Technical Guidance: Mouse Bite Panelization Guide

The conventional method of panelization uses V-grooves. However, for irregularly-shaped boards or special requirements (such as JLCPCB's economic SMT assembly), mouse bite panelization, which resembles postage stamps on an envelope, is required. PCBs panelized using this method are called "mouse bite panels" or "mouse bite connections".

Mouse bite panelization can be referred to as "universal panelization." As long as there is a position to add mouse bites, boards of various shapes can be interconnected using mouse bites. The number of mouse bite connection positions, their sizes, and the overall stability of the panel directly affect the quality of SMT assembly.

It should be noted that mouse bite panelization may result in serrated edges after the panels are separated.

■ Mouse Bite Size: It is recommended to use sets of 5 to 8 holes with a diameter of 0.60 mm each (it is not recommended to have fewer than 5 holes in a set).

■ Mouse Bite Spacing: The distance from hole edge to hole edge should be 0.35-0.4 mm. A minimum spacing of 0.3 mm should be ensured for sufficient connection strength (thinner boards may require slightly larger spacing).

■ Number of Mouse Bite Sets: At least 2 symmetrically placed sets are needed for boards within 30 mm wide on both sides. Adjust the number of sets based on the actual board size and component weight. It is recommended to add a set of mouse bites every 50-60 mm.

■ Mouse Bite Placement: Add mouse bite holes in the centerline of the board frame or extending one-third into the board. If there are vias, traces, mounting holes, or protruding components along the board edge, avoid mouse bites in those areas.

■ Panelization Spacing: The typical spacing is 1.6 mm or 2 mm, with a minimum requirement of 1.2 mm (going below this value may cause issues like drilling bit breakage or misalignment).

⊙ To facilitate board separation, mouse bites should be positioned in the larger blank areas of the board.

❶ Mouse bites are not needed on the process edge side (as marked by the red circle in the figure). Mouse bites are only required to be added on one side of the board outline, but for connecting boards to other boards, mouse bites should be added on both sides (as indicated by the red arrows in the figure).

❷ For circular boards, it is recommended to add mouse bites in positions with blank board space, ensuring a lager blank board area to apply force to when separating the boards.

⊙ To facilitate manufacturing, please add mouse bites according to the guidelines.

Requirements

Regarding non-compliant panel files provided by customers, the following requirements are provided.

① If the spacing between mouse bites in the panel files provided by the customer is insufficient, our engineering team will adjust it to a minimum of 0.3mm (to ensure sufficient support and prevent accidental detachment) without notifying the customer.

② For non-compliant designs, because they require adjustments, we cannot guarantee that each production will be exactly the same. Thus, it's possible to have variations in the results between different batches. Please be aware!

③ For panel designs specified by the customer as text description or outline drawings without gerber files, we make our own adjustments for non-compliant positions (such as mouse bites, connection positions, clearances, etc.). Tooling holes and fiducials should be added by the customer. We do not add data that is not present on the drawings.

④ For panel designs provided by the customer as gerber files, if they require tooling holes or fiducials, please add them yourself. Data not present on the drawings will not be added by us. Click here for more information.

⑤ For customer-provided panel layout drawings where unit boards (or process edge) are not identical, our engineering team will by default adjust them to zero spacing panelization. For panels supplied as gerber files, we follow the file's specifications. Click here for more information. Partially flipped panelization method please check more details here.

A strong emphasis: To ensure that the PCBs match your stencil and fixture precisely, please download our engineering data from the system to create your stencil and fixture.

Example Panel Layouts