It is inevitable to not utilize a Laser Drill in designing a Rigid Flex PCB since it has become an essential piece in the evolution of technology in the market.
Similar to other advancements, the Laser Drill Machinery needs certain tools and methods to carry out a Rigid Flex PCB design. It must therefore be well comprehended.
In this post, we will comprehensively discuss Laser Drilling, its applications, benefits, costs, and constraints in Rigid Flex PCB Construction.
What is Rigid Flex PCB Laser Drilling?
Only with aid of a Light Amplification produced by Stimulated Emission of Radiation, Laser Drilling is a technique for cutting a hole into the panel, as its name suggests. In simple terms, it utilizes significantly powered Laser Energy to puncture the board.
Another term for this particular approach is Laser Ablation; hence, do not get confused whenever this approach is referred to as an Ablation. In comparison with the traditional drilling technique wherein it uses a mechanical drill bit to bore, Laser Drilling uses a beam of laser.
Although the fact that laser drilling is considerably more advanced than traditional Mechanical Drilling, their layout is nearly identical. Furthermore, they are trying to attain a similar goal; and that is to puncture the board into the desired program with various classifications of its sizes. Also, it is regarded that Laser Drilling weighs more advantages than Mechanical ones.
In line with this, some of its capabilities include the dimensions it can bore. In case the application necessitates as little as 0.002 inches diameter for its hole; then, Laser Drilling can perform it because the Mechanical Drill’s minimum hole capability is 0.006 inches.
Overall, there are countless considerations in using a Laser Drill; hence, it would be beneficial to have detailed knowledge about them, especially for Rigid Flex PCBs.
Understanding Laser Drilling
Applications for Laser-Drilled Holes and Pockets in Rigid Flex PCB
Essentially, countless applications in Rigid Flex PCBs can be achieved by Laser System Design Techniques. Each of the boring approaches will be thoroughly discussed.
Blind Vias
Among all of the existing via approaches, the Blind Vias is the frequently performed puncturing method since they are helpful in High-Density and BGA purposes. Almost all of these operations employ an SMT Pad wherein it necessitates a tiny via; hence, a Blind Via that can perform this action is widely preferred. After that, the base is sealed and soldered across to produce a smooth solderable platform for the element.
Through Vias
In terms of Flexible and Rigid Flex Designs, the widely used via hole is the Through Vias. Although its term is far different than the Blind Via, it can still produce a tiny size slot; thus, it can be used in High-Density Circuit systems.
Part Outline Cutting
As its term indicates, the Part Outline Cutting is commonly performed in areas that are versatile since they can leave a ragged edge during the routing and tracing phase. Also, whenever mechanical routing is performed, it doesn’t produce a flawless output. Thus, it necessitates the Part Outline Cutting to trim such imperfections. As for applications, they are commonly found in Prototype PCBs and Low Volume PCB Assembly.
Complex Portion Outlines or Holes
As its name suggests, this particular via is performed in the intricate phases of the board. Since a Laser Drill can puncture at the smallest diameter needed, they are preferred in such scenarios. Further, it produces a significantly high accuracy and excellent size tolerance.
Diameter Restrictions for Laser-Drilled Holes in Rigid Flex PCB
Despite the Laser Drill’s ability to create holes as small as 0.002 inches, it is not always advised because it can be an inefficient and difficult-to-manufacture method.
As an illustration, we’ll make use of Blind Via operations since it has a restriction in terms of its hole barrel because of plate deposition. Since the hole performed in such a scenario isn’t visible, it can prevent the plate deposition from traversing through either side of the board.
As a result, there should be a comprehensive proportion between the hole’s diameter and its depth at a ratio of one to one (1:1). However, some may find this guideline absurd since a larger dimension of the hole could mean consuming more space in the board. It can be disadvantageous to applications wherein it uses a High-Density BGA Pad since it has a limited surface area.
