Design your own Circuit Boards using Kicad Part 2

so welcome to part two in the series so in this video we're going to focus on laying out the components for our circuit board designing a circuit board laying down the copper tracks and ultimately generating Gerber files which is necessary in order to order PCBs from companies such as jlc PCB to begin we're going to open up the dot k CAD PCB file in our project tree and this is what the PCB editor looks like and to start off we need to load the netlist we generated in the previous video now it should automatically find the netlist but if it doesn't you can use the Browse function and browse for the netlist and I'm just going to hit update PCB and then hit close and now you can see all the components are lumped together let's take a look over here at the right-hand side we can see we've got all these colors and each color represents a layer in the circuit board now in order to understand how to use these layers we first have to understand the layers that make up a circuit board so here is a simplified PCB that's going to explain the layers for us so if we take a look from this aspect we can see we've got a copper trace we've got a copper through-hole we've got some text and we've got a green layer on the top and bottom so now let's take a closer look at the layering system and Kai CAD if we mouse over one of the layers we get to see the full description for that layer so we've got front copper layer so in our example this would be this layer right here and the copper trace on top bottom copper layer and some of these layers we don't need to pay any attention to because we don't need to edit them so gloss over the ones we won't use front silks is the silkscreen on the front of the board so that's the white text over here this is also the layer where you can apply names and logos to the front mask is the green transparent layer that goes over top of the copper to insulate it and provide protection the bottom mask is exactly the same but on the underside eco one user is a layer where you can draw graphical designs and this might be useful if you need to give of components a certain amount of space around them and you want to visualize that while you were designing the PCB but it's not actually a layer that ultimately makes it into the end product of the PCB it's just more for the designing process edge cuts defines the size of the PCB so we'll go over that and feel the detail when we get to that point so when we import the netlist into the PCB editor all the components are just lumped together now we need to arrange them in a fashion that makes sense and as orderly and what I mean by that is for instance r3 has to be connected to d1 and we can tell that because we've got a white trace which follows the connections around so it wouldn't make any sense if r3 was at one end of our circuit board and then d1 was over here so I need to arrange these components where the runs are as short as possible and all the components have enough clearance from each other but there isn't any wasted space either oh well look at that through the magic of editing it's all done now notice there's - lots of text on screen we've got the white text and we've also got the turquoise blue text here the turquoise blue is the front silkscreen layer and that's the layer which will be in white printing on top of the circuit board this white text here is only for our reference while we're designing a circuit board it won't it won't actually make it into the final product so I like to turn off this white text because it can get quite annoying so I'm going to go over here and turn that off and that immediately starts to clean up the design but you'll notice some of the field references for the components overlap so we need to move these about now you'll notice when you start to move a field reference will be a blue line that attaches it to its corresponding component so I'm going to place that there right so now my field references are all in order and easy to understand so you'll notice in the background there is a grid of white dots we can change the grid spacing by using this menu and this is useful because not only do the components snap to points within that grid but so do the copper tracks so sometimes you'll need to change the grid in order to route copper tracks evenly around other components if you're not familiar with what a via is basically in a nutshell of the think of it like a pen that goes from one side of the circuit board to the other and connects two copper tracks so we can have a copper track start on the top layer then we have a video that passes all the way through and connects the top copper track to the bottom copper track and lastly we have our copper track width that we can select from so by default there's only one so if we need to add different options we can click on edit predefined sizes and under tracks and vias we can add extra sizes so I'll add 0.5 millimeters one millimeter and two millimeter and you can also add different size fears over here if you want so hit OK now in order for us to know the correct width copper trace we need to be using we can use tools such as this PCB trace width conversion calculator now it's a mouthful so here we've got our data inputs so let's say my circuits going to use half an amp and when it's referring to thickness here it's asking us the thickness of the copper layer on our circuit board so when we order circuit boards we've got the option normally for either 1 or 2 ounce per square foot copper thickness I'm going to stick with one