1. The term V-cut refers to the process where the PCB manufacturer creates a segmentation line at a specified location on the PCB using a rotary cutter, based on the customer’s design specifications. This pre-cutting aids in the subsequent SMT circuit board assembly, earning it the name “V-cut” due to its cut shape resembling the English letter [V].
2. The necessity for V-cut design on the circuit board arises from the inherent strength and rigidity of PCBs. Attempting to manually break or separate the PCB is nearly impossible; even the strongest individual would struggle, potentially damaging the components on the board. Thus, the pre-cut V-cut design enables operators to easily separate the original panel into individual boards, a process referred to as de-paneling.
3. V-cut is utilized by PCB manufacturers to create dividing lines in specific locations as per customer drawings, using a rotary cutter. This approach streamlines the assembly of SMT circuit boards, hence the term de-panel, which reflects its V-shaped cut.
4. Typically, the production of bare circuit boards involves initial panelization and break-away processes. Once the circuit board has been populated with components and assembly is complete, it is essential to perform the dividing operation.
5. The board can only be installed in the machine after panelization, as usually, a single product does not incorporate more than two identical assembly boards (PCBAs). The rationale behind the necessity for panelization and edge addition will be discussed in the next article!
**V-Cut PCB**
**The Purpose of Designing V-Cut and the Process of V-Cut Splitting**
As previously mentioned, the primary goal of designing a V-cut is to facilitate the de-paneling of the board after the assembly of the circuit board. When splitting a PCBA, a V-Cut board splitter, commonly referred to as a scoring machine, is typically employed. The V-shaped grooves pre-cut into the PCB are aligned with the circular blade of the scoring machine, and then a firm push is applied. Some machines feature an automatic board feeding design; with the press of a button, the blade moves automatically to cut through the V-Cut sections of the circuit board. The blade’s height can be adjusted to accommodate varying V-Cut thicknesses. (Note: In addition to using V-Cut scoring, there are alternative methods for PCBA splitting, such as routing and stamped holes.)
While the V-Cut on the PCB can be manually snapped, this method is not recommended. Manual breaking can lead to bending at the force application point, increasing the risk of cracks or micro-cracks, especially in electronic components like capacitors, thereby reducing product yield and reliability. Issues may arise even after a period of usage.
**V-Cut Design and Usage Limitations**
Despite allowing for easy board separation and edge removal, V-Cut has certain design and usage constraints.
Firstly, V-Cut can only produce straight lines that extend to the end; it cannot change direction or create shorter segments like a sewing thread. This limitation arises because the V-Cut groove is created by a chainsaw-like mechanism with two upper and lower discs. Similar to a carpenter cutting wood, the PCB cutting must be extremely precise (to the millimeter), preventing half cuts or retracting the blade. While technically possible, it is often more efficient to forgo the V-Cut process in favor of routing for complex cutting paths.
Secondly, V-Cut grooves are unsuitable for excessively thin PCBs. Generally, boards thinner than 1.0mm should not have V-Cut designs, as this can compromise the structural integrity of the PCB. When heavy components are mounted, the board may bend under gravity, which is detrimental to SMT soldering operations, potentially causing solder voids or short circuits.
Furthermore, during the high temperatures of the reflow furnace, the PCB can soften and deform if it exceeds the glass transition temperature (Tg). Poorly designed V-Cut positions and groove depths can exacerbate this deformation, adversely affecting the secondary reflow process.
**What is V-Cut? Why is There a V-Cut on the PCB?**
**Design Recommendations for V-Cut Residual Thickness**
In defining the size of the V-Cut groove, the focus is often on the remaining thickness, which is the thickness of the material between the two inverted V ports of the groove. This thickness is crucial in determining the board’s susceptibility to breakage and deformation.
It is generally recommended that the residual thickness of a V-Cut be about 1/3 of the overall board thickness, with a minimum of 0.35mm. Thinner sections pose a higher risk of premature breakage during manufacturing. Conversely, the maximum recommended residual thickness should not exceed 0.8mm, as a thicker V-Cut may prevent the scoring machine from cutting through in a single pass, potentially damaging the cutting blade and reducing its lifespan.
**PCB V-Cut**
**Angle Definition of PCB V-Cut**
The V-shaped included angle of V-Cut is now defined. Typically, V-Cut features three angles: 30°, 45°, and 60°, with 45° being the most commonly used.
As the angle of the V-Cut increases, more of the board edge is affected. Consequently, the circuit on the opposite PCB must be positioned further inward to prevent damage from the V-Cut or cutting issues during the process.
Conversely, a smaller V-Cut angle theoretically allows for better PCB space design, but it adversely affects the lifespan of the PCB manufacturer’s saw blade. A smaller angle results in a thinner blade, making it more susceptible to wear and breakage. Additionally, for thicker boards, deeper cuts are necessary, which typically requires a larger V-Cut angle. Boards thicker than 1.6mm generally discourage the use of a 30° V-Cut angle, unless in large-scale production, where Router cutting is preferred.
