GLAST BTEM Tracker Construction

1. Summary of HDI Assembly
2. Summary of Bad Strips
   Exhaustive list of all the bad strips are below.
   • Sorted by UCSC test result (PDF file)
   • Sorted by Hamamatsu report (PDF file)
3. Summary of Ladder Production
4. Summary of Detector Test
5. Detector Deliveries by Manufacturer

HDI

Summary

HDI	# HDI	HDI ID
Total	35	H5-H39
Rejected	3	H11,H30,H39
No problems	9	H5,H14,H21,H24,H27,H28,H34,H36,H38
With problems	23	H6-H8,H9,H10,H12,H13,H15-H20,H22,H23,H25,H26,H29,H31-H33,H35,H37




PC board with Problems

HDI	# HDI	HDI ID
Traces shorted	12	H6,H8,H10,H12,H13,H19,H22,H26,H32,H35,H37,H39
Trace damaged	8	H7,H15,H17,H20,H23,H31,H33,H35
Wrong component	1	H20(C160)




Replacement of chips

GTFE	# chips	HDI ID (chip address [0-24])
Pads damaged	13	H11(9,12,13),H17(12-15),H30(12-17)
Found broken	13	H17(12-17),H18(19),H29(2,24),H30(12,13,15,16)
Shorted to PCB	6	H6(8,12,14,16),H16(20),H25(2)
Replaced	12	H6(8,12,14,16),H16(20),H17(12-15),H18(19),H25(2),H29(2)
NOT replaced	12	H11(9,12,13),H17(16,17),H29(24),H30(12-17)
GTRC replaced	1	H16(R) (Found to be a wrong diagnosis)




Rebonding

HDI	Repairs made
H6	Wrong wire bond on chip 10 (RESETPAD and AVDD shorted), fixed
H9	CLKN rebonded to chip 0
H16	CTRLREG and A4 rebonded to chip 17
H16	Interchip connection between chips 20 and 21 rebonded
H23	TOUT of the left-most GTFE rebonded




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Bad Strips (found during assembly)

Coupling short --- 10 in total

	# strip	Remark
Reported by Hamamatsu	6
Tested at SCIPP	4	3 actually shorted, 1 found OK
Newly found at SCIP	7	3 with wedge marks, 4 with none reported




Al strip short --- 6 in total

	# strip	Remark
Reported by Hamamatsu	9
Tested at SCIPP	7	5 two-strip shorts, 1 three-strip short, 1 not shorted (*)
Newly found at SCIP	0

(*) Bypass strips are not counted in the number of strips in a short.


Al strip break --- 2 in total

	# strip	Remark
Reported by Hamamatsu	60
Tested at SCIPP	45	1 actually broken, 44 found OK(*)
Newly found at SCIP	1	This might be created during our assembly

(*) Those could be due to bad probing in Hamamatsu's test.



Mysterious strips --- 23 in total

We found 23 strips which have slightly higher coupling capacitance, say, C = 1.91-1.95 nF (a nominal value is around 1.81 nF). Meanwhile, Hamamatsu reported a coupling short on a neighboring bypass strip of 17 of those high-C strips. Since Hamamatsu reported only 21 coupling shorts on a bypass strip, this can not be a coincidence. But, I have no idea how it can happen.

	# strip	Remark
Strip with slightly high-cap.	23	All found on a 6-inch detector
Coupling short on bypass strip	21	Based on reports by Hamamatsu
Pair of above two neighboring	17




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Detector Ladder

Summary

Production Step	Number	Ladder ID
Mounted on Tray	130	L1-L139
Rejected	4	L26, L38, L96, L134
Mounted on Shake-Test Tray	5	L1, L2, L4, L5, L7
Assembled in total	139	L1-L139




Ladders Repaired

Ladder ID	Date	Problem	Repairs made
L3	4/9/99	High current at detector E (D75)	Detector E replaced (D75 -> D179)
L24	4/27/99	Glue joint between detectors B and C broke	Reglued
L73	7/15/99	High current (temporary)	Not repaired
L93	7/9/99	High current (temporary)	Not repaired
L15, L19, L29, L31	8/27/99	Epoxy blob found on the backside	The blob removed with the milling machine
L30	8/27/99	Detector D chipped when removed from a storage shelf	All wires between detectors C & D removed
L97 & L99	8/27/99	Stuck to a storage shelf	Removed from the shelf carefully




Ladders Rejected

Ladder ID	Remark
L26	Detector D cracked. The ladder was glued on a storage shelf.
L38	High current at Detector B, C, D, or E. The ladder was fine after bonding. Will be taken to Hiroshima Univ. to identify a high current detector.
L96	Detector C misaligned too much. Most likely, the glue joint became loose or completely separated after bonding.
L134	High current at 60 V and above




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Detector

Hamamatsu 6.4 cm x 6.4 cm

	Number	Detector ID
Used for Prototype Tower	285	D5-D311
Rejected	7	D25, D28, D34, D75, D127, D293, D301
In First Test Ladder	4	D46-D49
In Total	296	D5-D311




Hamamatsu 10.68 cm x 6.4 cm

	Number	Detector ID
Used for Prototype Tower	246	D501-D758, D903, D910, D923
Not Used	1	D730
Rejected	2	D555, D556
Received at SLAC	249	D501-D758, D903, D910, D923
Stored at Hiroshima U.	5	D46, D47, D151, D168, D183
In Total	254	D501-D758, D903, D910, D923




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Delivery of the detectors

Hamamatsu 6.4 cm x 6.4 cm

Date	Detector ID	Bias resistor (M ohm)
		Min.	Ave.	Max.
4/23/98	D5-D33	46.9	60.0	70.1
	D34-D61	67.9	75.3	103
6/2/98	D62-D113	61.5	71.5	111.0
6/9/98	D114-D142	64.9	80.6	101.0
8/3/98	D143-D181	63.7	73.2	102.0
	D182-D218	73.8	91.2	114.0
	D219-D251	57.3	73.5	91.7
12/14/98	D252-D280	74.0	89.3	134.0
	D281-D311	78.5	97.8	113.0




Hamamatsu 10.68 cm x 6.4 cm

Date	Detector ID	Bias resistor (M ohm)
		Min.	Ave.	Max.
3/12/99	D501-D545	-	-	-
	D546-D564	-	36.5	-
	D565-D600	-	38.9	-
7/30/99	D741-D758	-	49.9	-