in the reflow oven rather than by a wave or by hand. It removes a process step and it puts a…

DFM Review Items Before PCB Release A design for manufacture review asks a short set of questions about a design before it is built, and the questions are the same for every board. They are asked at the point where the answers are cheap, which is before the artwork is…

PCB Traceability Checklist: What to Check 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 explains PCB traceability…

PCB Traceability Improvement: Getting Better Each Lot 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 traceability improvement gives you a practical advantage when you choose…

PCB Labeling Plan: Laying It Out First 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 labeling plan gives you a practical advantage when you choose…

PCB Labeling Limits: Where the Edges Are 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 labeling limits from the perspective of a PCBA factory floor, covering understanding…