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PCB traces

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freeskier89

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Hi, I have the materials to make two 4x6 press and peel printed circuit boards, and I have not ever made pcbs before. I need to use one full board for a project and I really need to get it right the first time. Do you have any tips or pointers?

Well, my specific question is, what do you think is the minimum trace width that I can make with out error? Does my pcb look structurally alright? The max current I will be running through sections of the board is 1A. The pcb below is not finished.

Thanks,
-freeskier89 :D
 

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Those Pads are So Small I Doubt they will even Etch OK.
Even if they do, The Drill Bit will probably Distroy them, Long before the Soldering Iron.

Try using IC Pads of about .07 Inch Square.

Use Traces of .03 to .05, Bigger if needed for High Current.

Use Parts Pads of .08 to .1 Inch, Bigger if for mounting Large Parts such as Power Transformers and Large Relays.

Fill In Some Ground Areas.

Besides, The Bigger the Traces and Pads, The Less Etchant you use.
 
Thanks for all of the replys, they are really important suggestions. I'll fix the pcb and then repost it. Im using ExpressPCB, and the image export kind of screws up the image, so the pads are probably a bit bigger than they appear. I still agree that they need to be larger though.

Thanks again,
-freeskier89
 
Alright I modified the pads, and everything fits under your guidelines chemelec. Thanks they helped alot :D the to-220 pads are a bit too close together so I need to reduce them in size. The computer/program makes everything smaller, but when printed everything looks much better. I have one more question, Do you normally drill the holes before or after the etching process?
 

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Without knowning how critical the circuit is, it is hard to give you all the guidelines of drafting it.

But the 3 pads, top right have Very large holes. Use Small holes to guide your drill better. You can still drill it lage if required.

If the Circuit is Low Frequency (Not Critical Layout), You can Fill Areas to result in Less Etchant.

Having a Small Pad with no trace often results in it being pulled off when Drilling it. A Small short trace to one side is usually not a problem.
Or Make a Bigger Pad. You have Lots of room for Either on this particular pattern.
 

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Just as a Note: Look at my File Size compared to yours.
I Converted it to 2 Colors and saved it as a PNG format.
Much Smaller and a Quicker Loading time.
 
wouldn't it be better if the tracks are straighter?

and I suggest not using tracks thinner than 0.5mm
 
The big holes should be fine, and Ill check them before I make the pcb. It is for a DC power jack.

The unused pads will be used later. The layout is not completed yet.

Thanks for the tips! I will make sure to fill in the large unused areas, but when the design is done there won't be many open spots like there are now. About the filesizes, I was aware of that, ill use a png with a 2 color indexed color palette next time :)

Thanks
 
Alright here is my final pcb. Does it seem to look alright? Also I have one more question. :lol: Once I get done etching it, I am not required to apply soldermask to it or anything, right?

ps: Sorry about the bad quality. I had to print the image then scan it in. ExpressPCB does not have an image export option to my knowledge. :?
 

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I had to print the image then scan it in. ExpressPCB does not have an image export option to my knowledge.

You can make use of the "PRINT SCREEN" key to capture the entire screen, if you are running windows. Then you paste the image in an image editing program of your choice.

Alright here is my final pcb. Does it seem to look alright? Also I have one more question. Once I get done etching it, I am not required to apply soldermask to it or anything, right?
My slow internet connection doesn't give me enough time to view all three images, BUT I did see 1/2 the first image.

You almost did it right. When you make your press and peel copy, you want to make sure that only the tracks are printed.

If you print the outlines of each component as well, what you will be creating is a decorative circuit board that produces a short circuit.

There are only two things you need to understand with a circuit board:

1. Copper
2. No Copper

and there are two things you need to understand when printing:

1. pixel (black ink)
2. no pixel (no ink)

What is common? there are two things. So forget the colour printer. Forget grayscaling, and forget all the features that may make the image pretty.

all you need to deal with is ink and copper.

At least remember this if the above confuses you:
Whatever is printed on paper is printed on copper, therefore, only print tracks.

Here's an example. If you had an LED, resistor and battery in series, you will only be printing three lines. Don't print three lines, an LED outline, and a resistor box, because the LED will NOT light.
 
mstechca,
I know about the print screen command, I just don't know why I did not use it :lol: The second image was the one that I was going to print. The first one just vaguely showed the silkscreen layer so you can get an idea of what components I am putting in. Sorry that the images are taking so long to load :(
 
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