Complete Guide to Mouse Bite Panelization

1. What are Mouse Bite Panelization?

Mouse Bite Panelization refer to a series of small holes designed along the edge of a printed circuit board (PCB). These holes are arranged similarly to the perforations on the edge of a postage stamp, hence the name "stamp holes." This design allows for easy separation or detachment of multiple PCB boards. The name "stamp hole" originates from the resemblance to the perforated edge of a postage stamp.

Types of Mouse Bite :

1、Half-hole: A common type of stamp hole characterized by a relatively small diameter, used for positioning and securing on the PCB.  

2、Smaller half-holes: A variation with even smaller diameters, ideal for applications requiring more precise positioning.

3、Edge-tangent holes: These holes are positioned close to the edge of the PCB and are typically used for specific connection or securing needs.

Different types of mouse bite serve distinct roles in PCB design. Selecting the appropriate type of stamp hole based on specific application requirements is key to ensuring the PCB functions reliably.

2. Functions of mouse bites

•  Connecting small PCBs into a group: When you need to connect several small PCBs that are too tiny for connectors, stamp holes can be used to join them. The perforations allow electrical current to flow between the PCBs, connecting them.
•  Transmitting power and data between different PCBs/devices: Stamp holes can be used for power and data transmission between different PCBs or devices, enabling communication between them.

3. Common Design Techniques for PCB mouse bites

• Number of mouse bites : Typically, stamp holes are grouped in sets of five to connect components. However, the number of holes may vary depending on the PCB design.

• mouse bites size : The standard size for PCB stamp holes is usually 0.020 inches (approximately 0.5 mm) in diameter. The actual size may vary based on the design and the thickness of the PCB material.
•  Hole spacing: The typical spacing between PCB stamp holes is 0.030 inches (0.76 mm) to prevent components from being too close and causing short circuits.
• Sufficient tabs for support: Since stamp holes create an open space, it's essential to ensure that the tabs holding the PCB together are strong enough to support the components above and prevent short circuits between the separated PCB parts.
• Avoiding sensitive components: mouse bites  should be placed away from sensitive components, as the tabs can easily be damaged, leading to electrical shorts.

• Spacing between two mouse bites should be between 60mm and 90mm: If the space between two mouse sites is too large, it can make component placement inconvenient. If the spacing is too small, solder may flow to other areas, causing short circuits.
• Minimum 0.125-inch clearance from nearby components: Especially in high-density PCBs, a minimum clearance of 0.125 inches should be maintained betweenmouse bites and nearby components to prevent solder bridging between pads and traces.

4. Difference Between PCB Stamp Holes and V-Cut

V-Cut: V-Cut is one of the most common methods for PCB panelization. It involves cutting V-shaped grooves between PCB boards, allowing for easy separation during or before packaging. Double-sided V-cuts are typically controlled to a depth of about one-third of the board thickness (the sum of both sides' grooves). Accurate control of groove size and depth is crucial to ensure easy separation without compromising the strength of the board.

                                                V-Cut

Use cases for V-Cut: It is suitable for linear-connected PCBs. V-Cut is simple to design and easy to handle, but the depth and width of the groove must be precisely controlled to allow for easy separation while maintaining the board's strength.

Advantages of stamp holes: mouse bites provide greater strength and can be broken off directly without the need for milling equipment. They are well-suited for irregularly shaped PCBs or applications requiring high precision. After detachment, the edges remain neat, similar to the edge of a postage stamp.

Summary

V-Cut is ideal for linear PCB panelization due to its simple design and ease of use, but the groove depth and width must be tightly controlled.

mouse bits offer better strength and are suited for irregular PCB shapes or applications requiring high precision. They can be broken manually without additional cutting equipment, making them more suitable for complex shapes and ensuring cleaner edges after separation.