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PCB design files are a process that includes many tasks, and it is not always possible to give each of them the necessary attention. But is it your fault that you don't give your projects as much love as they deserve?
You may be spending too much time creating perfect circuits or choosing the best components, but if you can't put all of those elements together and create a product that will work in the real world, then what's the point? Before your project becomes a headache for you and your manufacturer, be sure to study the guidelines below in order to design your next PCB like a true professional.
Before these glowing copper tracks are on your board, every detail needs to find its place on it. This process requires the developer to be a true master puzzler, you must become a specialist who is both an artist and a scientist. To make it easier for you to achieve this balance, we have prepared a few tips:
Be sure to position all components of the same type in the same direction. Thanks to this, the pcb design files assembly process will be perfect when your board is in the oven. If you place components haphazardly, don't be surprised where a lot of solderless connections come from, and the board just doesn't work.
Recommended Component Orientation
If you are working with Surface Mount (SMT) parts, be sure to place them on one side of the board. For Through-Hole (TH) mounting, all components must be on top of the PCB.
This allows you to install all surface mount components at the same time using a robotic pick and place machine without requiring additional steps.
This saves you financial resources by saving time spent manually assembling through-hole parts.
And of course, having components of a similar purpose nearby makes it much easier to manufacture and inspect a printed circuit board.
When locating components, always keep in mind how long the tracks need to be to connect the pins. By placing the appropriate components next to each other, you make the routing process easier and more efficient by pinning elements to the same area of the PCB.
It's getting hot in here
Heat dissipation is a problem in all electronic devices due to the fact that all active components and tracks give off a large amount of heat. As packages get smaller and PCBs get more stuffed, heat can be reduced as follows:
Use extra copper
If you feel that heat generation is a problem with your product, we recommend adding copper around the pads of the surface mount parts. This will increase the heat dissipation area. Study the specifications of all components in order to use pad space as a heatsink.
Did you know that vias can be used to move heat from one side of a PCB to the other? This can come in handy when you need to lower the temperature of the components by directing the heat to the other side of the board.
Keep hot parts away
A number of components generate more heat, including diode bridges, diodes, MOSFETs, inductors, and resistors. We recommend keeping them away from heat-sensitive parts such as thermocouples and electrolytic capacitors. If these capacitors get hot, they will lose their ability to hold a charge.
Microcircuits (ICs) offer a huge amount of functionality in one small, compact package. But among other things, they have a set of their own problems that also need to be resolved. Here are some tips to make chip placement and routing easier:
Microcircuits that contain many pins, and for that matter any microcircuit, need to be given enough space for convenient routing. Many novice developers make the mistake of placing chips too close to each other, leaving a limited area for all the necessary pins.
Try to keep a distance of 0.350" - 0.500" between chips and even more space for larger parts.
Place the chips up/down or left/right to keep them organized and organized. By doing this, you will place the first contact of the chips in one direction, which will greatly facilitate the routing and design process.
For proper power supply of microcircuits, we recommend using a common line for each power source. Also, be sure to use solid and wide traces to allow power to easily reach power-hungry ICs, and avoid daisy-chaining between components to avoid voltage spike problems.
Signal traces are the route to connect all the components on the PCB layout. And for you, as for any other engineer, the process of signal path routing is an interesting opportunity for organized creativity. Before you dive into pcb design files routing, pay attention to the following guidelines:
Avoid sharp 90° bends on signal tracks. Keeping their width really gets tricky, especially when they get narrower. Instead, line up 45° turns to keep everything running smoothly.
Be sure to use the track width calculator before laying tracks. With it, you can easily determine what thickness and width the tracks should be, taking into account the specific requirements of the project. And if you end up with extra space on your board, keep using wider traces as this is not an extra cost to the manufacturer.
Remember where the heat goes
If you are designing a multilayer PCB, remember that all the traces on the outer layers have much more cooling capacity than the traces on the inner layers. The inner traces have a long way to go through layers of copper and other materials in order for heat to escape, so place them at the top and bottom of the board whenever possible.
Turn the power on and off
When all signal tracks are placed, you need to check that they are all receiving the necessary energy. The mains carry the current necessary to power the entire circuit board, and all this is easy to implement, following our recommendations:
Tracks carrying a large amount of energy must be wider than standard signal tracks to store a larger load. The values shown may be recommendations for possible track widths for certain streams:
Place noisy earthen paths as far as possible from signal paths that require peace and quiet. You can also place the internal conductive ground layer directly below noisy signal traces to reduce resistance for high speed development.
Once your PCB design is fully designed, you can move on to another all-important step - design evaluation with a contract manufacturer ! You need to double check that each signal track is routed correctly. You can do this by looking at the wire-by-wire diagram and comparing it to the path of the tracks on the PCB layout. Everything is fine? Then it's time to go to production.
Many end product standards require end product printed circuit boards to be built to UL safety standards. The following product categories are just an example of what UL standards cover:
All of the above products must be certified and UL marked in accordance with three standards: UL 796, UL 745 and UL 94. These standards are divided into several sub-categories, including:
It provides recommendations for Printed Wiring Boards (PWBs), standard rigid PCBs, metal-based boards, and boards with high interconnect density.
PCB Standard UL 796F: This extension of the standard covers electronics made from flexible materials, including flexible and rigid-flex printed circuit boards.
PCB Standard UL 746E: This standard covers all structural laminates and materials used in the manufacture of printed circuit boards.
PCB Standard UL 746F: This standard covers all flexible dielectric film materials used in the manufacture of printed circuit boards.
UL94. It provides fire safety requirements for plastics and printed circuit boards.
In accordance with UL 796, UL 746 and UL 94 standards, printed circuit boards are rigorously tested under various conditions to evaluate the risk of electric shock, flammability and mechanical strength. Here is an overview of each category and the tests carried out:
Whether you are designing medical equipment, information technology equipment, or even a PCB for home appliances, chances are your PCB will need UL certification. The bulk of the certification process is already done by the manufacturer as it works with UL in terms of material and component testing.
However, as a PCB designer, you still need to take the time to research and define your PCB requirements as determined by your final product requirements.