At 12:00 AM 12/14/01 -0600, you wrote: >Date: Fri, 14 Dec 2001 00:00:04 -0600 >Reply-To: TechNet <[log in to unmask]> >Sender: TechNet <[log in to unmask]> >From: Automatic digest processor <[log in to unmask]> >Subject: TechNet Digest - 13 Dec 2001 (#2001-776) >To: Recipients of TechNet digests <[log in to unmask]> > >There are 8 messages totalling 516 lines in this issue. > >Topics of the day: > > 1. porosity of gold plating on nickel (2) > 2. Inefficient solder on Toshiba micro BGA (2) > 3. .050 PWB (2) > 4. PCB Density Study/Design Quoting > 5. photoplotters > >--------------------------------------------------------------------------- >------ >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: Thu, 13 Dec 2001 15:30:15 -0500 >From: "Vandendolder, Ron" <[log in to unmask]> >Subject: Re: porosity of gold plating on nickel >MIME-Version: 1.0 >Content-Type: text/plain; charset="iso-8859-1" > >Kris, > >Although not quantitative, I was impressed with some SEM's (Scanning >Electron Microscope) >pictures taken of some gold plated Duroid boards that were not performing as >expected. The pictures showed globular deposits of gold on the top surface. >Where the globular deposits didn't >touch, nickel was clearly showing. > >Ron VandenDolder >Product Development Group >Telaxis Communications >SouthDeerfield, MA >413-665-8551 > >-----Original Message----- >From: Kris Keating [mailto:[log in to unmask]] >Sent: Thursday, December 13, 2001 2:31 PM >To: [log in to unmask] >Subject: [TN] porosity of gold plating on nickel > > >Does anyone know of a fairly simple method of determining porosity of gold >plating over nickel on a PCB? > > >Kristopher J. Keating >Technical Service Engineer >Circuit-Wise, Inc. >400 Sackett Point Rd. >North Haven, CT 06473 >Tel. (203) 281-6511 >Fax (203) 287-8409 > >---------------------------------------------------------------------------- >----- >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: Thu, 13 Dec 2001 13:44:57 -0700 >From: Steve Abrahamson <[log in to unmask]> >Subject: Re: Inefficient solder on Toshiba micro BGA > >Hey Stacy, > >It sounds as though on paper, your process is OK. Just to fill you in on >aspect ratio, that is aperture width/stencil thickness. This is a good rule >of thumb for rectangular apertures such as for fine pitch components. For >small circular or square apertures most people use the area aspect ratio >which is aperture area/wall area. The area aspect ratio should be above >..66. Thus on a .005" thick stencil with a .0135" square aperture you are >looking at (.0135*.0135)/((.0135*.005)*4) = .675. >Actually the area aspect ratio for a .0135" round aperture is the same as >that for a square aperture, yet release on the square aperture has generally >been proven to be better (don't forget a .002" or .003" radius on the >corners). > >Anyway my point was going to be that I had the exact same apertures ordered >on one particular project, and the apertures all clogged up (luckily we >caught them at the visual step). It seems the apertures were severely >undersized (more like .0122" x .0122"). So are your apertures really >..0135"? > >As Kathy mentioned, kneed or condition your paste. The paste may take a few >prints to fully mix and provide the thixotropic characteristics that you >want. We use a dummy board for the first print, and then print our first >production board. > >Personally I think you could get away with a .015" aperture if you are >dealing with a .0315" pitch product. Even if they undercut your stencil, >you should be fine. > >Good luck.... > >Steve A > > > > -----Original Message----- > > From: My Nguyen [SMTP:[log in to unmask]] > > Sent: Tuesday,December 11,2001 11:43 AM > > To: [log in to unmask] > > Subject: [TN] Inefficient solder on Toshiba micro BGA > > > > Hello all, > > > > Problem description: > > > > Been happening on Rambus - part number tc59rm81xmb. > > Ball diametter: 0.5 mm; ball pitch: 0.8 mm, ball > > height: 0.4 mm. Pad size: 0.3 mm (11.5 mils) > > 5-10% of the time (we run huge amount of them) failure > > modules came from opening soder join or no solder join > > at all. As we inspect the screen printing process (we > > use 5 mils stencil - Dek screenprinting, cleaning > > rate: 2 per print, cleaning cycle Wet-Vacuum/Dry), we > > found un-event solder deposit. Some pad even has very > > little solder or no solder at all. > > > > Stencil is electro-polish; Diamond shape aperture, > > 13.5 mils open used trapezoid shape. > > > > We afraid that if we open the apperture bigger, then > > we may