Problem Description

As shown below, the drill layer might appear shrunk into a small corner or the distribution of the drill holes might be abnormally large. This indicates that the drill file has not been correctly parsed.

Analysis of the Cause

Most original drill file formats are not fully standardized. In JLCPCB’s DFM system (including the ordering system), drill file format analysis is required. Drill holes need to align with the pads on the copper layer (typically referring to pads, but also including vias) to confirm the drill file format is correct.

In extreme cases, automatic alignment may not be possible due to the following factors:

· The PCB is very simple, containing only NPTH (non-plated through holes) with no corresponding pads on the copper layer to verify the format.

· The copper layer has pads, but these pads are not standalone objects. Instead, they are formed by small line segments, making it difficult to capture the center point. The example above is a case of this issue, with a wireframe view shown in the image below.

Solution

For the case shown above, our recommended solution is to design the original pads so that each pad is a single object, typically circular or rectangular. It’s not necessary for every pad to be like this, achieving this for about 80% of the pads is sufficient to ensure alignment. Usually, designing all via pads as circles will provide enough information for alignment to succeed.

Note: If not intentionally designed otherwise, most EDA software outputs Gerber files without these issues. If you are using a less common EDA software and encounter this problem, it is advisable to find out how to avoid it.