Tag Archives: PCBs

Why Use a Multi-Layer PCB?

Although a multi-layer PCB is more expensive than a single or double-layer board of the same size, the former offers several benefits. For a given circuit complexity, the multi-layer PCB has a much smaller size as compared to that a designer can achieve with a single or even a double-layer board—helping to offset the higher cost—with the main advantage being the higher assembly density the multiple layers offer. There are other benefits of a multi-layer PCB as well, such as increased flexibility Read more [...]

What are Multi-Layer PCBs?

Most electronic equipment have one or more Printed Circuit Boards (PCB) with components mounted on them. The wiring to and from these PCBs determines the basic functionality of the equipment. It is usual to expect a complex PCB within equipment meant to deliver highly involved performance. While a single layer PCB is adequate for simple equipment such as a voltage stabilizer, an audio amplifier may require a PCB with two layers. Equipment with more complicated specifications such as a modem or a Read more [...]

Whisker Growth in Printed Circuit Boards

in whiskers are not fanciful or imaginative items, but are real and pose a serious problem for all types of electronic manufacturing. Pure tin is often used as a finish material on printed circuit boards (PCBs) to protect the exposed copper pads from tarnishing. However, pure tin spontaneously grows conductive whiskers, thin wire like growth that can form electrical paths and affect the operation of the PCB assembly. Understanding Tin Whiskers and their Effects First reported in the 1940s, tin Read more [...]

Preventing or Mitigating Whisker Growth in PCBs

Growth of whiskers puts PCB assembly at considerable risk, since whiskers interfere with components, and this automatically qualifies a good product as a defective one. Although a growing tin whisker may seem harmless, it can pose a very real threat to both the product as well as to the human operator. In PCB assembly, one of the most common problems that whiskers create is a short circuit or arcing. This can cause breakdown of electrical equipment, as well as harm people from the arcing. Either Read more [...]

Variables in Lead-Free Reflow for PCBs

Reflow ovens often show degrees of variability from profile to profile. This may depend on the distribution of components on the board, especially those that are slow heating, heat-sensitive, or of high mass. In general, reflow systems cannot generate one single reflow profile producing capable thermal results for all products. For instance, a large BGA package on the PCB may not allow more than five degrees of variation near the peak of the reflow profile curve. Therefore, even while the BGA Read more [...]