Countersinks and Counterbores for Printed Circuit Boards
This is a continuation of our PCB-101 series. In this post, we will talk about Countersinks and Counterbores.
This video provides a quick overview. Read on after for more details:
Countersinks and Counterbores
First I will highlight what these are and then what we need to know when manufacturing a printed circuit board that needs to have counterbores and countersinks.
Countersinks and counterbores are not anything unique to printed circuit boards, by the way. They are used in a variety of manufacturing of both metal, wood and other materials.
I also want to thank Dingo from our fabrication department. Dingo has been working with Bay Area Circuits since it’s inception more than 37 years ago, and has been working in PCB manufacturing since 1966. He took me to school (maybe a little old school even) on countersinks and counterbores.
What is a Countersink?
A countersink is a conical hole that is cut in order to allow for a flat head screw to be used.
Why do you need it?
Makes it possible for a flat head screw to sit flush with the surface to make for a very clean look and installation.
What information do we need to know to manufacture countersinks?
Countersinks most commonly will have either an 82 degree or 90 degree angle so a primary consideration is the desired angle. Additionally, you would need to specify the diameter of the smaller hole, and either the maximum diameter or the depth of the countersink. And, whether that hole is to be plated or non-plated. In most cases, these are non-plated but there could be situations where you may be grounding to a chassis and would need to have plating in the hole.
What is a Counterbore?
A counterbore is a cylindrical flat-bottom hole that is cut that also allows for a socket cap screw (has a flat head) to be used. The socket cap screw usually has an allen wrench drive (hex) hole.
Why do you need a Counterbore?
It is typically needed for much more secure and stable mountings.
What information do we need to know to manufacture counterbores?
For a counterbore, we need to know the dimensions of the smaller hole and the dimension of the larger hole as well as the depth of the bore.
Again in most cases, these will be unplated mounting holes but in some cases you may require plating. We just need to know what you want the finished hole size to be.
Ok there you have it, the basics of countersinks and counterbores for printed circuit board manufacturing.
If you have any questions comments or examples of how you have used them please post in the comments below.
This is another post in our ongoing PCB 101 series.
For more information on the basics of PCB manufacturing, check out our related posts:
Printed Circuit Board Manufacturing Double Sided ancd Multi Layer Post 1
Printed Circuit Board Manufacturing Multi Layer Image Process
Printed Circuit Board Manufacturing Lamination and Drill
Printed Circuit Board Manufacturing Outer Layer Image and Solermask
Printed Circuit Board Finishes
Printed Circuit Board Manufacturing Rout and Fabrication
Printed Circuit Board Manufacturing Electrical Testing