4-chip module on pixel stave(let) Joseph Finley 1 November 2013 - PowerPoint PPT Presentation

4-chip module on pixel stave(let) Joseph Finley 1 November 2013

Pixel Stave at LBL

First Stavelet ● 5 tabs on one side and 4 on the other side. ● Serial Power

Stavelet Fabrication ● Stavelet cables ● Aluminum power lines ● carbon foam, carbon face sheets, aluminum spacer ● Cured in autoclave ●

Stave and Stavelet problems In order to achieve the correct thickness on the end of stave card, 2 pcbs are joined together. To create vias, metal is flowed through the holes. This was not always successful, and some vias were open. Some cables had no open vias while others had a majority After repairing all the vias on the stavelet there were still several problems: ● On the 5-tab side, the power is open on the first tab ● several traces have high impedance (~60 ohms)

FE-I4B 4 Chip Module We recently received the 4 chip FE-I4B flex for serial powering and I have started creating a wire bonding diagram

FE-I4B Flex Layout

Tabs on the NTC DOB N_1 stave/stavelet only have CMD N DOB P_1 CMD P DOB N_2 2 pairs of data output CLK N DOB P_2 CLK P NTC traces, while the 4 chip module needs 4 pairs. Power HV 1 To work around this Ground problem we will be using HV 2 a multiplexing board

Multiplexing Board LVDS clk Receiver Some difficulties in designing the multiplexing board was the limited space on the flex to place the board, as 2-1 well as the limited CMOS power supply (< 2.5 mux V across FE-I4B) for use with the discrete chips on the mux board. LVDS data Buffer/Inverter to Receiver create differential pair

Multiplexing Board Setup To the Single Chip Card Test Board was originally designed to be used on a 2-chip or 4-chip module, but because we currently only have single chip cards, I had to copy the output from the chip to where the second output would be. I tried to copy command and clock signals to a second single chip card but reflections distorted the signals too greatly To USBpix

STcontrol software ● Using a version of STcontrol created by Johannes Agricola ● This version allows for parallel readout of chips as well as multiplexing options

First Results using a Single Chip Card Muxed Chip Single Chip Analog Scan

First Results using a Single Chip Card Single Chip Muxed Chip Digital Scan

Future plans ● Figure out problem with digital scan using mux board ● Bonding diagram for 4-chip module ● Adapter board for 4-chip module to test off the stave

Questions