The Backdrill PCB Leader in China

Backdrill PCB Needs? Count on PCBMay!

Backdrilling a PCB is a technical job. You need to make sure the one doing it is an expert. That is why you can trust PCBMay to make Backdrilling PCBs for you.

• Correct back drill diameter used
• The correct depth for PCB, considering PCB layers
• Correct measure for residual stub in the PCB
• The correct choice of circuit segment
• Use Altium or other design software to plan back drilling

Durability is very important once you have the Backdrill PCB finished. We can guarantee that our product will last you a long time because of our high standards. Unlike subpar manufacturers of PCBs, our circuit boards run less risk of defects. We only use raw materials that pass international certification.

What’s more? Our engineering team is composed of senior PCB experts. They have trained in the biggest companies known in the PCB manufacturing world. For sure, they are skillful in using design software for your Backdrill PCB needs. You can count on our competent crew.

If in the slight instance you detect a problem, we’ll get right down to it. We will give you a full 8D report so you can determine the root cause. After that, we will follow through to help you with additional concerns.

In case you need your order urgently, we also do Fast PCB. PCBMay only partners with reputable couriers so your Backdrill PCB will arrive on time.

Finally, we offer flexible payment terms, depending on your specific details. Kindly contact us, and let’s begin our business together.

Backdrill PCB: The Ultimate FAQ Guide

Are you struggling with durability and signal flow in multilayer printed circuit boards? Backdrill PCB will be the proper solution for you. It is a particular type of depth drilling where supreme control and skill are required.

Proper execution of PCB backdrilling improves the robustness and longevity of your electronic projects. PCBMay has been offering this service through expert technicians for an extended period. Do you have sufficient knowledge about backdrill PCB?

If not, this FAQ guide will be the best support for you. Let’s make a move to explore back drilling in PCB.

What Is Backdrill In PCB Fabrication?

Backdrill is a helpful technique for fortifying signal strength in PCBs having a high layer count. PCB back drilling or controlled depth drilling produces PCB vias by eliminating stubs of multilayer wiring board modules. Here, traditional numerically controlled drill equipment is applied for achieving accuracy.

It involves drilling a hole that’s diameter is a little bit larger than plated through-holes.

It develops signal flow between different PCB layers with supreme reliability and integrity. Usually, high-frequency PCBs get affected by excessive stubs. In this case, backdrilling improves the performance of these circuit boards by removing stubs.

Backdrilling a PCB is entirely a technical process. So, it is required to use correct design software and ensure suitable circuit design, dimensions of back drills, etc. Then, you can get the highest output from this process during PCB fabrication.

Watch this video to get a better knowledge about PCB backdrilling:

Backdrill In Printed Circuit Board Fabrication

Why Is Backdrilling Required For PCB Manufacturing?

Backdrilling is an essential issue for PCB manufacturing. Especially in high-speed multilayer PCBs, backdrilling is highly required. This process is applied to prevent signal attenuation caused due to stubs.

Signal reflection and signal loss are not desired in high-quality signal transmission applications. Backdrilling improves the signal quality by reducing EMI and crosstalk.  Besides, it is effective for promoting the durability and functionality of multilayer circuit board modules.

That’s why the implementation of backdrill PCB is a must choice in electronic devices where high-speed is a mandatory requirement.

Backdrilling In PCB Manufacturing

What Are The Backdrill PCB Specifications?

Backdrill PCB has improved the manufacturing quality of multilayer PCBs due to its outstanding features. The most noteworthy backdrill PCB specifications are-

• Compatible with multilayer (more than eight layers) circuit boards.
• A little bit larger than vias.
• Plated through-hole compatibility for large backdrill PCBs.
• Appropriate for rigid circuit boards
• Suitable board thickness is more than 2.5mm.
• Impressive depth tolerance of backdrilling. It is around 0.05mm.
• The lowest hole diameter is around 0.30mm.
• Properly measured residual stub. The stub length needs to be less than ten mills. Otherwise, it can cause signal reflections.

Backdrill PCB Specifications

What is Backdrill Via?

Backdrill via is a process of transferring signals between PCB layers with reduced signal attenuation. This process has taken the place of blind and buried vias in some cases due to its tremendous efficiency and low cost.

Backdrill PCB via is applied in multilayer circuits by decreasing the stub length. So, it is effective for preventing noise during signal flow.

Backdrill Via In PCB Design

What Are The Major Advantages Of Backdrill PCB Vias?

Backdrill PCB includes immense positive points to multilayer circuit board designs. That’s why its use in advanced electronic applications is continuously increasing. The significant advantages of PCB backdrilling are-

Reduced Bit Error Rate

Backdrill PCB offers error to a low extent. This is a technical task. So, you need to ensure that the technicians have expertise in this service. Skilled engineers can assure you of a reduced BER (Bit Error Rate) in printed circuit board applications.

