printed circuit boards (PCBs) are made of non-conductive substrates coated in conductive laminate copper sheets. The substrates used in PCB are mainly divided into two categories: organic substrates and inorganic substrates. Among them, the organic substrates are made of several types of materials which refer to the reinforcing materials, such as glass fiber cloth, fiber paper, glass felt, etc. These reinforcing materials are impregnated with resin adhesive and dried, then covered with copper foil at high temperature and high pressure. This type of substrate, known as copper clad laminate (CCL), is the main material used to make PCB.
Because of the complex systems PCBs ultimately manage and serve, they have to be carefully built and tested. Part of this process includes the manufacture of a PCB prototype—a model that can be tested as a stand-in for the eventual product—that is used to look for design, mechanical, and electrical flaws. Although PCB prototypes are used in testing, there are differences in the way they are manufactured, the purposes they serve, and the materials used.
Plastic PCB Prototyping Techniques
Many industrial manufacturers include prototyping machines as part of their production line, but before a prototyping machine can be incorporated it’s critical to examine the process and what kind of material best suits an application. Several different materials and processes are available for PCB prototyping. Plastic is a commonly used material because it is easily cut and manipulated in ways the prototyping process demands.
When plastic is used, the prototyping process can employ rapid prototyping processes. Rapid prototyping processes create individual parts based on a computer generated model, and then layer each part to produce the final component. Common techniques include stereolithography, deposition modeling, laser sintering, and three dimensional printing.
Rapid prototyping is beneficial to manufacturers because it generates a prototype printed circuit board in a short amount of time, enabling the production process to progress at a fast pace. Once the plastic prototype is created, it can then be used to test for strength, durability, and aesthetics, and can also withstand drop testing and sterilization. Because rapid prototyping means a new model can be made quickly, any changes to the prototype can be reincorporated into the design and a new prototype can be generated.
Although plastic prototyping starts off as a cost effective option, production costs may increase with each set of improvements to the new model. In some cases, metal molds can be used with rapid injection molding, which can create sturdy plastic components from an array of resins. The parts themselves can withstand the same kind of testing as a rapid prototyping formed component.
Materials of CCL:
Copper foil is a cathodic electrolytic material deposited on a thin, continuous layer of metal foil on the base of the circuit board. It is easily bonded to an insulating layer, accepting a printed protective layer, and corroded to form a circuit pattern.
A prepreg (from pre-impregnated) is fibreglass impregnated with resin. The resin is pre-dried, but not hardened, so that when it is heated, it flows, sticks, and is completely immersed. Prepregs are thus fibreglass strengthened by an adhesive layer (similar to FR4 material). The name of each prepregs derives from the type of fibreglass used.
The prepreg types of different suppliers vary in thickness; in addition there are the versions "SR" Standard Resin, "MR" Medium Resin "and" HR "High Resin, depending on the resin content. The best possible material is used depending on the desired final thickness, layer structure or impedance. The mentioned thicknesses are thus to be considered only as examples. If you have any problem, please contact us---PCBWay for technical advice.