Please remove me from your distribution list. Thanks.
-----Original Message-----
From: Automatic digest processor [mailto:[log in to unmask]]
Sent: Friday, January 26, 2001 12:55 PM
To: Recipients of TechNet digests
Subject: TechNet Digest - 26 Jan 2001 - Special issue (#2001-51)
There are 11 messages totalling 907 lines in this issue.
Topics in this special issue:
1. Drilling through Assemblies
2. Skip plating in Ni
3. Circumfrential Void (2)
4. Silver vs OSP surface finish
5. PCB Equipment Rating
6. Spread the knowledge...let's share...reason for BGA crack (2)
7. Conversions and terms
8. fractured joints
9. SMD soldering problems
----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----
----------------------------------------------------------------------
Date: Fri, 26 Jan 2001 09:49:49 -0500
From: Phil Nutting <[log in to unmask]>
Subject: Re: Drilling through Assemblies
Barry,
If this were a small quantity of boards, I'd probably use a regular high
speed drill and throw the drill bit away when I'm done as the board material
is abrasive and will ultimately dull the bit.
For large quantities of boards a carbide bit is preferred. It lasts much
longer and can withstand a larger range of bit speeds.
As for a drill press, use what fits the board and bit size and is clean
(free of grease and oil). I've used large floor mounted drill presses and
small "Unimat" style drill presses. Sometimes it's simply a matter of what
do you have that will work. The Yankee in me will keep from buying
unnecessary equipment if I have something that works for the short run.
Phil Nutting
Manufacturing Engineer
Kaiser Systems, Inc.
High Voltage Power Supplies That Work(tm)
126 Sohier Road
Beverly, MA 01915
ph: 978-922-9300
fx: 978-922-8374
[log in to unmask]
-----Original Message-----
From: Barry Gallegos [mailto:[log in to unmask]]
Sent: Friday, January 26, 2001 9:09 AM
To: [log in to unmask]
Subject: [TN] Drilling through Assemblies
Good day to all.
We have accepted an order of PCB's to assemble for a customer. this customer
has requested that we make some modifications to the boards that they are
providing. the want for us to Drill several holes in the board to insert
some through hole components into.
my question is this. is there any special type dill press that we should
use, or any special type of drill bit. what speed should the drill run at
and any other special precautions that I should be aware of.
Barry Gallegos, PE
Western Electronics, LLC
1550 South Tech Lane
Meridian, Idaho 83642
Phone 208-955-9771
Fax 208-955-9751
------------------------------
Date: Fri, 26 Jan 2001 10:16:17 -0500
From: "Brown, Matthew" <[log in to unmask]>
Subject: Skip plating in Ni
Our chip carrier product is experiencing a very interesting problem.
Random
features on the product are not plating in the Ni cell. A thick Cu seed
layer
with a photo mask is pattern plated in Cu and then goes directly to our
Ni/Au
operation. After Ni/Au we find that some features are totally devoid of
Ni! The
Au still plated (to full thickness) so I know the seed was still intact
(commoned).
The Cu plated well, so I discounted the possibility of a resist residue.
A colleague
mentioned skip plating. I've heard the term before, but I can't find
detailed
information in any of my reference books. Anybody want to fill me in? Or
speculate
on this intriguing phenomenon?
------------------------------
Date: Fri, 26 Jan 2001 10:39:06 -0500
From: Ian Hanna <[log in to unmask]>
Subject: Re: Circumfrential Void
This is a multi-part message in MIME format.
------=_NextPart_000_002C_01C08784.35031080
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
The trick is to establish where and when the void occurred; poor
metalization (black-hole in this case), poor electroplating, or poor Sn(pb?)
plating and thus an etched void.
Shop history and a keen read of the micro-sections will provide the biggest
clues.
Ian
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Sandy Kumar
Sent: Thursday, January 25, 2001 5:14 PM
To: [log in to unmask]
Subject: [TN] Circumfrential Void
I am looking for information on the possible causes of circumfrential voids
(occuring inside the hole barrel), that I am seeing in the cross sections of
multilayer FR4 boards with 10 mil holes with aspect ratio of 10. After
drilling, these boards go through Blackhole graphitic carbon / Cu flash /
image / Cu pattern plate with Sn as etch resist / strip dry film, etch Cu
and strip the Sn/ LPI and HAL.