Impedance Stability

Backdrill in PCB fabrication ensures impedance stability along with reduction of signal attenuation. This PCB feature promotes the quality of multilayer stackups in high-frequency PCBs.

Usually, you need to handle dielectric thickness, copper thickness, and trace width for achieving impedance matching. Backdrilling is an effective process of maintaining a smooth signal flow by taking care of these properties.

Low Design Impact

This process has minimal effects on PCB layout design. The designer enjoys enough flexibility to create vias without interfering with circuit board design. Thus, backdrill PCB is useful for optimum design accuracy in multilayer PCB designs.

Improved Bandwidth

It improves the channel bandwidth to a large extent. That’s why the signal transmission becomes more effective with superb integrity.

Flawless Signal Transmission

Backdrill in PCB manufacturing is supportive of high-speed signal transmission systems. It significantly increases the data transmission rate in high-frequency applications. Moreover, it has a significant impact on reducing signal resonance.

That means you can achieve excellent data propagation through PCB backdrilling. After processing a successful PCB backdrilling, the clock timing becomes more accurate. Again, jitter in signal flow is also reduced because of properly executed backdrilling.

EMI Reduction

Backdrill removes stubs in circuit boards. So, EMI or EMC radiation from the stabs in multilayer PCBs is reduced to a large extent. This feature promotes signal quality. Besides, it prevents crosstalks between PCB vias.

Effective Cost Performance

PCB backdrilling requires a low cost compared to sequential lamination in multilayer circuit boards. That’s why you can apply this effective process in high-volume PCB manufacturing at a large scale.

Moreover, Low expense enhances its compatibility with versatile electronic projects.  

Positive Sides Of Backdrill PCB

What Is The Process Of PCB Backdrilling?

PCB backdrilling is a computer-controlled technique. Backdrilling is performed in the last section of PCB manufacturing. Since it is a technical process, it requires high precision for achieving maximum output.

Based on your design requirements, you just need to tell the operator about the correct drilled hole diameter and drilling process. Then the operator chooses a program that determines the X-Y ordinate of drilled holes.

Using a suitable drilling method for PCB backdrilling is of great concern for PCB manufacturers. There are two popular types of drilling. Here, the drill size is slightly larger compared to the via size.

Mechanical Drilling

PCB backdrilling is usually conducted mechanically. This is comparatively easier to operate than laser drilling. Besides, mechanical drilling is cost-effective.

Laser Technology

Using the laser for PCB backdrilling is expensive and requires supreme accuracy. Otherwise, it causes considerable complications in PCB functionality. But, if you can execute laser backdrilling properly, you can assure of getting the highest output.

Backdrill PCB manufacturing has a little bit of complexity than other PCB lamination processes. But, it can deliver the best result in terms of signal flow and functionality in advanced electronic appliances.

Process Of PCB Backdrilling

How To Design A Backdrill PCB?

Backdrill PCB design is the most crucial part of backdrilling on the PCB surface. It requires a high level of accuracy and experience. There is numerous design software to plan backdrilling in PCB manufacturing.

You can choose Altium Designer because of its reliable features and various advantages. Here are the required steps to design a PCB backdrilling.

• Before introducing the navigation part, you should set up the backdrill.
• Run Layer Stack Manager.
• Choose the backdrill. It is usually located on the upper right part of the feature segment.
• Go to the design section and install a backdrill by using specific tabs on the settings.
• Click the backdrill tab that takes you to the alternative parts of the backdrill.
• Set the design parameters of PCB backdrilling based on your design.
• Identify the first and last layer of PCB backdrilling.
• It is essential to keep the drilling symmetrical from both ends.
• Specify the net where backdrilling is required to apply. You need to use design rules for this purpose.
• Choose Max Via Stub Length option for implementing a new rule in high-speed signal transmissions.
• Backdrilling is conducted automatically after completing the specifications and activating the rules.
• There is an opportunity of adding multiple back drills. You can also remove the unused backdrills if required.

PCB backdrilling in Altium can be displayed in both 2D and 3D modes. It contains two specific colors. One indicates the starting layer, and the other color indicates the ending layer of backdrilling.

This two-color system is effective for identifying backdrill location in the backdrill PCB design. Besides, you need to make a list of necessary documents required for this design. Such as:

• Placing backdrilling on the PCB structure
• Numerically controlled drilled file
• PCB drawing that contains backdrill vias.

Backdrill PCB Design

What Are The Significant Backdrill PCB Applications?

Backdrill PCB is reputable for its excellent durability and signal transmission. It is used in versatile electronic sectors due to its worthwhile specifications. Its significant applications are described here for your convenience.

