Step 6: Silk Screen

A silk screen is all the printing, information and component outlines shown on the top of the PCB. This is useful for stuffing components and later for troubleshooting. Probably you will do parts of this procedure in conjunction with the traces but I made it a separate step.
So we have to create an image for the silk screen.
Eagle: In the board editor, there is a little icon called Display (Show/Hide Layers). Click on it, select <None> then click on (highlight) these layers:
Now, just the silk screen and pads should be displayed.
Select <File><Export><Image>
          <Browse> Select the directory and file name that you want.
          Click <OK> to export as image.
Again you will notice that the stuff you want printed is in white and needs to be black so again we need to Invert. So what isn’t so obvious is that since the silk screen goes on the opposite side of the traces we need to flip the image. Here’s my procedure.
Make Invert and Flip:
Open Image with PhotoShopElements
<Image><Crop> Crop <Check>   Crop the image to contain the outline and dimensions
<Select> All
<Image><Rotate><Flip Horizontal>
See picture. Note that the printing is mirrored.
Use the same procedure as with traces.
Mark the blank printer sheet.
Print the silk screen.
Cut the vinyl.
Attach it to the printed page.
Stick the paper/vinyl in paper feed.
See picture.
Cut the paper/vinyl leaving about ¼” border around the silk outline.
Aligning the silk screen with the traces:
I know when I cut copperclad and tape it to traces it is far from perfect. This makes it a little harder to aligning the silk screen with the traces.
So what I do is take the etched PCB, find a couple of pads on opposite sides of the PCB and drill them out.
I find the same holes on the paper/vinyl and drill them out or open them with an Xacto.
Next I take a couple of cut off resistor leads, insert them into the two holes and insert them into the matching holes in the silk screen. See picture.
Now the silk screen should be properly aligned with the PCB.
Scotch tape the PCB to the silk screen.
Remove the resistor leads and trim the paper/vinyl.
Warm up the laminator and follow the same procedure as with traces.
Be careful, the copper side gets hot. Use gloves if you want.
The silk screen came out pretty good. The backside of copperclad is not the best surface to be printing on. I’m not sure how to keep the silk screen from wearing off. I imagine there’s some good spray on clear sealant?
See picture.
TIP: I’ve been doing another thing, I didn’t mention. In Photoshop Elements, I open a blank file and copy the traces and the silk to it. Depending on the size, you can have multiple copies of each. With this file you can print the traces and the silk at the same time and even make multiple copies if you’re planning to make more than one PCB.
Conclusion: I like this method of making PCBs with my laminator and vinyl stickers. They seem to be more consistent and it apparently will do much smaller traces then my old glossy paper & iron method. 
I did not have much success with toner transfer with glossy magazine. <br><br>Using vinyl for transfer is much better, and this attached photo is the very first time I use this method for toner transfer. The reault is very good, almost 100% toner is transfered. I see some distrotion near the edge, probably due to uneven pressure + very hot temperature from iron. <br>
Very nice job. Yes, I like the vinyl better than glossy paper. I also like using my modified laminator instead of an iron. It seems to apply a more consistent pressure. But also since I'm old it's less strain on my back.<br><br>LOG
1 Question , are the switches N.C &quot;Norm Closed&quot; or N.O &quot;Norm Open&quot;.. im thinking N.C but making sure before i buy this stuff.. thank you
Yes, the thermal switches are N.C. <br> <br>LOG
so do you leave the vinyl on the board then etch it?? I have access to a professional vinyl sticker plotter.. it could easily print and cut my trace pattern... do I just print the pattern I want and stick it to the board then etch it? I haven't etched a board yet, but Im planning on doing so real soon.. If I stick the vinyl sticker to the clad and soak it it will the solution eat away the vinyl sticker too???
