1. PCB board layout designers are generally not involved in planning the layer stackup used to build the circuit board they are designing.
2. To set up the design tool, they obviously need to know the correct number of layers and their configuration, but beyond that, they typically do not have further involvement.
3. This is primarily due to three reasons: The performance requirements for PCB boards were less stringent in the past. Fewer materials were used in PCB manufacturing. PCB design tools lacked the advanced layer stack-up and configuration capabilities of today’s tools.
4. Fortunately, this aspect of PCB board layout has significantly evolved, with most major design tools now offering advanced PCB layer configuration capabilities.
5. Nevertheless, designers are still responsible for configuring the correct layer stack-up for their designs.
6. In this article, we will explore the process and discuss strategies for building and configuring layer stacks in PCB design software.
1. The number of layers on printed circuit boards is directly related to the number of nets that need to be routed. With the increased circuit demands on PCB boards, the number of components also rises, leading to more final nets. At the same time, the complexity and pin count of active components are also increasing, which raises the net count on the board. To address these increases, designers must either reduce the trace width, increase the number of layers, or both—though this unfortunately leads to higher manufacturing costs.
2. While the average number of components on a PCB board has increased, so have the board’s electrical performance metrics. Designers have found that achieving the desired electrical performance, which previously required four layers, now often necessitates up to eight layers. Some reasons for these additional layers include: 1) More room for controlled impedance routing. 2) Limiting differential pair routing to as few layers as possible. 3) Configuring microstrip and stripline layer stacks. 4) Adding plane layers for multiple power and ground nets.
3. As board functionality continues to evolve, another factor comes into play in creating a board layer stackup. Higher operating speeds of today’s circuit boards may require more advanced fabrication materials than those used previously. This also applies to high-power boards or those intended for harsh environments. These materials may alter the transmission line properties of circuits originally designed for standard FR-4 materials, potentially requiring changes to the layer stacking configuration.
4. With today’s advanced electronics, creating the correct board layer stackup is crucial to ensure high performance. As discussed, layout designers are under increased pressure to get the stacking correct. Let’s explore other difficulties that layout designers face.
5. The urgency to bring products to market is greater than ever. Companies are not only facing increased competitive pressure but also other forces at play. For instance, the recent COVID-19 outbreak has heightened the demand for new medical devices to combat the virus. As all aspects of design are pressured to meet these demands, PCB board designers in particular must complete boards quickly and accurately.
6. As noted earlier, the requirements for layer configurations and board materials are becoming increasingly complex. Many designers are unfamiliar with these processes or materials and may need external assistance to create the appropriate layer stack for their design. Some PCB design tools are still not user-friendly enough, slowing down the design process and potentially affecting the board’s quality.
7. PCB layout designers face many challenges in ensuring the board performs as expected while being manufacturable without errors and at a reasonable cost. Let’s examine how PCB design tools can assist designers in overcoming these challenges.
8. PCB CAD tools offer several features to help layout designers create and configure board layer stackups. The first is incorporating an automatic generator or wizard, which allows designers to specify the number and configuration of layers, streamlining the creation process.
9. Additionally, these tools should give designers full control over layer stack-up details, including specifying conductive and dielectric plate materials. Designers should be able to set values, tolerances, and layout parameters effectively.
10. However, not all the support designers need comes from these tools. Designers must have substantial industry knowledge to understand the materials and processes involved. Building relationships with PCB contract manufacturers can be highly beneficial, as these manufacturers have extensive experience and can provide accurate information for creating board layer stackups.
11. As mentioned, manufacturers are experts in this field. Layout designers should engage with their PCB contract manufacturers early in the design process to ensure the correct lay-up before beginning PCB design.
2. To set up the design tool, they obviously need to know the correct number of layers and their configuration, but beyond that, they typically do not have further involvement.
3. This is primarily due to three reasons: The performance requirements for PCB boards were less stringent in the past. Fewer materials were used in PCB manufacturing. PCB design tools lacked the advanced layer stack-up and configuration capabilities of today’s tools.
4. Fortunately, this aspect of PCB board layout has significantly evolved, with most major design tools now offering advanced PCB layer configuration capabilities.
5. Nevertheless, designers are still responsible for configuring the correct layer stack-up for their designs.
6. In this article, we will explore the process and discuss strategies for building and configuring layer stacks in PCB design software.
1. The number of layers on printed circuit boards is directly related to the number of nets that need to be routed. With the increased circuit demands on PCB boards, the number of components also rises, leading to more final nets. At the same time, the complexity and pin count of active components are also increasing, which raises the net count on the board. To address these increases, designers must either reduce the trace width, increase the number of layers, or both—though this unfortunately leads to higher manufacturing costs.
2. While the average number of components on a PCB board has increased, so have the board’s electrical performance metrics. Designers have found that achieving the desired electrical performance, which previously required four layers, now often necessitates up to eight layers. Some reasons for these additional layers include: 1) More room for controlled impedance routing. 2) Limiting differential pair routing to as few layers as possible. 3) Configuring microstrip and stripline layer stacks. 4) Adding plane layers for multiple power and ground nets.
3. As board functionality continues to evolve, another factor comes into play in creating a board layer stackup. Higher operating speeds of today’s circuit boards may require more advanced fabrication materials than those used previously. This also applies to high-power boards or those intended for harsh environments. These materials may alter the transmission line properties of circuits originally designed for standard FR-4 materials, potentially requiring changes to the layer stacking configuration.
4. With today’s advanced electronics, creating the correct board layer stackup is crucial to ensure high performance. As discussed, layout designers are under increased pressure to get the stacking correct. Let’s explore other difficulties that layout designers face.
5. The urgency to bring products to market is greater than ever. Companies are not only facing increased competitive pressure but also other forces at play. For instance, the recent COVID-19 outbreak has heightened the demand for new medical devices to combat the virus. As all aspects of design are pressured to meet these demands, PCB board designers in particular must complete boards quickly and accurately.
6. As noted earlier, the requirements for layer configurations and board materials are becoming increasingly complex. Many designers are unfamiliar with these processes or materials and may need external assistance to create the appropriate layer stack for their design. Some PCB design tools are still not user-friendly enough, slowing down the design process and potentially affecting the board’s quality.
7. PCB layout designers face many challenges in ensuring the board performs as expected while being manufacturable without errors and at a reasonable cost. Let’s examine how PCB design tools can assist designers in overcoming these challenges.
8. PCB CAD tools offer several features to help layout designers create and configure board layer stackups. The first is incorporating an automatic generator or wizard, which allows designers to specify the number and configuration of layers, streamlining the creation process.
9. Additionally, these tools should give designers full control over layer stack-up details, including specifying conductive and dielectric plate materials. Designers should be able to set values, tolerances, and layout parameters effectively.
10. However, not all the support designers need comes from these tools. Designers must have substantial industry knowledge to understand the materials and processes involved. Building relationships with PCB contract manufacturers can be highly beneficial, as these manufacturers have extensive experience and can provide accurate information for creating board layer stackups.
11. As mentioned, manufacturers are experts in this field. Layout designers should engage with their PCB contract manufacturers early in the design process to ensure the correct lay-up before beginning PCB design.
