Re: Hall D FDC prototype

[Howard Fenker <hcf@jlab.org>]

I would propose epoxying the kapton-based cathode board permanently to
an appropriate G-10 frame, obviously holding the flexiboard and frame
flat during the curing time. If it's possible to attach the output
connectors from the flexiboard side of the assembly then it would seem
that the G-10 thickness doesn't need to change just to accomodate
connectors. Alternatively, use connectors with pins long enough to
reach through the G-10 board. Maybe I've misunderstood something here?

Yes- we should acquire an ample quantity of bare G-10 frames for all
the different configurations of cathode planes.

	Howard

> 
> II). Figure: cathodeV4.pdf  (cathode board)
> 
>  1). The cathode board design still has a number of open questions.  When 
>      last we talked, we decided to make the cathode plane (the copper-cladded 
>      kapton) larger in size so that we could include dowel pin holes to 
>      improve the alignment and positioning.  I assume that we are mounting 
>      this on top of a G10 frame.  The question is how we will attach this
>      to the G10.  In my mind it seems that we will have to epoxy the
>      cathode plane to the G10 to ensure that it cannot move and also to
>      ensure that our chamber remains gas tight.  Once the attachment is
>      made, then we will have a mechanically sturdy cathode board that we
>      can mount Fernando's signal on.
> 
>      Randy's response: I am not sure how it is planned to be mounted to the 
>          G10. I have asked that as well and not received and answer yet.  The 
>          connection to Fernando's readout is at the signal connector pads on 
>          the left and right side of the drawings.  I would guess we would make 
>          a G10 frame with a step down to .062" where the connectors are.  The 
>          G-10 gives the mechanical strength and Kapton gives the electrical 
>          connection to solder to.
> 
>      You have not received an answer yet probably because I am supposed to
>      provide the answer.  However I want to discuss this with the group.
>      Perhaps Howard Fenker can provide some input to this question based
>      on his experience.  Also because it seems that we have to permanently
>      attach the cathode sheets to the G10, and because we are testing
>      sets of cathode sheets with different cathode strip spacings, we will
>      have to order enough G10 frames for each.
>