The design of a PCB circuit board mainly includes defining product requirements, designing PCB hardware system, device selection, PCB drawing, PCB production proofing, welding debugging and other steps. So what are the points to pay attention to in these steps? Xiaobian takes you fine, be sure to be fine!
First, clear demand
At the beginning of a hardware PCB design, the first thing to do is to define the product requirements, including the functional requirements and shape. The main functions need to be defined, and a few additional functions can be added later, but the main functions of the product should not be affected. The determination of product shape is very important, which will affect the later PCB drawing and component selection.
Second, the hardware system design
In hardware design, the power supply mode, sensor type, communication mode, man-machine interaction mode and reserved interface of the product should be determined according to the functional requirements of the product. Generally, Visio can be used to draw the block diagram of the system. The block diagram of the system should be able to describe the relationship between each module circuit of the hardware system and the components of the whole system.
III. Device Selection
In the stage of device selection, it is necessary to select related devices according to their own product functions, generally including the selection of power supply, main control, sensor, communication, storage and other chips. Type selection needs to consider the function, price, supply and other factors of the chip to choose a chip suitable for your own product. The channel of chip selection can be compared by large-scale chip electronic component malls such as Lichuang Mall, Yunhanxin City and Dejie Electronics.
Iv. PCB drawing
PCB drawing involves EDA software of PCB design. At present, the mainstream PCB design tools used by engineers and technicians engaged in circuit design in China are Allegro, PADS and Altium Designer. Altium Designer is recommended for beginners, and there will be more tutorials online.
V. PCB production proofing
After the PCB is designed, you can go to the PCB manufacturer for proofing. Before production, you need to provide the manufacturer with production documents, and one is to directly provide the PCB documents. This method will risk the product being leaked, so it is safer to provide gerber documents. The sample proofing price is generally 50-100 yuan, and the delivery time is generally 24 hours. Of course, the special PCB will be different. It is recommended to go to Huaqiang PCB, Jialichuang, Jiepei and other manufacturers for proofing, so as to avoid abnormal debugging in the future due to PCB production problems. This situation will lead you to doubt life later.
VI. Welding test
And PCB components are in place, you can weld. The necessary tools for welding: soldering iron and air gun. As for tweezers, it depends on the technology. Generally, welding is divided into direct manual welding and steel mesh welding. Welding directly tests the craft, and it doesn’t look good when welded. If you brush the steel mesh for welding, you can place a steel mesh order together when producing PCB. Generally, a steel mesh is 50. After using the steel mesh to brush the solder paste, put it on the computer if possible, and put it on the hand if not. Set a stove for reflow soldering, or blow it with an air gun.