ounce per square foot for this example and for most circuits that will be just fine that sir can tolerate a 20 degrees Celsius temperature rise and my ambient temperature is 30 degrees Celsius we don't have to worry about trace length and I'm going to change the output unit to millimeters so in order to carry half an amp of current we only need a trace that is 0.1 9 millimeters thick so I'm going to select one millimeter thick copper tracks I'm going to work on the front copper layer first so I've got that selected and now we're going to click on route tracks and my preferred method is to leave the bottom copper layer exclusively for all the ground connections we can add a ground plane later on makes it super simple for all the ground points and that leaves all the other connections on the front copper layer which is what I'm working on now so all the white traces you see between the footprints of the components electrical connections that ever get to be made they will automatically disappear once the once a copper track connects one point to another point so I'm going to start off on this connection and you'll notice when we click on a connection it highlights all the other connections that are all electrically connected together so we're going to start connecting all these points together so I've had a bit of a roadblock here in my design I need to connect this connection to this connection but the component is surrounded by other copper tracks and won't allow me to connect these two points together so how do we get around a situation like this so one way we could get around this problem is by selecting the bottom copper layer and then we can run a track from that component to that component and it's done and you'll notice that the copper tracks are color coded to what layer on so the red is the front copper layer green is the bottom copper layer but I as I mentioned earlier I like to try and leave the bottom copper layer as a ground plane so let's look at another alternative what we could do is delete this copper trace here go back to my front copper layer and we could route the copper trace around like that and then that leaves us an opening to connect these two connections the other method we could use is by adding a via so I'm going to start off by selecting one of my connections and I'm going to drag a copper trace out to here I'll lay the copper trace down press escape to cancel and then I'm gonna come over here and select add vias we've got a place of via right there then I'm gonna switch to my bottom copper layer go back to rail tracks click on the VI placed before and then route the copper track over to there and that's how you add vias to your projects so with some careful planning I should be able to place all my connections on the front copper layer and I shouldn't need to add any vias so the only connections that I haven't made yet is the ground connections and I'll be showing you how to add a ground plane in a moment but first I want to add some mounting holes to my circuit board so that I can use some screws or whatever to secure the circuit board in place so to do that we're going to click on add footprints lift click on the PCB editor and that will open up the footprint library and then we're going to scroll down to mounting holes and here you can select what size mounting holes you want I like to choose three point two millimeters that's the one I'll go with I'll get rid of this bit of text because I don't want that printed on my front silkscreen so now I've got my four mounting holes laid out we start to get an idea of how big our circuit board will be so now we're going to click on the edge cuts layer and we're going to click on add graphic lines and what we're doing now is defining the size of our circuit board so I'm just going to draw a box around my circuit if you're making your circuit board to a specific dimension you can always use the measured distance tool and select two points then you'll get a readout of the measurement so it is thirty six point eight three millimeters long by twenty nine point two one millimeters high so now I can add my ground plane on the bottom copper layer so I'm going to select back copper layer and I'm going to select eed filled zone I'm going to start off by selecting this point here and then it's the option menu is gonna pop up and we're on the correct layer on the bottom copper layer and it's asking us what net class to assign this to and we need to select ground and then press ok and drag a line down here and click come over here and click and come to this point and double click and just like that we have made a ground plane and if we zoom in we can see that all the ground connections have these little tabs which extend out from the ground plane and they are all connected now so at this point we've finished out design so the final thing before exporting the Gerber files is to run this tool here perform design rules check this is basically an automatic checking robot to make sure our design meets the specifications so we can add minimum track width via size and so on and make sure our design fits those specifications so I'm gonna hit run DRC under problems and markers no problems there everything's fine but there is a problem under unconnected items and we can see right here I have forgotten to connect these two footprints together so I'll go back and make a copper trek between those two points go back to the checker I'll hit delete all markers run the DRC again and this time there is zero errors and one really cool feature of Chi CAD as we can go up to