3.6 Starting layout in orcad  (Page 2/9)

While a layer is active, you can press the ‘-‘ key to make it visible or invisible. Try it now for the top layer. Your screen should look a little different, and the coloring in the drop down box will change to indicate that the layer is now invisible.

Make the top layer visible again. You will want to see that one while placing parts and routing. For now, select the following layers and make them invisible: SMTOP , SMBOT , AST , ASB , DRD , DRL . You will also notice that there are a bunch of lines connecting your parts. These are connections that are still unrouted, and this is usually referred to as the ratsnest. When placing parts, it is sometimes useful to turn this off. So click the View Spreadsheet icon and select Nets . Remember when you used this spreadsheet before? It had just one net called DEFAULT . Now, every net in your design should appear in this spreadsheet. This spreadsheet can be a useful way to see if you have misnamed nets in your schematics. Highlight every net by clicking the cell labeled Net Name . Right-click and choose Properties . Uncheck the Routing Enabled box and click OK . The ratsnest should have disappeared.

You are now ready to place parts on your design. To get into parts placement mode, make sure that the Component Tool is selected.

Give this component a reference designator of MT1 . Then click the Footprint button and select the BUMPER footprint from your library. Click OK when finished. The part will now be attached to your cursor and you can place it on the board. We actually want to place this mounting hole so that the large pad is on the bottom of the board. Press ‘ T ’ to flip the part to the other side of the board, and then place at the edge of the board in the lower left corner.

We want to place a mounting hole in each corner of the board. You could go through the procedure that you just did to place this component, but there is an easier way that will also allow you to precisely place components. Click the View Spreadsheet icon and choose Components to open the components spreadsheet. Scroll down until you see the component you just placed, MT1 . Like in other spreadsheets, you can press CTRL-C to make a copy of the component. Do this 3 times to make components MT2 to MT4 . When you copy the component, it will be placed at 0,0, all three need to be moved. Double-click MT2 to bring up the Edit Component dialog box.

Change the coordinates for this part to 2800,200 and click OK . Now do the same for the other two parts and place them each 200 mils from the corners of the board. Before closing the spreadsheet, highlight all four parts using the CTRL key. Right-click and select Properties to bring up the Edit Component dialog again. Since these are non-electric parts, uncheck the box labeled Non-Electric . Also, we don’t want to accidentally move the part, so check the box labeled Fixed and the box labeled Locked . Finally, uncheck the box labeled Route Enabled . Click OK to close the dialog and then close the spreadsheet. Your board should now look like this.