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04-05-2007
It should be noted that according to our ISO 9002 standards all our boards must conform to the IPC-A-600 Class 2 specifications.

How can I transmit files to Omni Graphics?

You can email them to us at omnimail@omnigraph.com. You can also ftp them to us, details on our upload page. Note that many email systems will not handle files over 2M. If your file is this large, ftp is recommended.

Also be sure to archive your files into a single file, such as a *.zip file. This is needed for error protection for anything sent on the internet.
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What files are needed?

We need a gerber file for each copper layer, each solder mask, and silkcreen. One of the gerber files should have a board outline. A fabrication drawing would be helpful, though not necessary. We would also need the aperture information associated with each gerber file. We recommend, but do not require, RS274X format since it is becoming the industry standard. This format has the aperture information embedded into the gerber file itself.

We also need an excellon drill file and the associated tool sizes.

Finally, if a readme.txt file containing all important information is not yet industry standard, then it should be. A good example of a readme.txt file can be found here.
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What is the deadline to get a job going?

We need to have complete job files and authority to proceed, usually in the form of a purchase order, by 10 AM Pacific time for that day to count as working day for the board production. So, if we have files and a go-ahead for a 5 day turn by 10 AM Monday morning, the boards would be ready by end of the day on the following Friday. This is for turns of 5 days or more. Weekends do not count as working days.
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How does timing for quick turn jobs work?

For quick turn jobs of 5 days or more, see above answer. For turns of less than 5 days, it is works on a 24 hour basis, so a 3 day turn would be 72 hours, a 2 day turn 48 hours, and a 1 day turn is 30 hours. If we begin production at 11 AM Monday morning for a 2 day turn, but order should be ready 11 AM Wednesday morning. Weekends do not count as working days.
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Can you reproduce this board?

Sometimes job files for old boards cannot be found, or it was done in the old tape-up days. We can reproduce a board based on a sample only, if it's single or double sided, and if all the parts are removed so we can measure the features. We charge by the hour though, so it's usually cheaper to lay it out again. It's only cost effective for simple designs.
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What is the minimum annular ring?

We require minimum 0.005" copper pad ring around drill holes. Under ISO 9002 standards Omni does not recommend a board with a smaller copper ring than this. This includes our "No Tooling" prototypes.
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What Gerber Data Format?

It is a good idea to tell us your data format for both drill and gerber files in your readme file. Our recommeded format is 2.4 leading absolute coordinates for the gerber files, and 2.4 trailing absolute coordinates for the drill file. Set software arcs to "on", vector plotter type, and "no" to G54 data. We previously advised 2.3 data, but that leads to round-off errors on tight designs.
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What is the finest silkscreen resolution possible?

Our best resolution for the silkcreen layer is 5mil.
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What are the minimum Traces & Spaces?

Extra base copper on a board will limit the size of the features on it. The following is a list of the minimum traces and spaces:

Base Cu / Oz Traces / mil Spaces / mil
0.5 4 4
1 10 10
2 12 12

We may be able to go below these guidelines under some circumstances, depending on the layout of the board.
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What is silkscreen clipping? Does Omni Graphics clip silkscreens?

This is when the CAM operator removes all silkscreen elements that would be printed on the pads. Omni only clips the silkscreen on request or when the boards are to be electrically tested. We do not routinely clip the silkscreen because that decision is a design issue, not a manufacturing issue.
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What does copper thickness: 0.5 + 0.7 Oz Cu mean?

The first number refers to the base copper we start with. The second refers to how much we plate up the board by. So 0.5 + 0.7 Oz would be a little over 1 Oz Copper.
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What is the recommended Copper Thickness?

The thickness of the copper on a board is a design issue, and so Omni cannot make a recommendation on this issue. We can say that most boards we make have 1 Oz finished Cu. In our download section, we have a copy of a small program that replicates the current capacity chart, it may be of some use.
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What if I'm designing with AutoCad?

If you are designing a board in AutoCad, and don't have the gerber file add-on, you can export the design into HPGL format. We would also need the plotter type it was written for, and the pen width table. We can also import *.dxf files, it is best to save in AutoCAD 12 format. It is more efficient to use a layout program to design a board rather than using AutoCad. AutoCAD files have to have the drill file created in CAD, and the layouts are generally not formatted the same way files from layout software would be. Consequently, building from AutoCAD usually has extra editing charges. A freeware layout program is available here. Functional demo software can also often do the job, try our links page.
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What is the Dieletric Constant of FR4?

The Dieletric Constant of our FR4 is about 4.7 at 1 MHz. However, we cannot give a fixed value for this since it tends to drift from batch to batch. If a fixed dieletric is required, it is possible to build on specialty materials. Omni has experience with Rogers materials, duriod and polyimides. These materials are not kept in stock, but can be special ordered.
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