What are Plated Half-Holes/Castellated Holes?

Plated half holes or castellated holes are holes made off the edge of the boards which are then plated with copper using a specialized process. The plated edges are useful in producing mini PCB modules, much like Seeed's own WiFi modules, which are soldered onto a larger board in a similar way to ICs. Seeed Fusion uses a high quality bespoke plating process to plate half holes, we do not just cut the holes out. This results in cleaner, smoother and stronger edges and no sharp burrs or deformation.

Plated half holes are available in both standard and Advanced PCB services. For the standard PCB service, the minimum diameter of castellated holes is 0.5mm. If you need smaller castellated holes (as low as 0.35mm), please use the Advanced PCB service. When "Yes" is selected f
or this option, the half cut holes on the edges of the board will be plated with copper.  


If "No" is selected, half holes will not be plated with copper.



How to indicate castellated holes on your design?

Add a via or plated hole directly on the outline of the boards where the plated half hole is required. Ensure that half of the via is on the board and half is on the outside of the outline.  

Due to the nature of the plating process, the plated edges must be on an outer edge of the panel. Please take this into consideration when panelizing your designs. For example, if a board has plated half holes on both left and right edges, then the boards can only be panelized on the non-plated edges (top and bottom). If a rectangular board has plated edges on all four sides then it cannot be panelized.

If there appears to be plated half holes in your design, but the option for castellated holes is not selected, we may contact you directly to confirm whether castellated holes are required.

Fusion Technical Support

  1. What is Gerber file?
  2. What are the PCB panelization rules?
  3. How to generate the Gerber (manufacturing) files?
  4. What is the correct way to draw the silkscreen on the bottom side?
  5. My PCB does not require Solder Mask, what should I do?
  6. My PCB does not require Drill Holes, what should i do ?
  7. Which layer should I use in EAGLE for milling?
  8. What is the depth and width of the v-cuts/grooves?
  9. I don't want silkscreen on my PCBs, how can I proceed with a PCB Assembly order?
  10. What are the dimensions for Dielectric Separation thickness?
  11. What is the thickness of the inner copper layers?
  12. What are Blind and Buried Vias?
  13. What is the The Min Track/Spacing for 1oz./2oz./3oz. Copper weight
  14. What are Plated Half-Holes/Castellated Holes?
  15. How do I design non-plated through holes?
  16. What PCB materials are available in Seeed Fusion?
  17. What is the thickness of Fusion PCB?
  18. What PCB surface finishes are offered in Seeed Fusion?
  19. What color options are available for the solder mask/resist?
  20. What is the PCB copper weight?
  21. What is Impedance Control?
  22. PCB quantity
  23. How to generate Gerber files from PCBE
  24. How to generate Gerber and Drill files from Eagle
  25. How to generate Gerber files in Altium Designer
  26. How to generate Gerber files from CircuitMaker
  27. How to generate Gerber and drill files from KiCad
  28. How to generate Gerber files from DipTrace
  29. How to generate Gerber files from Proteus
  30. How to generate Gerber files from DesignSpark
  31. How to convert drilling layer from Gerber to Excellon format in CAM350
  32. Recommend size for BGA
  33. Solder Mask Dam
  34. What is the difference between Fusion standard PCB and Fusion Advanced PCB?
  35. What should I do if my Gerber files are too big (over 4MB)?

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