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Updated Standard Offers New Guidelines on Surface Mount Component Carrier Tape Orientations
 The Electronic Industries Alliance (EIA) has released a revised version of EIA-481-D, 8 mm Through 200 mm Embossed Carrier Taping and 8 mm & 12 mm Punched Carrier Taping of Surface Mount Components for Automatic Handling, which establishes requirements for taping surface mount components so that they can be automatically handled. The new version further clarifies how surface-mount components should be oriented when they are placed on the carrier tape used in circuit board assembly operations.
Establishing clear rules about component orientation was critical, says Scott Carter, chair of the committee responsible for developing and maintaining the standard. “When a circuit board manufacturer receives a certain batch of reels full of components, they expect the components to be oriented on the tape on the reels in a certain way. So what this latest update did is clarify those rules. There was frankly a little bit of angst in the industry with regard to the version that was published in 2003. So we gathered input from the industry to help clarify these orientation rules.”
What the committee was looking to clarify were the rules associated with commonly used components such as SOT 23 and SOT 143. In the previous version of the standard, the committee had developed general rules regarding component orientation that could be applied to new components as they were developed. But, as Carter points out, “some of the orientations that were developed for some of these more common components that have been around for years didn’t follow a simple and consistent set of rules for components in general.”
Carter goes on to explain that “the grandfathered orientations did actually make sense at the time because these orientations were special cases that either maximized the component density on the tape or permitted a narrower tape to be used. However, it would have been too complex to implement these parameters into a general component orientation scheme.”
Rather than try to make those components fit the new rules, the latest version of
EIA-481 now allows for the grandfathering of their traditional orientations. In addition, EIA-481-D features updated camber measurement guidelines.
Orientation rules and camber measurement methods are only two of the many requirements specified in EIA-481-D. Other information in the standard includes:
- The characteristics of 8 mm to 200 mm embossed carrier tape and 8 mm
and 12 mm punched carrier tape
- Maximum component rotation and lateral movement requirements
- Bar code label area specifications
- Minimum bending radius
- Cover tape peel force
- Leader and trailer lengths
- Reel dimensions
Guidelines such as these have helped make the standard a must-have document for many electronics manufacturers.
“It is a popular standard around the world because anyone that produces surface mount components has to put these into carrier tape,” Carter says. “And they need to be done according to the standard so that what they send to their customers will fit onto and work in the various automation systems around the world.”
The standard is harmonized with documents created by other development bodies, including the International Electrotechnical Commission and the Japan Electronics and Information Technology Industries Association. But the EIA document is the only one to date that offers guidelines about component orientation.
Even though EIA has just published EIA-481-D, the committee is already looking ahead to the next version of the standard. “We are looking at some other things that aren’t currently encompassed in the standard. One of them is to evaluate a 4 mm-wide tape that’s starting to be developed and promoted in Japan,” says Carter.
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