Seven Considerations in PCB Design

Schematic diagram is based on the design of the project, as long as the electrical connection is correct, nothing to say below, I summarized some experience to share with you:

1. Making a physical border

The closed physical border is a basic platform for the layout and routing of components. It also plays a role in the automatic layout. Otherwise, the components coming from the schematic will be overwhelmed. However, we must pay attention to the accuracy here, otherwise the installation problems will become more troublesome. There is also the best use of circular arcs in the corners. On the one hand, it can avoid sharp-edged workers, and at the same time it can reduce the stress. In the past, one of my products was always in the process of transportation. There were cases where the surface-mounted PCB board was broken on individual machines. It would be better to use a circular arc instead.

2. Introduction of components and networks

Bringing elements and networks into a good frame should be simple, but there will always be problems here. Carefully follow the suggested mistakes one by one to resolve, and then you need to spend more effort. The problem here is generally the following:

The component package cannot be found, component network problems, and unused components or pins. The control tips for these issues can be quickly resolved.

3. The layout of the components

The layout and alignment of the components have a great influence on the product's life span, stability, and electromagnetic compatibility, and should be paid special attention. In general, there should be some of the following principles:

3.1 Placement order

First place components that are fixed in position relative to the structure, such as power outlets, indicator lights, switches, connectors, etc. These devices are placed and locked with the software's LOCK function so that they will not be misplaced in the future. Place special components and large components on the line, such as heating elements, transformers, and ICs. Finally place the small device.

3.2 Pay attention to heat dissipation

Component layout also pays special attention to heat dissipation issues. For high-power circuits, those heat-generating components such as power transistors and transformers should be placed as close to the side as possible to disperse the heat, not to concentrate in one place, and not to be too close to avoid premature aging of the electrolyte.

4. Routing

The principle of Routing: The knowledge of the route is very profound, and each person will have his own experience, but there are still some general principles.

5. Adjust and improve

After completing the wiring, all that needs to be done is to make adjustments to the text, individual components, alignment, and copper (this work should not be too early, otherwise it will affect the speed and cause trouble to the wiring). It is also for the convenience of production. Commissioning and maintenance.

Copper encapsulation usually refers to a large area of copper foil to fill the blank area left after the wiring, you can shop GND copper foil, you can also shop VCC copper foil (but this short-circuit is easy to burn the device, it is best to ground, unless it has to be used To increase the turn-on area of the power supply to withstand large currents before connecting to VCC). Parcels usually refer to the use of two ground lines (TRAC) to wrap a signal line with special requirements to prevent it from being disturbed or interfered with by others.

If you use copper instead of ground wire, you must pay attention to whether the entire ground is connected, the current size, flow direction, and whether or not there are special requirements to ensure that unnecessary errors are avoided.

6. Check the check network

Sometimes due to misoperation or negligence, the network relationship between the drawn board and the schematic is different. At this time, the inspection is very necessary. Therefore, you must not rush to hand over to the platemaking manufacturer after you have finished the drawing. You should do the check first and then follow up.

7. Using the simulation function

After completing these tasks, software simulations can be performed if time permits. Especially the high-frequency digital circuit, this can find some problems in advance, greatly reducing the future debugging workload.