GLAST LAT Project
Oct 05
GLAST Large Area Telescope:
Gamma-ray Large
Area Space
Telescope
Electronics, Data Acquisition &
Flight Software W.B.S 4.1.7
Analysis of cPCI Backplane
Connector Assembly xray’s
4.1.7 DAQ & FSW
V1
Gunther Haller
[email protected]
(650) 926-4257
1
GLAST LAT Project
Oct 05
Backplane Analysis
• Method: give following information for each backplane
– Starting point: list of pins supplied by GSFC identified as
under-fill
– Identify pins in that list which are not used
• Pins already identified on SLAC’s spread-sheet
• Pins not on the spread-sheet
– There is no reason to spend time discussing the fill of any
pins not used anyways
– Of the remaining pins, list of pins used
• Pins already identified on SLAC’s spread-sheet
• Pins not on the spread-sheet
• Discuss fill of both
4.1.7 DAQ & FSW
V1
2
GLAST LAT Project
Oct 05
Notes (1)
•
•
•
Number of pins soldered on backplane excluding shield-pins (which are not used and thus ignored)
– P1: 25 rows
– P2: 22 rows
– P3: 19 rows
– P4: 25 rows
– P5: 22 rows
– Each row: columns Z, A, B, C, D, E, F
• Z and F are shield pins, not used
– Total number of pins potentially used
– 113 x 5 = 565 for each slot, times 4 slots = 2,260 pins
– Identification of 4 slots
• X1: CPU (3u-card in P1, P2)
• X2: CPS (3u-card in P4, P5)
• X3: SIB (6u-card in P1-P5)
• X4: LCB (6u card in P1-P5)
Connectors not used for flight
– X1: P3, P4, P5
– X2: P1, P2, P3
– X3: P2, most of P3
• (P3 only uses: A19 (dclk); A1-E1 (gnd); A5-E5: (3.3V); B8-B14 (gnd); gnd and 3.3V redundant
on other connectors)
– X4: P2, P3
Following connector are used for EGSE only, thus ignored for flight crates
– X1: P4/P5 holds custom Serial card, not used/integrated for flight
– X2: P1/P2 holds commercial Ethernet card, not used/integrated for flight
4.1.7 DAQ & FSW
V1
3
GLAST LAT Project
Oct 05
Notes (2)
• Comment to intentionally shorted shield pins (3 pins on row Z
or row F) apparent on some xrays
– Mostly, center pin identifies row in which pin was to be
touched-up
– Wanted some kind of indication that correct pin was in fact
touched-up just in case that no change might be apparent
before/after touch-up
– Shorts were removed after xray but before QA, although
shorts would have no effect since
• Shield pins already shorted to each other via
board/connector
• LAT does not use shield pins anyways
4.1.7 DAQ & FSW
V1
4
GLAST LAT Project
Oct 05
First Flight Backplane 2414
•
•
•
•
Total of ~ 2,000 pins looked at in xray
22 pins identified on GSFC list
Not used (16 pins)
– Already identified on SLAC list
• X1: P5-D11; P5-C12; P5-D12;
• X2: P1-B17
• X3: P1-B17
– Not used from remaining identified (X1-P5, X2-P1 not used as stated)
• X1: P5-E11
• X2: P1-A19
• X2: P2-C10, B11, C11, D11; P4-C6
• X3: P1-B2 ; P1-B6 (red+5); P5-B2 (ch-gnd); P5-C14 (red+5), P4-B21 (redGND);
• X4: P5-B5 (red+3.3)
Used
– Already identified on SLAC list
• X1: P1-B15 (Frame#);
• X3: P1-A7 (AD30);
–
4.1.7 DAQ & FSW
Not on SLAC list
• X1: P1-C23 (AD3) ;
• X3: P1-D16 (stop_n)
V1
5
GLAST LAT Project
Oct 05
Second Flight Backplane 2415
•
•
•
Total of ~ 2,000 pins looked at in xray
18 pins identified on GSFC list
Not used
– Already identified on SLAC list (7 pins)
• X2: P1-B3; P4-A15; P4-B23;
• X3: P1-B8; P2-C12; J4-C1, J4-C16
– Not used from remaining identified
• X1: P1-A19 (3.3V, one of 7 pins, not needed)
• X3: P2-B12; P3-C1 (red+5), C3 (red+5), E4
• X4: P1-B1
•
Used
– Already identified on SLAC list
• X4: P1-C23(AD3); P4-C11(EI_PRIM_5_N); P4-C21(EI_PRIM_2_P)