Communication Equipment

Backdrill PCBs are widely used in communication equipment. Backdrilling offers utmost integrity in data transfer. Besides, it ensures low crosstalk and resonance in the signal flow.

That’s why you can enjoy smooth data transmission in different communication devices without any interruption. Mobile PCB, transmitter PCB, radio PCB, etc are integrated with the backdrilling process.

Medical Instruments

This PCB is effective for numerous medical instruments. Such as scanners, X-ray machines, thermal testing, etc.

Military Equipment

Backdrilling in PCB manufacturing ensures sufficient robustness along with impressive durability. Military and aerospace equipment requires such robustness for their optimal performance. That’s why PCB backdrilling is applied to the military industry on a large scale manufacturing.

Except for these, backdrilling is used in home appliances, large servers, computers, microwave devices, etc. If you are worried about your high-speed and high-density PCB productions, you should rely on PCB backdrilling without any doubt.

Backdrill PCB Notable Applications

What Is The Most Effective Backdrill PCB Design Software?

Altium Designer is the most effective and reliable backdrill PCB design software nowadays. PCB backdrilling in Altium is easy to locate, and you can check the design rules conveniently.

Altium enables the designer to use this design software fast. Its specific settings are convenient for developing the quality of high-speed signals. Besides, it consists of improved libraries and design tools.

Backdrill PCB Design Software

The designer can overcome the challenges of PCB backdrilling with super effectiveness. It is easy to maintain design accuracy and controlling precision because of the easygoing features of Altium Designer backdrilling.

That’s why you can rely on this design software to improve your device performance. Check this video about PCB backdrilling in Altium:

How Does Stub Length Affect Backdrill PCB Designs?

Stub length has significant effects in backdrill PCB designs. Keeping the residual stub length within a specific limit for controlling signal attenuation in high-speed PCB projects is required.

When the signal flow starts through the length of a via, it gets separated into two parts. One part of signal flow takes the path of the internal layer and reaches the receiver end. The other part of the principal signal moves to the back of the stub.

Since stub is an undetermined signal transmission path, it travels back to the junction where the primary signal splits. Thus the main signal is distorted, and noise is created in high-density interconnects.

Increased stub length causes numerous problems in signal propagation. It promotes deterministic jitter that is a problematic form of signal flow. The bit error rate in high-speed data transferring is primarily dependent on jitter.

That’s why you have to decrease the stub length during the backdrill PCB design. It acts in lowering the bit error rate through proper control over deterministic jitter.

Besides, decreased stub length in PCB backdrilling is suitable for impedance matching in high-frequency PCB transmission lines. This phenomenon is highly effective for reducing signal attenuation. So, it would be best for you to consider the stub length with optimum priority.

Backdrill PCB Stub Length

What Are The Main Design Parameters Of A Backdrill PCB?

The main design parameters of a backdrill PCB design are-

• Backdrill hole diameter
• Top and bottom layer of PCB backdrilling
• Residual stub length
• Depth of backdrilling
• Backdrilling placement
• Backdrill tolerance

You should choose intelligent design software like Altium Designer and KiCAD. Then, it will be more convenient for you to set the design parameters for a successful backdrill PCB.

Backdrill PCB Design Parameter

How Does Backdrill PCB Via Stub Cause Noise In High-Speed Signal Transmission Systems?

Increased stub in Backdrill PCB vias causes noise in high-speed signal transmission systems. A high stub length increases jittering, distortion, and noise in signals.

It also improves the BER, which prevents noise reduction in circuit boards. If the data rate increases in signal transmission systems, the noise caused by via stub also increases. It maintains an exponential relation while increasing. That means a slight rise in stub length causes very high signal noise.

Most noteworthy, stub length causes signal reflection in data propagation systems. Thus, the signal is disturbed, and the communication device doesn’t start functioning properly.

Via stubs act like antennas in some cases. Antenna generates electromagnetic interference. Besides, attenuation makes the signal weaker.

Again, unnecessary stubs on both upper and lower PCB layers are not effective for impedance matching. Unbalanced impedance is also supportive of distortion in transferring high-frequency signals.

High-Speed Backdrill PCB Via Stub

How To Reduce Signal Distortion In Backdrill PCB?

Signal transmission in PCB vias like blind and buried vias suffer from distortion in most cases. In multilayer and HDI (High-Density Interconnect) applications, vias signals get interrupted while transferring to the receiver end.

It is caused due to increased jittering and a high bit error rate of PCB via signals. Backdrill PCB keeps the high-speed signals free from attenuation and jittering. Backdrilling reduces the length of stubs that is a common source of EMI.

