Custom Backdrilled Multilayer PCB with 2 to 64 Layers, 16:1 Aspect Ratio, and ±5% Impedance Tolerance

Custom Backdrill PCB (Stub Removal)

Huayihai fabricates custom backdrilled PCBs for high-speed designs. Backdrilling removes the unused portion of a plated through-hole — the stub — after lamination, so backdrilling removes the unused portion of a plated through-hole after lamination, reducing the reflections and signal degradation caused by via stubs in high-speed channels.

Backdrilling supports cleaner impedance behavior on high-speed channels and is often specified together with controlled impedance and thick boards, where long through-holes create the largest stubs. Huayihai backdrills boards on 2 to 64 layer stack-ups with aspect ratios up to 16:1, under IPC-A-600 workmanship standards.

Custom Manufacturing Only

We fabricate backdrilled PCBs according to customer Gerber files and technical specifications. We do not supply ready-made or standard stock boards.

Product Specifications

Key Features

• Removal of unused via stubs after lamination

• Cleaner signal integrity on high-speed channels

• Available on 2 to 64 layer stack-ups with aspect ratios up to 16:1

• Combined with controlled impedance at ±5% tolerance

• Applied to connector and backplane style through-holes

• Manufactured under IPC-A-600 workmanship standards

Manufacturing Highlights

Backdrilling is a controlled-depth drilling step performed after plating, so the remaining stub length depends on depth control relative to the target layer. Huayihai manufactures backdrilled PCBs according to customer stack-up requirements and designated backdrill depth specifications.

Key fabrication elements include:

• Stack-up and backdrill depth scheme review

• Plated through-hole formation before backdrilling

• Controlled-depth backdrilling of designated holes

• Visual and cross-section inspection of drilled holes

• Impedance verification where high-speed channels require it

• 100% electrical testing before shipment

Typical Applications

Backdrilled PCBs serve designs where stub effects degrade high-speed signals:

• Backplanes and Connector Interfaces

• Communication and Data Transmission Equipment

• High-Speed Digital Boards

• Test and Measurement Instruments

• Industrial Control Systems

• Other High-Speed Applications

Why Choose Huayihai

• Over 20 years of PCB manufacturing experience

• Backdrilling available on stack-ups up to 16:1 aspect ratio

• Supported by ±5% impedance control capability

• Quality management based on ISO 9001, ISO 13485, IATF 16949 and UL

• IPC-A-600 workmanship standards

• Prototype, low-volume, and mass production support

Manufacturing Process

• Gerber file and stack-up review 

• Lamination and plated through-hole formation

• Outer layer imaging and plating

• Controlled-depth backdrilling of designated vias

• Solder mask and surface finish

• Electrical testing and final inspection

FAQ

Q1: What does backdrilling do?

It removes the unused portion (stub) of a plated through-hole so high-speed signals pass through a cleaner path.

Q2: Which boards need backdrilling?

Typically thick, high-layer-count boards with high-speed channels in connectors and backplanes.

Q3: What aspect ratios can be backdrilled?

Stack-ups up to 16:1 aspect ratio.

Q4: Does backdrilling work with controlled impedance?

Yes, backdrilled boards are commonly built with controlled impedance at ±5% tolerance.

Q5: What is the standard lead time?

3–5 working days for PCB prototypes and batches, after file review is complete.

Q6: What information is needed for a backdrill PCB quotation?

Gerber files, stack-up information, and designated backdrill requirements help us prepare an accurate quotation.

Q7: Can backdrilling be combined with HDI?

Yes. Backdrilling can be applied to multilayer and HDI designs where specified by the customer.

Request a Quote

Need backdrilled PCBs for cleaner high-speed channels?

Send us your Gerber files and stack-up details for a quotation. Learn more at nexuspcba.com.