Cómo se realiza el proceso de fabricación de PCB de forma supereficiente

Printed circuit boards, or PCBs, are the foundation of most electronic devices and is achieved through the PCB manufacturing process. They are made by layering thin sheets of copper onto a non-conductive substrate, and then etching away the excess copper to create the desired circuit pattern.

Las placas de circuito impreso pueden ser muy sencillas, con sólo unas pocas trazas de cobre, o extremadamente complejas, con varias capas de circuitos interconectados, formando efectivamente una malla 3D. El proceso de fabricación debe controlarse cuidadosamente para garantizar que la placa de circuito impreso acabada cumpla las especificaciones deseadas sin que falte ningún contacto o sea intermitente.

There are several methods that can be used to create the circuit pattern on a PCB. The choice of method will depend on the complexity of the desired pattern. The key common methods, used also in the 2 videos below, for creating circuit patterns on PCBs are photolithography and etching.

PCB Manufacturing Steps

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    Fotolitografía is a process of using light to create the desired circuit pattern on the PCB. This first step of the PCB manufacturing process begins with the application of a photosensitive resist onto the PCB surface, which is then selectively exposed to ultraviolet light through a mask that contains the desired circuit pattern. The exposure hardens the photosensitive material in the areas corresponding to the circuit design, while the unexposed areas remain soft and are subsequently removed during the development phase. This leaves a detailed pattern of the circuit on the board, allowing for the etching of the underlying material to create conductive paths. Photolithography allows for high precision and repeatability, making it possible to produce complex and densely packed circuits that are essential for modern electronic devices.

  • Grabado: this next step is to etch away the exposed copper to create the desired circuit pattern. There are many different etching chemicals that can be used, depending on the type of copper being used and the desired results. Once the etching solution is applied, it reacts with the exposed copper, efficiently eroding it away while the protected areas remain unaffected. This method allows for the precise and efficient creation of complex circuit designs, making it a vital step in the manufacturing of electronic devices. Advanced etching techniques and equipment have been developed over time to improve accuracy and reduce environmental impact, further enhancing the capabilities and sustainability of PCB production. Once the etching is complete, the remaining photoresist is removed, leaving behind the desired circuit pattern on the PCB.
  • The next step is the application of solder mask, a protective layer that insulates the copper traces and prevents solder bridges during component placement. This is typically done through a process called solder mask application, where a liquid photoimageable film is applied and then cured using UV light.
  • Next, the silkscreen process is employed to print component identifiers, logos, or other necessary markings on the board. Following this, the boards undergo a surface finish process, such as hot air solder leveling (HASL), immersion gold, or other methods, to prepare the copper pads for soldering by enhancing their solderability and protecting them from oxidation.
  • Drilling is another critical step in PCB Manufacturing, where precise holes are created for component leads and vias, often using computer-controlled machines to ensure accuracy. Once drilling is complete, the boards may undergo plating to coat the drilled holes with copper, creating electrical connections between different layers.
  • Finally, electrical testing ensures that the PCB functions as intended by checking for shorts, opens, and other defects. Each of these processes is vital to producing a reliable and high-quality printed circuit board ready for assembly.

Estos pasos se muestran con mucho más detalle y explicaciones en las dos fábricas de placas de circuito impreso que se muestran a continuación, desde la entrada de pedidos hasta el control y el embalaje, logrando los impresionantes KPI de

• tiempo total de entrega desde la recepción del pedido hasta el envío: de 2 a 4 días
• Más de 5000 pedidos al día

y esto para pedidos unitarios, no necesariamente clientes que regresan, para profesionales y no profesionales -lo que implica posibles errores en la demanda-, y algunos controles de diseño y calidad a lo largo del proceso. ¡Inspírese!

En PCBway:

And then how its main competitor does it, JLCPCB

For further electronic vocabulary, PCB types, and components footprints, refer to the PCB and electronic reference detailed Post or Wikipedia PCB Manufacturing página.