Mail*Link(r) SMTP FWD>FAB: Dissipation Loss Specs John, In brief, "dissipation loss (factor)" is the energy absorbed (lost) in the insulation system from the dissipated signal. Dissipation factor (loss) is generally defined as a ratio of the energy dissipated to the energy stored in the dielectric per unit Hz, or as the tangent of the loss angle. For dissipation factors less than 0.1, the dissipation factor may be considered equal to the power factor of the dielectric, which is the cosine of the phase angle by which the signal's current leads voltage. A classic application for "dissipation loss" would be your microwave oven, if you were trying to couple a microwave signal to your transmitting antenna through your microwave oven (with food stuff), most of your signal would be dissipated in the oven and not get to the antenna. The same holds true for printed board and other dielectrics, the goal (generally) is to have the in/out signal to have 100 percent coupling through the interconnection network, and not absorbed in the dielectric. With "high power" signals (transmitters), a "high loss" dissipative factor material could result in a fire (called advanced dielectric heating). In the case of very weak electrical signals or signals needing high signal integrity, you want low loss materials. As a rule of thumb, many of the lower loss materials have low molecular weight, such as polyethylene, propylene, styrene, and one of the frequently used printed board "high frequency" base materials -- teflon. Hope this helps, Ralph Hersey [log in to unmask] -------------------------------------- Date: 8/28/96 9:13 AM From: [log in to unmask] I am having trouble understanding what EXACTLY "dissipation loss" is WRT laminates. Can someone please enlighten me? What are the units, etc.? Enquiring minds want to know. Regards, John R. Kretsch, P.E. Sr. Engineer, Design Assurance [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. * *************************************************************************** ------------------ RFC822 Header Follows ------------------ Received: by quickmail.llnl.gov with SMTP;28 Aug 1996 09:13:10 -0700 Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) id KAA05062; Wed, 28 Aug 1996 10:56:47 -0700 Resent-Date: Wed, 28 Aug 1996 10:56:47 -0700 Received: by ipc.org (Smail3.1.28.1 #2) id m0uvlvO-0000UxC; Wed, 28 Aug 96 09:48 CDT Resent-Sender: [log in to unmask] Old-Return-Path: <[log in to unmask]> From: [log in to unmask] Date: Wed, 28 Aug 96 10:54:46 CST Encoding: 13 Text Message-Id: <[log in to unmask]> To: [log in to unmask] Subject: FAB: Dissipation Loss Specs Resent-Message-ID: <"MSEN32.0.jwF.Cn59o"@ipc> Resent-From: [log in to unmask] X-Mailing-List: <[log in to unmask]> archive/latest/6002 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. * ***************************************************************************