Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and AnswersTopic Posted by: Reliability & Maintainability Forum (email@example.com )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Original Message:Posted by: Mark Chapman
Date posted: Tue Jul 12 7:43:19 US/Eastern 2005
Subject: Connection/Interconnection FR
I need some help please. I am doing a 217F N2 prediction using MILSTRESS and there are different component connection failure rates that are being generated. One is IR (interconnection rate) and the CR (connection rate). I know that CR is dependant upon the number of pins and whether the components connection is through hole or SMT and it is what I have always used. My customer is asking me to create a separate block category keyword ST - IA,Surface Mount Tech and then put all of the components under it. This automatically creates a FR of 0.592 fpmh and does not take into consideration the component-board soldering. Section 16.2 of 217F N2 states that this failure rate does not include soldering!! IMHO I would have thought that the components should be created in the normal way taking into consideration soldering and then the SMT board FR of 0.592 fphm added at the end. Can anyone please comment on this. Thanks.