Ralph, Your modification illustration assumes surface copper lands from which the addedcomponent must be isolated. For small chip components and a little bit of open real estate, what are your thoughts on bonding the component directly to the "main" pwb and then soldering the jumper wires to the component terminations? Jeff > From [log in to unmask] Thu Jul 18 11:56 EDT 1996 > Resent-Date: Thu, 18 Jul 1996 10:53:42 -0700 > Resent-Sender: [log in to unmask] > Old-Return-Path: <[log in to unmask]> > Date: 18 Jul 1996 08:21:16 -0700 > From: "Ralph Hersey" <[log in to unmask]> > Subject: FWD>RE>ASSY revision J-STD- > To: "IPC Technet" <[log in to unmask]> > X-Mailer: Mail*Link SMTP-QM 3.0.2 > Resent-Message-ID: <"R4jsa2.0.JEJ.dKbxn"@ipc> > Resent-From: [log in to unmask] > X-Mailing-List: <[log in to unmask]> archive/latest/5249 > X-Loop: [log in to unmask] > Resent-Sender: [log in to unmask] > Content-Type> : > text> > Content-Length: 5128 > > Mail*Link(r) SMTP FWD>RE>ASSY revision J-STD-001 > > Phil, > > Currently there is no procedure for mounting additional components as a > modification, in particular surface mounted components, to printed board > assemblies. > > In a prior life, as chairperson of the IPC's repair committee, there was a > proposal to add a modification/repair method that would meet you requirements. > Currently, I'm not sure what the status of the modification, perhaps if Jeff > Ferry is listening/watching/reading he could give us an update. > > In any case, your "gut reaction" is close to the proposal. What the proposed > method was, was to add (adhesively bond) a small printed board (with > additional lands) to the surface of the printed board for the additional > component mounting and electrical terminations. As you mentioned, then > adhesively spot-bond the wires in place. > > The following is an attempt to illustrate most of the modification: > > _______________ > | added comp. |w > w|_______________|wwwwwwwwwwwww > ____cccccc__________cccccc_____ > |____________added PB___________| > _______cccccc_______ccccccc_______________ > / the main PB \ > /__________________________________________\ > > The "c"s are the lands or other conductors on the printed boards. > > The "w"s represent on the left-side a jumper wire that is lap-soldered along > the surface of the component's electrical terminal and the land; on the > right-side, the wire is formed into an "L" shaped wire lead end and soldered > to the land and the component's electrical terminal. > > Not shown are the adhesive for bonding the "added PB" to the "main PB", the > jumper wire's lead dressing, wire staking, or the solder. > > A "thin" printed board slightly larger than the land pattern is manufactured > and attached to the surface of the printed board using a suitable adhesive. > The "slightly larger" is to provide the necessary electrical spacing. The > component is soldered to the lands using good hand-soldering surface mounted > component methods. The jumper wires and wire terminations would be much like > the current R-700, Rev C, Method 5.2.4 on page 185. > > This repair (intuitively) looks like it will meet about any of the IPC's > performance/functional Class requirements. > > Hope it helps, > > Ralph Hersey, [log in to unmask] > > > > > -------------------------------------- > Date: 7/17/96 6:05 PM > From: Phil Bavaro > Mike, > > Is there any standard which covers the repair of a completed CCA such as > the addition of a 0805 chip capacitor which doesn't have metallized lands > beneath it? > > We need to do some repair due to an electrical engineering change which > will require components and jumper wires to connect them. I know I've seen > this covered in an official procedure but cannot recall if it was an IPC > document or a Military spec or what. I looked through the 700 document but > it only covers the jumper wire installation. > > My gut reaction is to attach the component body to the pwb using the > wavesolder adhesive dot process and then to install the jumpers (with lots > of stress relief in them), making sure to stake the wires down every inch > of length. > > Any help would be appreciated. > > > > *************************************************************************** > * TechNet mail list is provided as a service by IPC using SmartList v3.05 * > *************************************************************************** > * To unsubscribe from this list at any time, send a message to: * > * [log in to unmask] with <subject: unsubscribe> and no text. * > *************************************************************************** > > > ------------------ RFC822 Header Follows ------------------ > Received: by quickmail.llnl.gov with SMTP;17 Jul 1996 18:04:43 -0700 > Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) > id TAA14324; Wed, 17 Jul 1996 19:56:04 -0700 > Resent-Date: Wed, 17 Jul 1996 19:56:04 -0700 > Received: by ipc.org (Smail3.1.28.1 #2) > id m0ugh1Z-0000LNC; Wed, 17 Jul 96 19:33 CDT > Resent-Sender: [log in to unmask] > Old-Return-Path: <[log in to unmask]> > X-Sender: [log in to unmask] > Message-Id: <v02140b07ae1344aa2c69@[129.46.191.218]> > Mime-Version: 1.0 > Content-Type: text/plain; charset="us-ascii" > Date: Wed, 17 Jul 1996 17:40:30 -0800 > To: Mike Buetow <[log in to unmask]> > From: Phil Bavaro <[log in to unmask]> (Phil Bavaro) > Subject: Re: ASSY revision J-STD-001 > Cc: [log in to unmask] > Resent-Message-ID: <"60BxD1.0.Tz8.gOOxn"@ipc> > Resent-From: [log in to unmask] > X-Mailing-List: <[log in to unmask]> archive/latest/5242 > X-Loop: [log in to unmask] > Precedence: list > Resent-Sender: [log in to unmask] > > > > *************************************************************************** > * TechNet mail list is provided as a service by IPC using SmartList v3.05 * > *************************************************************************** > * To unsubscribe from this list at any time, send a message to: * > * [log in to unmask] with <subject: unsubscribe> and no text. * > *************************************************************************** > > *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************