8.14.2013 Hybrid Meeting

Hybrid meeting

Discussion points:

* Latest physical layout (Tim)
* Connector suggestions for hybrid and FE board (Ben)

Minutes

Tim showed the latest version of the hybrid physical layout. He had addressed most of the issues that Forest had mentioned during work with the old hybrid (see email form Tim pasted below). Other main changes except for the shorter but wider overall dimensions are that the components related to amplification on the hybrid will go away and there needs to be two holes in the boards.
This hybrid design was passed along to Forest who responded quickly saying that it looked fine and Tim has sent this layout to Ryan. Ryan will go to Tung and flesh out the details for a first layout that we can review fully, hopefully the week of 26th of Aug.

Ben showed the connector that was suggested for the hybrid: Samtec lpaf series. The reference material can be found here, here, here and here.
Hybrid: 6x10 pins (need 32 pins in total)
FE board: 6x30 pins (need 32*4 pins in total)
The HV spec is 250V/pin so the larger connector allows us to keep clearance between HV and other signals. Hopefully we'll be able to remove pins in between to further improve the spec. This connector was decided to be ok and we will use it for the layout.

There was some discussion on what do to qualify L1-3 for 1kV bias:
* First of all we need to build a small transition board that will interface the existing pigtail to the flex cable with the loaf connector. Most likely we will place this transition board on the outside of the cooling support channel.
* Since the DB connector on the pigtail is not rated for 1kV we will remove the HV pins and connect directly to transition board. Signal and power stays which meant the transition board will house a mating DB connector on one side.
* Ryan was not worried about the bond pads on the hybrid holding 1kV but we should still test.
* There was some worry about the HV components on the hybrid; a backup solution would be to bypass some stages but would require rework of the hybrids. We need to remember that these are all encapsulated at this point which might limit the possibilities (?).
* Main worry was the twisted pair wires on the pig tail which are rated for 600V. Pelle will check the spec and see if it's per isolation layer (would be good to 1.2kV then).
* Tests (Pelle and Ben):
- Do a HV test on existing twisted pair wires
- Do a HV test on a bad hybrid; Tim suggested hybrid 09t that was in his office.