Minimum trace thickness

[Rame]

Minimum trace thickness required in recent times

What is the standard trace thickness used for multi layered,multi signal board.?

 

[KlausST]

Hi,

Did you try to find the information on your own? (I doubt it.)
Where? At the place where it is produced: the PCB manufacturer.

A simple search "pcb copper thickness" gives many, many, many results.
Often you find: 1oz Cu per square foot, 1.0oz. = .0014″ (35 microns) , 35um, 0.035mm
Other thickness for sure is possible...

Klaus

 

[Rame]

Hi,

Did you try to find the information on your own? (I doubt it.)
Where? At the place where it is produced: the PCB manufacturer.

A simple search "pcb copper thickness" gives many, many, many results.
Often you find: 1oz Cu per square foot, 1.0oz. = .0014″ (35 microns) , 35um, 0.035mm
Other thickness for sure is possible...

Klaus

Thanks a ton for your prompt reply,do appreciate.Yep I did try gathering some info on that.However trace thickness varies according to the PCB Manufacturing capability and I was curious to know from this perspective from different region globally.
You did respond to me on info for the copper thickness whereas I did ask for minimum trace thickness used generally in digital boards.Anyway thanks again for your reply.

Regards,
Ramesh

 

[KlausST]

Hi,

Copper thickness = trace thickness.

Or do you mean minimum trace width?

If you want to know minimum values you have to contact the manufacturers, individually.

Klaus

 

[FvM]

Sounds like Rame means trace width rather than trace thickness (copper weight).

These days, I get 150 µ or 125 µ from most PCB manufacturers at no extra costs. Thus I would rate it as industry standard technology. High volume production might choose wider traces to increase reliability and production yield if technically possible.

Complex PCBs often use 100 µ trace width, real high density possibly 70 µ.

 

[c_mitra]

Sounds like Rame means trace width rather than trace thickness (copper weight)...

Right; width is often spoken as thickness. It is an Indian peculiarity.

 

[Warpspeed]

Re: Minimum trace thickness required in recent times

What is the standard trace thickness used for multi layered,multi signal board.?

Your best bet is to talk to some of the local circuit board manufacturers about what they can do for least cost. That applies to copper thickness, track width, and minimum clearances. There will be some typical figures that the board manufacturer is used to working with, and will generally be the lowest cost.

Then design your boards around what can be put through the board manufacturers normal manufacturing process requiring no special steps or extra precautions.

 

[Rame]

Thanks a ton guys to everyone for pitching in and answer my query.I'm in touch with couple of PCB Manufacturers and got the info i needed.Thanks to Fvm for understanding my query and thats what meant in my query though.Anyway here in india trace width is considered in mils(1 inch=1000 mils).

As to our standard from bangalore the minimum trace width in any digital boards are 3 mil width with 3 mil spacing,and I guess USA and other european countires would do much less then the one said above beacuse of their advance technology in pcb manufacturing.If any of our guys could shed light on this topic would appreciate;-)

 

[Warpspeed]

One other slight detail might be preferred hole sizes.

They probably have some king of automatic drilling machine that selects drill sizes from a pre set inventory of standard sizes. If you specify an odd size, someone will have to load the required drill into the machine and reprogram the machine to recognise the change. Its a very minor matter, but its still a bit of extra work for someone.

So if you can get a preferred list of standard drill sizes from the board manufacturer, and stick to specifying just those, they will love you.

The trick to getting a low quote is really to make everything as easy and trouble free as possible for the guys that get to make your boards.

 

[jane810314]

Hi Rame,,

In PCB manufacture, we don't say trace thickness, we always say copper thickness.

Trace thickness=copper thickness, 1oz is most customers choice, if the boards isn't power PCB.

Hope it can help you.

Jane Soong

 

[mtwieg]

Sounds like Rame means trace width rather than trace thickness (copper weight).

These days, I get 150 µ or 125 µ from most PCB manufacturers at no extra costs. Thus I would rate it as industry standard technology. High volume production might choose wider traces to increase reliability and production yield if technically possible.

Complex PCBs often use 100 µ trace width, real high density possibly 70 µ.

If they don't charge extra for 150u, then chances are that means they are overcharging for the wider feature specs :razz:

Typically I go with 8mil trace/space, and 6mil on designs that need it. I don't do high density digital designs, though.

One other slight detail might be preferred hole sizes.

True, in my experience via size will be as much as a limiter as width/spacing limitations. A good fabhouse will allow down to 8mil holes with 18mil annular ring diameter with no extra cost.

 

[c_mitra]

My best suggestion is that use the widest trace consistent with your signals and power requirements. I of course do not know how complex your circuit is.

 

[Mattylad]

If your going down to 3mil then your putting the cost of the board up so like C_Mitra suggests, use the widest track width available to you (considering spacing, voltage spacing etc).

Down below 4 mil can put the cost up esp if your designing something for high volume cheap costs.

 

[c_mitra]

Trace thickness=copper thickness, 1oz is most customers choice, if the boards isn't power PCB...

The units used are often so confusing: 1 oz copper is about 50 micron; or 2 mils (this is easy to remember: 1 mil is one thousand part of an inch or 25 microns)

After cleaning polishing etching etc. perhaps 40 micron will be left over. For mechanical purpose, it is good to have width double the thickness- or about 50-100 micron or 2-4 mils.

The copper is stuck to the base with some glue. Thin traces will heat more with high current.

By the way, how many layers you are going to use? double side PCBs are rather routine and four layers are not uncommon.

 

[Rame]

We have left with no option here as it is for prototype boards so we need not worry on the cost because we have aleady got money allocated from our authority.So lets see how the things going to turn out on couple of testing we are planned to carry out on the board after assembly.

Thanks to everyone here who contibuted to this thread;-)
Regards,
Ramesh

 

[nikihong]

Re: Minimum trace thickness required in recent times

What is the standard trace thickness used for multi layered,multi signal board.?

If only the ordinary two-tier board, a wide line of 8mil is ok, that is about 0.2mm,
If the alignment of the multi-layer board, the mill can process 5mil line, that is about 0.125mm

Best regards,
Niki

[email address removed]

 

[bilal_oct]

If in a layout the trace width is reduced let's say from 20 mil to 5 mil. Does it radiate more ? which also means more cross talk ?

 

[Warpspeed]

If in a layout the trace width is reduced let's say from 20 mil to 5 mil. Does it radiate more ? which also means more cross talk ?

Current density through the track will have no effect on magnetic radiation, only on voltage drop and track heating.
Magnetic coupling depends on total current flow, frequency, and enclosed loop area.

 

[mypcbshop.com]

In our case it depends on the copper base and many other factors.
Still I assume it works the same way for other manufacturers as well

 

[PCB Designers]

Re: Minimum trace thickness required in recent times

What is the standard trace thickness used for multi layered,multi signal board.?

If you are asking about trace width then :

Few weeks ago, we routed a board for a Taiwan Fab House where trace width was 1.8 mils under the BGA Vias.