Test Point Design for Probe and Fixture Access Test points are the interface between the board and everything that has to prove the board works. They are usually added at the end of the layout, which is why they are often the reason a test fixture is difficult and a…

Audio Codec Interface Circuit Design An audio codec puts analogue to digital and digital to analogue conversion, a serial audio interface and usually a small mixing and gain stage on a single die. That integration removes a great deal of design work, and it also concentrates the places where digital…

Failure Analysis: Root Cause and Escape on Assemblies When a unit fails, the first answer is usually a guess. The failure analysis process exists to replace the guess with evidence, and it is only useful if it is followed before the unit is disturbed. Before Anything Is Touched The failed…

PCB Revision Control: Knowing Which Version 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 revision…

PCB Record Retention: Keeping the Proof 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 record…

Solder Mask Sliver and Dam Width Control on Dense Boards Solder mask is not a cosmetic layer. On a dense board it is a structural part of the assembly process, keeping solder where it belongs, protecting copper from the environment and defining the dams that stop a bridge between two…

PCB Component Shortage Handling: When a Part Is Missing 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 component shortage handling from the perspective of a PCBA factory…

Thermal Via Fabrication and Conductive Fill Materials A thermal via is a hole through the board that is used to move heat rather than to carry a signal. It is one of the few features where the fabrication method decides the thermal performance directly, because a hole that is plated…

PCB Substitute Part Approval: May We Use This Instead 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 substitute part approval from the perspective of a PCBA factory…

Electric Toothbrush Circuit Design: Motor and Charger An electric toothbrush contains a motor, a battery, a radio and a charger inside a sealed handle about twenty millimetres across. The circuit is small, and every choice is dominated by the space and the sealing. What Fits Inside the Handle The board…