– Not on SLAC list
• X1: P1-B19 (AD15), P1-A20 (AD12) ;
4.1.7 DAQ & FSW
V1
6
GLAST LAT Project
Oct 05
Third Flight Backplane 2420
• Total of ~ 2,000 pins looked at in xray
• 5 pins identified on GSFC list
• Not used
– Already identified on SLAC list
• None
– Not used from remaining identified
• X1: P2-C21
• X2: P1-D25
• X3: P2-E8, B13
• X4: P5-C22
• Used
– none
4.1.7 DAQ & FSW
V1
7
GLAST LAT Project
Oct 05
Fourth Flight Backplane 2418
•
•
•
Total of ~ 2,000 pins looked at in xray
17 pins identified on GSFC list
Not used
– Already identified on SLAC list
• None
– Not used from remaining identified
– X1: P2-B5, P4-E7, D8, E8, D9 (P4 not used)
– X2: P1-D11, B23, B24, C24; P2-B1, C1; (P1, P2 not used)
– X2: P4-C9 (red+5); P5-A5 (red-28)
– X4: P5-D21
•
Used
– Already identified on SLAC list
• None
– Not on SLAC list
• X1: P2-B6 (GBM RDNT)
• X3: P1-E7 (AD27)
4.1.7 DAQ & FSW
V1
8
GLAST LAT Project
Oct 05
Fifth Flight Backplane 2419
• Total of ~ 2,000 pins looked at in xray
• 6 pins identified on GSFC list
• Not used
– Already identified on SLAC list
• X1: J5-C13, B15
– Not used from remaining identified
• X1: P5-C15, A18 (X1-P5 not used)
• X3: P2-D10
• X4: P2-A10
• Used
– none
4.1.7 DAQ & FSW
V1
9
GLAST LAT Project
Oct 05
First Flight Spare Backplane 2416
•
•
•
Total of ~ 2,000 pins looked at in xray
46 pins identified on GSFC list
Not used
– Already identified on SLAC list (17)
• X1: P2-C10
• X2: P1-D11, A17, D19, A21 (P1 not used as indicated) P1-D11, A17, D19, A21 (X2 not used as
indicated); P5-B6, C6 (redundant as indicated)
• X3: P3-A4, B4, C5, D5, D6 (P3 not used as indicated)
• X4: P3-E10
– Not used from remaining identified
• X1: P2-B12, B13, C21
• X2: D25 (gnd red)
• X3: P2-A7, B7, A8, B8; P4- D24 (not used), C25(gndred), D25 (not used);
• X4: P2-B18, C18; P4-D6 (not used),
•
Used
– Already identified on SLAC list
• None
–
4.1.7 DAQ & FSW
Not on SLAC list
• X2: P4-D2 (PRIM_SPO1_P), D3 (PRIM_SPO0_N), C25 (CLK_OUT_PRIM_P), P5-D2
(SPARE_TO_LCB_0), B21 (28V_RET), D21 (SPI_PRIM_RDNT_SEL)
• X3: P1-A22 (AD7); P4-D20 (SC_RDNT_PWR_PDU_RDNT_SEL), P5-A19 (PRIM_1553_P)
• X4: P4-C23 (EI_PRIM_1_P); P5-D1 (GND)
V1
10
GLAST LAT Project
Oct 05
Summary
• 5 Flight boards (2414, 2415, 2420, 2418, 2419)
– > 10,000 pins checked
– 68 pins called out by GSFC as questionable
– Of those 14 were already on SLAC spread-sheet identified
as not used
– 54 pins remaining
– Of those 42 are not used (no need to discuss fill)
– Remaining are 11 pins to examine (of those 6 were on SLAC
list)
– Next pages show all 11 pins
• 1st flight spare (2416)
– 46 pins called out by GSFC as questionable
– Of those 42 are not used (no need to discuss fill)
– Remaining are 11 pins to examine
– Next pages show all 11 pins
4.1.7 DAQ & FSW
V1
11
GLAST LAT Project
Oct 05
Flight
4.1.7 DAQ & FSW
V1
12
GLAST LAT Project
Oct 05
X-ray of pins 2414: X1-P1-B15
Void a bit bigger than on one of
the previous cross-sections
shown below.
Would estimate that to be about
75% fill and the pin on the right
to be at least 65%
GLAT2414 X1 P1 B15
FRAME#
4.1.7 DAQ & FSW
V1
13
GLAST LAT Project
Oct 05
X-ray of pins 2414: X1-P1-C23
Fill ~ 75%, based on simple
ratio of 3 out of 4 shows
solder fill.
GLAT2414 X1 P1 C23
AD3
4.1.7 DAQ & FSW
V1
14
GLAST LAT Project
Oct 05
X-ray of pins 2414: X3-P1-A7
Fill >80%, assuming 5
out 6 ratio filled.
GLAT2414 X3 P1 A7
AD30
4.1.7 DAQ & FSW
V1
15
GLAST LAT Project
Oct 05
X-ray of pins 2414: X3-P1-D16
Fill ~ 80%, based on simple
ratio of 3.5 out of 4.5 shows
solder fill.