have bridging or solder ball. If we reduce the > > stencil to 4 mils to reduce the blockage or > > resistance, then we may have in-efficient solder or > > many other problem relating thin stencil (damage, > > short-life, etc) > > > > What would be your solution? > > > > Thanks, > > > > Stacy > > > > __________________________________________________ > > Do You Yahoo!? > > Check out Yahoo! Shopping and Yahoo! Auctions for all of > > your unique holiday gifts! Buy at http://shopping.yahoo.com > > or bid at http://auctions.yahoo.com > > > > -------------------------------------------------------------------------- > > ------- > > 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: Thu, 13 Dec 2001 12:49:52 -0800 >From: Mark Mazzoli <[log in to unmask]> >Subject: Re: porosity of gold plating on nickel >MIME-Version: 1.0 >Content-Type: text/plain; charset="us-ascii"; format=flowed > >Hi Kris, >Try IPC TM-650 2.3.24.2 Nitric Vapor Test. That's the easiest one I'm >aware of. >Here's a link:http://www.ipc.org/html/2.3.24.2.pdf > >Mark Mazzoli > > > > > > >At 02:30 PM 12/13/01 -0500, you wrote: >>Does anyone know of a fairly simple method of determining porosity of gold >>plating over nickel on a PCB? >> >> >>Kristopher J. Keating >>Technical Service Engineer >>Circuit-Wise, Inc. >>400 Sackett Point Rd. >>North Haven, CT 06473 >>Tel. (203) 281-6511 >>Fax (203) 287-8409 >> >>-------------------------------------------------------------------------- >>------- >>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: Thu, 13 Dec 2001 13:44:57 -0700 >From: Steve Abrahamson <[log in to unmask]> >Subject: Re: Inefficient solder on Toshiba micro BGA >MIME-Version: 1.0 >Content-Type: text/plain; charset="iso-8859-1" >Content-Transfer-Encoding: 7bit > >Hey Stacy, > >It sounds as though on paper, your process is OK. Just to fill you in on >aspect ratio, that is aperture width/stencil thickness. This is a good rule >of thumb for rectangular apertures such as for fine pitch components. For >small circular or square apertures most people use the area aspect ratio >which is aperture area/wall area. The area aspect ratio should be above >66. Thus on a .005" thick stencil with a .0135" square aperture you are >looking at (.0135*.0135)/((.0135*.005)*4) = .675. >Actually the area aspect ratio for a .0135" round aperture is the same as >that for a square aperture, yet release on the square aperture has generally >been proven to be better (don't forget a .002" or .003" radius on the >corners). > >Anyway my point was going to be that I had the exact same apertures ordered >on one particular project, and the apertures all clogged up (luckily we >caught them at the visual step). It seems the apertures were severely >undersized (more like .0122" x .0122"). So are your apertures really >0135"? > >As Kathy mentioned, kneed or condition your paste. The paste may take a few >prints to fully mix and provide the thixotropic characteristics that you >want. We use a dummy board for the first print, and then print our first >production board. > >Personally I think you could get away with a .015" aperture if you are >dealing with a .0315" pitch product. Even if they undercut your stencil, >you should be fine. > >Good luck.... > >Steve A > > > > -----Original Message----- > > From: My Nguyen [SMTP:[log in to unmask]] > > Sent: Tuesday,December 11,2001 11:43 AM > > To: [log in to unmask] > > Subject: [TN] Inefficient solder on Toshiba micro BGA > > > > Hello all, > > > > Problem description: > > > > Been happening on Rambus - part number tc59rm81xmb. > > Ball diametter: 0.5 mm; ball pitch: 0.8 mm, ball > > height: 0.4 mm. Pad size: 0.3 mm (11.5 mils) > > 5-10% of the time (we run huge amount of them) failure > > modules came from opening soder join or no solder join > > at all. As we inspect the screen printing process (we > > use 5 mils stencil - Dek screenprinting, cleaning > > rate: 2 per print, cleaning cycle Wet-Vacuum/Dry), we > > found un-event solder deposit. Some pad even has very > > little solder or no solder at all. > > > > Stencil is electro-polish; Diamond shape aperture, > > 13.5 mils open used trapezoid shape. > > > > We afraid that if we open the apperture bigger, then > > we may have bridging or solder ball. If we reduce the > > stencil to 4 mils to reduce the blockage or > > resistance, then we may have in-efficient solder or > > many other problem relating thin stencil (damage, > > short-life, etc) > > > > What would be your solution? > > > > Thanks, > > > > Stacy > > > > __________________________________________________ > > Do You Yahoo!? > > Check out Yahoo! Shopping and Yahoo! Auctions for all of > > your unique holiday gifts! Buy at http://shopping.yahoo.com > > or bid at http://auctions.yahoo.com > > > > -------------------------------------------------------------------------- > > ------- > > 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: Thu, 13 Dec 2001 16:10:13 -0500 >From: Tony Steinke <[log in to unmask]> >Subject: Re: .050 PWB >MIME-Version: 1.0 >Content-Type: text/plain; charset="iso-8859-1" >Content-Transfer-Encoding: 7bit > >Darrel, >I don't mean to sound sarcastic, but almost all board shops should be able >to manufacture you construction with their eyes closed. >----- Original Message ----- >From: Darrel Therriault <[log in to unmask]> >To: <[log in to unmask]> >Sent: Thursday, December 13, 2001 1:41 PM >Subject: [TN] .050 PWB > > > > Technet..... > > > > PWB designer and fab folks........We are considering building an .050" > > PWB with 2 oz Cu, 6-8 layers. > > > > Any heartburn or horror stories with this design or is this within > > normal capability from the design and fab perspective?? > > > > DT > > > > > > > > > > -- > > Darrel Therriault > > VP, Mfg. Operations > > INCEP Technologies, Inc > > (858)547-9925 223 > > [log in to unmask] > > > > -------------------------------------------------------------------------- >------- > > 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: Thu, 13 Dec 2001 16:10:06 -0500 >From: Hinners Hans M Civ WRALC/LUGE <[log in to unmask]> >Subject: Re: .050 PWB >MIME-Version: 1.0 >Content-Type: text/plain; charset="iso-8859-1" > >Tony's right unless >you do something "unadvisable" such as an unbalanced construction, isolated >traces without thieving . . . > >Hans >Integrity First - Service Before Self - Excellence in All We Do >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Hans M. Hinners >Electronics Engineer >Warner Robins - Air Logistics Center (WR-ALC/LUGE) >226 Cochran Street >Robins AFB GA 31098-1622 > >mailto:[log in to unmask] > >Com: (478) 926 - 5224 >Fax: (478) 926 - 4911 >DSN Prefix: 468 > > >-----Original Message----- >From: Tony Steinke [mailto:[log in to unmask]] >Sent: Thursday, December 13, 2001 4:10 PM >To: [log in to unmask] >Subject: Re: [TN] .050 PWB > > >Darrel, >I don't mean to sound sarcastic, but almost all board shops should be able >to manufacture you construction with their eyes closed. >----- Original Message ----- >From: Darrel Therriault <[log in to unmask]> >To: <[log in to unmask]> >Sent: Thursday, December 13, 2001 1:41 PM >Subject: [TN] .050 PWB > > > > Technet..... > > > > PWB designer and fab folks........We are considering building an .050" > > PWB with 2 oz Cu, 6-8 layers. > > > > Any heartburn or horror stories with this design or is this within > > normal capability from the design and fab perspective?? > > > > DT > > > > > > > > > > -- > > Darrel Therriault > > VP, Mfg. Operations > > INCEP Technologies, Inc > > (858)547-9925 223 > > [log in to unmask] > > > > -------------------------------------------------------------------------- >------- > > 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: Thu, 13 Dec 2001 16:25:07 -0600 >From: Mike Clemente <[log in to unmask]> >Subject: PCB Density Study/Design Quoting >MIME-Version: 1.0 >Content-Type: text/plain; charset=US-ASCII > >Hello everyone, > >I need to find an accurate PCB density study method and also an efficient >method of quoting PCB designs. > >Has anyone used the density study in IPC-2221? Is it accurate for >Thru-hole and SMT? Are there other methods out there for density study? > >Also, does anyone have any specifics or know where to obtain information >on Quoting PCB design from Schematic to Layout, to Manufacture and >Assembly of PCB? > >Thanks, > >Mike Clemente, C.I.D. >Sr. PCB Design Specialist >dZinit Applied Technologies >Tel: 847-545-8170 >Fax: 847-545-8175 >Email: [log in to unmask] >Date: Thu, 13 Dec 2001 15:27:57 -0800 >From: Karla Thompson <[log in to unmask]> >Subject: photoplotters >MIME-Version: 1.0 >Content-Type: text/plain; charset="iso-8859-1" > >I'm in the process of looking at Photoplotters and would appreciate any >input any of you may have. We currently have a 5-6 year old Barco Crescent >30. I'm looking at EIE, Orbotech, and Barco/Mania. If any of you have any >comments on those, or any others (?) I'd appreciate it. > > >Karla Thompson >CAM Technician >Electronic Controls Design, Inc >Tel: (503) 829-9108 >email: [log in to unmask] Hi, I will be back on 12/17/01. Regards, Jong