Control depth drilling also inhibits the excitation of resonance modes. Reduced residual stub length causes negligible crosstalk that does not distort signals to a large extent.

You need to use high-class backdrilling materials to minimize signal distortion. Besides, it is required to take care of drilled hole diameter and other factors that affect attenuation in HDI printed circuit board applications.

Reduction Of Signal Distortion In Backdrill PCB

What Are The Main Differences Between Blind Vias And Backdrilling In PCB Design?

Backdrill and blind vias are effective for high-quality PCB designs. Both of these vias are used for minimizing stab. It is a pre-requirement for reducing EMI during signal flow.

But, these two have some differences that are highly crucial for backdrill PCB manufacturing. We are here with the comparisons between blind vias and backdrilling in multilayer PCB designs.

Cost Performance

The use of blind vias in a multilayer stackup is expensive. It increases the manufacturing cost of printed circuit boards used in communication devices.

On the contrary, PCB backdrilling is around 40% less expensive than blind vias. This cost depends on the layer count and lamination process. Backdrill PCB is a popular alternative to PCB blind vias because of its cost-effective nature.

Easy Processing

Backdrilling in PCB fabrication is easier compared to the application of blind and buried vias. You can easily backdrill the connector pins which are not buried or blind. But, you won’t have large numbers of vias as you go from connector to connector.

It is a common scenario while using backdrilling in the backplane. If you are looking for a comparatively simplified noise and EMI reduction method, backdrilling is the right choice.

Range Of Application

Despite its high cost, blind vias are immensely used in multilayer designs. But, backdrilling has gained enormous credibility in recent times. Its applications are also increasing consistently.

Its low cost and tremendous benefits make it preferable to many manufacturers. So, you don’t need to hesitate about your choice between blind vias and backdrill vias. As backdrilling offers better performance than blind vias, you should go for this technique.

Different PCB Vias

How To Increase Backdrill PCB Tolerance?

Backdrill PCB tolerance is a vital factor in PCB manufacturing. The depth tolerance for PCB backdrilling is  0.05mm. It can be increased if you take care of some factors. You need to use a drilled hole diameter larger than vias.

Besides, the implementation of effective drilling equipment is essential for improving the backdrill PCB tolerance. Moreover, you must keep in mind that the residual stub length shouldn’t cross the limit.

What Are The Major Challenges Of Backdrill PCB Designs?

Backdrill PCB designs are worthwhile for multilayer electronic applications. But, there are several challenges in applying backdrill on printed circuit boards. You need to be aware of these difficulties so that you can overcome them with supreme efficiency.

The significant challenges of PCB backdrilling include-

Precision Control

The design and drilling accuracy of backdrill PCB is essential. Precision control of this PCB is affected by the following factors-

• Functionality of drilling equipment
• Expansion and contraction of the circuit board
• Punching technique

It is highly critical to achieve these factors without optimum quality control. That’s why precision control is a great challenge for the backdrill PCB fabricators.

Depth Control

This is another critical issue for PCB backdrilling. Depth control depends on drill bit resistance and the angle of the drill bit. Maintaining accuracy in these issues requires supreme attention and skill.

Besides, the tolerance of the backdrill is related to depth control. So, you have to apply the most appropriate drilling equipment and method for overcoming this challenge.

 Challenges In Backdrill PCB

How Do You Select A Backdrill PCB Manufacturer In China?

You can select a backdrill PCB manufacturer in China if you consider some criteria. Such as:

• Use of correct design software like Altium.
• The ability to maintain proper dimensional stability in hole depth, backdrill diameter, etc.
• Experience in choosing the right circuit segment
• High-quality backdrill equipment along with factory service.
• Skilled engineers and customized services
• Affordable cost for the fabrication of backdrill PCB.
• Smooth customer service.

What Are The Reliable Methods Of Backdrill PCB Inspections?

Backdrill PCB design contains double color for top and bottom back drilling layers. So, it is easy to configure this circuit board and check it. You can conduct an automated optical test or automated X-ray inspection for detecting faults in back drill PCBs.

In the case of AOI, various 2D and 3D images of PCB back drilling are compared with an ideal back drill PCB. Then, an inspector can identify its faults.

On the contrary, X-ray inspection deals with mechanical errors, like defects in the hole diameter, depth, stub length, etc.

Backdrill PCB Inspection

Conclusion

PCB backdrilling plays a significant role in promoting the circuit board’s performance in modern electronic gadgets. If you execute this process appropriately, you can almost get rid of signal distortion in high-speed transmissions.

PCBMay is the leading service provider of backdrill PCB in China. We have intended to inform you of the pros and cons of backdrilling in PCB manufacturing in simple words. We hope you can solve your confusion about this PCB processing through this FAQ guide. If you have further queries, feel free to contact us.