Hi Technetter,

I've got some questions regarding bare boards Electrical testers capabilities.

1) Is it correct that bare boards electrical testers may not detect opens caused by complete copper cracks (circomfrential) inside via holes because the pressure from the test pins do close the crack? ( I personally do not think so. The copper crack width measured from the cross section is 0.0004"). The boards I'm talking about are Immersion Silver plated.

2) How about via copper cracks if the boards are HASLed. Would the Tin/lead inside the via holes allow enough conductivity to "hide" the copper crack?

3) If the copper plating thickness inside the hole is considerably reduced (for example, down to 0.0004" from 0.001") would that be detected by the E-tester as high resistance?

4) How the test parameters affect the above issues?

Your response is greatly appreciated.

Have a good weekend.



Sherif Refaat, Eng.





 





---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------