Silkscreen trace widths and font sizes

[Thermal Runaway]

Hi everyone,

With regard to component dimensions drawn in the silkscreen layer (to aid clarity of component location/orientation), I have the following queries which hopefully a more experienced PCB designer can clear up for me.  If not I'll just ask a local fab house instead.  Here goes:

1. Is there any agreed standard for the width of the lines? I've been using 0.2032mm (0.008"), but I wonder if there are set widths that fab houses generally use? Or, will they literaly print any width I want provided that it's above a certain minimum width (obviously there'll be a limit to how fine a line you can physically print with silkscreen paint)?

2. Is there any agreed standard for the proximity of silkscreen print to copper pads? I've been sticking to a 1mm gap.  So, if I've drawn an outline of a component, I always make sure that the outline stops once it gets within 1mm of any pad.  Does this sound reasonable?

And, with regard to text placed in the silkscreen layer:

1. Are there agreed sizes of text that fab houses will print? Or can I literally generate text any size I want provided it's bigger than some minimum (dictated by the physical properties of the silkscreen paint)?

What I'm trying to avoid is any situation where I draw something in the silkscreen layer that I think is going to be a certain width/size, and then the fab house automatically steps it up/down to meet their requirements.  If this is going to be the case I'd rather meet their requirements in the first place so that I can be certain that my PCBs are going to look like I expect them to.

Thanks in advance all.

PS Dave, if you happen across this post, any chance of a dedicated PCB design section for related queries?

Brian H.

[Time]

You could put the mona lisa in your silk screen and most places would print it.  Its basically like a printer so its really just whatever size you think looks best.

[johnmx]

You could put the mona lisa in your silk screen and most places would print it.  Its basically like a printer so its really just whatever size you think looks best.

I’m not sure about that.

There is no standard width. E.g. Eurocircuits can print lines with a minimum of 7mil. Anything higher will be OK. They also recommend using a minimum text height for good readability of 39.5mil.

About the distance from copper pads, they have a minimum of 4mil. This distance is measured from the text line to the soldermask opening or the copper layer in the absence of a soldermask layer. The minimum distance from the board edge is 10mil.
Don’t place any silkscreen text on top of the cooper layer without a soldermask layer.

Last Edit:
“Amiga Computer fan…” it reminds me of my youth. I spent very good times in front of an A500 and later an A1200. Great nights without sleeping 

[Thermal Runaway]

Thanks both, very helpful indeed.

JohnMX:

Yeah I was a huge Amiga fan as well, and I also spent many an evening on my miggy - first an A500+, and then later an A1200.  Much like yourself really.  The only difference is, I'm still an Amiga computer fan!

I still use my Amiga regularly.  Unfortunately I had to demote her from the position of my main machine in 2004 because all the electronics related applications I use are on Windows.  I still use her for general computing, some programming stuff, some hardware development and also general purpose internet browsing/emails.  Firefox is being developed for AmigaOS at the moment, as is Open Office.  Once those two applications are released then I'll probably be able to justify her use a bit more!

Here's some screen grabs from my A1200 back in 2004.  I should do some recent ones - she's running OS4.1 now.

www.brianhoskins.co.uk/images/AmigaOS3.9_April2004_1.png
www.brianhoskins.co.uk/images/AmigaOS3.9_April2004_2.png

Thanks again for the advice,

Brian H

[baljemmett]

www.brianhoskins.co.uk/images/AmigaOS3.9_April2004_1.png

I approve of the playlist; the first album has some real crackers on it that sadly go unnoticed by many!

[Thermal Runaway]

I approve of the playlist; the first album has some real crackers on it that sadly go unnoticed by many!

+1 to that! I have all their studio albums - excluding "best ofs".  Actually I rarely listen to playlists, I'm much more an album person.  That's why I generally don't do "best ofs" ;-)

Brian H

[johnmx]

Speaking of computers…Unlike most of the people that started with the legendary ZX Spectrum, I started with a Philips MSX2 (see attached picture) when I was seventh (1986). It had 128k of RAM, one internal 3.5" Floppy disk drive (single side 360k), printer, cartridge with MIDI interface and internal microphone and a MIDI keyboard. I made music with digital samples of my voice! That was simply amazing for that time. Unfortunately I lost all the recordings made on tape. For me the best game ever developed was definitely ‘Alest’ (1988):


Meanwhile I bought a Timex 2048, a Spectrum +2 and also a +3 (all of them in second hand). All garbage compared to MSX2.

Some years later I sold the MSX2 to buy a new A500. Later I sold the A500 to buy the Amiga 1200. After a while I had the A1200 equipped with an 80G 2½” HDD, modem Supra Fax (2400bps), 2 external floppy drives, 500 floppy disks with games (X-copy rocks!!) and a lot of joysticks.
In 1994 I exchange the A1200 for a 486SX@50Mhz, the worst thing I ever done. That was the end of Commodore era for me.

Almost forgot, my biggest brother offered me a CDTV with infrared trackball and infrared mouse. But since the A1200 was a better computer I only used this one to listen CD music. I didn’t have any game in CD, just in floppy disks. Don’t remember what I have done with it…probably I sold it to someone…

By the way, do you know SLAY Radio? I hear it almost every day
http://www.slayradio.org/home.php