The accuracy of PCB copy boards generally depends on two important links in the PCBA processing and production process of patch processing plants. One is the accuracy of the pcb circuit board software, and the other is the original pcb circuit board. Image precision. According to the current understanding of various PCB copy board companies in the industry, the technical capabilities of PCB copy board accuracy cannot be unified. Strong, the accuracy of PCB copy board can reach below 1mil, so how should the patch processing factory control the accuracy of PCB copy board?
For software precision, 32-bit floating-point representation is usually used, so it can be said that there is no precision limit, so the most important thing is to depend on the image precision of the original scan. For example, a 1-megapixel photo, a 5-inch photo can be washed out, but if you want to make a 20-inch photo, it will not be clear at all. The reason is actually the same, so for a pcb circuit board that requires high precision, if you want to copy a very high-precision pcb diagram, choose a higher DPI when scanning.
DPI means how many dots per inch, it can also be said that the distance between every two points on the scanned image is 1000/DPI, and the unit is mil. If the DPI is 400, then the distance between two points on the image is 1000/400=2.5mil, that is to say, the accuracy at this time is 2.5mil. This is the most scientific basis, so some people in the industry say that the accuracy can reach less than 1m, and this is all premised. In fact, the accuracy of PCB reproduction mainly depends on the scanning accuracy of the original.
To sum up, when the pcb board manufacturer smt technology sets the DPI when scanning the board, it depends on the accuracy required by the actual board. It should be set above 1000DPI. The scanners on the market can fully meet this condition and meet the standard requirements.
The higher the DPI, the clearer the picture of the pcb circuit board, and the higher the precision of the pcb circuit board, but the disadvantage of DIP is that the picture is too large and requires high hardware, so it should be set according to the specific situation; the circuit board usually uses 400DPI to meet the standard Conditions, the mobile phone PCB circuit board can be set above 1000DPI.