I would like to find out the cause for these voids. I deeply appreciate any
valuable advice on how to fix this problem.
Thanks.
Sandy
------=_NextPart_000_002C_01C08784.35031080
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html xmlns:v=3D"urn:schemas-microsoft-com:vml" =
xmlns:o=3D"urn:schemas-microsoft-com:office:office" =
xmlns:w=3D"urn:schemas-microsoft-com:office:word" =
xmlns=3D"http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<meta name=3DProgId content=3DWord.Document>
<meta name=3DGenerator content=3D"Microsoft Word 9">
<meta name=3DOriginator content=3D"Microsoft Word 9">
<link rel=3DFile-List href=3D"cid:[log in to unmask]">
<!--[if gte mso 9]><xml>
<o:OfficeDocumentSettings>
<o:DoNotRelyOnCSS/>
</o:OfficeDocumentSettings>
</xml><![endif]--><!--[if gte mso 9]><xml>
<w:WordDocument>
<w:Zoom>0</w:Zoom>
<w:DocumentKind>DocumentEmail</w:DocumentKind>
<w:EnvelopeVis/>
</w:WordDocument>
</xml><![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;
mso-font-charset:0;
mso-generic-font-family:swiss;
mso-font-pitch:variable;
mso-font-signature:16792199 0 0 0 65791 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0in;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:12.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"Times New Roman";}
p.MsoAutoSig, li.MsoAutoSig, div.MsoAutoSig
{margin:0in;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:12.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"Times New Roman";}
span.EmailStyle15
{mso-style-type:personal-reply;
mso-ansi-font-size:10.0pt;
mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;
mso-bidi-font-family:Arial;
color:navy;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;
mso-header-margin:.5in;
mso-footer-margin:.5in;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext=3D"edit" spidmax=3D"1027"/>
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext=3D"edit">
<o:idmap v:ext=3D"edit" data=3D"1"/>
</o:shapelayout></xml><![endif]-->
</head>
<body bgcolor=3Dwhite lang=3DEN-US style=3D'tab-interval:.5in'>
<div class=3DSection1>
<p class=3DMsoNormal><span class=3DEmailStyle15><font size=3D2 =
color=3Dnavy face=3DArial><span
style=3D'font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Th=
e trick
is to establish where and when the void occurred; poor metalization =
(black-hole
in this case), poor electroplating, or poor Sn(pb?) plating and thus an =
etched
void.<o:p></o:p></span></font></span></p>
<p class=3DMsoNormal><span class=3DEmailStyle15><font size=3D2 =
color=3Dnavy face=3DArial><span
style=3D'font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Sh=
op
history and a keen read of the micro-sections will provide the biggest =
clues.<o:p></o:p></span></font></span></p>
<p class=3DMsoNormal><span class=3DEmailStyle15><font size=3D2 =
color=3Dnavy face=3DArial><span
style=3D'font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'><!=
[if =
!supportEmptyParas]> <![endif]><o:p></o:p></span></font></span></p>
<p class=3DMsoNormal><span class=3DEmailStyle15><font size=3D2 =
color=3Dnavy face=3DArial><span
style=3D'font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Ia=
n<o:p></o:p></span></font></span></p>
<p class=3DMsoNormal><span class=3DEmailStyle15><font size=3D2 =
color=3Dnavy face=3DArial><span
style=3D'font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'><!=
[if =
!supportEmptyParas]> <![endif]><o:p></o:p></span></font></span></p>
<p class=3DMsoNormal><span class=3DEmailStyle15><font size=3D2 =
color=3Dnavy face=3DArial><span
style=3D'font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'><!=
[if =
!supportEmptyParas]> <![endif]><o:p></o:p></span></font></span></p>
<p class=3DMsoNormal><span class=3DEmailStyle15><font size=3D2 =
color=3Dnavy face=3DArial><span
style=3D'font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'><!=
[if =
!supportEmptyParas]> <![endif]><o:p></o:p></span></font></span></p>
<p class=3DMsoNormal><span class=3DEmailStyle15><font size=3D2 =
color=3Dnavy face=3DArial><span
style=3D'font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'><!=
[if =
!supportEmptyParas]> <![endif]><o:p></o:p></span></font></span></p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
