A critique of IPC-A-610E: a master trainer assesses the revised industry guidelines for PCB acceptability.

Author:Wettermann, Bob
Position:PCB STANDARDS
 
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The visual acceptance criteria for post-assembly soldering and mechanical assembly requirements, IPC-A-610, Acceptability of Electronic Assemblies, was recently "up-reved" as it tries to keep pace with the numerous new component packaging types and other changes to electronics assemblies. The "D" revision, published in 2000, ushered in Pb-free acceptance criteria at the time RoHS standards were put in place. The new "E" revision addresses some more recent technologies since the last revision was published.

The standards task groups made several changes to the Revision "E" document, including but not limited to package-on-package (POP) and leadless device packages, flexible circuits, board-in-board connections and newer style SMT terminations.

One area where there was a noticeable change is damaged components (found in Section 9 in the new document). Where the previous version held all the information associated with a damaged component termination style under the section on those part types, now all damaged components are in the same section. This will save users time flipping between the various sections. Specifically, sections on damaged transformer, connector and relays are the most significant upgrades.

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There have been upgrades to Section 8, the area array section of the standard. This section now deals with differences in both wetting and collapse characteristics of Pb-free solder balls. Since very few area array devices are available with tin solder balls, this is a welcome upgrade. While this is a welcome change, users still complain about the lack of detail in this section.

Another device type that has exploded in terms of its usage since the printing of the last version is the leadless device package. These are addressed in the new revision, also in Section 8. While the revision offers expanded inspection criteria, it does not go far enough in defining the criteria for the myriad different package types available today.

One of the other changes made to this version is the organization of terminals as...

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