I've been playing around with Eagle for about a week and I have come up with my first PCB design! The board consists of an ATTiny that controls a dual N-channel MOSFET ( http://www.digikey.com/product-detail/en/SI1970DH-T1-E3/SI1970DH-T1-E3CT-ND/1656832), and a dual NPN transistor (http://www.onsemi.com/pub_link/Collateral/BC846BDW1T1-D.PDF ) which in turn drives an H-Bridge (http://www.diodes.com/datasheets/DMHC3025LSD.pdf). The values I intend to use are: R1-R6= 100 ohm, R7 and R8 = 47k ohm, and C1= .1uF. Initially, I had wanted to try to etch my own board and assemble it myself but it appears far too intricate for my current soldering skills. Maybe if i had a reflow oven... I digress. I would greatly appreciate your constructive comments and suggestions. Do you think if I sent this design to a company they would be able to make it?
I realize I uploaded the schematic instead of the board. oops. the handle for that chip is way off the screen to the lower right. my bad...I have to go home to fix this.
I don't know how a company wants a pcb design, but I noticed a few things:
Under R4 is connection point in the bottom layer. Why under R4, there is lots of open space.
In the bottom-left corner is the connection circle of the upper layer too close to the via. Soldering that would be a problem.
The connection circle of that upper layer wire (in the bottom-left) is also a via ?
C1 is the only component on the bottom side ? Can you place it on the component side ?
At R7, the upper layer seems to shortcut under R7.
The text on the right is outside the board. Or is that not to be printed on the pcb ?
There is no version text on the board. Also no text what to connect to the pins.
The holes would better be on a 1/10" grid.
The connections next to the unlabled component in the middle are too close to the component. That is hard to solder. The upper layer wires of those connections are also not actually connected to the upper-left and lower-right of the component.
The vias are connected to te upper and bottom layers. But there are two square "via alike" things, and they are not connected.
Thanks for input! Regarding space and the general layout, the center of the board is most likely going to have a big hole cut out of it to make clearance for another part. That is what I had to do with the first prototype.
@ Erdin
... connection circle of that upper layer wire (in the bottom-left) is also a via ?
I had a hard time finding a suitable size hole "part" within the library so I tried to make my own. Then I thought why not just use a via? Is there a better way to do this?
-I put C1 on the backside because it was the shortest distance between V+ and ground for the uC.
-At this point I haven't been to concerned with the text and silk screening just the technicalities of the layout, but now you mention I will definitely consider going back and fixing this.
I made some changes based on your comments, please let me know if missed anything.
@lax123
I like the idea of using power planes, and I will try to implement this later.
At some places the upper layer traces are very close to each other.
For example at the left of R2.
And also at the left of IC1.
Try to measure the distance between the traces, you will be surprised.
The traces at the top seem very close to the border of the board.
I would expect at least some space between the trace and the edge.
Will there be a coating ? If not, for example a fingerprint can be conductive between the traces.
its a typical pcb service... read what they want from you for ur pcb
there download the eagle design rule file to check if your layout is consistent with most of their needs for production
try to make straight lines with 90° angles, even top and right outline of the white boardline are not in 90°, maybe you need to zoom in in your screen to see it, if you right click the top outline and click properties you can adjust the position of the line, try 0.72 and 0.72 for the two fields on the right side
also try to increase the resolution of your routing grid, makes it easier to place all the routes in a proper way
also what do you use these "connected vias" for? u dont have something like that in the schematic
-i would really rearrange your components, you have a lot of space so better place them to save lots of long routes and moving around corners, switching between bot and top layer. just remove all routs and look how you could improve it
-you still can put in a ground planes covering the complete pcb for bot and top. its very good for absorbing and dissipating heat.
I just needed holes to connect wire leads to. How is that typically done?
-you can use a termin screw block as u can find under con-phoenix, vias is a good idea too, but i would clean up that design and place them properly like in the first picture at one spot
-i would really rearrange your components, you have a lot of space so better place them to save lots of long unnecessary routes and moving around corners, switching between bot and top layer. just remove all routs and take a look on how to improve it
-i would use 45° angles on all those corners and not ur 90°, like in this picture http://www.sparkfun.com/tutorial/Eagle-DFM/Routing.jpg just use the 2nd and 4th routing mode
-u still use weird angles eg right side - bottom
-i guess u still didnt try that drc file, which gives like 100 design rule errors
-you could transform a via into a library part for eagle, so you could use the via as a connector in your schematic, there are plenty of tutorials eg youtube, also then eagle would give you airwires for those and tell you if any lines cross or something like that