color=3Dblack
face=3DTahoma><span =
style=3D'font-size:10.0pt;font-family:Tahoma;color:black'>-----Original
Message-----<br>
<b><span style=3D'font-weight:bold'>From:</span></b> TechNet
[mailto:[log in to unmask]]<b><span style=3D'font-weight:bold'>On Behalf Of =
</span></b>Sandy
Kumar<br>
<b><span style=3D'font-weight:bold'>Sent:</span></b> Thursday, January =
25, 2001
5:14 PM<br>
<b><span style=3D'font-weight:bold'>To:</span></b> [log in to unmask]<br>
<b><span style=3D'font-weight:bold'>Subject:</span></b> [TN] =
Circumfrential Void</span></font></p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D3 =
face=3D"Times New Roman"><span
style=3D'font-size:12.0pt'><![if =
!supportEmptyParas]> <![endif]><o:p></o:p></span></font></p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D3 =
color=3Dblack
face=3D"Times New Roman"><span =
style=3D'font-size:12.0pt;color:black'> </span></font><font
color=3Dblack><span =
style=3D'color:black;mso-color-alt:windowtext'><o:p></o:p></span></font><=
/p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
color=3Dblack
face=3DArial><span =
style=3D'font-size:10.0pt;font-family:Arial;color:black'>I am
looking for information on the possible causes of circumfrential voids
(occuring inside the hole barrel), that I am seeing in the cross =
sections of
multilayer FR4 boards with 10 mil holes with aspect ratio of 10. After
drilling, these boards go through Blackhole graphitic carbon / Cu flash =
/ image
/ Cu pattern plate with Sn as etch resist / strip dry film, etch Cu and =
strip
the Sn/ LPI and HAL.</span></font><font color=3Dblack><span =
style=3D'color:black;
mso-color-alt:windowtext'><o:p></o:p></span></font></p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D3 =
color=3Dblack
face=3D"Times New Roman"><span =
style=3D'font-size:12.0pt;color:black'> </span></font><font
color=3Dblack><span =
style=3D'color:black;mso-color-alt:windowtext'><o:p></o:p></span></font><=
/p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
color=3Dblack
face=3DArial><span =
style=3D'font-size:10.0pt;font-family:Arial;color:black'>I
would like to find out the cause for these voids. I deeply =
appreciate any
valuable advice on how to fix this problem.</span></font><font =
color=3Dblack><span
style=3D'color:black;mso-color-alt:windowtext'><o:p></o:p></span></font><=
/p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D3 =
color=3Dblack
face=3D"Times New Roman"><span =
style=3D'font-size:12.0pt;color:black'> </span></font><font
color=3Dblack><span =
style=3D'color:black;mso-color-alt:windowtext'><o:p></o:p></span></font><=
/p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
color=3Dblack
face=3DArial><span =
style=3D'font-size:10.0pt;font-family:Arial;color:black'>Thanks.</span></=
font><font
color=3Dblack><span =
style=3D'color:black;mso-color-alt:windowtext'><o:p></o:p></span></font><=
/p>
<p class=3DMsoNormal style=3D'margin-left:.5in'><font size=3D2 =
color=3Dblack
face=3DArial><span =
style=3D'font-size:10.0pt;font-family:Arial;color:black'>Sandy</span></fo=
nt><font
color=3Dblack><span style=3D'color:black'> </span></font><font =
color=3Dblack><span
style=3D'color:black;mso-color-alt:windowtext'><o:p></o:p></span></font><=
/p>
</div>
</body>
</html>
------=_NextPart_000_002C_01C08784.35031080--
------------------------------
Date: Fri, 26 Jan 2001 16:14:12 +0100
From: "Ingemar Hernefjord (EMW)" <[log in to unmask]>
Subject: Re: Silver vs OSP surface finish
George,
I begin to get a feeling that ENIG may not be best solution for soldering
BGAs and other components. One of the biggest have removed ENIG from their
board processing and that makes me think a little. Anyway, thanks for your
kind attention, can't promise I won't come back to you./Ingemar
-----Original Message-----
From: Wenger, George M (George) [mailto:[log in to unmask]]
Sent: den 26 januari 2001 12:05
To: [log in to unmask]
Subject: Re: [TN] Silver vs OSP surface finish
Ingemar,
Our board vendors know not to send us IAg boards if there are "exposed
copper pads" (i.e., features not plated). If they happen to miss them in
their inspection (accidentially or not)our operators at stencil printing
reject boards that have exposed copper pads.
