Mail*Link(r) SMTP FWD>DES/FAB/ASSY: Ruggedized PWA's Jeff, When we "ruggedize" a product it means we do some things to improve the product's survivability when subjected to a particular environment. Many Class 2 products can be "ruggedized" to meet more severe "industrial/commercial" environments without becoming Class 3 products or having Class 3 product requirements. Remember, Class 3 products are for critical applications where failure is not acceptable. Depending on your customers "ruggedized" requirements, if you have to meet all environments (shock/vibration, thermal/power cycling, wide ranging environmental temperature, then you definately will approach a Class 3 like product. However, many electrical/electronic products are "ruggedized" without going to Class 3. Think of some of you portable electronic instruments, industrial controllers and sensors, etc., I suspect many of these are "ruggedized" Class 2 products. 1) If thermal shock/cycling or power cycling is a concern, then design and manufacture to minimize the effect on component mountings (solder joints), that is design compliance (stress relief) into the design. 2) If your product is to be subjected to shock/vibration, design for shock/vibration, or retrofit shock/vibration reinforcement stiffeners/dampeners into the product. Better yet, if the product hasn't been designed (or can be revised) modify the design to "break-up" large spans of unsupported printed boards. 3) If your product is subjected to a hot/cold environment then thermal management needs to be evaluated. As an example, consider "ruggedizing" the very popular personal computer mother boards. In general they are would not be considered a "ruggedized" product. But, if all the module plug-in connectors in the mother board were securely mounted to a mounting frame, and a standoff spacers (screwed type, not press or slide-in) were located on a grid of about 75-100 mm centers, then the mother board would become more robust and low frequency resonances would be eliminated. The plug-in boards are a problem, so you would need to design a "card-cage" to secure the one-end that currently is not supported, and along the length of the longer plug-in printed board assemblies. You also may need to worry about thermal management. In a more severe environment, the ventilation system would not hack-it. So you would need to design in a more efficient method of heat transfer (removal). (In the case of a "ruggedized PC" it would be cheaper to buy one from those who currently manufacture them.) IMO, Class 3 IPC products do not have to be "ruggedized", this is because the products use-environment may not require it. A classic example is a heart pace-maker: it doesn't need to survive say a 50g shock, 5 g vibration 20 minutes each axis 5-2000 Hz, or a 100 or so -50 to +125 degree thermal cycles because the implanted pace-maker might survive, but the patient would most probably croak and be long-gone. The key for you is to work with your customer and identify the requirements for "ruggedizing" the product. Ralph Hersey, e-mail [log in to unmask] -------------------------------------- Date: 7/22/96 4:41 PM From: Jeff Seeger Hello, TechNet! I have a situation where our customer is being asked for "ruggedized" product. The product category is generally Type 3 and 4 PWB's, with Class 2 expectations, fine pitch components both sides, (of course) moderate high-speed rules. Product is built in ~100 piece lots. Is there a general scheme of "ruggedizing" the PWA, or does this simply imply an upgrade to Class 3 standards? I'm not sure density will allow a full Class 3 implementation. Is there anything non-subjective about "ruggedizing"? I've not seen it mentioned anywhere. Would selective upgrades to Class 3 qualify as "ruggedized"? Which areas? Of course, I have no specific performance requirements, just the word "ruggedized". From the nature of the product, I would guess there could be application for mobile equipment. Can any "rugged" folks out help an old soft-in-the-head design guy? Thanks alot, and best regards, Jeff Seeger Applied CAD Knowledge Inc Chief Technical Officer Tyngsboro, MA 01879 [log in to unmask] 508 649 9800 *************************************************************************** * 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;22 Jul 1996 16:40:22 -0700 Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) id SAA00449; Mon, 22 Jul 1996 18:30:23 -0700 Resent-Date: Mon, 22 Jul 1996 18:30:23 -0700 Received: by ipc.org (Smail3.1.28.1 #2) id m0uiTXY-0000MUC; Mon, 22 Jul 96 17:33 CDT Resent-Sender: [log in to unmask] Old-Return-Path: <simon.ipc.org!bort.mv.net!rapidcad!jseeger> Date: Mon, 22 Jul 96 18:24:35 EDT Message-Id: <[log in to unmask]> From: "Jeff Seeger" <simon.ipc.org!bort.mv.net!rapidcad!jseeger> Subject: DES/FAB/ASSY: Ruggedized PWA's To: [log in to unmask] X-VMS-Mail-To: UUCP%"[log in to unmask]" Resent-Message-ID: <"MVZMh2.0.TM6.f60zn"@ipc> Resent-From: [log in to unmask] X-Mailing-List: <[log in to unmask]> archive/latest/5303 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. * ***************************************************************************