C.3 Bump bonding
One of most difficult parts of realizing CdTe and/or CdZnTe pixel detectors is to establish a simple and robust connection technology for these fragile devices. It should be noted that high compression and/or high ambient temperature would damage the CdTe crystal.
Also, the coplanarity of the CdTe wafer is measured to be 2 µm at most, which is much worse than that of usual silicon wafers. Usual indium-ball soldering might not be appropriate for this purpose. Also, indium is easily oxidizable and needs flux which could contaminate the detector surface.
Therefore, we adopted a stud-bump method［83，130］. To prevent possible stress on the device, we choose a combination of soft metal, gold and indium, as a stud. In order to attain good connection between the bond pad on the readout board and the pixel electrode on the CdTe wafer, a needle-shaped stud consisting of two stages of gold studs is prepared on the bump pad (Fig. C.5). Studs are made from a gold stud bonder with a 25 µm diameter gold wire, and a thin layer of indium is printed on the top of the stud to improve connectivity. The total height of the stud from bottom to top is 150–
200 µm. The CdTe wafer and the fanout board are then pressed together with 20 g of compression per bump under controlled temperature conditions. To increase mechanical strength, epoxy resin with low viscosity is filled into the space between the CdTe wafer and the fanout board.
Figure C.5: Photograph of studs［83］
References
［1］D. Winkler et al. Astronomy and Astrophysics, 411 L1-L6, 2003
［2］K. Mitsuda et al. Publ. Astro. Soc. Japan 58, SP1, S1–S8, 2007
［3］A.A. Moiseev, Nucl. Instr. and Meth. in Phys. Res. A 588 pp. 41-47, 2008
［4］V. Schoenfelder et al. Astroph. J. Suppl. Series 86, pp. 657-692, 1993
［5］V. Schoenfelder, New Astronomy Reviews, 48, pp.193-198, 2004
［6］V. Schoenfelder et al., Nucl. Instr. and Meth. 107, no 2, pp 385-394, 1973
［7］V. Schoenfelder et al., Astron. Astrophys, 110, pp. 138, 1982
［8］V. Schoenfelder et al. Astron. Astrophys 120, pp. 13- 21, 1996
［9］K. Koyama et al. Nature 378, 255-258, 1995
［10］T. Tanaka et al. ApJ, 685, 988-1004, 2008
［11］W. Johnson et al. ApJS, 86, 693, 1993
［12］W. Mahoney et al. ApJ, 262, 742, 1982
［13］V. Schoenfelder, “The Universe in Gamma Rays“, Springer 2001
［14］S. Pluschke et al. ESA SP-459: Exploring the Gamma-Ray Universe, 91, 2001
［15］U. Oberlack et al. ApJ, 92, 433, 1994
［16］A. Caspi et al. American Astronomical Society, SPD meeting, vol. 38, 253, 2006
［17］W. Arnett et al. ARAA, 27, 629, 1989
［18］D. Morris et al. N.Y.Acad.Sci, 759, 397, 1995
［19］A. Iyudin et al. ESA, SP-382, 37, 1997
［20］J.G. Skibo et al. ApJ, 397, 135 1992
［21］P. von Ballmoos, ApJ, 380, 98, 1991
［22］R. Lingenfelter et al. ApJ, 343, 686, 1989.
