Universal printed boards are intended for prototyping electronic circuits and for experimental verification of circuit concepts. They are also used for the production of unitary electronics. Universal boards also allow you to create adapters between chips in SMD and THT packages. Mostly they are intended for soldering components, but in addition there are contact versions with spring clips designed for hobbyists.
The assortment of available universal PCBs is very wide. PCBs differ mainly in size: from rectangles with a size similar to a postage stamp, to large PCBs with a side length of several dozen cm. There are also round versions focused on LED lighting applications. Other PCBs have the shape of Eurocards with an edge connector and are intended for prototyping computer cards. They are made of glass-epoxy and paper laminates with several thicknesses from 0.7 to 1.6 mm, in one-sided or double-sided version.
The mosaic of universal PCBs can consist only of soldering points with a raster adapted to the assembly of popular systems in DIP packages or with soldering points connected with paths along with power distribution lines. The holes are placed in a different raster and except the basic inch - 2.54 mm, there are also PCBs with holes arranged more densely (1.27 mm) or less frequently. PCBs with a metric raster can also be found. Other solutions have holes prepared for soldering joints.
Universal PCBs designed for assembly SMD components usually have mounting fields for popular housing sizes. Typically PCB has a pad system that enable to mount chips of different sizes.
Universal PCBs are also available in mixed versions. They contain both a field with a mosaic of holes without paths as well as a place for mounting the system in the SMD package. Most of the boards have paths coated with tin and solder mask.