Victor
If you are referring to the document I authored, it only concerns plating in
the barrel. It was presented at this springs APEX. I understand that IPC
will furnish this paper on request. I suggest you call Tom Newton.
Best regards
Lee
J. Lee Parker, Ph.D.
JLP Consultants LLC
804 779 3389
----- Original Message -----
From: "Victor G. Hernandez" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, July 25, 2007 9:22 AM
Subject: Re: [TN] Question on plated through holes general 07 24 07
What is the acceptable wall thickness for Lead Free Process with
reference to the above stated document? I assume that the IPC document
dated 1997 is for SnPb product.
Victor,
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Lee parker
Sent: Tuesday, July 24, 2007 1:22 PM
To: [log in to unmask]
Subject: Re: [TN] Question on plated through holes general 07 24 07
Roger
Werner is correct.
The paper I presented at Apex found a linier relationship between the
current density and the cooper distribution in the hole which is often
refered to as dog boning. My model combined the well known Navier Stokes
equations for viscous flow and Faraday's law for electroplating. As the
plating solution passes through the hole the copper ion concentration in
the
solution is diminished and consequently, the plating rate is reduced.
I have been in the PCB business for over 30 years and was located in the
AT&T shop in Richmond as part of Bell Laboratories staff. This was one
of
the largest shops in the world. We constantly saw the empirical evidence
of
this relationship. My paper confirmed the existence of the relationship
using a first principals mathematical analysis.
Best regards
Lee
J. Lee Parker, Ph.D.
JLP Consultants LLC
804 779 3389
----- Original Message -----
From: "EIMCNews" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, July 24, 2007 12:55 PM
Subject: Re: [TN] Question on plated through holes general
> There seems to be a continuing misunderstanding of the forces at work
in
> plating through holes. First, you're reporting fairly thick copper at
the
> knee of the hole. The assumption is that the thickness diminishes
toward
> the center of the hole. If the hole is cross-sectioned do you find
this
> to
> be the case? If so, this is normal but not really desirable.
>
> There's more expansion at the knee of the hole (Werner can you weigh
in on
> this too please?). If the physical properties of the deposit are poor
> then
> there's the likelihood of cracks at the knee.
>
> As for plating thick boards at low current density, the only reason
for
> doing this is that there's additional time for the electrolyte to
better
> circulate through the barrel of the hole. Contrary to some popular
> beliefs,
> the holes of circuit boards are NOT low current density areas. The
> thickness of the deposit in the hole is less than on the surface of
the
> board because the hole doesn't see the same circulation of fresh
> electrolyte
> as the surface. Ogden and Tench proved this over 20+ years ago.
Numerous
> attempts have been made over the years to improve plating solution
> circulation through the hole. It becomes more difficult with thick
boards
> and/or smaller holes.
>
> Sincerely,
>
> Roger Mouton
>
> EIMC - Advanced Plating Technologies
> 949 481-5194
> www.smartcatshield.com
> [log in to unmask]
>
>
> Notice of Confidentiality
> The information contained in and transmitted with this email may be
> confidential and is intended only for the individual or entity named
> above.
> If you are not the intended recipient, you are hereby notified that
> inadvertent disclosure of this information to you does not constitute
a
> waiver of confidentiality privilege and that any review, disclosure,
> copying, or use of the contents of the email by you is prohibited.
>
> ----- Original Message -----
> From: "Lee parker" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Tuesday, July 24, 2007 5:49 AM
> Subject: Re: [TN] Question on plated through holes general
>
>
> > Ralph
> >
> > I presented a paper at IPC this spring on the variables which affect
the
> > copper uniformity in PTHs. You can probably get a copy by contacting
Tom
> > Newton at IPC.
> >
> > It is difficult for me to imagine a greater copper thickness causing
the
> > barrel to become more susceptible to cracks. The thicker the copper
the
> > lower the stress for a given load and consequently the lower the
strain.
> > What may be going on is the uniformity of the copper which causes
stress
> > concentrations and the ductility of the plated copper. As I
> > mathematically
> > demonstrated in my paper, the current density used in plating has a
> > strong
> > impact on these parameters. The thicker the board the greater the
need
> > for
> > low current density.
> >
> > I would ask the supplier to measure the ductility of the plated
copper
> > for
> > several current densities and draw your own conclusions.
> >
> > Best regards
> >
> > Lee
> >
> > J. Lee Parker, Ph.D.
> > JLP Consultants LLC
> > 804 779 3389
> >
> >
> > ----- Original Message -----
> > From: <[log in to unmask]>
> > To: <[log in to unmask]>; <[log in to unmask]>
> > Sent: Tuesday, July 24, 2007 9:00 AM
> > Subject: RE: [TN] Question on plated through holes general
> >
> >
> > Lee,
> >
> > Do you also have any inromation about max Cu thickness in the PTH?
In
> > the recent past we had some cracks and the min was ok but the max
showed
> > values aroung .045mm. Our supplier said that the crack was caused
due to
> > too thick copper. The crack location was on the top just below the
Cu
> > ring.
> > Do you or anybody else has a suggestion how to handle or specify
this?
> >
> > Regards
> > Ralph
> >
> > -----Original Message-----
> > From: TechNet [mailto:[log in to unmask]] On Behalf Of Lee parker
> > Sent: Friday, July 20, 2007 10:42 PM
> > To: [log in to unmask]
> > Subject: Re: [TN] Question on plated through holes general
> >
> > David
> >
> > I always advise one mil or more in the PTH. Given the non-uniformity
> > often seen in the PTH I would also spec the drill quality and the
ratio
> > of the copper at the top of the hole and in the center.
> >
> > Best regards
> >
> > Lee
> >
> > J. Lee Parker, Ph.D.
> > JLP Consultants LLC
> > 804 779 3389
> >
> >
> > ----- Original Message -----
> > From: "David Harman" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Friday, July 20, 2007 4:23 PM
> > Subject: [TN] Question on plated through holes general
> >
> >
> > I have a quick question and our standard that we have maybe an older
> > one. We currently use the ANSI/IPC-A-600 Rev E
> >
> >
> >
> >
> >
> > Page 70 Micro section:
> >
> >
> >
> > There is a table describing copper plating thickness min,
requirements
> >
> >
> >
> >
> >
> > Class 1
> > Class 2 Class 3
> >
> > Average Min Thickness .020mm (0.0008in) 0.025mm
> > (0.001 in) 0.025 mm (0.001 in)
> >
> >
> >
> > Minimum this area .0015 mm( .0006 in)
0.020 mm
> > (.0008 in) 0.020mm (.0008 in)
> >
> >
> >
> >
> >
> >
> >
> > Can anyone tell me if this still is a current standards for copper
> > plating thickness measurements.
> >
> >
> >
> > David Harman
> >
> >
> >
> >
> > ---------------------------------------------------
> > 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
> -----------------------------------------------------
>
---------------------------------------------------
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
-----------------------------------------------------
|
