/What information do we need to prepare for PCB assembly?
PCB assembly preparation is mainly about preparing all kinds of process documents used in circuit assembly. It mainly includes product technology process documents and work documents needed to organize production. The former is divided into two categories: one is based on projection relationship drawing, used to explain the requirements of product processing and assembly, parts, printed circuit board assembly drawings, etc. The other is based on graphic symbols drawing, used to describe the design content of the circuit. Such as system diagram, block diagram, circuit diagram, wiring diagram and so on.
1. block diagram
A block diagram is a diagram with annotations that outlines the basic composition, interrelationship and main features of an electronic product. The “box” in the block diagram represents a functional block, and the “wire” represents the route or sequence of signals passing through the circuit.
2. schematic diagram of circuit
Circuit schematic diagram, also known as electrical schematic diagram, electronic circuit diagram, it is the product of the components in order to arrange the drawings. Circuit schematic diagram does not consider the actual position of components, does not represent the shape and size of each component, it is drawn on the basis of circuit block diagram, is the basis for design, wiring and product performance analysis and maintenance.
The drawing of circuit schematic diagram requires accurate, beautiful and reasonable layout. The input signal is usually on the left side, the output signal is on the right side, and the symbols of the components conform to the drawing requirements. The same component symbols are numbered from left to right or from top to bottom. The wires between the components in the circuit diagram represent the wires, and the joints of two or more wires are marked with (solid point). It means that two or more wires should be crossed but not connected. In the circuit diagram, the “floor” is represented by the symbol “X”, and all the “Earth” must be connected by wires.
3. supporting materials list
The supporting materials list is a list of the names and specifications of the materials needed for electronic products. Quantity and no device code forms for procurement and assembly.
4. schematic of parts and components
The schematic diagram of the components includes printed circuit board assembly diagram and chassis panel sketch.
(1) printed circuit board assembly drawing
PCB assembly drawing is a drawing that shows the connection relationship between components and parts and PCB. It is suitable for assembling and welding PCB process drawings.
The circuit schematic diagram and the actual circuit board are connected by the PCB assembly diagram. It is an indispensable diagram for electronic assembly and maintenance. It is sometimes used to test and repair to find the position of components.
(2) schematic diagram of chassis panel
The schematic diagram of the chassis panel is an illustration showing the installation of various components in the chassis panel. Since the superheterodyne radio is a simple electronic product, there is no schematic diagram of the chassis panel.
For complex electronic products, the technical process documents also include wiring diagram and wiring table, which are not explained here.
5. wire drawing
For the connection of uncomplicated electronic products, it should not be necessary to tie the wires, but for complex products, because there are more connecting wires, the connection is complex, not easy to find or affect the aesthetic, it is generally required to draw the line tie.
6. assembly diagram of the whole machine
The assembly diagram of the whole machine points out the assembly position and the overall appearance of the parts.
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