Solder Voids in Thermal and BGA Joints What a Void Is A void is a cavity inside a solder joint, filled with gas or with a vacuum, where solder should be. It appears in an X-ray image as a lighter region inside a dark joint because there is less material…

PCB Copper Trace Impedance Matching: Keeping the Path Even 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 copper trace impedance matching gives you a practical…

Impedance Tolerance: What to Specify What the Tolerance Applies To An impedance specification is meaningless until it says which impedance, measured where and over what frequency. A single line has a characteristic impedance that varies along its length because the dielectric thickness and the trace width vary, and a differential…

Laser Drilling Microvias: Parameters and Limits Why Laser Instead of Mechanical A mechanical drill below about 0.15 mm is impractical: the bit is fragile, the spindle speed needed to keep the surface speed reasonable becomes extreme, and the drill tends to wander. A laser removes material without contact, so the…

SMT Reflow Solder Joint Intermetallic: The Layer Between Metals 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 SMT reflow solder joint intermetallic gives you a practical…

Silkscreen and Solder Mask: What Each Layer Does Two Different Layers The solder mask and the silkscreen are both printed onto the surface of a board and they are often drawn on the same screen by a designer, but they do completely different jobs. The solder mask is a permanent…

PCB Surface Finish Wire Bond: A Finish That Takes a Bond 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 surface finish wire bond from the perspective of…

High Tg Laminates: When They Are Worth It What Tg Describes The glass transition temperature is the point at which a resin changes from a rigid, glassy state to a softer, more rubbery one. Below Tg the laminate behaves like a stiff solid; above it the resin softens, the coefficient…

PCB Copper Wrap and Edge Plating Tolerance What Copper Wrap Means Copper wrap is the connection of a surface copper feature around the edge of the board to copper on another layer, so that the two are joined by metal that passes over or through the edge rather than by…

SMT Component Placement Angle: The Rotation of the Part 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 SMT component placement angle gives you a practical advantage…