Router cutting can effectively address many disadvantages associated with V-Cut cutting. So, why opt for V-Cut design? The answer lies in cost differences! In this world, affordable and efficient solutions are rare; if one exists, it tends to dominate, leaving few alternatives.
2. The necessity for V-cut design on the circuit board arises from the inherent strength and rigidity of PCBs. Attempting to manually break or separate the PCB is nearly impossible; even the strongest individual would struggle, potentially damaging the components on the board. Thus, the pre-cut V-cut design enables operators to easily separate the original panel into individual boards, a process referred to as de-paneling.
3. V-cut is utilized by PCB manufacturers to create dividing lines in specific locations as per customer drawings, using a rotary cutter. This approach streamlines the assembly of SMT circuit boards, hence the term de-panel, which reflects its V-shaped cut.
4. Typically, the production of bare circuit boards involves initial panelization and break-away processes. Once the circuit board has been populated with components and assembly is complete, it is essential to perform the dividing operation.
5. The board can only be installed in the machine after panelization, as usually, a single product does not incorporate more than two identical assembly boards (PCBAs). The rationale behind the necessity for panelization and edge addition will be discussed in the next article!
**V-Cut PCB**
**The Purpose of Designing V-Cut and the Process of V-Cut Splitting**
As previously mentioned, the primary goal of designing a V-cut is to facilitate the de-paneling of the board after the assembly of the circuit board. When splitting a PCBA, a V-Cut board splitter, commonly referred to as a scoring machine, is typically employed. The V-shaped grooves pre-cut into the PCB are aligned with the circular blade of the scoring machine, and then a firm push is applied. Some machines feature an automatic board feeding design; with the press of a button, the blade moves automatically to cut through the V-Cut sections of the circuit board. The blade’s height can be adjusted to accommodate varying V-Cut thicknesses. (Note: In addition to using V-Cut scoring, there are alternative methods for PCBA splitting, such as routing and stamped holes.)
While the V-Cut on the PCB can be manually snapped, this method is not recommended. Manual breaking can lead to bending at the force application point, increasing the risk of cracks or micro-cracks, especially in electronic components like capacitors, thereby reducing product yield and reliability. Issues may arise even after a period of usage.
**V-Cut Design and Usage Limitations**
Despite allowing for easy board separation and edge removal, V-Cut has certain design and usage constraints.
Firstly, V-Cut can only produce straight lines that extend to the end; it cannot change direction or create shorter segments like a sewing thread. This limitation arises because the V-Cut groove is created by a chainsaw-like mechanism with two upper and lower discs. Similar to a carpenter cutting wood, the PCB cutting must be extremely precise (to the millimeter), preventing half cuts or retracting the blade. While technically possible, it is often more efficient to forgo the V-Cut process in favor of routing for complex cutting paths.
Secondly, V-Cut grooves are unsuitable for excessively thin PCBs. Generally, boards thinner than 1.0mm should not have V-Cut designs, as this can compromise the structural integrity of the PCB. When heavy components are mounted, the board may bend under gravity, which is detrimental to SMT soldering operations, potentially causing solder voids or short circuits.
Furthermore, during the high temperatures of the reflow furnace, the PCB can soften and deform if it exceeds the glass transition temperature (Tg). Poorly designed V-Cut positions and groove depths can exacerbate this deformation, adversely affecting the secondary reflow process.
**What is V-Cut? Why is There a V-Cut on the PCB?**
**Design Recommendations for V-Cut Residual Thickness**
In defining the size of the V-Cut groove, the focus is often on the remaining thickness, which is the thickness of the material between the two inverted V ports of the groove. This thickness is crucial in determining the board’s susceptibility to breakage and deformation.
It is generally recommended that the residual thickness of a V-Cut be about 1/3 of the overall board thickness, with a minimum of 0.35mm. Thinner sections pose a higher risk of premature breakage during manufacturing. Conversely, the maximum recommended residual thickness should not exceed 0.8mm, as a thicker V-Cut may prevent the scoring machine from cutting through in a single pass, potentially damaging the cutting blade and reducing its lifespan.
**PCB V-Cut**
**Angle Definition of PCB V-Cut**
The V-shaped included angle of V-Cut is now defined. Typically, V-Cut features three angles: 30°, 45°, and 60°, with 45° being the most commonly used.
As the angle of the V-Cut increases, more of the board edge is affected. Consequently, the circuit on the opposite PCB must be positioned further inward to prevent damage from the V-Cut or cutting issues during the process.
Conversely, a smaller V-Cut angle theoretically allows for better PCB space design, but it adversely affects the lifespan of the PCB manufacturer’s saw blade. A smaller angle results in a thinner blade, making it more susceptible to wear and breakage. Additionally, for thicker boards, deeper cuts are necessary, which typically requires a larger V-Cut angle. Boards thicker than 1.6mm generally discourage the use of a 30° V-Cut angle, unless in large-scale production, where Router cutting is preferred.
Router cutting can effectively address many disadvantages associated with V-Cut cutting. So, why opt for V-Cut design? The answer lies in cost differences! In this world, affordable and efficient solutions are rare; if one exists, it tends to dominate, leaving few alternatives.