After further research, the experts have reached into conclusion that the minimum and common diameter of the hole should be at 0.004” to be able to withstand the design stack up per the Rigid PCB Component Thickness in the upcoming phases. Moreover, this means that its depth would be at 0.004” as well. The laser is also localized to a dimension of 0.004″, enabling optimum energy dispersion and removing the necessity to parallelize a greater permeability in rings to punch the slot inside one zone.
Benefits of Laser Drilling in Rigid Flex PCB
Although there are countless benefits one could get from Laser-Drilled Systems, we’ll only discuss the fundamental advantages of it.
Non-Contact Approach
Unlike the Mechanically Drilled System wherein it directly touches the board to puncture it, the Laser-Drilled System doesn’t necessitate direct contact with it. Consequently, it can significantly reduce the occurrences of damage due to vibration.
Accurate Control
Generally, the Laser-Drilled System is powered by a programmed controller, it can offer exceptionally high accuracy. In that same sense, we can dictate the beam intensity, heat output, and longevity of the laser beam.
High Aspect Ratio
As mentioned, the diameter and the depth of the Laser-Drilled System have a balanced proportion at 1:1 for Blind Via; thus, giving it a significantly excellent aspect ratio. On the other hand, the Microvia can accommodate a ratio of 0.75:1. Although they are not the same value, they can still offer a High Aspect Ratio.
Multi-Tasking
Typically, the Laser Drilling Machine cannot only be used for boring holes but can be employed for other PCB Production processes, such as cutting and trimming. In terms of Flexible PCB, it can have enhanced control for its depth.
Expenditure for Rigid Flex PCB Laser Drilling
Essentially, Mechanical Drilling is way more cost-efficient than Laser Drilling. It has been like this because of the Mechanical Drilling’s countless spindles that can produce a simultaneous panel. On the other hand, due to its optical synchronization, Laser Drilling might be costlier. Furthermore, it can only accommodate one output at a time, making it time-consuming, and limiting the output produced. Ultimately, Mechanical Drilling can produce individual holes way more swiftly than Laser-Drilled ones.
Cost Calculation for Laser Drilling
Tolerances for Device Dimensions and Laser Precision for Rigid Flex PCB
Since the Laser Drill can optically align the desired positions into the surface area of the board, it has significantly increased its accuracy count since it can completely eradicate the intrinsic constraints brought on by locating the pieces in the state actually with machining pins.
In addition, one important benefit of laser drilling is that it enables the system to effectively eliminate most of the part’s intrinsic structural fluctuations. Furthermore, it is regarded that the materials in Flexible and Rigid-Flex PCBs are not dimensionally reliable during the construction and manufacturing procedure; however, through the help of a Laser Drilling Technique, this would not be an issue.
Instead of this, there are still restrictions in achieving positional accuracy regardless of its countless benefits, including the quality of the fiducials, optical recognition, and the CNC system. As for its hole and location tolerance, it is at an approximate value of ± 0.002 inches up to ± 0.003 inches.
Accurate Dimension Measurement for Laser Drilling
Summary
Overall, the Laser Drilling Technology has greatly contributed to the Rigid Flex and Flexible PCB’s exceptional drilled output compared with the Mechanical Drilling Technology. In addition, with the help of the Laser Drilling Method, the tiny and intricate requirements are met with high precision and quality that a Mechanical Drilling System cannot achieve. Nevertheless, it has its one downside, and that is the cost.
If you’re interested in learning more about this, we have an excellent service to go through your designs to determine whether the application necessitates Laser Drilling System or otherwise. In the case that it will demand a Laser Drilling Technique, we guarantee that we at MV Flex Circuit will provide a cost-efficient solution that will perfectly suit your desired budget.
Feel free to contact us with our socials for quicker accommodation; our experts are always available to gladly assist with your questions and concerns. Come and try out MV Flex Circuit excellence today; we guarantee that you won’t regret it!