We don't use lots of ENIG boards so we have little experience with ENIG
solderability. I think it is safe to say that if a copper pad changes color
when ENIG plated the copper pad should be solderable. However, once plated
with ENIG you can no longer solder to the copper, you must solder to the
nickel. Our limited experience indicates that nickel easily passivates and
if it does it solderability degrades. One experiment we did was to
Temperature/Humidity condition ENIG and IAg boards and then do double sided
surface mount solder assembly. The ENIG boards had solder defects and the
IAg didn't. The 4 microinches of IAg will not stop diffusion of the
underlying material any more than 5 microinches of IAu on ENIG boards.
However, the under lying material on IAg boards is copper but for ENIG
boards it is nickel. The flux we typically use were designed to work with
copper oxide but they don't touch nickel oxide.
Regards,
George
George M. Wenger DMTS
Bell Laboratories Princeton, Supply Network Solutions
Engineering Research Center FMA / AQA / RCA Lab
(609) 639-2769 (Office); 3210 (Lab); 2343 (Fax)
[log in to unmask]
-----Original Message-----
From: Ingemar Hernefjord (EMW)
[mailto:[log in to unmask]]
Sent: Friday, January 26, 2001 4:22 AM
To: [log in to unmask]
Subject: Re: [TN] Silver vs OSP surface finish
Interesting George,
is that a std among board makers or do you have to imply that method in your
own Incoming Inspection? In the later example it's too late, the boards are
already delivered, so I assume it's something one has to perform immediately
before final plating. My question: is there a corresponding inspection
method for judging nickel solderability before gold immersion is put on? I
talk for ENIG of course. There are many soaps that react with nickel but
using a std method would be best. Wetting balance on test coupons will
probably not tell the whole truth.
Ingemar Hernefjord
Ericsson Microwave System
The primary advantage of IAg is that it changes the color of the copper pad.
OSP doesn't change the color of the copper pad. We use IAg not as a
solderable surface finish; we use IAg as a visual inspection aid to know
that the underlying copper is solderable (i.e., if the copper changes color
because the silver plated on it we know that the board fabrication process
didn't leave any residue such as solder mask or incomplete tin strip on the
pad that won't show up until you commit expensive components at assembly.
Regards,
George
George M. Wenger, DMTS Bell Laboratories Princeton
Supply Network Solutions
PO Box 900, Princeton NJ 08542-0900
Route 569 Carter Rd., Hopewell, NJ 08525
(609)-639-2769 (Office), 3210 (Lab), 2343 (Fax)
[log in to unmask]
-----Original Message-----
From: Michael Forrester [mailto:[log in to unmask]]
Sent: Wednesday, January 24, 2001 10:51 AM
To: [log in to unmask]
Subject: [TN] Silver vs OSP surface finish
What are the advantages of using Silver (Alpha level) Vs OSP (Entek) as a
surface finish? Since Alpha level
has an OSP over the silver why bother with the silver? Wouldn't less
interfaces
between the component
and trace be better? Thank you.
Best Regards,
Michael Forrester
LeCroy Corp.
----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----
----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----
----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----
----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----
------------------------------
Date: Fri, 26 Jan 2001 11:40:31 -0600
From: Dave Kell <[log in to unmask]>
Subject: PCB Equipment Rating
I am looking for a resource that rates equipment manufacturers. In =
particular, I am looking a bare board AOI equipment. If anyone would be =
interested in answering some concerns by my upper management, please =
contact me off-line.
Dave Kell
Product Assurance Engineer
Minco Products, Inc.