I don't understand what you mean by 'cut my trace pattern.' Does that mean it's like a stencil? I think I've heard of somebody doing this but don't know how it works. I think what you may be talking about is something like this Instructable: <br>https://www.instructables.com/id/Fast-and-Easy-PCB-Prototyping-with-Vinyl/ <br> <br>My method is a toner transfer method. If the plotter uses a laser to print then it should work. What I do is print traces on vinyl with a laser. Then tape the printout to the clad. Run it through the laminator to transfer the toner to the PCB. Then remove the vinyl sticker. Then etch. <br> <br>LOG
what I mean is print the traces where I want the copper traces to be on vinyl and stick it to the clad and put it in the etch solution to remove the rest of the copper that I don't want on the board. the plotter prints and cuts with lasers. It would be very easy for me to print and cut the pattern in the second picture in step 2 where the traces are black and the rest white and stick just the black parts on the clad where the traces are. My question is after I print and stick just the black lines could I put it in the solution and remove all the copper around it without it eating the vinyl away also? We have a large professional laminator I could use to transfer the way you stated also, but I was wondering if I could just put the lines on the clad and soak it that way... for that matter we also have an iron on transfer machine where I could just print the trace pattern on an iron on and use the transfer machine to stick it to the clad that way also... Ive just never made a printed circuit board before but will have the need to real soon and just want to do it the easiest way possible.. thanks
I don't know what would happen if you put the vinyl in etchant. I've never tried it. <br>In that other Instructable I referred to, it sounds like the vinyl won't dissolve in etchant but I'm not sure if you're using the same stuff. <br>Not sure about the iron on either as I've never used it. <br>About all, I can suggest is try various mehods and see if they work. <br> <br>LOG
agreed,, I will just have to try it.. It just seems like that would make it very easy to make my boards... after my last comment I got to thinking, and we have a sandblaster at the shop designed to etch glass around vinyl designs,, so the media doesn't hurt the stickers when its blasted in there, so I could just print the trace stickers, stick them to the clad and blast the copper off the clad around them too.. easy enough and no harmful chemicals at all.. might be a new instructable coming up..
Wow, I didn't know vinyl could withstand sandblasting. I'm not sure if sandblasting would eat away the copper though. But it might be worth a try. <br> <br>LOG
A DIY bubble etch-tank reduces the etching time to few minutes and etches evenly. I built one under &pound;20 using a Tupperware jug, aquarium tube and an air pump. I even added a plastic valve so the acid wouldn't flow back to the pump. If you place a section of the flexible tube on the bottom and make tiny holes on it, you'll get lots of bubbles (the more the better!). Pic <a href="https://lh5.googleusercontent.com/-wdVUoja3Knc/Tkj5dFZneII/AAAAAAAAAVc/ad87_KfYi8w/s818/IMAG0756.jpg" rel="nofollow">here</a>.
Thanks, I've heard of this and might try it. <br> <br>LOG
&quot;Mine were originally 110C and 135C. I think there is a good reason for two different values&quot; <br> <br>If there are two settings on the laminator for different plastic types, there's obvious answer #1. <br> <br>Less obvious answer: However, it could be they are used as a pair to sense the temperature RANGE, as the sensors only give an above/below indicator. So they are wired to keep the temperature above 110'C but below 135'C with a &quot;hysteresis band&quot; to stop the heater cycling madly on and off. If that's the case, replacing both with the SAME sensor may cause the heater to cycle on and off faster than normal. Or maybe not come on/get stuck on, depending on your degree of bad luck. Just a thought :)
Or even: the 110'C on lights the &quot;Ready&quot; light, to show &quot;hot enough to use&quot;, and the 135'C one cuts off the heater as it's too hot, cutting back in before it falls too far.
Correct. I did go into more detail in the above comment. <br> <br>LOG
I donno about your laminator, but I know in dryer's and electric heaters, they have 2 temperature sensors, one opens at a certain temperature, and closes at anything below that. the other, usually a fuse, is at a higher temperature. It's designed so that if the lower temperature switch fails, the 'fuse' pops and shuts things down, requiring someone to physically change the fuse, and hopefully figure out why the lower temperature switch didn't do it's job.. Again, I don't know about your laminator....
I kind of reverse engineered this laminator. Along with the two thermostats, there are two heater circuits. When cold, they're both heating, when the first threshold is reached, one is heating and one isn't, when over the higher threshold both heaters are off. <br> <br>In addition there is a thermal fuse that I assume opens up if the temperature is over it's limit. <br> <br>LOG
Your are basically correct. I drew out a wiring diagram/schematic. The heating elements are AC but each thermal switch is connected through a diode so will only be connected 1/2 of the AC 60Hz. So both heaters are on up to about 110C. From 110 to 135, one is on and both are off above 135C. So it is hysteresis. In addition the thermal switches have hysteresis themselves. <br>So my using two 165Cs, I would guess that the temperature is going to be more consistent but the thermal switches will 'switch' more often and probably wear out faster. <br> <br>LOG
Nice Ible. Thanks. <br>Have you tried photo exposure copperclad and acetate (clear plastic/transparencies) with laser printer? All you have to do is lay the transparency on top of the copperclad under UV light for 5 mins, then etch as usual.
