When it comes to PCB processing, it is not often that you are able to come up with something completely new. There may be some notable exceptions, but often a new process is more honestly an adaptation of a similar process, perhaps from another industry segment or a different application.
Examples of this re-purposing are processes like drop-on-demand printing of ident and solder mask. The print heads that were most commonly used for early PCB machines originated from the packaging industry for marking their products. Print heads have now evolved quite a long way and current machines have versions that are much more appropriate to use with electronic manufacturing materials; however, the basic principle remains the same.
In many instances, process technology is not really new but it is new to the user. When a customer upgrades an etch line from a standard machine to an etch chamber that uses vacuum technology, the process is most definitely new technology for that user. In this respect, there is a large amount of new technology around currently in our industry. The vacuum etch process uses topside vacuum heads after each line of spray nozzles to remove the puddle from the top side of the printed circuit.
The effect of this is that the top and bottom side etching is a lot more even. The effect can be useful if you are making products with fine line and space or if you are using heavy copper materials. Even for standard products there should be a notable improvement in performance. Right now, vacuum etch is a hot product.
Another process that is new to a lot of customers is vertical continuous plating (VCP). Instead of using a traditional gate-type transporter arrangement, VCP is laid out in a single line of process with the process panel being carried though the process in a linear direction, similar to an old-fashioned tab plater (remember what I said about there being very few truly original ideas).
Conveyorised platers have been around for quite a while, but many of the horizontal versions have quite a few shortcomings when it comes to maintenance and care of process. VCP allows easy access to the spray bars and sumps and topping up soluble anodes is very simple. VCP works in a similar way to a horizontal process line but turned on its side.
This process has picked up steam already in Asia, but interest is now starting to gather in other parts of the world with some interesting applications being put forwards to benefit from the technology. Similarly to the vacuum etch mentioned above, VCP offers improvements in distribution—especially when combined with pulse rectification. I have seen trials of this combination that have been able to offer a better than 1:1 ratio of copper in the hole compared to the surface of the panel. This allows some products to be manufactured by a simple and relatively cheap panel-plate process that could only have been made by pattern plating before.
Sometimes it is the actual PCB manufacturing process which undergoes innovative changes. Recent years have seen some interesting developments such as stretchable flexible circuits. These circuits have a base material and circuit pattern that allows them to stretch and flex in ways that a traditional flexible circuit would never be able to. Applications for this technology are only just starting to develop. The dynamic nature of these circuits allows them to be integrated into fabrics and clothing. Electronic medical equipment and sensors could quite literally be part of the clothing being worn by the patient with much more flexibility and comfort than more traditional electronics.
Military clothing could be made to monitor the condition of the heart rate and blood pressure of the wearer and communicate back to mission control. In cold climates, emergency heating could be integrated within your underwear.
Outfits for stage performers could quite literally be part of the light show and these high-tech clothes could be safe to pass through the washing machine.
Another recent development has been supersized multilayer flexible circuits. A company called Trackwise in the UK is currently manufacturing multilayer flexible circuits more than 40 meters long. They have developed a manufacturing method allowing them to replace traditional wiring in a wide range of applications.
They can even offer options such as impedance control over extended track lengths, which in turn is allowing their customers to develop their products in ways that were previously simply not possible.
It is wonderful how the PCB industry continues to develop and evolve. Good ideas and innovation will continue to open new opportunities and markets. For those of us who work in the supply of equipment, we are constantly having to push our designs to better serve the new ideas of our customers. If somebody wants to electroplate a circuit that is more than 40 meters long it takes some fresh thinking to come up with a cost-effective method.
The long-term success of machinery suppliers is very much tied to that of our customers, so we too need to play our part in the development chain and make sure we can meet everchanging demands. There can be a downside to some of these new manufacturing ideas. If you want a oneoff special machine to enable you to produce your new and innovative product, there is usually a cost premium to be paid. There must be a reasonable market for your new products to make commercial sense of the time and effort and expense of making changes to manufacturing processes.
Change can be difficult for all kinds of reasons and costs of improvement can be hard to control. The alternative, however, is not really an option. If nothing changes it certainly will not get any better. If you use your new technology wisely then you can get a step in front of your competition.
My advice this month: innovate and prosper!
Marc Ladle is director at Viking Test Ltd. To read past columns or to contact Ladle, click here.
To read the March 2018 issue of PCB007 Magazine, click here.