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`Case 1:17—cv—OO300—UNA Document 1-3 Filed 03/20/17 Page 1 of 30 Page|D #: 53
`
`EXHIBIT 3
`
`EXHIBIT 3
`
`

`

`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 2 of 30 PageID #: 54
`
`U 7608123
`
`UNITED STATES DEPARTMENT OF COMMERCE
`United States Patent and Trademark Office
`
`October 27, 2016
`
`THIS IS TO CERTIFY THAT ANNEXED HERETO IS A TRUE COPY FROM
`THE RECORDS OF THIS OFFICE OF:
`
`U.S. PATENT: 7,154,200
`ISSUE DATE: December 26, 2006
`
`By Authority of the
`Under Secretary of Commerce for Intellectual Property
`and Director of the United States Patent and Trademark Office
`
`R GLOVER
`Certifying Officer
`
`LWILL'LLELIIPi
`
`allaUL1141
`
`illkl
`
`IA-11T01117EVALPI.
`
`niminintuaiminnnniumninni unui
`
`

`

`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 3 of 30 PageID #: 55
`
`1111111111111111111111111111111111JI111151!11091111111111111111111111111
`
`(12) United States Patent
`Neal
`
`(10) Patent No.: US 7,154,200 B2
`(45) Date of Patent:
`Dec. 26, 2006
`
`(54)
`
`MOTOR
`
`(75)
`
`(73)
`
`Inventor:
`
`Griffith D. Neal, Alameda, CA (US)
`
`Assignee: Encap Technologies, Inc., Alameda,
`CA (US)
`
`4,128,527 A
`4,352,897 A
`4,387,311 A
`4,492,889 A
`4,572,979 A
`4,679,313 A
`
`12/1978 Kinjo et al.
`10/1982 Ogata et al.
`6/1983 Kobayashi et al.
`1/1985 Fukushi et al.
`2/1986 Haar et al.
`7/1987 Schultz et al.
`
`*)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(Continued)
`
`FOREIGN PATENT DOCUMENTS
`
`(21)
`
`Appl. No.: 11/439,733
`
`(22)
`
`Filed:
`
`May 23, 2006
`
`(65)
`
`Prior Publication Data
`
`US 2006/0208580 Al Sep. 21, 2006
`
`Related U.S. Application Data
`
`(63) Continuation of application No. 10/874,142, filed on
`Jun. 21, 2004, now Pat. No. 7,049,715, which is a
`continuation of application No. 09/470,428, filed on
`Dec. 22, 1999, now Pat. No. 6,753,628.
`
`BE
`
`870878
`
`1/1979
`
`(Continued)
`
`OTHER PUBLICATIONS
`
`Product Information from Dupont Engineering Polymers entitled
`"Electrical/Electronic Thermoplastic Encapsulation," (no date),
`Publ: Reorder No. H-58633 (R, 96.7), 20 pages.
`
`(Continued)
`
`Primary Examiner—Joseph Waks
`(74) Attorney, Agent, or Firm—Steven P. Shurtz; Brinks
`Hofer Gilson & Lione
`
`(60) Provisional application No. 60/146,446, filed on Jul.
`29, 1999.
`
`(57)
`
`ABSTRACT
`
`A motor has a stator substantially encapsulated within a
`body of thermoplastic material; and one or more solid parts
`used in the motor either within or near the body. The
`thermoplastic material has a coefficient of linear thermal
`expansion such that the thermoplastic material contracts and
`expands at approximately the same rate as the one or more
`solid parts. In another aspect, a motor for a hard disc drive
`comprises at least one conductor, at least one magnet, at least
`one bearing and a shaft; and a monolithic body of thermo-
`plastic material substantially encapsulating the at least one
`conductor. The bearing is either encapsulated in the ther-
`moplastic material, housed in a hollow cylindrical insert
`encapsulated in the thermoplastic material, or secured in a
`bore formed in the body of thermoplastic material. The
`motor has improved shock resistance.
`
`16 Claims, 14 Drawing Sheets
`
`(51) Int. Cl.
`(2006.01)
`HO2K 35/00
`(52) U.S. Cl. 310/43
`(58) Field of Classification Search None
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`11/1960 Towne 310/43
`4/1971 Voland et al.
`6/1971 Frescura
`1/1972 Zimmerman
`4/1975 Dochterman et al.
`3/1976 Kristen et al.
`9/1976 Schwider et al.
`3/1977 Tanaka et al.
`9/1977 Kaufman, Jr. 310/89
`
`A *
`
` *
`
`AAAAAAAA
`
`2,961,555
`3,575,621
`3,590,328
`3,638,055
`3,874,073
`3,942,054
`3,979,530
`4,015,154
`4,048,530
`
`Copy provided by USPTO from the PIRS Image Database on 10/24/2016
`
`

