Printed Circuit Board Assembly

Printed Circuit Board Assembly

Also referred to as a PCA, the Printed Circuit Board Assembly follows on from Printed Circuit Board Manufacture. This is where the components are placed onto the PCB or Printed Circuit Board and the electrical connections formed.

 

In this post I will focus on volume manufacturing techniques. We also make Printed Circuit Board Assemblies in house by hand loading very small quantities. This is appropriate for prototypes and Niche Manufacturing quantities.

 

To start with, let’s look at the 2 types of components we most work with. The first type is the Through Hole Component. These have pins that go through the PCB to make electrical connection. These components dominated PCB Assemblies until the 1980s when higher PCB loading density requires a change of technology. They are still widely used where mechanical strength, tall components, heavy components or high current levels are involved. An example is shown below with the connectors, relays, transformers and removable components as Through Hole with the Surface Mount Components toward the centre:

 

Through Hole Technology

Through Hole Technology

The second type is the Surface Mount Component or Surface Mount Device and the overall process is referred to as Surface Mount Technology or SMT. These devices do not require holes through the PCB to mount them and so can be placed closer together and it also improves track routing options because tracks can run on the other side of the PCB without having to avoid the through holes. An example of all Surface Mount assembly is shown below in close up:

 

Electronics Hardware

Electronics Hardware

Printed Circuit Board Assembly Process

The infographic below was provided by Algen Cruz of Advanced Assembly in the USA. Algen also provided a brief explanation to go with it and I have added that as well. You can click on the infographic to view a larger version.

 

Printed Circuit Board Assembly

Printed Circuit Board Assembly

 

“Design-for-Assembly (DFA), although not as well known as Design-for Manufacturing (DFM), needs to be taken into account during the design phase. And the first step in being able to design-for-assembly is to understand the assembly process. This infographic features this process by showing how a board goes from an unpopulated printed circuit board (PCB) to a final product, ready to be packaged and sent to consumers.” Algan Cruz

 

 

Successful Endeavours specialise in Electronics Design and Embedded Software Development. Ray Keefe has developed market leading electronics products in Australia for nearly 30 years. This post is Copyright © 2015 Successful Endeavours Pty Ltd.

The Future of Low Cost Electronics Manufacture

High End Electronics

In the early days Electronics was hand wired on a chassis. Some high end valve amplifiers still do this. Check out:

 

Hayden Valve Guitar Amplifiers

 

Guitar Player reviews 6 hand wired valve amplifiers

 

Gibson valve amplifiers

 

Fender Vibro-King Custom

 

Torres amplifiers – build it yourself

 

Marshall Hand Wired Series

 

But of course this isn’t very compact. For those who didn’t know, I am a guitarist and use a Carvin MTS3212 Master Tube Series tube amplifier which I still enjoy very much. So when compact isn’t a priority and cost isn’t as important as the sound, then you go for this sort of amplifier. This is another example of the trade-offs we discussed in the Project Priorities Perspective where it’s about Performance and Cost is the lowest priority.

 

 

Low Cost Electronics Manufacture

For Low Cost Electronics Manufacture however, there are other factors that come into play. You want quality and you want it in a timely manner but the cost has to be low so that you have a decent profit margin. So hand wiring is out because that is expensive.

 

Very well designed Printed Circuit Board PCB can produce excellent results and with the move to Surface Mount Technology SMT and the Surface Mount Device SMD the Component Loading Cost is also reduced as components are put in place by machines and there are no leads or tails to trim after soldering. So this really helps with Electronics Manufacturing Cost and for at least the next little while will remain the way to go.

 

Another strategy for reducing cost is to use a modern Integrated Circuit IC because you can fit more functions into a more complex device and although it sometimes costs more for that individual device, you can reduce cost by removing other devices, reducing size and reducing loading and handling costs.

 

Reducing size reduces cost because you get more Printed Circuit Boards on a Panel and the cost of a panel in general is roughly the same ragardless of how many PCBs there are on it.

 

 

Emerging Electronics Technologies

But the future is approaching and there are some very interesting developments under way. These involve Organic Semiconductors and Printable Electronic Circuits. Check out the following links:

 

printable electronics – a game changer

 

printable electronics on the rise

 

printable electronics to surprass $7 billion in 2010

 

Organic Semiconductors

 

Organic Semiconductors in a spin

 

I was particularly interested in the idea that the number 1 piece of equipment purchased by universities and Research and Development corporations conducting Electronics Research would be an inkjet printer! And did you notice the convergence between these 2 Low Cost Electronics Technologies?

 

We are in for interesting times indeed when you can design your circuit and then prototype it on your printer.

 

Ray Keefe has been developing high quality and market leading electronics products in Australia for nearly 30 years. For more information go to his LinkedIn profile. This post is Copyright © Successful Endeavours Pty Ltd.