Electronic Design - Use different methods to design PCB circuit board jigsaw

Like many processes in the electronics industry, PCB paneling has countless possibilities and variants. Since each manufacturer has its own method, as a designer, you must choose to adjust your design accordingly or find other production partners from time to time. The three most common methods are described below:

V-groove paneling: In this method, the individual circuit boards are separated from each other by milling V-shaped grooves, the height of these grooves is one-third of the height of the panel. The subsequent separation is performed by a machine more suitable for straight cutting. Therefore, this method is particularly recommended for PCBs that meet the following three requirements: no protruding components, no rounded corners, and sufficient distance between the component boundary and the PCB edge .

Panelization through lug wiring: Here, the circuit board moves along its contour-while maintaining a small amount of material bridges that firmly hold the circuit board in place during the panel manufacturing and assembly process. This type of panel is not suitable for printed circuit boards with large transformers and other heavier parts, which can complicate the separation. At the same time, it should be noted that this method reduces the load on the printed circuit board, thereby reducing the risk of chipping.

Paneling by flange wiring with a perforated material bridge: This process is similar to the simple flange wiring described above. However, the material bridge here is additionally drilled with small holes, which greatly simplifies the separation process, and because it is easy to predict the fracture process, it also provides a greater degree of control. However, this method is not even suitable for printed circuit boards with heavier components whose weight may damage the material bridge.

Disadvantages of PCB board

The PCB panel is a way to protect your integrity. In addition, panelization allows Chinese PCB manufacturers to assemble multiple boards at the same time, thereby reducing costs and shortening production time. The panel must be manufactured correctly to prevent damage to the printed circuit board or damage during the separation process.

challenge:

The panel poses many challenges in the following aspects: 1. Go

Panelization-the disadvantages of some de-panelization methods:

If a router is used, additional cleaning may be required before shipment. This method generates a large amount of dust that must be removed.

2. Replace the pre-wiring parts to avoid interference with the sub-board: prominent

Parts may fall into adjacent parts.

3. Incomplete data files-PCB manufacturers sometimes provide incomplete files, which will increase costs in many ways:

"Hole holes" or "mouse pits"-these small holes allow the use of small circuit boards in the array.

Cumulative and logarithmic tolerances-If there are no strict tolerances in the data file, the cumulative effects of small deviations can cause errors. If there are multiple tables in the array, the records will no longer be centered.

DFM and PCB paneling

When companies develop printed circuit boards in large numbers, they will look for ways to reduce manufacturing costs. If the production details are discussed in detail early in the design process and considered in the development of the printed circuit board, this will require relatively little work. (highly recommended). Relative to the planned manufacturing process, the early optimization of this design is often referred to as "design for production" or "design for manufacturing" (abbreviated as DFM).

There are several DFM methods that can save you a lot of long-term costs. The preferred strategy is to simply contact the manufacturing company as early as possible and understand their specific skills, challenges and business models. In this way, I can understand which aspects of my design can be easily achieved (so the cost is lower) and which elements require extra effort (correspondingly require higher costs).

PCB board reduces costs

A low-level and widely used DFM method is so-called panelization. Using this method, various circuit board designs can be applied to larger substrates or panels and then assembled in this way. The desired savings comes from the ability to manufacture multiple PCBs at the same time.

After completing the manufacturing and assembly process, the panel is divided into individual printed circuit boards. In this way, you can get a bunch of finished products and (hopefully) fully functional PCBs at once, waiting to be installed and sold. It sounds easy, doesn't it? But not so fast: In order to make the mass production of PCBs as smooth as possible and provide the required savings, some important details need to be considered when manufacturing the panels.

Factors affecting the cost of PCB paneling

Of course, most designers are less interested in the technical details of the various processes than in the associated costs and challenges. The basic rule of thumb here is that the cost and workload depend on the complexity of the design to be manufactured and developed with it. It should also be noted that panel-based manufacturing brings the following challenges, which also have an impact on costs:

Separation: If a router is used to separate a fully assembled PCB, chips and other debris will remain on the surface of the PCB, which must then be removed in another later step, which will involve workload and additional costs. If you want to use a saw instead of a router planer, when designing the circuit board outline, remember that only straight cuts can be made here. The third option is to use modern lasers. However, this laser can only be used with PCB thicknesses of 1mm or less, so in this case, you cannot create a multilayer PCB design of any thickness.

Fracture: Most separation processes leave rough fractures on the side of the workpiece. -Especially in the case of paneling via flange wiring with perforated material bridges (see above). In order to safely handle individual PCBs, they must be grounded at the relevant location, which in turn means extra work.

Suspended components: As mentioned earlier, protruding components can greatly limit the number of paneling methods that can be used in your design. In this case, the separation of the completed PCB may also be problematic because the milling head may collide with the protruding component, thereby damaging the entire panel. Needless to say, such failures involve unforeseen costs and delays.

The possibility of detecting and taking preventive measures as early as possible to solve potential problems.

Experienced PCB designers rely on a variety of reliable methods to detect and correct potential problems early.

As mentioned earlier, the design based on the DFM principle can effectively ensure that the panel and production are as profitable as possible. For PCB panels, among other things, it is necessary to understand the correct manufacturing company and its manufacturing process at the initial stage of the design project. In this way, you can design the best for production from the start.

In addition, if you use first-class design software, many of the challenges associated with automatic PCB manufacturing will be easier to master. Since the original design is not simply copied to the panel, but linked to the panel, changes to the original design are immediately obvious in the panel design.

Of course, in addition to the panel, there are many other ways to save manufacturing costs. However, this point deserves special attention, because errors here can quickly lead to unforeseen additional costs, or even completely inappropriate PCBs.

Therefore, you should definitely pay attention to the DFM techniques and principles found here and in many other articles, and pay attention to production-oriented design throughout the design process. This not only saves your time, but also reduces manufacturing costs and the risk of post-correction.