Making Circuit Ready For PCB Printing

Discussion in 'General Electronics Chat' started by khushal1988, Nov 14, 2010.

  1. khushal1988

    Thread Starter Member

    Nov 12, 2010
    hi , Can any one help me out as i am new to electronics and i want to do PCB printing for my experiment , actually i have designed a circuit and i deisgned it in paint so i want to know how to get the circuit ready for printing if i have the circuit in jpg format what are the steps to be performed in order to get it ready for printing please help me out my circuit is attached , this circuit is for stereo mic.
  2. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    That is actually called a schematic. It shows how you intend to make various electrical connections, but it does not show the physical layout and where the printed circuit (PCB) tracts should be. In order to do that, the dimensions of each device need to be specified. The devices are then arranged so they will fit on a PCB and the connecting tracts are drawn.

    Your drawing does not appear to have been done originally in Paint; although, it may have been copied from or into a Paint file. The software used to draw the original schematic probably has a program associated with it to draw the PCB pattern.

    1) You could try to draw the PCB pattern free hand or with a drawing program. That is a lot of work and is fraught with problems and potential errors. For a start, do you know the exact dimensions of each component?

    2) Get a free PCB and schematic capture program (many possibilities have been mentioned on this site). I use Eagle at . Redraw the schematic. The program will require you to specify which components you are using, but the details about each component are in the database, so when you switch to schematic, they will already be shown properly.

    3) Get someone else to do it for you.

    Last edited: Nov 14, 2010
  3. spinnaker

    AAC Fanatic!

    Oct 29, 2009
    I like expresspcb. The free Eagle has a pretty small limit on the size of the PCB, from what I remember. Plus I just find espress very easy to use.

    You can get expressschematic draw your schematic with that then run expresspcb, link it to your schematic and it will help you make the right physical connections.

    But if you are just experimenting, why not consider a solderless breadboard? You should prototype your design first anyway.
  4. iONic

    AAC Fanatic!

    Nov 16, 2007
    Prior to spending money on costly printed circuit boards I would first build the circuit on a bread board or proto board and make sure it works and meets your needs without any alterations. When this is all said and done, then it would be time to spend the money.

  5. gootee

    Senior Member

    Apr 24, 2007
    First, you need to specify the components' makes and models, and then get the measurements of the pcb "footprint" (arrangement of pads) and the measurements of the package/case for each component.

    Then you can draw the pads and the connecting traces to implement the circuit as a PCB. You will have to decide what pad sizes and trace thicknesses to use, and how to best place the components and route the traces.

    If any heatsinks are needed, don't forget to leave room for them, and possibly a way to mount them. And don't forget that the PCB might need screw holes, for its own mounting.

    For your particular circuit, one thing to worry about is the "gnd" traces. It looks like C4 is a 100 uF bypass capacitor, which might shunt ripple current to "gnd". You don't really want the other (signal) gnd return traces sharing a return path with the gnd from C4, all the way back to the power supply gnd, since the ripple current and the inductance of the return conductor could then induce a ripple voltage on all of the PCB's gnd traces (which would then be arithmetically summed with your signals). I would consider adding a third pin for "audio gnd" to the JP3 connector, to have a separate ground return conductor all the way back to the power supply for all of the "gnd" traces except the one from C4, and have the C4 gnd, alone, use the original "gnd" pin of JP3.

    If you are going to make the PCB yourself, then any black-and-white artwork should be sufficient. (MS Paint would work, but would be tedious to use.) But if you are going to have PCBs made for you, by a professional fabricator, you will usually need to use a "real" PCB-drawing software package, since you usually need Gerber and Excellon Drill files to send to them.

    If you want to try making a PCB yourself, you could look at my pcb-making page at . Also, you probably should join the Homebrew_PCBs discussion group, at .

    Once you have a little experience at that "clothes iron" toner-transfer method, you could probably go from an on-screen PCB layout to a finished board in under an hour. My laser-printer/toner-transfer method uses supplies and chemicals that are available almost everywhere in the civilized world, except for the PCB blanks, which can be found on by searching for "FR4", or bought online at places like I also provide a downloadable PCB pattern bitmap for a prototype board. The method can also be used to easily apply the component-side artwork to the fiberglass side of a one-sided board. The method works very well for trace widths down to 0.01 inch or even smaller.

    Note that on my pcb-making page, at the link above, the Staples glossy inkjet photo paper that is mentioned is reportedly no longer available (or is now actually a different paper). So you would probably have to experiment with running different types of glossy inkjet photo paper (or glossy magazine paper) through a laser printer, to find a paper that works well. I would try doing a search at the Homebrew_PCBs group, for the latest on that.


    Last edited: Nov 14, 2010
  6. Still Learning

    New Member

    Jul 19, 2010
    Spinnaker, in expresspcb: how do you mirror the board image when printing? I liked the look of the program but never could figure that part out.. Some other option? I've also hear of using PrimoPDF-apparently it has a Mirror function..??
  7. spinnaker

    AAC Fanatic!

    Oct 29, 2009
    It already does it for you. :) Just print to your laserjet. Iron it on and you are ready to go,