Precision PCB Fabrication, High Frequency PCB, High Speed PCB, Standard PCB, Multilayer PCB and PCB Assembly.
The most reliable PCB custom service factory.
PCB Tech
How to solve the problem of circuit board production process
PCB Tech
How to solve the problem of circuit board production process

How to solve the problem of circuit board production process

2021-11-11
View:114
Author:Jack

In the production process of pcb boards,
        First of all, the CAM data of the pcb board generated by CAD must be transmitted to the pcb board manufacturer. The pcb board manufacturer uses the CAM 1 data editor to check and edit the film data, hole data, etc.
Add reference marks, correction values, etc. or perform data synthesis required for the production of pcb boards. For example 1, check whether the distance between the pad and the aperture is reasonable
The pads are usually tin-plated, and the plug-in holes are hollow. As can be seen from the pcb design, the pad is ring-shaped.

pcb board manufacturer

         A few tenths of a millimeter in the PCB design process is all right, but in fact, manufacturers need to have a minimum width standard, and the width design is too small to be done. On top of the usual design standards, the actual production standards of the pcb board manufacturer need to be used to calibrate the design standards.
PCB board production process
       For example, the minimum width of the pad: some manufacturers can achieve a minimum width of 0.2mm, and some manufacturers can achieve a minimum width of 0.25mm. If 0.2mm is required, the formation of a pad cannot be guaranteed. For example 2, check the distance between the window opened on the solder mask and the pad.
Usually, a layer of green film texture on the pcb board is the solder mask. As the name suggests, the solder mask cannot be soldered normally.
      The window of the solder mask is usually designed to be larger than the diameter of the pad. This is to maintain a certain distance between the window and the pad.
      It is usually set to 0.2mm, so that even if a certain error occurs on the board, the solder mask will not cover the pad, resulting in poor soldering. Example 3, check the minimum width of traces and the minimum spacing of traces. The usual process can achieve the minimum width and minimum spacing of 0.2mm, respectively. When it is smaller, a special process is required. Only the minimum standards that manufacturers can achieve under normal circumstances are introduced here. Example 4, check the minimum distance between the edge of the pcb board or the non-tin plated through hole (NPTH) and the trace.
       The minimum distance between the edge of the pcb board and the trace is usually set to 1mm (0.5mm if necessary, not recommended) to prevent the trace from being split when the pcb board is divided.
Set to 3mm. When using a machine to solder components to the pcb board , due to the limitations of the actual machine itself, it can avoid damaging the traces near the edge of the pcb board .
        The outline line of the pcb component (indicated by silkscreen) is usually kept at a distance of more than 1mm from the edge of the pcb board (except for the components whose positions are specified in the design).
The pad of the component and the edge of the pcb board should be kept at least 1mm, usually 3mm to 5mm. In addition to preventing cracking, it also reduces the fatigue caused to the pad and prevents the pad from falling off the pcb board due to relative stress.
      The minimum distance between non-tinned holes (NPTH) and traces is determined by the use of non-tinned holes.
Normally, the distance between the component through hole and the trace is usually set to 1mm or more (if necessary, it can be set to 0.5mm, not recommended), and for the M3 screw hole, it is usually specified that wiring is prohibited within 10mm in diameter and components are placed. Prevent metal screws from touching the traces and causing short circuits.

Note: The above minimum setting is the design standard of the pcb board , not the setting value of CAM. All of the above inspections can be automatically carried out by setting CAM 3. When the inspection and correction work is completed, data for various processing devices can be generated.
Remark:
1. CAM: Computer Aided Manufacturing
2. The pcb design standards mentioned here are on top of the unwritten standards in the industry, which I delineate in the design. Readers need to refer to the standard of the pcb board manufacturer in the PCB design to develop their own design standards.
The old people say it well, no rules can't make a circle.