149
［23］G. Weidenspointner et al. Nature 451, pp. 159-162, 2008
［24］P. Jean et al. A&A 445 pp. 579. 2006
［25］W. Wang et al. Astronomy and Astrophysics, vol. 446, Issue 3, 943–948, 2006
［26］D. Smith et al. ApJ, 414, 165, 1993
［27］J.K. Daugherty et al. ApJ, 252, 337, 1982
［28］K.S. Cheng et al. ApJ, 300, 522, 1986
［29］R. Sunyaev et al. A&A 143 374 1985
［30］W. Coburn et al. Nature 423 415 2003
［31］A.J. Dean et al. Science 321, pp.1183-1185, 2008
［32］F. Lei et al. Space Science Review, vol. 82, pp.309-388, 1997
［33］J. Legere et al. Proc. SPIE 5898, 413, 2005
［34］N. Produit et al. Nucl. Inst. and Meth. A 550, pp. 616, 2005
［35］S. Gunji et al. Proc. International Cosmic Ray Conference, 2779, 2003
［36］R.D. Evans. The Atomic Nucleus, Copyright 1955, McGraw-Hill Book Company
［37］G.F. Knoll, Radiation detection and measurements, 3rd ed. New York: J. Wiley, 2000
［38］R. Ribberfors, Phys. Rev. B 12 , pp. 2067-2074, 1975
［39］D. Brusa et al. Nucl. Instr. and Meth. in Phys. Res. A 379 pp. 167-175, 1996
［40］F. Biggs et al., Atomic Data and Nuclear Data Tables, vol. 16, no. 3, pp. 201-309, 1975
［41］R. Ribberfors and K. F. Berggren, Phys Rev. A 295 (1990) 231
［42］J.A. Lockwood et al. J. Geophy Res 84 pp.1402 1979
［43］F. Ait-Ouamer et al. IEEE Trans .Nucl. Sci 37, pp. 535, 1990
［44］H.O. Anger, Rev. Sci. INstrum. 29, pp. 3838, 1969
［45］R.W. Todd et al. Nucl. Inst. and Meth. 107, pp. 132-134, 1974
［46］M. Singh, Medical Physics, vol. 10, no 4. pp. 421-427, 1983
［47］M. Singh and D. Doria, Medical Physics, vol. 10, no 4. pp. 428-435, 1983
［48］J.B. Martin et al. IEEE, Trans. Nucl. Sci. vol. 40, no. 4, pp. 972-978, 1993
［49］J.W. LeBlanc et al. IEEE Trans. Nucl. Sci., vol. 45, no. 3 pp. 943-949, 1998
REFERENCES 151
［50］J.W. LeBlanc et al. IEEE Trans. Nucl. Sci., vol. 46, no. 3 pp. 201-204, 1999
［51］J.W. LeBlanc et al. Nucl. Instr. and Meth. A vol. 422, pp. 735-739, 1999
［52］T. Kamae et al. IEEE trans. Nucl. Sci. vol. 35, no. 1, pp. 352-355, 1988
［53］N. Dogan et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 299. no1-3 pp. 501-506, 1990
［54］E.A. Wulf et al. IEEE Trans. Nucl. Sci. vol. 51, no. 5 pp. 1997-2003, 2004
［55］R.A. Kroeger et al. IEEE Trans. Nucl. Sci., vol. 49, pp. 1887-1892, 2002
［56］J.E. McKisson et al. IEEE Trans. Nucl. Sci., vol 41, no. 4 pp. 1221-1224, 1994
［57］B.F. Phlips et al. IEEE Trans. Nucl. Sci., vol 43, no. 3 pp. 1472- 1475, 1996
［58］G.J. Schmid et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 459. pp. 565, 2001
［59］T. Niedermayr et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 553. pp. 501, 2005
［60］L. Mihailescu et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 570. pp. 89, 2007
［61］K. Vetter et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 579. pp. 363-366, 2007
［62］S. Boggs New Astronomy Reviews 50, pp. 604-607, 2006
［63］S. Boggs et al. NASA Vision Mission Concept Study Report Decenber 2005
［64］S. Boggs et al. New Astronomy Reviews 48, pp. 251-256, 2004
［65］T. Takahashi et al. Proc. SPIE 5488, pp. 549-560, 2004
［66］T. Takahashi et al. Proc. SPIE 6266, 2006
［67］http://www.cesr.fr/∼pvb/dual/