`

`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 4 of 30 PageID #: 56
`
`US 7,154,200 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`4,760,299 A
`7/1988 Dickie et al.
`1/1989 Dye
`4,801,833 A
`8/1989 Mayumi et al.
`4,853,576 A
`8/1989 Matsushita et al.
`4,855,853 A
`8/1989 Gregory
`4,858,073 A
`4,868,970 A
`9/1989 Schultz et al.
`9/1990 Schultz et al.
`4,954,739 A
`4/1991 Marshall et al.
`5,008,572 A
`8/1991 Fox et al.
`5,036,580 A
`12/1991 Takagi
`5,073,735 A
`12/1991 Teruyama et al.
`5,075,585 A
`5,121,021 A
`6/1992 Ward
`7/1992 Sumi et al.
`5,134,327 A
`8/1992 Stine
`5,142,103 A
`9/1992 Steffen
`5,147,982 A
`5,204,044 A * 4/1993 Yoneshige
`5,206,554 A
`4/1993 Perrot
`5,241,229 A * 8/1993 Katakura et al.
`5,268,607 A
`12/1993 McManus
`5,331,483 A
`7/1994 Muller et al.
`5,334,897 A
`8/1994 Ineson et al.
`5,345,129 A
`9/1994 Molnar
`5,382,852 A
`1/1995 Yuhi et al.
`5,396,210 A
`3/1995 Purohit et al.
`5,400,218 A
`3/1995 Val
`5,414,317 A
`5/1995 Reid et al.
`5,459,190 A * 10/1995 Nakamura et al.
`5,461,772 A
`10/1995 Puri
`5,481,144 A
`1/1996 Dunfield et al.
`5,490,319 A * 2/1996 Nakamura et al.
`5,500,780 A
`3/1996 Boutaghou et al.
`5,506,458 A
`4/1996 Pace et al.
`5,541,787 A
`7/1996 Jabbari et al.
`5,548,458 A
`8/1996 Pelstring et al.
`5,558,445 A
`9/1996 Chen et al.
`5,579,188 A
`11/1996 Dunfield et al.
`5,587,617 A
`12/1996 Dunfield et al.
`5,598,048 A
`1/1997 Dunfield et al.
`5,610,463 A
`3/1997 Dunfield et al.
`5,619,083 A
`4/1997 Dunfield et al.
`5,619,389 A
`4/1997 Dunfield et al.
`5,621,372 A
`4/1997 Purohit
`5,633,545 A
`5/1997 Albrecht et al.
`5,664,314 A
`9/1997 Pelstring et al.
`5,666,242 A
`9/1997 Edwards et al.
`5,668,427 A
`9/1997 Morna
`9/1997 Viskochil
`5,672,927 A
`10/1997 Huang et al.
`5,675,196 A
`10/1997 Komura et al.
`5,675,201 A
`5,688,575 A * 11/1997 Sheer et al.
`5,694,268 A * 12/1997 Dunfield et al.
`12/1997 Obara
`5,698,919 A
`3/1998 Saxelby, Jr. et al.
`5,728,600 A
`3/1998 Dunfield et al.
`5,729,404 A
`4/1998 Moser
`5,742,450 A
`5/1998 Hayashi
`5,751,085 A
`5/1998 Hyde et al.
`5,751,514 A
`6/1998 Ong
`5,766,535 A
`5,783,888 A * 7/1998 Yarnano
`8/1998 Parsoneault et al.
`5,793,129 A
`9/1998 Trago et al.
`5,806,169 A
`9/1998 Terada et al.
`5,814,412 A
`10/1998 Moritan et al.
`5,822,846 A
`11/1998 Oku
`5,831,355 A
`11/1998 Pieterse et al.
`5,835,513 A
`12/1998 Dunfield et al.
`5,850,318 A
`3/1999 Ito et al.
`5,880,179 A
`3/1999 Molnar
`5,881,447 A
`8/1999 Shioya et al.
`5,942,824 A *
`9/1999 Ong
`5,958,466 A
`10/1999 Engelberger et al.
`5,973,424 A
`
`5,982,057 A * 11/1999 Imada et al. 310/43
`5,986,365 A 11/1999 Kuwert et al.
`5,990,247 A 11/1999 Terada et al.
`6,002,185 A 12/1999 Nakao et al.
`6,019,516 A
`2/2000 Leuthold et al.
`6,020,661 A * 2/2000 Trago et al. 310/43
`6,034,841 A
`3/2000 Albrecht et al.
`6,043,583 A
`3/2000 Kurosawa et al.
`6,069,421 A * 5/2000 Smith et al. 310/43
`6,071,014 A
`6/2000 Lee et al.
`6,075,304 A * 6/2000 Nakatsuka 310/216
`6,102,636 A
`8/2000 Geise
`6,148,501 A 11/2000 Grantz et al.
`6,163,952 A 12/2000 Takehara
`6,201,321 Bl * 3/2001 Mosciatti et al. 310/43
`6,215,219 Bl
`4/2001 Hwang
`6,232,687 Bl * 5/2001 Hollenbeck et al. 310/88
`6,300,695 Bl 10/2001 Neal
`6,362,554 Bl
`3/2002 Neal
`6,433,448 Bl * 8/2002 Hatton 310/67 R
`6,437,464 Bl
`8/2002 Neal
`6,501,616 Bl 12/2002 Neal
`6,518,683 Bl* 2/2003 Hanon 310/42
`6,617,721 Bl
`9/2003 Neal
`6,753,628 Bl
`6/2004 Neal
`6,844,636 Bl
`1/2005 Lieu et al.
`6,892,439 Bl
`5/2005 Neal et al.
`6,911,166 Bl
`6/2005 Neal
`6,941,640 Bl
`9/2005 Neal et al.
`7,019,422 Bl
`3/2006 Neal et al.
`7,036,207 Bl
`5/2006 Neal
`7,049,715 Bl
`5/2006 Neal
`7,067,944 Bl
`6/2006 Lieu et al.
`7,067,952 Bl
`6/2006 Neal
`
`FOREIGN PATENT DOCUMENTS
`
`BE
`DE
`DE
`EP
`EP
`FR
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`S1J
`S1J
`WO
`WO
`WO
`WO
`
`891258
`25 39 492
`42 21 429
`0 747 943
`0 883 171
`2 647 958
`352079207
`0 119 0256
`0 129 1652
`0 312 8645
`05336722
`4053336722
`0 818 6953
`409072362
`410271719
`09172748
`409172748
`10070870
`410243595
`10271719
`11082508
`1334297
`1494148
`WO 92/06532
`WO 96/20501
`WO 96/33533
`WO 97/39870
`
`Al
`
`3/1982
`Al 3/1977
`Al
`1/1993
`2/1998
`Al 12/1998
`12/1990
`7/1977
`7/1989
`11/1989
`5/1991
`A * 12/1993
`A 12/1993
`7/1996
`3/1997
`3/1997
`A * 6/1997
`A 6/1997
`3/1998
`9/1998
`A
`A * 10/1998
`3/1999
`8/1987
`7/1989
`4/1992
`7/1996
`10/1996
`10/1997
`
`A
`
`264/272.15
`
`310/51
`
`524/443
`
`29/596
`
`428/76
`360/98.07
`
`310/91
`
`OTHER PUBLICATIONS
`
`310/90.5
`
`The Epoxylite Corporation, article from the Internet entitled
`"Vacuum Pressure Impregnation (VPI) Systems", Nov. 19, 1999,
`<http://www.epoxylite.com/EpoxyliteEquipment.htm>, 3 pages.
`
`CODV provided by USPTO from the PIRS Imaae Database on 10/24/2016
`
`

