1. The process edge serving as the transmission edge of the PCB should leave a width of ≥6mm, and there should be no components or solder points within 10mm from the edge on both sides;
Wiring depends on the installation method of the PCB. Generally, PCBs installed in a guide groove should not have wiring due to frequent plugging and unplugging, while PCBs installed in other ways can be wired.
2. The four corners of the process edge should be rounded with a radius of 5mm to prevent jamming during transmission.
3. The process edge should be aligned with the furnace direction, requiring a clear directional marker indicating the furnace direction.
4. The connection method between the process edge and the motherboard generally adopts the V-CUT process, and the use of stamp holes for connection is not recommended. The remaining thickness of the V-CUT should be 1/3 of the board thickness.
V-CUT process schematic
To prevent uneven cutting and potential damage to the PCB during V-CUT separation, companies with conditions should not break the board directly by hand or pliers but instead use board separation tools or machines. Manual separation and cutting with pliers are not recognized by large manufacturers due to excessive bending stress caused by separation.
The board separation tool fixes the PCB and cuts it mechanically with blades or milling cutters.
5. V-CUT must not cut into the copper foil. Copper filling or traces must maintain a distance of at least 0.3-0.5mm from the mechanical edge of the PCB.
6. Buttons or other components must not exceed the board edge to ensure that the components will not be damaged or fall off during board separation.
7. The connection stamp holes of the process edge should be reasonable and should not cause difficulties in board separation; stamp holes should be used as little as possible. After cutting, stamp holes may be uneven. When connecting the process edge with stamp holes, consider the impact of residual edges on assembly. The residual edges of the PCB must not interfere with the frame. When there are stamp holes in double-sided or multi-layer PCB designs, the stamp holes must not be copper-plated, otherwise, it will cause difficulties in board separation.
8. When should stamp holes be used?
For regular board frames, the mechanical layer’s lines are cut down by the V-cut knives, but a thickness of 0.4mm cannot be cut with a V-cut knife.
Irregular board frames cannot use V-CUT; boards that are too thin (less than 0.6mm) cannot use V-CUT.
8. The process edge is generally defined by the long edge of the entire board (including the spliced board). When the ratio of the short edge to the long edge is ≤80%, the long edge must be the process edge.
[1] Interest-driven Passion
[2] Should Hardware Engineers Draw PCBs Themselves?
[3] How Long Should PCB Traces Be?
[4] How Wide Should PCB Traces Be?
[5] The Inner Layers of PCB
[6] Via Holes
[7] Can PCB Traces Have Sharp Angles and Right Angles?
[8] Should Dead Copper Be Retained? (PCB Islands)
[9] Can Vias Be Placed on Pads?
[10] What Material Does FR4 Refer To?
[11] Why Is the Solder Mask Layer Often Green?
[12] Stencils
[13] Pre-layout
[14] Key Points of PCB Layout and Routing
[15] Cross-segment Routing
[16] Signal Reflection
[17] Dirty Signals
[18] Surface Treatment Processes Such as Gold Plating, Gold Coating, and Tin Spraying
[19] Line Spacing
[20] Placement of Capacitors
[21] Crosstalk
[22] Flying Probe Testing of PCB
[23] Overview and Simulation of FPC
[24] Why Do PCBs Deform and Bend? How to Solve?
[25] Understanding “Characteristic Impedance” in One Article
[26] Layer Design of PCB
[27] Reflow Path for High-Speed Circuit PCB
[28] Power Processing and Plane Segmentation in PCB Design
[29] Zigzag PCB Routing—Tabbed Routing
[30] What Is the Dielectric Loss Angle of PCB?
[31] The Effect of Copper Foil Roughness on High-Speed Signals
[32] Why Should Crystals Not Be Placed on the Edge of the PCB?
[33] What Are High-Speed Signals?
[34] What Is a Transmission Line?
[35] Pre-emphasis, De-emphasis, and Equalization
[36] How to Utilize PCB Heat Dissipation
[37] Stubs in PCB Design
[38] The Dilemma: Should There Be Ground Protection Lines Between Traces?
[39] PCB Copper Pour
[40] Rules to Follow When Designing PCBs
[41] “False Eight-Layer” in PCB Layer Design
[42] Besides Stripline and Microstrip, There Is Also “Co-Planar Waveguide”
[43] Related Parameters of PCB Pad Design Process
[44] Why Should Ground Holes Be Drilled on PCB Edges?
[45] PCBs That Are Easier to Dissipate Heat: Aluminum Substrates
[46] Why Should Reference Planes Be Hollowed Out?
[47] PCB Design of Crystals
[48] Designing DC/DC Power PCB with EMC Principles
[49] PCB Turns, It Is Not Always Best to Route with Arcs
[50] Why Should Vias Be Sealed with “Conductive Via Plugging Process”?
[51] Key Points of Power PCB Layout and Routing
[52] Mark Points on PCB
[53] Simulating High-Speed Signals Across Segments with ADS
[54] Rigid-Flex Boards (Rigid-Flexible Combination Boards)
[55] Mixed Signal PCB Design
[56] Placement of Capacitors in PCB Design
[57] The Impact of Via Stubs in PCB Design
[58] Placement and Routing of Decoupling Capacitors in PCB Design
[59] PCB Design Checklist: Structure
[60] PCB Design Checklist: Power
[61] PCB Design Checklist: Routing
[62] PCB Design Checklist: High-Speed Digital Signals
—— Recommended Hardware Books ——
