Common Design Issues and Recommendations for PCB Optimized Design

To help customers avoid common issues that may arise during the PCB production process due to design problems, we' ve summarized the most frequent cases below. These issues have been detailed on our website to assist customers in identifying and addressing them more effectively. The following points include important design considerations and suggested modifications:

1. Missing Slots, Cutouts, Millings and V-Cut

Issue: Missing Slots, Cutouts, Millings and V-Cut due to improper design.

Recommendation: Ensure Slots, Cutouts, Millings and V-Cut are designed on the same outline layer. If there are multiple outline layers, prioritize the mechanical layer with the smallest number.

For more details, refer to our [ordering instructions]

Note: The mechanical layer should take precedence over the keepout layer.

2. Gold Finger Chamfering Issues

Issue: Gold fingers do not have the required chamfered edges.

Recommendation: Ensure that the gold fingers are designed at the board edge and that there is adequate clearance from traces to prevent damage during chamfering. The chamfering principle is illustrated below.

For further details, refer to our guide on [gold finger chamfering]

3. Mirrored Single Sided PCB Designs

Issue: Mirror image processing on single sided boards.

Recommendation: For single layer of Aluminum and Copper Core boards, ensure that the copper, solder mask, and silkscreen are all correctly designed on the top layer. In production, to avoid burrs and spikes, mirrored designs may be used, but this won' t affect the final design structure. Please note that our FR4 single sided boards are limited to one copper layer, one solder mask layer, and two silkscreen layers (depending on the customer's design).

4. Gerber Viewer Accuracy

Issue: Discrepancies between Gerber Viewer and the actual production file.

Recommendation: The Gerber Viewer is for reference only and may not guarantee accurate representation. It is crucial to choose the "confirm production file" option before submitting your order. For details on confirming production files, please refer to the [confirmation guide].

5. Mismatch Between Gerber Files and Hole Attributes

Issue: Holes not matching Gerber file attributes, such as plated versus nonplated.

Recommendation: Ensure that hole attributes are consistent with the Gerber file to avoid issues during production.

Please refer to the example below. The holes is designed as plated in Gerber file, but the properties are defined as non-plated.

6. Incorrect Barcode or Serial Number Placement

Issue: QR codes and serial numbers placed randomly or incorrectly on the board.

Recommendation: QR codes should be designed in the silkscreen layer as solid blocks (5x5, 8x8, or 10x10 mm). If both QR codes and serial numbers are selected, only the QR code needs to be designed, and the serial number will automatically be placed beneath it. Ensure the design aligns with order options to prevent discrepancies. For detailed instructions, see [this link].

7. Via Covering Issues

Issue: Failure to cover vias in certain conditions.

Recommendation: Vias will be not plugged if they have single or double-sided pad openings; ≤0.35mmdistance from pads cannot be plugged. For more information on via covering, refer to [this article].

8. Short Circuit Detection

Issue: Short circuits due to improper DRC (Design Rule Check) settings.

Recommendation: Use DRC during design to automatically detect potential design errors when designing. However, be aware that different design rules may have varying results.

9. NPTH Not Properly Designed

Issue: NPTH not properly isolated from copper traces, causing short circuits.

Recommendation: Leave at least 2mm clearance between npth and copper traces to prevent short circuits. Review this incorrect design example for reference.

10. Discrepancies Between Gerber Files and Order Options

Issue: Tented vias produced despite selecting untented options (or vice versa).

Recommendation: Ensure that order options align with the Gerber files to avoid mismatches during production. In case of any conflict between the options and the files, we will follow the Gerber files you provided.

11. Important Ordering Notes

1. If you do not want the order number printed on your PCB, select the "remove mark" option.
2. When choosing "panel by customer," please upload the panelized file instead of the single board file.
3. Special stencil thickness requests can be noted in the remark section.
4. Aluminum PCB is single sided only.
5. Ensure that the layers in your Gerber files match the selected options.
6. Castellated holes: If your design includes castellated holes, please select this option in the order. If not selected, we assume you accept the potential risks, such as copper traces being incomplete. Additionally, the minimum size for castellated holes is 10*10mm.

12. Overlapping Drills and Slots

Issue: Overlapping drills and slots can cause production issues.

Recommendation: Ensure that drills do not overlap with slots or use the remark section to specify which layer should take precedence. If there is any overlap in the outline layer, we will prioritize the smaller dimension for processing; If both of them are in the drill layer, we will use the bigger one; While if one of them is in the outline layer, the other is in the drill layer, we will make the size according to the one in the outline layer, and make the attribute according to the one in the drill layer.

13. Breaks in Process Edges or Connection Points

Issue: Process edges or connection points breaking during production due to insufficient mechanical strength.

Recommendation: Increase the width of the process edges or add more connection points. For SMT assembly, we recommend a process edge of 5 mm, 2 mm tooling holes, and 1 mm fiducials placed 3.85 mm from the panel edge.

For more information, refer to our [specifications].

14. Layer Naming Standards

Issue: Inconsistent or incorrect layer names leading to misinterpretation during manufacturing.

Recommendation: Follow standardized naming patterns for layers to improve recognition accuracy.

A guide to suggested naming patterns is available [here]

15. Stencil Opening Mismatch

Issue: The stencil openings do not match the pads for soldering.

Recommendation: Stencils are created based on the solder paste layer and not the solder mask or other layers. Double check your design to ensure proper alignment.

Important Reminders:

1. Testing: Always test your PCB before soldering components to prevent further damage.

2. Order Confirmation: Please carefully check your Gerber file and confirm the production files before proceeding your order.

3. Return Process: Save your boards and packages until the customer service issue is resolved.

4. Logistics Claims: If your PCB arrives damaged due to shipping, initiate a claim and provide photos of the packages and damaged boards.

5. Please note that we only accept complaints based on the original order. Therefore, we strongly recommend inspecting the first batch of PCBs upon arrival to ensure there are no issues before placing a re-order. This will ensure a safer and smoother process.

6. IPC 2 Class Standard: Our production quality follows the IPC 2 Class standard, and products within this standard are acceptable. Complaints based on this standard will not be accepted.

7. Design Validation: We do not verify design errors in Gerber files. Please ensure thorough checks before submitting.

8. Updates: Customer feedback may result in updates to our website. Please stay tuned for any changes.

By following these guidelines and reviewing the provided resources, you can significantly reduce the occurrence of production issues and ensure a smoother PCB manufacturing process.