763-586-2889
E-mail: [log in to unmask]
------------------------------
Date: Fri, 26 Jan 2001 11:06:03 -0800
From: Ken Patel <[log in to unmask]>
Subject: Spread the knowledge...let's share...reason for BGA crack
Nothing wrong in sharing a good info to Technet.
I have asked about the possible reason for open solder/crack at BGA to
TechNet few days ago. What we found out that the solder cracks are due to
dremer tool (?) used to remove the break away tabs. So watch out! Our mouse
bite with three hole with solid connection - no good design as it requires
lot of effort to remove break away tab. Hence our assembly house folks used
the dremer tool to remove break away tabs. Vibration of that tool generated
crack at the interface between board and the ball along the entire row
facing the break away tab.
Bottom line, do not use dremer tool and incorporate better mouse-bite design
with 4 or 5 holes with two corner holes half in the FR4 material so that
operator can initiate tab separation easily.
re,
ken patel
------------------------------
Date: Fri, 26 Jan 2001 13:20:12 -0800
From: pratap <[log in to unmask]>
Subject: Re: Conversions and terms
--------------199960688F222C2152290897
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Jason,
go to www.rampinc.com for acronyms. There is also a library section
for other links that include sites for conversion factors.
--------------199960688F222C2152290897
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
Jason,
<p>go to <u>www.rampinc.com </u> for acronyms. There is
also a library section for other links that include sites for conversion
factors.</html>
--------------199960688F222C2152290897--
------------------------------
Date: Fri, 26 Jan 2001 14:15:17 -0500
From: Bob Arciolla <[log in to unmask]>
Subject: fractured joints
This is a multi-part message in MIME format.
------=_NextPart_000_0008_01C087A2.686B7B60
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
The IPC standard states that all clipped leads must either be reflowed =
or checked under 10X magnification. Is this just a standard for single =
sided boards? If you have a double sided board and a good fillet on the =
component side of the board and you clipped the leads on the solder side =
what would be the cause of concern if a joint is fractured on the solder =
side?=20
[log in to unmask]
------=_NextPart_000_0008_01C087A2.686B7B60
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">
<HTML>
<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
<META content=3D'"MSHTML 4.72.2106.6"' name=3DGENERATOR>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT size=3D2>The IPC standard states that all clipped leads must =
either be=20
reflowed or checked under 10X magnification. Is this just a standard for =
single=20
sided boards? If you have a double sided board and a good fillet on the=20
component side of the board and you clipped the leads on the solder side =
what=20
would be the cause of concern if a joint is fractured on the solder =
side?=20
</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2><A=20
href=3D"mailto:[log in to unmask]">[log in to unmask]</A>=20
</FONT></DIV></BODY></HTML>
------=_NextPart_000_0008_01C087A2.686B7B60--
------------------------------
Date: Fri, 26 Jan 2001 13:44:17 -0800
From: pratap <[log in to unmask]>
Subject: Re: Circumfrential Void
Sandy,
Look at pages 150 - 169 for PTH defects and explanation of various
defect mechanisms in the book 'Failure modes and Mechanisms in
Electronics Packages'. The book is available from www.wkap.nl ( Kluwer
publications)
pratap
------------------------------
Date: Fri, 26 Jan 2001 13:50:51 -0600
From: Kathy Kuhlow <[log in to unmask]>
Subject: Re: Spread the knowledge...let's share...reason for BGA crack
This is a MIME message. If you are reading this text, you may want to
consider changing to a mail reader or gateway that understands how to
properly handle MIME multipart messages.
--=_CC978A3A.AACBA746
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
Ken,=20
I hve learned the hard way that the only reliable way to depanelize an =
assembly, especially with a BGA, is to use a router. Be extremely careful =
in having an operator depanel by flexing the border. You may very well =
change the cause of BGA opens but still have the problem.=20
Kathy
>>> [log in to unmask] 01/26/01 01:06PM >>>
Nothing wrong in sharing a good info to Technet.
