Werner and I both grew up in Bell Laboratories where we were taught the overriding importance of reliability. While we both still strongly believe  in this concept the the world that I at least live in has changed a great deal. With most CMs and OEMs, "PCBs have become commodities and should be priced as such". Large OEMs are now holding on line auctions for their suppliers; low bid wins. I only see a few examples of customers who still pay a premium for reliability. The driver for this attitude is not all together the PCB shop, but to a large extent the price objectives imposed by the purchasing managers; who are only trying to perform the job they have been given by their company. That is, get the price of the BOM below what our competitors are paying; even if it means negotiating "other issues". The price objectives are in cases below two cents per square inch of copper and in some cases slightly more than one cent. With these price objectives it is very difficult for a PCB supplier to meet the demonstrable reliability objectives to which I was accustom and Werner is suggesting.

Like it or not this is the world most of us live in and deal with. My approach in recent time has been to find a common ground between price and demonstratable reliability. I usually suggest end point requirements such as a specified finished hole sizes and a minimum copper thickness. At the same time some stress testing should be incorporate (IST, thermal cycling) at an agreed upon frequency. I also believe cross sections should be included in every shipment. The rub of course is who picks up the check for even these minimal expectations. 


Best regards

Lee

J. Lee Parker, Ph.D.
JLP Consultants LLC
804 779 3389  
  ----- Original Message ----- 
  From: Werner Engelmaier<mailto:[log in to unmask]> 
  To: [log in to unmask]<mailto:[log in to unmask]> 
  Sent: Tuesday, January 17, 2006 3:45 PM
  Subject: Re: [TN] Drill and plated hole callouts


  Hi Ofer,
  The reason for this is that many of the Fab houses still live in the past,
  and do not understand what is required for high reliability in high-density
  PCBs. The involved Fab houses cetainly understand those needs.



  Werner

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