From:	KEKVAX::UNNO         "Y. Nobu Unno, unno@kekvax.kek.jp" 23-JAN-1998 12:35:09.31
To:	ATLAS-SCT@ATLAS-LB.CERN.CH
CC:	UNNO
Subj:	RE: Definition of pig-tail cable and connectors (Revised)

  Dear collaborators,

  This note proposes a geometrical definition of the hybrid pigtail 
  cable and its connector of the Barrel modules. A few revisions are
  made to the 1st version after community's responses: definition of
  z-direction (along strips) of connector referenced to the hybrid, and
  the gender of connector. 

  Please send your comments/criticism to this version if you have
  concerns on the definitions. We would like to finalize this in the
  coming Jan. 98 module meeting...


                                        Nobu & Tony
                                        Module convenors


  ______________________________________________________________________

       Geometrical definition of pig-tail cable and connector 
          of the Barrel module  (Revised: 19 January 1998)
   __________________________________________________________________

   1) Length of the Kapton pig-tail cable of the barrel hybrid: 

   70 mm from the "centre-line of the hybrid" to the "centre-line of 
   the pig-tail connector".  This length is for the next round
   of module production in 1998 and the length will be reconsidered and
   optimised when we set the module-0 definition.  

   2) Pig-tail axis:  

   The axis of the pig-tail is aligned to the axis of the hybrid. This 
   results in modules with two different angles, 0 and 40 mrad, between 
   the connector axis and the axis of the cylinder.  These two angles will 
   be accommodated separately in the design of the opto-flex cable attached 
   to the cylinder.  

   3) Z (along strips) alignment of the hybrid and the connector

   The connector on the pig-tail is aligned in z (along detector strips)
   such that the 1st pin of the connector has the same z value as the
   front edge of the hybrid (the pitch-adaptor side of the hybrid).

   4) Connector type:

   For the next round of module, the pig-tail connector will be the 
   1.27 mm pitch, double-row, through-hole-pin, low-profile connector. 
   (There has been a proposal to use a single-row ZIF connector for
   mechanical and other reasons, but we suggest this discussion is again
   revisited later in 1998.) The gender of the connector will be described
   in the next.

   5) Gender of the connector:

   For the 1.27 mm pitch pin connector, 

   Pig-tail connector: Receptable (female) and through-hole-pin type
   Support card/opto-flex connector: Header (male) and through-hole-pin 
   					or surface mount

   Candidate connectors:  to be updated
	ELCO Torson 	- xxxx seriese
	BERG		- rib-cage 87011-620 or -625 (cut to 2x18, e.g.)
	SAMTEC		- SFM(receptacle) and FTS(header) series
	...

   6) Number of pins in the pig-tail connector:

   For the standard hybrid and 1.27 mm pitch double-row connector, the
   number of pins is "36".  Please see the Type 3 arrangement in the pin 
   assignment  note (Ref: SCT module page). 

   For the diagonostic, the number is "50".  

  ______________________________________________________________________