PCB Technical - PCB copy board, circuit board and schematic diagram

PCB copy board is also called circuit board copy board, so what is a circuit board and what is a circuit board PCB copy board? And what is the relationship between the circuit schematic and the circuit board and PCB copy board?

To be precise, the circuit board is an insulating substrate on which components such as pads, vias, copper mold wires, marked text, and mounting holes are placed. The pins of the components are soldered to the circuit board through the pads. The plates are connected by copper mold wires, and the bolts pass through the mounting holes to fix the circuit board.

The circuit board is composed of an insulating board and a conductive copper mold covering the board, and the copper mold plays the role of connecting wires. In the early days, the insulating materials of circuit board substrates were mainly bakelite boards, but now epoxy resin boards are the majority. The development trend is that the thickness of the boards is getting thinner and thinner, the toughness is getting stronger, and the number of layers is increasing.

According to the wiring level of the circuit board, it can generally be divided into three categories: single-layer boards, double-layer boards and multi-layer boards. For redundant multi-layer boards, the manufacturing technology of 4-layer boards is relatively mature, while circuit boards with 6-layer boards or more are generally only used in some advanced equipment due to the complicated process and high cost. With the continuous advancement of technology, more circuit boards up to nearly 30 layers have also begun to be applied.

Know the circuit board, and then come to know the circuit schematic diagram. The so-called circuit schematics refer to the drawings that describe the electrical connection relationship between the components in the circuit. It does not involve the specific size and shape of the components, but only cares about the type of the components and the electrical connection relationship between them. Circuit schematics usually include two basic elements, electrical components and link networks. Electrical components are the main part of the circuit schematic diagram, including resistors, capacitors, diodes, operational amplifiers, etc., and in the circuit schematic diagram, these electrical components only include the outline symbols of the parts, the serial numbers of the components and the components There are three types of information, but there is no other information such as the physical shape of the component, the size of the component, the distance of the pad and the position of the pad. In fact, this information is generally reflected in the circuit layout (PCB file diagram). In the circuit schematic diagram, the network connecting the components is the wire connecting the electrical nodes of each component. These wires describe the electrical connection relationship between the components and are the embodiment of the designer's design thinking.

Circuit boards and circuit schematic diagrams are deeply related to PCB copy board. PCB copy board means that on the premise that there are physical objects of electronic products and circuit boards, reverse analysis of the circuit board by reverse research and development technology is used to analyze the original There are product PCB files, bill of materials (BOM) files, schematic files and other technical files and PCB silk screen production files for 1:1 restoration, and then use these technical files and production files for PCB manufacturing, component welding, and flying. Needle test, circuit board debugging, complete copy of the original circuit board template. Since electronic products are composed of various types of circuit boards, the core control part performs work. Therefore, the use of a process of PCB copying can complete the extraction of a full set of technical data of any electronic product and the imitation and cloning of products.

It can be seen from the above definition that PCB copy board is the reverse design process of the circuit board, and it is also the reverse reasoning process of the circuit schematic diagram. Because the existing circuit board first has the circuit schematic diagram, and then is designed and implemented according to the circuit schematic diagram, while the PCB copy board is the reverse analysis of the circuit board that has been designed and implemented, and the PCB layout file and circuit are re-analyzed. The schematic file is deduced. Interconnection and influence among the three.