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Castellated holes on PCB, do you really know their applications, types, and design?

Castellated holes on PCB, do you really know their applications, types, and design

Castellated holes in a PCB are half-round or rectangular holes with arrays of small vertical walls coming out of them so that the hole resembles a fortification. It is interesting that the Latin word for castle, castrum, came to be used as the general term for any fortification, in part because early castles appeared to have square towers at the corners of rectangular walls. In this article, you will learn about castellated holes in PCBs by understanding a little more about their structure and functions.

What are castellated holes in PCB?

A PCB cast hole is a circular through-hole in the surface of a PCB that is cast during the manufacturing process and covered with a metallic or non-conductive plug after manufacturing. PCB cast holes are generally spaced at 100-mil (2.54 mm) pitch, though holes of other pitches are sometimes used.
What are castellated holes in PCBCast holes are generally reserved for mounting external components, and as a result, have oversize dimensions compared to other through-holes in order to accommodate leads through the outside of the PCB, or through-hole components. The features and performance of a printed circuit board (PCB) are largely determined by the type of through-hole technology used in its manufacturing.

What’s the type of castellated holes?

There are three types of castellated holes i.e., half holes, holes with smaller half holes, and holes tangent to the board’s edge. If the hole is half, then both edges of its flange touch with the board’s edge, but half a hole can be produced with only one part on board’s edge.

When a hole is created with the whole flange touching with the board’s edge, it is termed as full castellated hole, if a part of it touches with board’s edge, then half castellated hole will be created. When the holes are tanged to boards edge, that is it’s both part do not touch with the boards edge then we will have tangent castellated hole.

What’s the advantage and disadvantage of castellated holes?

What’s the advantage and disadvantage of castellated holes

Advantage: The castellated hole is round and has high strength and strong compression resistance, which supports and connects the PCB board more firmly, and does not require equipment to divide the board, and can be broken by hand.

Disadvantage: After the PCB board is separated, the hole will appear like a saw, which is easy to block the shell. In the design process, it is necessary to reserve a position or generally shrink the board. It will increase the cost, because the minimum castellated hole is 1.0MM hole, then the 1MM size is counted in the board

How do you use castellated holes?

Castellated holes, depending on the application in which they are used, can serve a wide variety of purposes. When encountering circular or special-shaped PCBs, it is possible to use castellated holes.Castellated holes are mainly used to connect and support between holes. In the early, castellated holes are the attachment method of choice for PCB assemblers when it comes to joining independent modules to one another, such as Wi-Fi or Bluetooth modules.

Castellated holes allow for a more secure and stable connection than other attachment methods. This is due to the fact that castellated holes provide a connection that is safe and dependable.

Castellated holes have the potential to be used in a wide variety of applications, some examples of which are video game consoles, outdoor phone booths, access panels, networking, and arcade machines. Castellated holes have other applications in the structural and building industries, including the construction of atria and through-wall heating ducts.

How to design castellated hole and consideration?

To design the Castellated Holes PCB Array, you need to:

Step 1: Place the PCB array inside the Gerber file so that all files are aligned as required.
Step 2: Place components in the positions where they are desired.
Step 3: Remove unwanted components from the Castellated Holes PCB Array by using editing tools.
Step 4: Send the Gerber file to a PCB manufacturer.
How to design castellated hole and considerationConsiderations about castellated hole design
①Size: It is recommended to use the largest possible size.
②Surface treatment: depends on the end use of the board, but ENIG is recommended.
③OL pad design: It is recommended to use as large an OL pad as possible on the top and bottom.
④Number of holes: It depends on the design. However, the lower the number of holes, the more difficult the PCB assembly process will be.

How do you solder castellated edges?

The process of solder castellated edges is to apply melted solder to the edges of printed circuit boards or integrated circuits in order to make electrical contact. When a high current or voltage flows through these circuits, the solder paste melts and forms a conductive path between two conductors or components thereby allowing an electrical connection.

This technique uses the physical and electrical properties of molten solder to provide reliable, high current interconnections between the layers in multi-layer printed circuit boards.

what’s the application of PCB with castellated holes?

PCBs with castellated holes can be used for a wide variety of applications. PCBs with castellated holes can be found in devices that are frequently found in hospitals and that are frequently used to infuse patients with liquids. These devices are frequently used to treat a variety of medical conditions.

PCBs with castellated holes are also present in automobiles for the purpose of fuel flow, and PCBs with castellated holes are frequently utilised in aeroplanes for the purpose of air-pressure controls. Both of these applications are potentially hazardous to human health.

PCBs featuring castellated holes are utilised by the pharmaceutical industry in a variety of hospital applications, including ventilators, infusion pumps, respirators, and anaesthesia machines.
what's the application of PCB with castellated holesIn addition, they find applications in commercial controls for heating, air conditioning, and refrigeration; power generation applications such as motors, circuit breakers, and bushings; and fire control in the military; self-powered lighting and instrumentation; and self-powered lighting and instrumentation.

PCBs with castellated holes are the most common type of the rigid, closed-cell structure foam material that is named for its cube-like shape. This is because the holes in the PCBs are shaped like castellations. The application determines the dimensional requirements for the PCBs with castellated holes that are used in these applications. Applications that require higher fluid flow rates call for castellated holes with larger diameters, while applications that require tighter pressure control utilise castellated holes with smaller diameters.

What is the diameter of castellated holes?

When adding castellated holes, it is recommended that 5 to 8 0.60mm (diameter) holes form a row (double rows are required) as a group. The distance between the holes can be 1.1mm or 1.25mm. The diameter of the left and right semi-circles is 2mm.There is a 1/3 hole size position at the sub-board. Generally, the castellated hole needs to be banned to prevent the wiring in the PCB board and the device from being too close to the castellated hole. The size of the forbidden area is more than 0.5mm larger than the hole on one side.What is the diameter of castellated holes


We hope that you have learnt a lot about castellated holes in printed circuit boards. For more information regarding more PCB,PCBA, PCB prototyping, electronic component and device, and PCB design,, please visit our blog on IBE website.

IBE provides one-stop service from PCB design, PCB prototyping, PCBA processing (including SMT and DIP ), PCBA testing, and PCBA product assembly and packaging out of the warehouse. Company has 14 SMT lines, 6 Dip lines, Lab, 75000 m²factory, and 4 product assembly production workshop, which will save your time and cost. If need. contact IBE to help you:

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