What is Counterbored Hole

By Bester PCBA

Last Updated: 2023-07-26

What is Counterbored Hole

Counterbored holes are cylindrical holes that are drilled into the surface of a PCB board. These holes are specifically designed to accommodate screw caps, providing a recessed space for the screw head to be flush with the PCB surface. The counterboring drilling method is used to create these holes, utilizing drills with two different cutting diameters to ensure an even surface on the inside wall of the hole. Counterbored holes are typically used for standard screw cap fixes and are relatively simple to drill due to their straight, vertical nature. However, it is important to note that counterbored holes have limited flexibility in terms of sizing or variation. They are specifically tailored to fit hex-headed screws and are not suitable for other types of fasteners.

Frequently Asked Questions

What Are the 3 Types of Holes

In engineering, there are three types of holes: blind holes (on the left), through holes (in the middle), and interrupted holes (on the right).

How Are Holes Drilled in PCB

In the process of drilling PCBs, various types of holes are created, such as component holes, mechanical holes, and via holes (including blind holes, buried holes, micro-holes, and thru-holes). To achieve the necessary accuracy, the holes are typically created by means of a manual or laser PCB drill.

What Is a Clearance Hole

A clearance hole refers to a hole in an object that is large enough to allow the threads of a bolt or screw to pass through, but not the head of the bolt or screw. This type of hole is designed to prevent the threads from biting into the material and allows for easy insertion of the screw or bolt.

Is SMD Cheaper Than Through-Hole

Surface Mount Technology (SMT) is often preferred over Through Hole Technology due to its higher reliability and cost-effectiveness. However, it is important to note that Through Hole Technology still offers unique advantages that make it relevant for the foreseeable future.

What Is the Difference Between a Mounting Hole and a Tooling Hole

Some sources may claim that tooling holes and mounting holes are identical, but this is not entirely accurate. The main distinction lies in the plating: PCB tooling holes are non-plated through-holes, whereas mounting holes are usually plated.

What Is the Maximum Hole Size for a PCB

Although there is no specific hole size requirement for a PCB, there is a range of standard drill hole sizes that can help you make a selection. Opting for a hole size within the range of 5 mil (0.13 mm) to 20 mil (0.51 mm) should allow your CM to accommodate your design, although smaller sizes may incur additional costs.

Why Do PCBs Have Holes

PCBs originally had tracks printed on just one side, but as technology advanced, both sides of the board were utilized. In addition, multi-layer boards were introduced. Plated-through holes (PTH) were then implemented to allow the components to establish contact with the necessary conductive layers.