-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueLevel Up Your Design Skills
This month, our contributors discuss the PCB design classes available at IPC APEX EXPO 2024. As they explain, these courses cover everything from the basics of design through avoiding over-constraining high-speed boards, and so much more!
Opportunities and Challenges
In this issue, our expert contributors discuss the many opportunities and challenges in the PCB design community, and what can be done to grow the numbers of PCB designers—and design instructors.
Embedded Design Techniques
Our expert contributors provide the knowledge this month that designers need to be aware of to make intelligent, educated decisions about embedded design. Many design and manufacturing hurdles can trip up designers who are new to this technology.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - design007 Magazine
Data, Data Everywhere. But...
April 17, 2013 |Estimated reading time: 5 minutes
Recently, the Voyager 1 spacecraft has made news by entering the very edges of our solar system, soon to pass into true interstellar space. Remarkably, since its launch in September 1977, the spacecraft has continued to transmit useful data to the terrestrial team of scientists monitoring its progress. I wish I could offer similar kudos to the PCB supply chain.
A little more than 10 years ago, I was working with a U.S. PCB manufacturer on an engineering automation project. The engineering manager was a colorful character. One day in the early stages of the project we were discussing various aspects of the information we required. At one point he quipped, “In God we trust; everyone else brings data.” I laughed, but only got a wry smile in return; I could see this was a serious point for him.
From concept through assembly, a tremendous amount of data is used to describe the various aspects of a PCB, the components, and final assembly. Massive amounts of data, in fact. Someone should print all of the info that goes into today’s smartphones. (Note: If you do, please use recycled paper or there’s going to be some serious deforestation, I suspect.)
Having said that, I’d like to point out that in reality, there’s not enough data. We actually need more.
The big picture of PCB data is being tackled today by the IPC-2581 Consortium. The members are volunteers from a wide range of companies including OEMs, designers, fabricators, and software companies. Their mission is to create an open, comprehensive data standard to describe all the aspects of the PCB for the entire supply chain. Sounds good right? I believe it is a just and noble cause and when adopted by the entire supply chain, it will greatly improve the transfer and updating of PCB data.
As such, I’ve recently involved myself in the consortium’s work and I try to help when I can. Much of the work has already been completed, notably a new data format that describes the physical form of the PCB layers. Currently, in the industry, we call this “Gerber.” Okay, I’m very tempted, but I’ll spare you another lecture about our industry’s use of that antiquated data format.
I’ve been working as a PCB engineer or with PCB engineers for most of my career. Transferring PCB data has been an important part of my career, especially for the last 10 years or so. I’ve spent a decade developing and deploying an engineering automation tool that, among other things, generates stackup and associated impedance requirements, production route/traveler, and so on.
Part of the market requirements we identified for the product was the need to integrate to other systems, and for PCB engineering this primarily means CAM and ERP. CAM data is used as a starting point for engineering jobs whereby we can get the layers and drilling information. From that we can generate the stackup with the manual input of the thickness and impedance requirements. Additional inputs are required to create the traveler and other supporting documentation. This includes items like board finish, mask type, legend color, date code format, specifications, and so on. Overall, it takes about 100 to 150 attributes to fully describe a PCB for bare board manufacturing, depending on its technology.
Interestingly enough, generating a quote requires only about 20 to 30 attributes. Let’s compare those two figures: About 20 attributes determine the PCB’s price, but another 80 or more are needed to build it correctly.
Once the engineering work is completed, typically it’s exported to an ERP/MES system. The engineering data drives all the critical manufacturing requirements to process the work orders. Prior to the advent of this type of system, data was usually manually extracted from CAM and manually entered into ERP. Bridging this data gap saved a lot of time and eliminated duplicate manual data entry, which is at best time-consuming and at worst error-prone.
Remember when I mentioned that we need more data? Although in the big scheme of things the stackup, impedance and general info are not a huge percentage of the total data, they are still critical to determine the price and actually manufacture the part correctly. So how do we as an industry handle this critical data exchange? PCB engineers can glean this information from:
- A PDF file of a fabrication drawing.
- A DXF file of a fabrication drawing.
- Either of the above and/or
- A text file with notes
- An email with notes
- A purchase order with notes
- Retained memory of the last time we did a job for you
- A customer cheat sheet we drew up last year
- General common knowledge of what is probably being asked for.
Perhaps there are a few other options I could list, but you get the point. Having all the critical info as part of a simple “button-click” import would be a huge help. Although PCB engineers are very good at manually entering, checking, and then double-checking the data they enter, it’s time-consuming and, by nature, error-prone. Ultimately it’s a waste of time and money.
The IPC-2581 standard should address this glaring data hole. I say “should” because it’s not complete yet. I hope to influence the consortium (along with many others) to ensure that this is taken care of in the standard. We’re in the midst of it right now, and it remains to be seen how it all transpires. I’m hopeful of a good result and a big step forward for our industry.
As an industry, we’ve been here before. The attempt to merge the GenCAM and ODB++ was ultimately a failure. While ODB++ has seen some successes in terms of adoption, it still only accounts for about 10% of data transfers. The rest is made up of “Old Man Gerber.” Industry-wide adoption of an open and comprehensive data standard for PCBs is quite simply a benefit for all. Let’s do what it takes to advance our industry with seamless, critical data transfer from the beginning of the supply chain to the end. After all, it can’t be that hard.
A 34-year old spacecraft is doing it from 10 gazillion miles away.
This article originally appeared in the January 2013 issue of The PCB Design Magazine.
Iain Wilson is president and co-founder of Iron Atom.