What is the Life span of etched PCB using Ferric Chloride

[yusuf]

Hi friends..
What is the Life span of etched PCB using Ferric Chloride.. I mean after etching process .. How many days will the copper track will work properly..

 

[JimB]

How many days will the copper track will work properly.

What a strange question!

The quick answer is forever.

This assumes of course that the etched circuit board is completely washed to remove all traces of ferric chloride.

JimB

 

[yusuf]

Thanks Jmib for your reply and help !

But , If the copper clad has being etched with ferric chloride solution.. and it will last forever ..

Then why the company's or industries doesn't uses it...
Why their board are different from our's (Which has being etched)

Is there are advantages and disadvantages of copper clad which has being etched by ferric chloride !

and What is UV technology , I have heard that this technology is also using in etching...

If this simple ferric chloride can accomplish all without any problem ; then Why these technology exists !

 

[JimB]

Have a look here to find lots of information about the manufacture of PCBs
https://en.wikipedia.org/wiki/Printed_circuit_board

But , If the copper clad has being etched with ferric chloride solution.. and it will last forever ..
Then why the company's or industries doesn't uses it...
Why their board are different from our's (Which has being etched)

The world is not black and white, there are often many ways of doing something, each was has its own advantages and problems.
Different companies chose a method which they think gives the best compromise for their situation.

Is there are advantages and disadvantages of copper clad which has being etched by ferric chloride !

I have no idea!

and What is UV technology , I have heard that this technology is also using in etching...

I have no idea!
It sounds like a way of getting the required copper pattern onto the etch resist.

If this simple ferric chloride can accomplish all without any problem ; then Why these technology exists !

Like I said before:
Different companies chose a method which they think gives the best compromise for their situation.

JimB

 

[yusuf]

Thanks JimB for your co-operations !
As you are senior for me !
Was pcb etching with ferric chloride was good and long lasting according to your life experience in etching pcb with ferric chloride...

I respect seniors and obey their commands !

 

[DirtyLude]

I have ferric chloride etched boards that are at least 10 years old now and don't show any signs of decay. If you want them to last, make sure they are very clean after etching. You can use some type of conformal coating to keep the copper from tarnishing. I don't know if it makes them last longer, but the ones I've used conformal coating on still look good and the ones I haven't are pretty tarnished.

 

[yusuf]

You can use some type of conformal coating to keep the copper from tarnishing.

What is conformal coating , friend ! And how do I implement on the PCB..

 

[jpanhalt]

The original question is unclear, but one could interpret the question about whether there is any advantage to using ferric chloride as being related to the quality of the board produced, not its longevity.

Undercutting is one of the major variables to consider in terms of quality. Of course, speed, cost, recycling, etc. are other considerations. ChemCut has published a study that focuses on undercutting and speed. Here is the link:

https://www.electro-tech-online.com/custompdfs/2012/01/Chemcut20Thoughts20on20Undercut_Doc.pdf

As for some of the other factors, here is a report from California. I searched to see what it had to say about ferric chloride, and it is not mentioned per se. One factor that is critical in commercial processes is the stability of tin/lead plating to the etchant. While ferric chloride gives low undercutting, it also affects such plating, which may explain why its use is not considered in this publication. Note the date on the CA publication is 1999. There may have been changes since then as use of lead has become much more restricted since.

https://www.electro-tech-online.com...ologies-printed-circuit-board-manufacture.pdf

John

 

[JimB]

Was pcb etching with ferric chloride was good and long lasting according to your life experience in etching pcb with ferric chloride...

Why do you think that a circuit board could be unreliable?
What has put this idea into your head?
As I said earlier, "What a strange question!"

Just looking at the test equipment in my workshop, there is an oscilloscope, signal generator, spectrum analyser and tracking generator all made in the 1970s, they are getting on for 40 years old, admittedly some of them were the very best available at the time, but there are no problems with the circuit boards.
Maybe a capacitor or transistor may fail now and again, but a circuit board trace - never.

JimB

 

[shokjok]

I have a homemade bike trailer taillight interface that I designed in 1987, etched with FeCl and still working to this day, even in sub-zero temps. The circuit has 14 components, all original, and operates from a garden tractor battery carried in the trailer. The PCB is larger than a credit card, easily serviced and has traces of tarnish nowhere near the green coppertop roofs of Canada's Parliament buildings in Ottawa, Ontario.
No photos of this interface exist, only the circuit. It fit inside a Micronta 270-212 plastic case ( from the former Radio Shack in Canada, nka Source by Circuit City).

 

[Boncuk]

Hi yusuf,

PCBs have to be etched with some kind of etchant which ferric chloride is one of.

The PCB should be well rinsed after etching to remove the smallest leftover of etchant.

When the board is populated and has been tested it is a good idea to spray clear laquer on the solder side to avoid oxydation of copper.

I built an rpm-meter about 50 years ago and after 30 years many narrow traces had deminished caused by oxydation.

It's not so much the etchant you have to worry about, but it is oxydation.

Copper roofs are somewhat different from a copper clad of 35um copper layer. The copper used for roofing has a thickness of at least 1mm and the oxyde layer turning green when aging prevents the copper from further and destructive oxydation.

Boncuk

 

[yusuf]

When the board is populated and has been tested it is a good idea to spray clear laquer on the solder side to avoid oxydation of copper

Thanks boncuk for your reply.. But what is laquer !
Is this any chemical or any type of spray... And what will be the ratio of applying.

 

[Boncuk]

Laquer is a kind of paint. (It's also calle varnish)

If you use a spray can the ratio is given by the content of the can.

Use three to four coats (after allowing enough time to dry) for a long lasting PCB.

Boncuk