I have asked about the possible reason for open solder/crack at BGA to
TechNet few days ago. What we found out that the solder cracks are due to
dremer tool (?) used to remove the break away tabs. So watch out! Our =
mouse
bite with three hole with solid connection - no good design as it requires
lot of effort to remove break away tab. Hence our assembly house folks =
used
the dremer tool to remove break away tabs. Vibration of that tool =
generated
crack at the interface between board and the ball along the entire row
facing the break away tab.
Bottom line, do not use dremer tool and incorporate better mouse-bite =
design
with 4 or 5 holes with two corner holes half in the FR4 material so that
operator can initiate tab separation easily.
re,
ken patel
---------------------------------------------------------------------------=
------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET =
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > =
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for =
additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 =
ext.5315
---------------------------------------------------------------------------=
------
--=_CC978A3A.AACBA746
Content-Type: TEXT/HTML
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="TEXT.htm"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=
--=_CC978A3A.AACBA746--
------------------------------
Date: Fri, 26 Jan 2001 15:02:18 -0500
From: "Bissonnette, Jean-Francois" <[log in to unmask]>
Subject: SMD soldering problems
This message is in MIME format. Since your mail reader does not understand
this format, some or all of this message may not be legible.
------_=_NextPart_001_01C087D2.E3121970
Content-Type: text/plain;
charset="iso-8859-1"
Hello,
Is there any one who as some good pictures of a cold solder in surface
mount??? I saw some boards that
I can't determine if a problem is present or not. Unfortunately, I don't
have any way to get a picture right
now, so I'll try to give clear description.
1- This is a very populated board, SMD and TH.
2- Most of the SMD solders look nice and shiny
3- On diodes (SOD-123 package) the solders look gray but if the solder is
lightly scraped,
it will look shiny
4- On some of these diodes there is a solder fillet, but I can see a clear
demarcation between the
Lead and the solder.
5- In some cases, a push with a pick dislodged the diode, leaving a clear
"footprint" to the lead
That's about all I can say. How can I tell (without trying to push'em off
all the time) if I have a cold
solder??? Anyone has a picture (other than the IPC book)?
Thanks!
JF
WABTEC CORPORATION CONFIDENTIALITY NOTE
The content contained in this e-mail transmission is legally privileged and
confidential information intended only for the use of the individual or
entity named herein. If the reader of this transmission is not the intended
recipient, you are hereby notified that any dissemination, distribution, or
copying of this transmission is strictly prohibited.
------_=_NextPart_001_01C087D2.E3121970
Content-Type: text/html;
charset="iso-8859-1"
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META content="MSHTML 5.00.2314.1000" name=GENERATOR></HEAD>
<BODY>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001>Hello,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>Is there any one
who
as some good pictures of a cold solder in surface mount??? I saw some
boards that</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>I can't
determine if
a problem is present or not. Unfortunately, I don't have any way to
get a
picture right </SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>now, so I'll try
to
give clear description.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>1- This is
a
very populated board, SMD and TH.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>2- Most of
the
SMD solders look nice and shiny</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>3- On
diodes
(SOD-123 package) the solders look gray but if the solder is lightly
scraped,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001> it will look
shiny</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>4- On some
of
these diodes there is a solder fillet, but I can see a clear demarcation
between
the</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001> Lead and the
solder.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>5- In some
cases, a push with a pick dislodged the diode, leaving a clear
"footprint" to the lead</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>That's about all
I
can say. How can I tell (without trying to push'em off all the time)
if I
have a cold</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=653052819-26012001>solder???
Anyone has a picture (other than the IPC book)?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001>Thanks!</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=653052819-26012001>JF</SPAN></FONT></DIV><CODE><FONT SIZE=3><BR>
<BR>
WABTEC CORPORATION CONFIDENTIALITY NOTE<BR>
The content contained in this e-mail transmission is legally privileged and
confidential information intended only for the use of the individual or
entity named herein. If the reader of this transmission is not the intended
recipient, you are hereby notified that any dissemination, distribution, or
copying of this transmission is strictly prohibited.<BR>
</FONT></CODE></BODY></HTML>
------_=_NextPart_001_01C087D2.E3121970--
------------------------------
End of TechNet Digest - 26 Jan 2001 - Special issue (#2001-51)
**************************************************************
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
|
