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" PCFET0NUWVBFIEhUTUwgUFVCTElDICItLy9XM0MvL0RURCBIVE1MIDQuMCBUcmFuc2l0aW9uYWwv L0VOIj4NCjxIVE1MPjxIRUFEPg0KPE1FVEEgY29udGVudD0idGV4dC9odG1sOyBjaGFyc2V0PWlz by04ODU5LTEiIGh0dHAtZXF1aXY9Q29udGVudC1UeXBlPg0KPE1FVEEgY29udGVudD0iTVNIVE1M IDUuMDAuMjYxNC4zNTAwIiBuYW1lPUdFTkVSQVRPUj48L0hFQUQ+DQo8Qk9EWSBzdHlsZT0iRk9O VDogOHB0IEFyaWFsOyBNQVJHSU4tTEVGVDogMnB4OyBNQVJHSU4tVE9QOiAycHgiPg0KPERJVj48 Rk9OVCBzaXplPTE+S2VuLCA8L0ZPTlQ+PC9ESVY+DQo8RElWPiZuYnNwOzwvRElWPg0KPERJVj48 Rk9OVCBzaXplPTE+SSBodmUgbGVhcm5lZCB0aGUgaGFyZCB3YXkgdGhhdCB0aGUgb25seSByZWxp YWJsZSB3YXkgdG8gDQpkZXBhbmVsaXplIGFuIGFzc2VtYmx5LCBlc3BlY2lhbGx5IHdpdGggYSBC R0EsIGlzIHRvIHVzZSBhIHJvdXRlci4mbmJzcDsgQmUgDQpleHRyZW1lbHkgY2FyZWZ1bCBpbiBo YXZpbmcgYW4gb3BlcmF0b3IgZGVwYW5lbCBieSBmbGV4aW5nIHRoZSBib3JkZXIuJm5ic3A7IFlv dSANCm1heSB2ZXJ5IHdlbGwgY2hhbmdlIHRoZSBjYXVzZSBvZiBCR0Egb3BlbnMgYnV0IHN0aWxs IGhhdmUgdGhlIHByb2JsZW0uIA0KPC9GT05UPjwvRElWPg0KPERJVj4mbmJzcDs8L0RJVj4NCjxE SVY+PEZPTlQgc2l6ZT0xPkthdGh5PC9GT05UPjxCUj48QlI+Jmd0OyZndDsmZ3Q7IEtQYXRlbEBa QUZGSVJFLkNPTSAwMS8yNi8wMSANCjAxOjA2UE0gJmd0OyZndDsmZ3Q7PEJSPk5vdGhpbmcgd3Jv bmcgaW4gc2hhcmluZyBhIGdvb2QgaW5mbyB0byANClRlY2huZXQuPEJSPjxCUj5JIGhhdmUgYXNr ZWQgYWJvdXQgdGhlIHBvc3NpYmxlIHJlYXNvbiBmb3Igb3BlbiBzb2xkZXIvY3JhY2sgYXQgDQpC R0EgdG88QlI+VGVjaE5ldCBmZXcgZGF5cyBhZ28uIFdoYXQgd2UgZm91bmQgb3V0IHRoYXQgdGhl IHNvbGRlciBjcmFja3MgYXJlIGR1ZSANCnRvPEJSPmRyZW1lciB0b29sICg/KSB1c2VkIHRvIHJl bW92ZSB0aGUgYnJlYWsgYXdheSB0YWJzLiBTbyB3YXRjaCBvdXQhIE91ciANCm1vdXNlPEJSPmJp dGUgd2l0aCB0aHJlZSBob2xlIHdpdGggc29saWQgY29ubmVjdGlvbiAtIG5vIGdvb2QgZGVzaWdu IGFzIGl0IA0KcmVxdWlyZXM8QlI+bG90IG9mIGVmZm9ydCB0byByZW1vdmUgYnJlYWsgYXdheSB0 YWIuIEhlbmNlIG91ciBhc3NlbWJseSBob3VzZSANCmZvbGtzIHVzZWQ8QlI+dGhlIGRyZW1lciB0 b29sIHRvIHJlbW92ZSBicmVhayBhd2F5IHRhYnMuIFZpYnJhdGlvbiBvZiB0aGF0IHRvb2wgDQpn ZW5lcmF0ZWQ8QlI+Y3JhY2sgYXQgdGhlIGludGVyZmFjZSBiZXR3ZWVuIGJvYXJkIGFuZCB0aGUg YmFsbCBhbG9uZyB0aGUgZW50aXJlIA0Kcm93PEJSPmZhY2luZyB0aGUgYnJlYWsgYXdheSB0YWIu PEJSPjxCUj5Cb3R0b20gbGluZSwgZG8gbm90IHVzZSBkcmVtZXIgdG9vbCBhbmQgDQppbmNvcnBv cmF0ZSBiZXR0ZXIgbW91c2UtYml0ZSBkZXNpZ248QlI+d2l0aCA0IG9yIDUgaG9sZXMgd2l0aCB0 d28gY29ybmVyIGhvbGVzIA0KaGFsZiBpbiB0aGUgRlI0IG1hdGVyaWFsIHNvIHRoYXQ8QlI+b3Bl cmF0b3IgY2FuIGluaXRpYXRlIHRhYiBzZXBhcmF0aW9uIA0KZWFzaWx5LjxCUj48QlI+cmUsPEJS PmtlbiANCnBhdGVsPEJSPjxCUj4tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS08QlI+VGVjaG5ldCAN Ck1haWwgTGlzdCBwcm92aWRlZCBhcyBhIGZyZWUgc2VydmljZSBieSBJUEMgdXNpbmcgTElTVFNF UlYgMS44ZDxCUj5UbyANCnVuc3Vic2NyaWJlLCBzZW5kIGEgbWVzc2FnZSB0byBMSVNUU0VSVkBJ UEMuT1JHIHdpdGggZm9sbG93aW5nIHRleHQgaW48QlI+dGhlIA0KQk9EWSAoTk9UIHRoZSBzdWJq ZWN0IGZpZWxkKTogU0lHTk9GRiBUZWNobmV0PEJSPlRvIHRlbXBvcmFyaWx5IGhhbHQgZGVsaXZl cnkgb2YgDQpUZWNobmV0IHNlbmQgdGhlIGZvbGxvd2luZyBtZXNzYWdlOiBTRVQgVGVjaG5ldCBO T01BSUw8QlI+U2VhcmNoIHByZXZpb3VzIA0KcG9zdGluZ3MgYXQ6IHd3dy5pcGMub3JnICZndDsg T24tTGluZSBSZXNvdXJjZXMgJmFtcDsgRGF0YWJhc2VzICZndDsgRS1tYWlsIA0KQXJjaGl2ZXM8 QlI+UGxlYXNlIHZpc2l0IElQQyB3ZWIgc2l0ZSAoPEEgDQpocmVmPSJodHRwOi8vd3d3LmlwYy5v cmcvaHRtbC9mb3J1bS5odG0pIj5odHRwOi8vd3d3LmlwYy5vcmcvaHRtbC9mb3J1bS5odG0pPC9B PiANCmZvciBhZGRpdGlvbmFsPEJSPmluZm9ybWF0aW9uLCBvciBjb250YWN0IEtlYWNoIFNhc2Ft b3JpIGF0IHNhc2Frb0BpcGMub3JnIG9yIA0KODQ3LTUwOS05NzAwIA0KZXh0LjUzMTU8QlI+LS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tPEJSPjwvRElWPjwvQk9EWT48L0hUTUw+DQo= --=_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 ---------------------------------------------------------------------------------