TECHNET Archives

October 2007

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Donald Vischulis <[log in to unmask]>
Reply To:
Donald Vischulis <[log in to unmask]>
Date:
Sun, 14 Oct 2007 20:15:36 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (119 lines)
I agree with Brian.  At that diameter and layer count, daisy chain or microsectioning sample coupons is the only method to determine compliance.  The CMI probe won't fit into a .020 diameter hole.  Both UPA and CMI measure the average copper thickness in the hole. The UPA has an accuracy of around +/- 7% (if I remember the fine print in their literature correctly).  Assuming that there are pads on all (or most) of the internal layers, both instruments will be affected by the internal pads to some extent.  Since they both evaluate the average thickness of copper in the hole, dogboning and internal pads, and voids alter the reading.  The thinner the board, the greater the influence of the internal pads.  All non-destructive instruments, to the best of my knowledge, provide an average reading.  Microvoids and larger voids will reduce the thickness reading but may not result in a reading below the 1.5 mil average.

Don Vischulis

-----Original Message-----
>From: Brian Ellis <[log in to unmask]>
>Sent: Oct 14, 2007 5:06 AM
>To: [log in to unmask]
>Subject: Re: [TN] SV: [TN] URGENT HELP NEEDED:- non-destructive method for via hole plating thickness
>
>I'm also for the test coupon and always recommended at least 
>half-a-dozen (preferably more) holes of each diameter, with separate 
>daisy-chaining for each diameter. A single hole test is statistically 
>invalid, no matter which test is done. I measured the resistance of each 
>chain and occasionally did a burn-out test by applying a small voltage 
>and ramping up the current until one hole burnt out, in a fume cupboard. 
>This is guaranteed to weed out weak holes, due to poor drilling; even 
>almost invisible faults by other methods would have fusing currents 
>dropping by several amps. The coupons can also be used for X-sectioning, 
>of course.
>
>Brian
>
>Hfjord wrote:
>> Gosh! Where did I get that from? Has nothing to do with Uranium. I mean 
>> My two rems.
>> 
>> -----Ursprungligt meddelande-----
>> Från: Hfjord [mailto:[log in to unmask]] 
>> Skickat: den 13 oktober 2007 22:52
>> Till: 'TechNet E-Mail Forum'; [log in to unmask]
>> Ämne: SV: [TN] URGENT HELP NEEDED:- non-destructive method for via hole
>> plating thickness
>> 
>> Don't know if Feinfocus X-ray has enough resolution, but may be worth
>> trying. A Feinfocus fitted with a Hamatsu image processor may fix it. There
>> is a contrast difference between Copper and Tin/Lead.
>> My two Bequerels
>> /Inge
>> 
>> -----Ursprungligt meddelande-----
>> Från: TechNet [mailto:[log in to unmask]] För [log in to unmask]
>> Skickat: den 13 oktober 2007 18:27
>> Till: [log in to unmask]
>> Ämne: [TN] URGENT HELP NEEDED:- non-destructive method for via hole plating
>> thickness
>> 
>> Hi to all,
>>  
>> Looking for service or friendly (aren't we all) PWB manu. who has the  
>> capability to measure COPPER plating thickness in via holes in FINISHED
>> BRD.  i.e. 
>> with HASL in via holes.  NON-DESTRUCTIVE TESTING
>>  
>> Description of brd:-
>>  
>> 20 layers
>> ~150 mils thick
>> Via holes are 20-22 mils finished.
>>  
>> Required plating is 0.0015 min.
>>  
>> A few I have learnt about are CMI (probe inside the hole) & UPA  (resistance
>> 
>> measurement)
>>  
>> Rush
>> 818-415-0030
>> 
>> 
>> 
>> ************************************** See what's new at http://www.aol.com
>> 
>> ---------------------------------------------------
>> Technet Mail List provided as a service by IPC using LISTSERV 15.0
>> 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
>> 847-615-7100 ext.2815
>> -----------------------------------------------------
>> 
>> ---------------------------------------------------
>> Technet Mail List provided as a service by IPC using LISTSERV 15.0
>> 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 847-615-7100 ext.2815
>> -----------------------------------------------------
>> 
>> 
>
>---------------------------------------------------
>Technet Mail List provided as a service by IPC using LISTSERV 15.0
>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 847-615-7100 ext.2815
>-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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 847-615-7100 ext.2815
-----------------------------------------------------

ATOM RSS1 RSS2