How much do you know about a single double-sided circuit board?

Single panel history:

Single-sided printed circuit boards were developed in the early 1950s with the advent of transistors and developed mainly in the United States. At that time, the main production methods were the direct etching of copper foils. From 1953 to 1955, Japan used the imported copper foil for the first time to make a paper phenolic copper foil substrate, and it was widely used in radios. In 1956, after the emergence of Japanese circuit board specialists, the manufacturing technology of single-panels quickly progressed. In terms of materials, the paper-based phenolic copper foil substrate was used as the main material. However, due to factors such as low electrical insulation of phenolic materials, poor solder heat resistance, and distortion, paper-based anisotropic resin, glass fiber epoxy, and other materials were successively used. The development of single-panels for consumer electronics machines currently uses almost paper-based phenolic substrate boards.

Single panel features:

The single panel is on the most basic PCB, the parts are concentrated on one side, and the wires are concentrated on the other side. Because the wire only appears on one side, we call this kind of PCB a single-sided board (Single-sided). Because single-board has many strict restrictions on the design circuit (because there is only one side, the wiring can not cross but must go around the unique path), only the early circuit use this kind of board;

The single-sided wiring pattern is mainly based on screen printing. That is, a resist is printed on the surface of the copper. After the etching, the mark is printed on the solder mask, and then the punching hole is used to complete the component guide hole. shape. In addition, some small and diversely produced products use photosensitive resists to form patterns.

Double-sided circuit board

Both sides of the Double-Sided Boards have wiring. However, to use two wires, it is necessary to have proper circuit connections between the two sides. This "bridge" between circuits is called a via. The via hole is on the PCB, filled with or coated with a metal hole, and it can be connected to the wires on both sides. Because the double-sided board is twice as large as a single board, and because the wires can be interleaved (wrap around to the other side), it is more suitable for use on circuits that are more complex than a single board.

Strictly speaking, the double panel is a very important kind of PCB in the circuit board. His use is very big. It is very simple to see whether a PCB is a double panel or not. I believe that my friends’ understanding of the single panel is completely acceptable. Grasping, the double panel is the extension of the single panel, meaning that the single panel of the line is not enough to go to the opposite side, the double panel has an important feature is that there is a through hole. The simple point is that the two-sided wiring, both sides have lines! One sentence is included: double-sided board is double-sided board! Some friends will ask, for example, a double-sided board, but only one side has electronic components. Is this board a double or single board? The answer is obvious. Such a board is a double-sided board, but only parts are mounted on the double-sided board.

The multi-layer circuit board simply distinguishes the circuit board according to the number of wiring surfaces to determine the difficulty of the process and the processing price. The ordinary circuit board is divided into single-sided wiring and double-sided wiring, commonly known as single-panel and double-panel, but high-end electronic products, because of products Space design factors, in addition to the surface wiring, can be stacked inside the multi-layer circuit, the production process, after making each layer of the line, and then through the optical device positioning, pressing, so that multi-layer circuit is superimposed on a circuit board. Commonly referred to as multi-layer circuit boards. Any circuit board that is greater than or equal to 2 layers can be called a multilayer circuit board. Multilayer circuit boards can be divided into multi-layer rigid circuit boards, multi-layer hard and soft circuit boards, and multi-layered hard and soft circuit boards.

The rise of multi-layer circuit boards due to the increased packaging density of integrated circuits has led to a high concentration of interconnects, which makes the use of multi-substrates necessary. Unpredictable design issues such as noise, stray capacitance, crosstalk, etc. occur in layout layout of printed circuits. Therefore, the PCB design must aim to minimize the length of the signal line and avoid parallel lines. Obviously, in a single panel, or even a double panel, these requirements cannot be satisfactorily answered because of the limited number of crossovers that can be achieved. In the case of a large number of interconnects and crossover requirements, to achieve a satisfactory performance of the circuit board, the board must be expanded to more than two layers, and thus a multilayer circuit board emerges. Therefore, the original intention of manufacturing a multilayer circuit board is to provide more degrees of freedom for selecting a suitable wiring path for complex and/or noise-sensitive electronic circuits. The multilayer circuit board has at least three conductive layers, two of which are on the outer surface, and the remaining one layer is synthesized in the insulating board. The electrical connection between them is usually achieved through plated-through holes in the cross section of the circuit board. Unless otherwise specified, multi-layer printed circuit boards, like double-sided boards, are generally plated through-hole boards.

Multiple substrates are manufactured by stacking two or more circuits on top of one another with reliable, pre-established interconnections between them. Since drilling and electroplating have been completed before all layers are laminated together, this technique has violated the traditional manufacturing process from the very beginning. The innermost two layers consist of traditional double panels, while the outer layers are different. They consist of separate single panels. Prior to rolling, the inner substrate will be drilled, plated through holes, patterned, developed, and etched. The outer layer that is drilled is a signal layer that is plated in such a way that a balanced copper ring is formed on the inside edge of the through hole. The layers are then rolled together to form a multi-substrate that can be interconnected using wave soldering (between components).

Rolling may be done in a hydraulic press or in an overpressure chamber (autoclave). In a hydraulic press, the prepared material (for pressure stacking) is placed under cold or preheated pressure (a material with a high glass transition temperature is placed at a temperature of 170-180°C). The glass transition temperature is the amorphous, polymeric (resin) or partially amorphous region of the crystalline polymer that changes from a hard, rather brittle state to a viscous, rubbery temperature.

The multi-substrate is put into use in professional electronic equipment (computers, military equipment), especially in the case of weight and volume overload. However, this can only be achieved by increasing the cost of the multi-substrate to increase the space and reduce the weight. Multi-substrates are also very useful in high-speed circuits. They can provide designers of printed circuit boards with more than two layers of planes to route wires and provide large ground and power areas.