GLAT2414 X3 P1 D16
STOP_N
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2415: X1-P1-A20
80% fill based on 4.5 out of
5.5 fill ratio.
GLAT2415 X1 P1 A20
AD12
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2415: X1-P1-B19
>90% fill.
GLAT2415 X1 P1 B19
AD15
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2415: X4-P1-C23
65% fill based on 2 out of
3 fill ratio.
GLAT2415 X4 P1 C23
AD3
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2415: X4-P4-C11
>70% fill assuming 2.25 out of
3 fill ratio. Summed voids to
get to 0.75 voids.
GLAT2415 X4 P4 C11
EI_PRIM_5_N
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2415: X4-P4-C21
80 % fill assuming 2.4 out of
3 solder fill.
GLAT2415 X4 P4 C21
EI_PRIM_2_P
4.1.7 DAQ & FSW
V1
21
GLAST LAT Project
Oct 05
X-ray of pins 2418: X1-P2-B6
70 % fill assuming 4 out of
5.5 solder fill.
GLAT2418 X1 P2 B6
GBM RDNT
4.1.7 DAQ & FSW
V1
22
GLAST LAT Project
Oct 05
X-ray of pins 2418: X3-P1-E7
65 % fill assuming >3 out of
5 solder fill.
GLAT2418 X3 P1 E7
AD27
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
Flight Spare
4.1.7 DAQ & FSW
V1
24
GLAST LAT Project
Oct 05
X-ray of pins 2416: X2-P4-D2
80 % fill assuming 4 out of
5 solder fill.
GLAT2416 X2 P4 D2
PRIM_SPO1_P
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2416: X2-P4-D3
75 % fill assuming 4.5 out of
6 solder fill.
GLAT2416 X2 P4 D3
PRIM_SPO0_N
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2416: X2-P4-C25
90 % fill.
GLAT2416 X2 P4 C25
CLK_OUT_PRIM_P
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2416: X2-P5-D2
75 % fill assuming 4.5 out of
6 solder fill.
GLAT2416 X2 P5 D2
SPARE_TO_LCB_0
4.1.7 DAQ & FSW
V1
28
GLAST LAT Project
Oct 05
X-ray of pins 2416: X2-P5-B21
80 % fill assuming 5 out of
6 solder fill.
GLAT2416 X2 P5 B21
28V_RET
4.1.7 DAQ & FSW
V1
29
GLAST LAT Project
Oct 05
X-ray of pins 2416: X2-P5-D21
80 % fill assuming 5 out of
6 solder fill.
GLAT2416 X2 P5 D21
SPI_PRIM_RDNT_SEL
4.1.7 DAQ & FSW
V1
30
GLAST LAT Project
Oct 05
X-ray of pins 2416: X3-P1-A22
> 65 % fill assuming 4 out of
6 solder fill.
GLAT2416 X3 P1 A22
AD7
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2416: X3-P4-D20
70 % fill assuming 3.5 out of
5 solder fill.
GLAT2416 X3 P4 D20
SC_RDNT_PWR_PDU_RDNT_SEL
4.1.7 DAQ & FSW
V1
32
GLAST LAT Project
Oct 05
X-ray of pins 2416: X3-P5-A19
>65 % fill assuming 4 out of
6 solder fill.
GLAT2416 X3 P5 A19
PRIM_1553_P
4.1.7 DAQ & FSW
V1
33
GLAST LAT Project
Oct 05
X-ray of pins 2416: X4-P4-C23
>65 % fill assuming 3 out of
5 solder fill.
GLAT2416 X4 P4 C23
EI_PRIM_1_P
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
X-ray of pins 2416: X4-P5-D1
70 % fill assuming 4 out of
5.5 solder fill.
GLAT2416 X4 P5 D1
GND
4.1.7 DAQ & FSW
V1
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GLAST LAT Project
Oct 05
Conclusion
•
•
•
•
•
•
All boards were conformal coated a while ago
The boards are at different stages in assembly
Touching up boards now will require stripping off some conformal coat (not
difficult)
Flight
– 2414: 4 pins ok
– 2515: 5 pins ok
– 2420: no issues
– 2418: 2 pins ok (might touch these up, but no great hope of improvement)
– 2419: no issues
Flight spare
– 2416: 11 pins. Looks ok although we will try to touch up several of those
pins.
In summary although fill is not ideal and what we would like, it is acceptable
considering all other constraints
– Qual testing of example boards (using short-open tests) did not show any
issue even with pins filled down to 30% fill.
– TC/Vib/Thermal-vacuum did not show any issues on the proto-flight SIU
crate (with flight assembled SIB/CPS/LCB/CBP/RAD750) and those boards
had more voids and underfill than the above flight backplanes)
4.1.7 DAQ & FSW
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