Thursday, July 17, 2014

What is Artwork and Artwork Scale in PCB Design?

Once a PCB is designed an accurate drawing of the PCB layout can be produced called the Artwork. The Artwork can also be scaled up or down while retaining the dimension. It can also be used to create the PCB pattern using photography process. The Artwork drawing shows drawing of the copper traces, the solder pads and any conducting parts, their location, dimension and clearances to be imprinted on the board.

It is not the actual PCB file that is used for PCB manufacturing. It is the Gerber files, NC drill files etc are used for PCB board manufacturing. However for small scale design using manual PCB design process, the artwork can be used for PCB design. Artwork design are used to show design prototype and for analysis.

artwork

Artwork Scale is a term that refers to information about the scaled version of the artwork. It is indicated in terms of ratio which gives the relative accuracy of the artwork scale dimension over the PCB area. For example, one talks about artwork scale of 2:1 or 4:1. What artwork scale of 2:1 means is that the artwork drawing is 4 times that of the actual PCB area. The 4:1 artwork would give artwork 16 times the actual PCB area. Thus 4:1 is finer, more accurate and more detailed than the 2:1 artwork.

Artwork scale is useful in the manual PCB production. A manual layout design may require more precision and thus higher artwork scale. Added to this requirement is also the type of design. An integrated circuit with plated through holes also requires precise artwork scale for the PCB design.





Wednesday, July 16, 2014

How to select a good PCB design software?

PCB design automation is essential in today's market competition. Even if it is not for selling design design professional want to know the best PCB design software for research for example. While small design can be completed with open source software, larger and complex design requires high accuracy, high performance software. In the PCB design process routing is perhaps the critical part that designers constantly focus on. Many PCB has auto router feature but often it does the provide the optimum path. And what is design automation if this part of work cannot be automated? Modern PCB software does take great deal of work load from the designer.

So how to select a good PCB design software?

Most of the PCB design software provides schematic design, simulation, PCB design, auto routing features.

A typical PCB CAD software vendor offers demo. The demo software has demo license and one should use it to exploit its strength and weakness. Once you have the demo software, you should look into couple of things as follows.

hole in pcb


Check the demo board but don't rely on that. Instead think of it as the best you can get from the software if the software really functions are advertized. Because the vendor always would, should and do provide their best PCB design to demonstrate the software capability.

Now what really matters and the things one should watch in the application is the Auto Routing program, the EMI and thermal technological support and restrictions, the accuracy of the wire frames, the units accuracy, the number of PCB layers it can support, the export to other CAD software, the CAM support. Another important selection criteria is the library support, the parts and documentation, how footprints have to be created, the simulation capability for the parts.


You don't want to spend time on debugging your design once you buy the PCB CAD. You want to have the PCB CAD automate most of the design work with high accuracy as much as possible.

See schematic and PCB design tutorials


Open Source Virtual Electronics breadboard Software

Fritzing is an open source Virtual Electronics design with virtual breadboard software. It is an interesting software because the look of the PCB and schematic looks very realistic. The components looks very realistic which makes it easy to understand and imagine the final design. The components can be dragged into the virtual breadboard and together they look very realistic. It is also a schematic drawing software which means schematic of the electronics circuit can be drawn easily and transferred to the PCB. Components if not available can be created with the component editor quickly.

A view of virtual breadboard and printed circuit board where components are placed is shown for illustration.



This virtual electronics design software is useful for students, beginners and electronics hobbyist and for teaching purpose. The realistic view of the design makes it easy to learn schematic and PCB design. Following shows a picture of parts which looks very nice and realistic.

 
Also various kinds and size of project can be completed with Fritzing such Arduino microcontroller project, RF project, robotics and others. A large number of schematic and pcb design tutorials are provided in the Fritzing website which makes it even more easier for people to learn designing with the software.