The latest IPC Designers Council held at Cadence in San José, CA, was all about IPC-2581. Presented by IPC Consortium Chair Hemant Shah, the lunch meeting answered why IPC-2581 is the go-to standard. Similar to the Mentor Graphics-owned ODB++ in terms of functionality, it takes the lead over its competitor for it is open and neutral. And when it comes to good ol’ Gerber, it might just be time to retire.
IPC-2581: intelligent, open and neutral
It is easy to say that IPC-2581 is open and neutral. But how open and neutral is it really? Released in 2004, the new data and transfer methodology promised to offer a smoother CAD-to-CAM data exchange process without human intervention.
Hemant Shah began his presentation with a well-known statement: Circuit board design comes with its share of files. And we’re talking about a lot of files to deal with: Netlist (IPC-356D), Excel and JPEG, Drill (Excellon), Artwork (Gerber RS274X), Readme files of notes and instructions, and so on.
As a PCB designer, why should you care about whether your manufacturer receives your design in one or a thousand files, as long as it is sound and thorough? More files mean more work and more work means more chance to make mistakes. When gathered in one single file, you can effortlessly import your design, augment it, and export it by any business system throughout the value chain. As simple as one single file: This is the intelligent part.
At some level of circuit complexity, you might want to consider opting for a highly organized and efficient means of exchanging data with your fabricator, therefore reducing the margin of error on both sides of the handoff.
All the way down to the factory floor
Hemant Shah carried on explaining the vision IPC had when the Consortium started working on the new standard, “The bottom line is the handoff of OEM to manufacturers. This is where we focused most of our attention so far because this is the problem that we wanted to solve. The vision was that IPC-2581 goes all the way to the machines that the manufacturers have, all the way down to the factory floor.”
IPC has a standard called CFX – which stands for Connected Factory Exchange – that passes machine specific data to different machines. That is one task designers don’t have to worry about. If you have a Pick-and-Place machine, all you need is the parts the machine needs to work on. This data for the pick-n-place machine will go to the machine in IPC-2581 format.
IPC-2581 is an IPC standard. Nobody owns it, everybody can implement it; thus comes the open part. The Consortium developed this IPC standard in 2004 in an effort to combine the best of ODB++X – which does no longer exist – and GenCam.
The first IPC-2581 circuit board
Even though the format was released almost 15 years ago, the first IPC-2581 circuit board was only fabricated in September 2012. The bare board was fabricated with a PCB design from Fujitsu Network Communications, which exported the fabrication data from Allegro. The communications equipment company announced that it reduced the overall fabrication preparation time by 30 percent.
Interestingly enough, it is around that time that Mentor announced that it supported its rival standard. Currently, many other tool providers support IPC-2581: We can name Altium, Cadence, Zuken, Siemens, Polar Instruments, Adiva, Wise Software… This is a clear hint that the neutral XML based standard is a must-have.
ODB++ users will love it: IPC-2581 offers all the advantages of the Mentor format without requiring its users to get a license. It was made to serve the Industry 4.0.
Why manufacturers support IPC-2581
It makes sense that some PCB designers may still be reluctant to use IPC-2581. Just like they were when OBD++ came around and they had the choice to move on from Gerber. To tell you the truth, as a PCB manufacturer, we still receive 80% of our customers’ designs in Gerber. How can we convince them to use IPC-2581 when they even haven’t switched to ODB++ yet?
At Sierra Circuits, we have already fabricated circuit boards imported with IPC-2581. What is the difference with the other circuit boards, you may ask? Our front-end CAM engineers appreciate the simplicity of the digital communication for more productive direct process engineering tasks. With Gerber files, they have to interpret how the data is expressed – whether this is in English units or metric units, for instance. The layer renaming, as well as the type and polarity defining are also some of the arbitrary decisions they have to take according to our protocol.
We estimated that it takes about 15 minutes per job just to identify the order of the layers. Sure, it doesn’t seem so bad put it this way. Now, multiply these 15 minutes by 120 orders that we receive on a daily basis. It is getting bad. Plus, if our operators make a mistake, then we have to deal with scrap. If the PCB designer makes a mistake, then we have to send the bill to the customer. Both scenarios are bad.
IPC-2581 allows our front-end team to easily output projects from CAD tools, avoiding to have to put jobs on hold because of data uncertainty due to disparate formats. This also benefits our customers bypass delays in production and get their prototypes faster.
Speaking of our customers, one of them who has recently requested a quote for a board using IPC-2581 explained that the syncing between the output and the database motivates him to use the IPC standard. Michael Edwards, Senior PCB Designer at Glenair, said, “With Gerber, it is possible to generate separately and at different times, and I have seen when it is not possible to know what database made what files. With IPC-2581 using the (free) WISE viewer it is very easy to check the output. The file also includes all the net lists and part information. I know people like the ODB++ tar ball, but it is just another ZIP file full of many files. For me, IPC-2581 is the best format.”
Another consumer electronics customer who was designing for controlled impedance confirmed that statement. He found the exchange with us very convenient. Instead of having to re-enter the data in different tools, he was able to use the stack-up data available in IPC-2581.
You can understand why your quickturn manufacturer advocates the use of an open and intelligent format that eases the CAD-to-CAM transfer and therefore save both time and money.
Sierra Circuits has been supporting IPC-2581 for a while now and we will continue to do so. We encourage our customers to try it once; it’s all it takes to adopt it! We currently fabricate and deliver more than 10,000 circuit boards each month. If 50% of our orders get to us through IPC-2581, we estimate that we will be capable of shipping 15 percent more PCBs. And again, we are not the only ones taking advantage of this innovation. You will save money because we will spend less time working on your boards. IPC-2581 is a win-win situation for both fabricators and customers.
IPC Designers Councils 2018 – Mentor Graphics and Cadence
Now, have you read our article about IPC Class 2 Vs Class 3: The Different Design Rules?