Bob Ko wrote:
> A customer has asked whether annular ring includes the plated thru hole
> barrel.
>
        Bob,
                From a design viewpoint, no. The annualr ring is calculated
        (per IPC-D-275) as being :

        1. The maximum drill hole.
        2. The MFG process allowance.
        3. The etchback (if required).
        4. Two times the minimum annular ring.

                From an inspection viewpoint, it probably does. The
measurement
        of the annualr ring would be taken from the edge of the finished
hole. This, by
        definition, would include the plated through hole barrel.

> .
>  Michael Hiteshew
>  Lockheed Martin Launching Systems
>  [log in to unmask]
>  (410) 682-1259
>
>
>
>

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################