I haven't heard of that one. It sounds interesting, though. Have you had good luck with it? <br> <br>LOG
The process as it is not new to me since i use it since a long time (with special toner transfer-paper, but none the less). <br>But what resulted in a facepalm (in my own direction!) was the idea of the second printing onto the finished (etched) board as silkscreen. <br> <br>The simplicity and cleverness of that are (for me) still mindboggling... Soooo simple and yet soooo nice to have! I feel ashamed to etch since a longtime and never tought of that one... Ahwell. :) <br>Thanks a lot!
The Good: Silk screen makes it so much easier to stuff the components with the right values. The vinyl makes very clear text and outlines. <br>The Bad: It's only laser toner so it will rub off pretty easily. This is okay for me as I generally only use it to stuff the PCB. <br> <br>LOG
Wow, I have been making PCBs for over 30 yrs..... I started out using light sensitive coated boards or spray on light sensitive materials with UV lighting , then etching. <br>Then 20+ yrs ago I progressed to Iron-on pcbs from &quot;techniks&quot; - I still use that today . <br>Print your image, the solder side (a xerox copy) on the &quot;blue&quot; coated sheets then cut the image out and Iron it on the cleaned PCB. let cool then etch SOOOOOOOO SIMPLE
I'm glad it works for you. I've never heard of it before. <br>Question: Do you have to use a full sheet of the blue when you want to make a PCB? <br> <br>LOG
I have been using this &quot;techniks&quot; blue material since the 1990's - they're from Scottsdale Az. originally. Unfortunately when you run the paper thru a copier it prints the whole sheet. So what I do is plan on the projects I have and make 2-3 or more images on one sheet before I use the &quot;blue&quot; that way I can make several boards from one sheet. The material is not that expensive, and it also comes in &quot;white&quot; iron on sheets that after you iron on the image you soak the entire board until the white paper floats off - leaving the image on the board. But it takes a lot more heat to transfer the image. So I use &quot;blue&quot;. And dont crank the iron on &quot;Hi&quot; it will melt the plastic material; <br>start off on low and slowly turn the iron up, you will find the right transfer temp that doesn't deform the plastic. Note that setting, the image turns blue black when ironed on. And peels off real easy after it cools <br>
I guess that's one advantage to the vinyl sticker. I only need to cut a piece slightly larger than the PCB. Saves some cost. <br>Although it's possible you could do something similar. Print to plain paper, Cut a piece of Blue slightly bigger and double sticky tape it to the printed paper, then reprint onto Blue. <br> <br>Thanks for the info. For now, I think I'll stick with my vinyl as I have a lot and don't see any advantages of switching to 'blue.' <br> <br>LOG <br>
Very nicely done and well explained. -Lee
The easiest method that actually works is just using a laser printer with normal paper. I have done it and all you have to do is iron and press for about 5 minutes with a lot of pressure.
Never heard of just using plain paper before! Does it take more pressure than glossy paper? <br> <br>LOG
Yes, but just a couple more minutes of pressure. Removing the paper is really easy. Just run it under water and scratch it off.
Ahh yes but with normal paper you have to SOAK the PCB in order to remove the paper ! <br> <br>With This Vinyl approach theres absolutely no time wasted soaking, just lift the vinyl off of the copper clad board as soon as it cools down from coming outta the laminator and hey-presto, the artwork is on there !!! <br> <br>No more messing around with soaking/paper pulp removal/broken traces from scrubbing the paper pulp off the board, no more collecting magazine paper/finding the right magazine paper or getting magazine paper jams in the laser printer and just beautiful boards perfecto everytime lol ;-) <br> <br>But then we had to start somewhere for our homebrew PCB's lol ! <br>Now were evolving lol !!! <br> <br>Dead simple Vinyl approach, LOVE it !!!!! <br> <br>Ive tried quite a few ways too and HIGH Praise to L.O.G for this instructable !!! Once again another Darn Great How-To for us !!! <br>;-)
This is definitely my favorite method of making PCBs. <br>And thank you for the tip. <br> <br>LOG

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