［68］P. von Ballmoos et al. New Astronomy Reviews 48, pp. 243-249, 2004
［69］T. Takahashi et al. in New Century of X-ray Astronomy, ASP, vol.251 pp. 210-213, 2002
［70］P.F. Bloser et al. New Astronomy Review, vol.50 pp. 619-623, 2006
［71］T. Takahashi et al. Proc. SPIE 4851, pp. 1228-1235, 2002
［72］H. Tajima et al. Proc. SPIE Int. Soc. Opt. Eng, vol. 4851 pp. 875-884, 2003
［73］Y. Fukazawa et al. Proc. SPIE vol. 5501, pp. 197-207, 2004
［74］S .Takeda et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 579. pp. 859-865, 2007
［75］T. Takahashi et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 436. pp. 111, 1999
［76］H. Tajima et al. IEEE, Trans. Nucl. Sci. vol. 51, no. 3, pp. 842-847, 2004
［77］T. Kamae et al. Proc. SPIE 2806, 314, 1996
［78］M. Tashiro et al. IEEE Trans. Nucl. Sci., NS-49 1893, 2002
［79］M. Kokubun et al. IEEE Trans. Nucl. Sci., 51 1991, 2004
［80］T. Takahashi et al. Focusing Telescopes in Nuclear Astrolysics. pp. 319-333. 2006
［81］S. Takeda et al. SPIE newsroom, http://spie.org/x20060.xml 2008
［82］T. Takahashi et al. Proc. SPIE 3446, pp. 29-37, 1998
［83］T. Takahashi et al. IEEE trans. Nucl. Sci. vol. 48, no. 3, pp. 287-291, 2001
［84］T. Takahashi et al. IEEE trans. Nucl. Sci. vol. 48, no. 4, pp. 950-959, 2001
［85］S. Watanabe et al. IEEE trans. vol. 49, No. 3, pp. 1292-1296, 2001
［86］S. Takeda et al. Proc. SPIE, vol. 6706, 67060S, 2007
［87］F.A. Harrison et al., Proc. SPIE X-Ray Optics, Instruments, and Missions, vol.
4012 pp. 693-699, 2000.
［88］T. Takahashi et al. 1st Space Wire Conference 2006
［89］S. Agostinelli et al., Nucl. Instr. and Meth. in Phys. Res. A, vol. 506. pp. 250, 2003
［90］M. Ozaki et al. IEEE Trans. Nucl. Sci., 53 pp.1310-1316, 2006
［91］R.M. Kippen. , Proc. SPIE, vol. 4851, pp. 1302, 2003.
［92］G4LECS http://public.lanl.gov/mkippen/actsim/g4lecs/
［93］T. Ishizuka et al. Jpn. J. Appl. Phys . 30, pp. 145-148, 1991
［94］S. Seidel, Nucl. Instr. and Meth. in Phys. Res. A, vol. 465. 267, 2001
［95］J. Yorkston et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 262. 353, 1987
［96］J. Janesick et al. SPIE, X-Ray Instrumentation in Astronomy, vol.597, pp.364-380, 1985
［97］Zhong He et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 463. pp. 250-267, 2001
［98］A. Zumbiehl et al. Nucl. Instr. and Meth. in Phys. Res. A 469 pp. 227-239, 2001
［99］G. Sato et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 541. pp. 372-384, 2005
［100］G. Sato et al. IEEE Trans .Nucl. Sci vol. 49, no. 3, pp. 1258-1263, 2002
［101］A. Cola et al. Nucl. Instr. and Meth. in Phys. Res. A 568 pp. 406-411, 2006
［102］J. Fink et al. Nucl. Instr. and Meth. A vol. 560, pp. 435-443, 2006
［103］S. Wilderman et al., IEEE Nucl. Sci. Sympo. vol. 3 pp. 1716–1720, 1998
REFERENCES 153
［104］A. Zolauer. PhD thesis, Technische Universitat Munchen 2005
［105］D. Xu et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 574. pp. 98-109, 2007
［106］http://www.spring8.or.jp/top.html
［107］T. Takahashi et al. Proc. SPIE 7011, 70110O, 2008
［108］T. Takahashi et al. New Astronomy Reviews, 48, pp. 309-313, 2004
［109］H. Tajima et al. IEEE Trans. Nucl. Sic. vol. 52(6), pp. 2749-2757, 2003