view and then click on 3d viewer and we get a preview of what else it would looks like with the components no less look at that and this is a great way of checking your design before ordering your PC these make sure all the footprints look right everything's spaced properly looks really neat now notice our circuit board has quite sharp edges and because it's fiberglass they can actually be quite sharp sharp enough to cut you so there is a little trick I like to do to round the corners of the circuit board off so close that and I'll go back to my edge cuts layer and I'm going to delete my lines and then we're going to choose the stool ad graphic ark so I'm going to select here and a drag out and then I'm going to make an ark I'm going to go back to add graphic lines and then I'm going to join the ax together now I'll go back to the 3d viewer and now you can see the circuit board has a Filat on the corners no sharp edges very nice the last thing I want to do is add some logos and some text onto the white silk screen layer so let's look at that now so I'm going to click on add footprints left click to open the footprint library I'm going to scroll down to symbol and this is the default symbol library so you can have a browse through here and find one you like you'll notice that some of the logos they they end with copper or silkscreen so optionally you can actually add a design into the copper layer or if you choose the silkscreen it'll be the white text on top of the circuit board so I think I'll try this one you also notice there's different sizes five six eight twelve millimeter and so on then choose this design and I think I'll place that down there and I'll add some text we can choose what layer we want the text to appear on so I'm going to choose front silks we can change the size of the text the thickness and so on whether we want italic that's all fine and I'll place that up here I like to add version numbers to all my circuits so if in the future I have a revision I know what circuit boards are old and which ones are the new ones so I'll call this one version 1.0 click the front silkscreen layer and we'll place that over here so let's go back to the 3d viewer and there we go we've got a nice high CAD logo here how to make PCB version 1.0 so now let's export the Gerber files to get this PCB into production so to generate Gerber files first click on file come down to plot plot format Gerber all this is the default settings so you shouldn't need to change anything and you all the default layers that are selected will be fine we don't need to change any of those so we need to select our output directory so I'm going to generate a new folder and call it Gerber's inside my project folder I'm gonna select that do you want to use this path yes and then we're going to hit plot and we'll get a list of all the Gerber files that have been created as a Gerber file for each of the layers in our circuit board and we're also going to select generate drill files he'll automatically select the same folder this is all the settings I use they're all default and hit generate drill file successfully created close that close up so here is the directory for my project files that I've been saving a ring to so go into the Gerber's folder that I just created and here are all the Gerber documents we need and what we need to do is add these to a zip archive so I'm going to select all and I use a program called WinRAR and it just allows me to select add two Gerber's area and it zips all those files into a arrear file which I can upload to web sites like jlc PCB to audit my PCBs from now go over some of the options you have when you're ordering your PCBs so of course I'll show you how to do this on jlc PCBs website so we don't have to worry about entry and dimensions or any of that information we can just click on quote now and now we need to upload our goober our ar4 we just generated you can see once they're uploaded we get a preview of what the front and back of the circuit would looks like and the dimensions are automatically calculated from our Gerber files so we don't have to change that basically you can use all the default settings you don't have to change anything for most circuit boards obviously the circuit board we've designed has two layers copper layer on the front and a copper layer on the back we can choose from these options for what color we want the solder mask to be personally my favorite is blue looks quite neat here we can choose the copper weight this is the thickness of the copper on the front and back of the circuit board it's obviously the advantage with thicker copper is it can carry more current but it does come at a cost so if you want to know more about any of the available options you can just mouse over the question mark and you can learn more about what those options do but for circuit boards like you've seen me designed I can just leave everything on the default settings safe to cut and then go through the checkout process if you found this video useful please drop me a like and leave any questions in the comment section also let me know what features you would like explained in ed in the next videos I'll show you how to add custom logos and how to design PCBs for high current applications and much more I'll see you on the next one bye for now

Channel: Schematix

Views: 25,654

Keywords: how, to, make, design, circuit, board, PCB, JLCPCB, software, Kicad, build, gerber, files, schematic, schematix, part 2, tutorial, free

Id: qw9WIm5M5R4

Length: 20min 35sec (1235 seconds)

Published: Tue Nov 12 2019