Before starting the PCB assembly process, the PCBasic engineering team will carefully review each customer's assembly file. Incomplete or unclear information is the main cause of production delays or assembly errors.
Below, we have listed 15 common file issues and their corresponding solutions. We hope that after reading this, it will help you complete the production more quickly and accurately.
1. Incomplete or missing files
If there is no silkscreen layer, assembly drawing or surface mount coordinate file in the Gerber file, production cannot commence.
Therefore, please make sure to provide the complete Gerber files, BOM, surface mount coordinate files (XY data), and assembly drawings (in PDF or image format).
2. Silkscreen is too messy or unclear
When the text overlaps or the silkscreen is blurry, it becomes difficult to identify the positions of the components.
So, please keep the silkscreen clean and tidy, avoid overlapping, and remove any unnecessary text or icons.
3. Missing component identification in silkscreen
Without reference numbers, we will be unable to determine the installation location of the components.
Hence, please ensure that each component has a unique and clear silkscreen marking (such as R1, C5, U2, etc.).
4. The coordinate file lacks identifiers
If the component numbers are not provided in the soldering paste file (XY file), the machine will be unable to perform the soldering process.
Thus, please provide the complete XY coordinates, rotation angle, and the corresponding component number.
5. The coordinate files on the top and bottom sides are mixed together.
Putting the data from both sides in one file will cause confusion.
So, please provide the soldering files for the Top layer and the Bottom layer respectively.
6. Lack of polarity or direction marking
Without clear polarity identification, components such as LEDs, ICs, diodes or capacitors may be installed in the reverse direction.
Therefore, please add the symbols “+”, “–” or “Pin1” in the silkscreen layer or the assembly diagram. If you do not want them to be printed on the PCB, you can also mark them separately in the PDF assembly diagram.
7. BOM does not match the coordinate file
Some component numbers in the BOM cannot be found in the soldering file.
Hence, please confirm whether these components are DNP (non-assembly) or update the soldering file to be consistent.
8. Inconsistent component parameters or models
The parameters in the BOM do not match the part numbers or supplier information.
Therefore, please verify the parameters, packaging and models of all components to avoid any purchase errors.
9. Inconsistent quantities
The quantities listed in the BOM do not match the actual quantities as designed.
So, please verify the quantities according to the actual design and update the BOM in a timely manner.
10. The BOM identification does not match the silkscreened number.
For instance, in the BOM it is "X2", but on the PCB the silkscreened number is "X6".
Thus, please make sure that the component numbers in the BOM, silkscreening and coordinate files are all consistent.
11. Incorrect naming rule
If resistors start with "C" and capacitors start with "R", it will cause confusion. Please use the standard naming convention:
C = Capacitor R = Resistor L = Inductor D = Diode U = Integrated Circuit Q = Transistor
12. The LED lacks color or parameter information
If the color, brightness or brand of the LED is not specified in the BOM, it is impossible to make an accurate purchase.
Please fill in the color, brand, voltage and package type of the LED in the BOM.
13. Duplicate component numbers appear in the BOM
The repetition of component identifiers may lead to missed installation or duplicate assembly.
Please remove any duplicate items and ensure that each component number appears only once.
14. Incorrect coordinate file format
Some coordinate files have inconsistent units (using both inches and millimeters), or the rotation angle is incorrect.
Please clearly specify the coordinate unit (mm or inch) and the rotation angle format (0–360°). Incorrect format may also cause component misalignment.
15. For components without specified special elements or those requiring manual soldering
Some components (such as connectors, large inductors, sensitive switches, etc.) need to be soldered manually, but this has not been stated in the document.
Please indicate "Hand soldering" or "Do not apply solder paste" in the BOM or remarks section.
If you are unsure whether the file is complete or meets the production requirements, please contact us. We will review and optimize it for you before production.