［110］NeXT Satellite Proposal, the NeXT working group, submitted to ISAS, 2003
［111］T. Kitaguchi. Ph. D Thesis, The University of Tokyo, 2009
［112］M. Murakami et al. IEEE Trans. Nucl. Sci., vol.50, No.4, pp. 1013-1019, 2003
［113］http://creme96.nrl.navy.mil/
［114］G. Weidenspointner et al. New Astr. Rev. 48, pp. 227-230 2004
［115］G. Weidenspointner et al. Astro. Jour. Supp. Ser. 156 pp. 69-91 2005
［116］C. Wunderer et al. 5th INTEGRAL Science Workshop
［117］R. Hartman et al. The Astrophysical Journal Supplement Series, 123, 79-202, 1999
［118］E. Nygard et al. Nucl. Instr. and Meth. in Phys. Res. A vol. 301 pp. 506-516, 1991
［119］O. Toker et al. Nucl. Inst. and Meth. A 340, pp. 572-579, 1994
［120］G. Luts. Semiconductor Radiation Detector, Springer
［121］T. Ozaki et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 380. pp. 141-144, 1996
［122］M. Funaki et al. Nucl. Instr. and Meth. in Phys. Res. A, vol. 436. pp. 120, 1999
［123］T. Mitani et al. IEEE Trans. Nucl. Sci., vol.50, pp. 1048-1052, 2003
［124］K. Nakazawa et al. Nucl. Instr. Meth. A, 512, pp. 412-418, 2003
［125］S. Watanabe et al. Nucl. Instr. Meth. A, 505, 118-121, 2003
［126］K. Nakazawa et al. IEEE Trans. Nucl. Sci., vol.51, pp. 1881-1885, 2004
［127］T. Tanaka et al. New Astronomy, Reviews, 48, pp. 269-273, 2004
［128］S. Ishikawa, Master Thesis, The University of Tokyo, 2008
［129］H.W. Yao et al., SPIE 3446, pp. 169, 1998
［130］K. Oonuki et al. Proc. SPIE, vol. 5501,2004
Acknowledgement
Words cannot express my thanks to Prof. T. Takahashi for guiding me throughout the five years at ISAS. I also wish to thank Dr. S. Watanabe, Dr. K. Nakazawa, Dr. H.
Tajima, Dr. M. Kokubun and Dr. T. Tanaka for their guidance and continuous support.
The Si/CdTe Compton camera consists of many semiconductors and a lot of acknowl-edgement. H. Odaka, S. Ishikawa and H. Aono who are the reliable “samurai”s of the Compton team in the Takahashi Lab have contributed to the Compton camera develop-ment, building and experiments. H. Yasuda and S. Okuyama from Hiroshima University and The University of Tokyo are the great contributors to the Double-sided Silicon strip detector. I thank Y. Kuroda, M. Onishi and K. Genba from the Nagoya Guidance and Propulsion System Works, Mitsubishi Heavy Industries Ltd. for collaborating with us in developing the Compton camera. S. Kubo from Clearpulse Ltd. helped me many times when the electronics of the Compton camera broke down. H. Toyokawa from SPring-8 who helped out on the experiments for polarization measurements. For the imaging ex-periment at Gumma University, I really appreciate the great effort by Dr. N. Kawachi from the Quantum Beam Science Directorate, The Japan Atomic Energy Agency. I am grateful to Dr. T. Nakano, Dr. H. Shimada and Dr. Y. Yamaguchi at Gumma University for the great kindness they showed us. For the mouse imaging at RIKEN, I thank Dr. S.
Motomura and Dr. S. Enomoto. I thank the Japan Society for the Promotion of Science (JSPS) for their economical support through my doctoral course.
Finally, I wish to thank my family for supporting my happy academic life.