See How Your Circuit Board is Made During Design with Altium Designer
Regardless of how good your printed circuit board (PCB) design may be for meeting your operational or performance objectives, it must be manufactured first. Although, you rely on a PCB manufacturer to actually build the circuit board your use of design for manufacturing (DFM) heavily influences turnaround time and quality of the finished product. The ability to see how your PCB is made during the design stage using Altium Designer allows you to view and implement the best DFM specifications and assist your PCB manufacturer to make your boards quickly and at high quality.
TOPICS IN THIS SOLUTION
The comprehensive software package that allows you to see how your PCB is made during design.
PCB Design generally begins with the selection of electronic components, usually by arranging them on a schematic, able to collectively meet defined performance criteria. This is followed by laying out the interconnections between these components within the confines of a PCB structure. The manufacture of your PCB proceeds in an opposite fashion. First, the PCB structure is constructed, which includes the etching of copper traces and drilling of holes for vias to provide the interconnection pathways. Next, the components are attached by soldering. These key stages of development, design and manufacturing, depend upon the alignment of the PCB structure used for the circuit layout with the PCB structure that is actually built.
It is essential that the physical constraints of the fabrication and assembly equipment and processes of your PCB manufacturer be incorporated as limitations on the PCB layout design. The process of synchronizing the designed PCB structure with the one manufactured is known as design for manufacturing (DFM). Having a PCB software design package where you can see how your circuit board is made during design allows you to make needed corrections and modifications easily and is an invaluable asset to your manufacturer for having your boards made as quickly and as accurately as possible.
Traditionally, the design and manufacture of PCBs have been two distinct and separate stages design and development in which virtually no interaction between the designer and manufacturer occurs until after design completion. This lack of collaboration continues to be the root cause of the many issues that cause board redesigns, extensive turnaround times and sometimes board failures once deployed in the field.
Over the last few years, new paradigms for PCB design and development have emerged from the recognition that development can be improved if designers were more aware of the circuit board manufacturing process. This has led to more robust PCB design software tools which allow for incorporation of DFM rules and guidelines into the layout of the PCB during design. The degree and accuracy to which this is done can significantly impact the not only the quality of your board, but whether it can be fabricated at all.
Easily Incorporate Material and Layout Data for Your Board’s Fabrication Using AD Tools
The first step in having your PCB manufactured is fabrication. PCB fabrication consists of the making the physical structure, which may be comprised of the core, substrate, prepreg and surface coating or solder mask, as well as the surface trace routes and drill holes that may include vias. Defining the parameters for all of these elements are requirements for the designer.
In order to accurately specify the many parameters that influence PCB fabrication requires an understanding of the parameters and their importance. Additional considerations are the range of specification or tolerance for these parameters is typically defined by the equipment used by your PCB manufacturer. Moreover, some of these specifications are defined by regulatory standards.
Staying abreast of the many constraints for your PCB’s fabrication can be quite a daunting task. However, you have resources to lessen this burden. First, in order to incorporate accurate DFM you must know the specific tolerances for your PCB manufacturer’s equipment and processes as these are not generic. Your other resource is the ability to institute your manufacturer’s DFM specifications for proper copper and layer management.
Depending upon your PCB design package this can be difficult or quite simple, as is the case with Altium Designer where there are multiple tools to specify your PCB layout.
- Understanding the many facets of board fabrication will help you to make better PCB layouts.
- The complexity of multilayer boards as compared to single layer PCBs is quite significant from a manufacturing perspective; therefore, you should know the advantages and disadvantages of each before making this design decision.
- In some cases, you may be able to get by with generally used layer specifications. But, if you design high power, high speed or other special PCBs this will not be adequate to ensure your board will function as intended reliably. For these cases, designing your PCB for performance is mandatory.
- Regardless of your board’s design requirements, you can easily specify them using AD’s PCB Rules and Constraints Editor. Moreover, this tool is structured such that you can target particular parameters or PCB manufacturing stages.
AD’s Easy to use PCB Rules and Constraints Editor
The final stage of PCB manufacture is assembly. During this stage your components are attached to the previously printed circuit board. Just as for PCB fabrication, there are rules and guidelines that you should specify. These specifications that are focused on the assembly of your PCB or placement of copper are referred to as design for assembly (DFA), a part of any good DFM utilization.
