PCB News - Electronic and mechanical design of PCB board

For a long time, we have a consensus that the PCB manufacturing industry usually migrates naturally to the countries with the lowest costs, and developed countries will suffer in this process. However, another view is that by outsourcing reproducible work, the resources previously engaged in low-value work will face greater opportunities. The same is true for design. By adopting design automation tools, engineers can improve their design efficiency. It's hard to imagine that today's engineers will design PCBs without using computer methods, even though they can do so sometimes.

Just as the economy must adapt to changes in global conditions, we encourage teams of engineers to use any efficient design tool. For electronic design engineers, the use of EDA tools can greatly improve the design process, from components to final products. With the acceleration of the design process, we can now simulate or simulate every detail of the electronic design before purchasing any components. For example, in the field of integrated circuit development, the last step of the long-term, high-cost design process is to submit the design or'trial production' into a silicon wafer. This step of manufacturing integrated circuits will cost a huge cost, and this cost can only be recovered when the integrated circuit is sold in large quantities in the future. Of course, not all electronic product R&D is the case. The engineering cost of remanufacturing most electronic products may not be high, but for mechanical design, the gap between the housing and the internal PCB board causes remanufacturing. Need high cost.

The progress made by EDA tools means that it becomes easier to simulate the composition and function of the product before it is manufactured. Even so, it is still different from IC design in that the development of design automation tools in the field of electronic products used to pay special attention to niche markets for applications in specific fields. PCB design tools are an example. There are many low-cost PCB design tools that can be used to design simple, single-sided or double-sided boards, but there are fewer tools that can handle high-speed signals and mixed-signal multilayer PCBs, and provide a perfect solution to signal integrity problems. PCB tools are even rarer.

For designs with these needs, design tools are essential. They provide the only feasible solution to help us live today's digital life. For example, without sophisticated EDA tools, it is impossible to implement mobile communications; the tools help talented engineers develop the complex mixed-signal equipment and systems needed to implement 3G networks and smart phones.

There are many relevant examples, but the basic trend can be summarized as: the more complex the design, the more sophisticated the tool needs to be. However, design tools are always used to develop products, regardless of the product's functional complexity or final market value.

Cross design field

The integration of electronic and mechanical design is inevitable. Most PCB designs are not only affected by the components installed on it, but also by the space it can occupy. There is only one PCB in many products today. In these cases, the size and shape of the PCB are seldom determined by its functionality, but are mainly affected by the casing that packs it. In fact, in some cases, especially in consumer products, the shape and size of the final product also determine the available space of the PCB and all the components on it. In this case, mechanical design will dominate the design of these two fields, but the interaction between mechanical CAD tools and electronic CAD tools is very limited.

Suppliers of electronic design tools are more focused on the complexity of electronic design, and their counterparts-mechanical tool suppliers are also working hard to improve mechanical design tools, they make full use of the latest PC and desktop computer processing and graphics functions. Nowadays, it is common for mechanical design engineers to use 3D to show their designs and render them in real time. As a means to improve design efficiency, we cannot deny the value displayed in the 3D environment of products designed by engineers, and such displays also support real-time viewing angle switching.

In addition, as IC continues to shrink in size, it is difficult or impossible to reduce the size of other supported components. Specifically, the basic principles define the physical dimensions of passive components such as transformers, resistors, capacitors, and inductors. Nowadays, the connectors that are no longer used in large quantities in electronic devices are also subject to many physical limitations, such as how far they can be reduced in size and where they must be placed on the circuit board. What we can benefit from is that there are many 3D models of standard components such as passive components and connectors. These models can be used in a growing number of CAD software packages.

The extensive creation of these 3D models shows the supplier's new efforts to integrate electronic design and mechanical design. Many people in the industry also believe that such integration will continue and will enable engineers in the two fields to significantly improve design efficiency.

Perhaps the most significant advancement in achieving full integration is the introduction of design interaction protocols that electronic design and mechanical design tool suppliers can confidently adopt. Although there have been many integration attempts in the two major areas in the past, they were all hindered by the lack of cooperation between suppliers, resulting in increasing complexity. However, with the introduction of STEP (Product Model Data Interaction Standard), especially the 3D model defined in version AP214, the exchange of design data has become simple. The MCAD field has quickly implanted the STEP AP214 model into their tools, but the E-CAD field has not yet done so. However, Altium Designer, the unified design environment from Altium, can truly support the import/export and generation of STEP files. Combined with its comprehensive PCB design functions, Altium Designer can raise the design efficiency of all electronic engineers to a new level.

3D functions in PCB space

Many mechanical design tools are now able to support 3D models in PCBs created by third-party tools, but in addition to providing visualization of the PCB board and housing assembly results, they cannot provide PCB designers with critical dimensions, gaps, or other spatial compliance. Question feedback. In addition, mechanical design engineers are often unable to meet the positioning requirements of specific components, especially in the presence of high-speed, mixed-signal or high-voltage signals.

Altium Designer uses the STEP format to overcome these limitations. It not only allows engineers to use the 3D model of the shell to present the final condition of the product, but also provides engineers with a three-dimensional design method. With enough data embedded in the AP214 file format, engineers can really use the imported housing model to determine the size of the PCB. It completely solves the problems caused by manually transferring key data from one field to another in the past. By closely linking mechanical design to the electronic design process, electronic design engineers have taken a big step forward in designing for manufacturing.

In addition, the ability to define gaps in the 3D format means that engineers in the two major fields of mechanics and electronics can immediately see the impact of design changes. By combining the housing with the PCB model in Altium Designer, engineers can generate a 3D display of the product and measure the gap between them. This unprecedented feature means that electronic engineers can confidently hand their designs to manufacturers.

In order to make this process more efficient, you can use the link model approach. In this way, changes made in one area can be reliably reflected in the other area. This means that the electronic engineer can see any changes to the housing, and similarly, any changes made to the PCB or components will also be seen by the mechanical engineer.

The key to this function is not only to be able to generate a single 3D model, but also to be able to establish the coordinates of each model in the 3D space based on the reference point. By accurately positioning the model of the housing and PCB components, design engineers can verify the gap between them to ensure whether the PCB can be installed in the housing or whether to add strong ribs and fixing devices, while maintaining the overall market goal of the product.

Another advantage of working in the virtual world is that engineers can make various attempts without cost. For example, when using three reference points to align a component, it is likely that one component will pass through another component. Imagine the situation where the PCB passes through the housing during adjustment. This may seem unconventional, but it provides clues for solving bottlenecks in the design. Using real models to achieve this effect will be time-consuming and costly, but in the virtual world it is as simple as changing a single reference point. Only with the STEP format, the close interaction between the electronic field and the mechanical field becomes possible. The inclusion of the STEP format in the PCB design environment signifies that we have achieved great results in creating a unified electronic product development method.