Yleiskatsaus painettuihin piirilevyihin
Tässä artikkelissa luodaan yleiskatsaus painettuihin piirilevyihin, ja se sisältää artikkeleita materiaaleista, suunnittelukonsepteista ja testauspisteistä. Käyttämällä esimerkkien ja tapaustutkimusten yhdistelmää lukija voi ymmärtää piirilevysuunnittelun perusteet ja niiden valmistusprosessin. Lisäksi siinä annetaan tärkeitä vinkkejä laadukkaiden piirilevyjen kehittämiseen.
Printed circuit boards
A printed circuit board is a flat composite board that has one or more layers of copper. The components are mounted on these pads and are soldered to them. Depending on their size and complexity, printed circuit boards can have one, two, or even multiple layers of circuitry.
Before a printed circuit board can be assembled, it must be designed and approved. This step is crucial because mistakes in a PCB design can cause the delivery of the product to be delayed. After the design is finalized, PCB fabrication will take place. It will typically contain copper, a dielectric material, a silkscreen, and a solder mask.
PCBs are chemical compounds with different properties. Once released into the environment, they do not break down readily, but remain there for long periods of time. In fact, they can even travel far distances, often being found in snow or seawater. While their widespread use has made them a concern for many, there is still much to learn about PCBs and their effects.
Some of the most common uses of PCBs include high-powered industrial machinery. These systems can handle high voltage and high currents. They can also be very lightweight and can fit into tight spaces. Another popular use is for LED lighting solutions. LEDs can be placed directly on a PCB, and the material can be bendable.
A PCB design concept is the basis for the creation of the circuit board for an electronic device. It defines the functions, features, interconnections, and placement of the electronic components. It also determines the approximate dimensions, temperature range, and environmental concerns. The final concept is a circuit schematic, which provides all the necessary information for an electrical device to function properly. The schematic includes component names, their values, ratings, and manufacturer part numbers.
PCB design is a complex process, and there are a number of important elements to consider. The layout of the circuit board is a critical consideration. If it is not done correctly, it can lead to electromagnetic interference or component conflicts. This can limit the function of the board, or cause it to fail altogether. It can also result in extra manufacturing time and costs.
Test points are conductive surfaces on the PCB that are used to verify the circuit’s functionality before mounting it. They can be solid copper circles, drilled pads, short wound pins, or offset leads that are connected to a component. Typically, test points are marked with a voltage and/or amperage value, which can be measured with a voltmeter.
A PCB may have a few test points, which are basically printed elements on the board. In some cases, the test point is a via that connects to an internal trace. Using a test fixture, a PCB designer can access these points during electrical testing. Various types of electrical tests can be performed on these points, such as continuity testing, in-circuit testing, or flying probe testing.
The multilayer PCC stack-up design is a complex topic with a tremendous amount of variation. While example stack-ups are not intended to meet critical requirements, they can provide designers with a helpful and easy-to-understand overview of the PCB build process and ensure consistent results.
A PCB’s dielectric properties are dependent on the type of dielectric material used in its construction. The more expensive PCBs generally contain high-end dielectric materials. However, PCBs can be manufactured using low-cost dielectric materials.
PCB designers may be asking themselves, “What is the Form Factor?” The form factor of a PCB refers to its physical properties, including the size of the board’s chassis, internal board configuration, mounting scheme, and more. There are a variety of different PCB form factors, so it’s important to know how each one will impact your design.
For example, 3.5 Inches boards don’t measure 3.5 inches; instead, they are larger than the drive they accommodate. This type of PCB is perfect for industrial PCs that are space-constrained and use a lot of SWAP. A board with this form factor can support up to four different interfaces.