Whether it’s as simple as annotating your solder mask, or more intensive like getting into nuances between copper and layer layout, circuit boards and their manufacturing process can be a tumultuous deal. From the outer layers through the copper, from a ground plane to potentially using ferric chloride for etching, you’ll want to have software that can work with you to get your circuit boards created accurately with the copper you want where you want it.
Good DFA begins by recognizing the importance of your choice of components to your board’s assembly. For example, if your design makes use of through-hole technology for some components and surface mount technology for others then multiple soldering steps must be included to assembly as the methods are different for each. Also, important is how and where your component traces are laid out and the types of connectors your components have. Not considering these differences can be quite problematic during PCB manufacture.
The Lack of Good DFA Specifications Can Pose Significant Problems
PCB assembly is far more complicated than simply attaching components. In fact, the assembly process is the last stage of PCB manufacture and therefore must contend with any errors from the fabrication stage and ensure that your components are securely connected for maximum signal transfer and durability.
Another major consideration is component packaging. If you choose surface mount devices (SMDs) with pins then you may have significant fanout which reduces available space for copper traces on the surface. Conversely, if you select components with pads underneath the device you will have to include vias that affect your PCB stackup and can pose problems during assembly depending upon your copper plating or fill and tenting or closure choices.
It is also critical for assembly that tolerances for spacing and clearances be adequate. These specifications determine solder masking, which is added during fabrication but has an impact on the assembly process. Solder masking provides protection against unwanted soldering connections forming, known as solder bridges. Solder bridges negatively affect your signal integrity and can even cause board failures and damage, such as short circuits. Solder masking is also affected by your solder relief specifications, which determine whether vias are tented or not. Don’t let solder bridges impede your printed circuit capabilities and map out your copper effectively.
Your understanding of how these and other DFA specifications affect the assembly of your board will determine the quality and reliability of your manufactured PCB. With Altium Designer, you can view the impact of your DFA specifications during design. This allows you to make any needed corrections before manufacture and avoid circuit board defects or component problems, including warpage.
- DFA, is an often overlooked aspect of good DFM. However, it is just as important to ensure that you make accurate specifications that impact your board’s assembly as it is to do the same for your board’s fabrication.
- There are a number of specifications that affect solder mask usage and coverage. You should familiarize with these as they as inadequate solder masking can lead to severe problems; including board failure.
- Probably the best way to gain an appreciation for the importance of DFA is by understanding the severity of problems, such as component warpage, that may arise if it is not incorporated.
Good PCB design is simply the first stage in successful PCB design and development. The process is completed by having your boards manufactured efficiently and at a high quality. The ability of your PCB manufacturer to accomplish your board’s fabrication and assembly to meet this goal depends to a good extent upon your incorporation of accurate and effective DFM specifications.
A strong manufacturing process will enable you to rest assured that your printed circuit will be printed correctly, with any copper foil being where it was planned to be, any solder mask being applied appropriately without the risk of solder bridges forming, and any layer being connected properly. PCB manufacturing should require some DFM planning, and it is not only on your shoulders as the PCB designer to plan it out. Utilize your design software, too.
Panel view of manufactured PCBs
Your incorporation of DFM into your design will be more effective if you understand its importance to your board’s manufacture and the design and development process in general. One of the best ways to acquire this is by being able to see how your copper or board specifications affect your PCB layout in real-time during design.
AD’s Advanced 3D View Capabilities Enhance Your Ability To Design for the Accurate and Efficient Manufacture of Your PCB
Altium Designer provides multiple ways for you to set parameters that impact the fabrication and assembly of your board. These include the comprehensive PCB Rules and Constraints Editor and multiple specific management dialogs, including the Stack Manager. You can also directly access PCB layout elements by clicking on them while viewing your design in 3D. In addition to these capabilities that enable you to see how a PCB is made, AD 18 includes advanced functionality for setting up the panelization of your design and integrating cases and enclosures.
- There is no better tool available to view how your PCB will be made while during design than AD’s 3D View.
- In addition to real-time viewing of how your board will be made during design, Altium Designer provide you with the ability to construct the panelization for the copper on your PCB or multiple PCBs.
- Whether designing your mechanical enclosure from within AD or importing from another MCAD tool, integration with your ECAD is simple and easy with AD 18.
The success of your PCB design and development depends upon coordination with your PCB manufacturer to ensure that you make the most effective use of DFM and copper placement. With AD 18, you have the ability to see how your circuit board is made during design, which simplifies the process and will ensure efficient and accurate manufacture of your boards.