Pease accept my apologies if these responses seem truncated or out of sequence, our email has been down I am only now able to respond to emails posted a few days ago. I know I have lost some of the responses in this thread. In response to Werner's question about a "lamination coupon"; we are testing a delamination sensing coupon that some may find interesting. For the past 9 months we have been characterizing a specifically designed test coupon that enables the detection of material delamination, even to the extent where and when the dielectric breakdown begins. The critical circuits are incorporated into our latest "Generic" test vehicles (IST coupons). You do not have to complete "traditional IST" testing to check for delamination, but simply measuring before and after assembly/rework is quite sufficient to detect the problem. You could use the coupon alone and detect the presence and location (by layer) of delamination. This methodology utilizes a capacitance measurement technique that has been characterized to identify specific electrical changes that are caused by delamination. To date excellent correlation has been achieved between this new technique and standard microsectioning. The coupon is usually fabricated along the edge of a PWB production panel. Coupons are initially measured for a combination of resistance and capacitance readings. The coupons are then subjected to the customer's specified assembly and rework conditions (E.g. 2 to 6 cycles @ 260C). A second measurement is taken which will indicate if delamination occurred during the assembly and/or rework process. Please note that we believe the lead-free assembly and rework process initiates and accelerates delamination but the propagation is caused in subsequent thermal cycling. The present methodology uses a static measurement before and after the thermal excursions, we are now developing the technique to monitor throughout every cycle. We expect this capability will be invaluable for determining when in the thermal cycle, or how many cycles before a material fails. A secondary benefit of this design permits the PWB manufacturer (or their customer) the ability to confirm the precise construction (stack-up) of the product. Additionally, knowing the dielectric thickness then affords the capability to extrapolate Dk and understand how it changes with temperature. There are further product/material attributes that can be defined, which at this time are still considered proprietary. The protocol is titled Dielectric Estimation and Laminate Analysis Method (DELAM). It is still in the development phase, we need to test a wide variety of material types, construction and design attributes before we can make absolute statements related to capability. We have recently received confirmation from certain strategic customers that they require their existing designs should be replaced with the new DELAM coupons. All indications are that we have developed a very powerful tool to support us for the emerging lead-free environment. We consider that DELAM testing is essential assessment and a prerequisite to reliability testing. Any testing of product that contains delamination may cause a false positive result. Sincerely, Paul Reid Program Coordinator PWB Interconnect Solutions Inc. Tel: 613-596-4244 Ext. 229 Fax: 613-596-2200 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------