`

`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 5 of 30 PageID #: 57
`
`US 7,154,200 B2
`Page 3
`
`Buchanan Motor Works, Inc., article from the Internet entitled
`"Epoxy Seal—Prevents Down Time and Keeps Equipment Running
`Longer," Jul. 14, 1999, <http://www.bmworks.com/VIP.htm>, 1
`page.
`Neeltran Inc., article from the Internet entitled "Vacuum Pressure
`Impregnation (VIP)", Nov. 19, 1999, <http://wvvvv.neeltran.
`thomasregister.com/olc/neeltran/nee19.htm> 2 pages.
`
`LNP Engineering Plastics, Press Release entitled "LNP Introduces
`First-Ever Line of Thermally Conductive Compounds," Jan. 28,
`1999 (2 pages).
`LNP Engineering Plastics, Advertisement entitled "Konduit.TM.
`Thermally Conductive Composites," undated (2 pages).
`
`* cited by examiner
`
`Conv nrovided by USPTO from the PIRS [mane Database on 10/24/2016
`
`

`

`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 6 of 30 PageID #: 58
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`U.S. Patent
`
`Dec. 26, 2006
`
`Sheet 1 of 14
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`US 7,154,200 B2
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`

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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 7 of 30 PageID #: 59
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 2 of 14
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`US 7,154,200 B2
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 8 of 30 PageID #: 60
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 3 of 14
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`US 7,154,200 B2
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 9 of 30 PageID #: 61
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 4 of 14
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`US 7,154,200 B2
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`F IG 4•
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`54
`42 50 52 ( 46
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`12
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 10 of 30 PageID #: 62
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 5 of 14
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`US 7,154,200 B2
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 11 of 30 PageID #: 63
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 6 of 14
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`US 7,154,200 B2
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 12 of 30 PageID #: 64
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`Dec. 26, 2006
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`Sheet 7 of 14
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`US 7,154,200 B2
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 13 of 30 PageID #: 65
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`U.S. Patent
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`Dec. 26, 2006
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`US 7,154,200 B2
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 14 of 30 PageID #: 66
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 9 of 14
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 15 of 30 PageID #: 67
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 10 of 14
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`US 7,154,200 B2
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`FIG. 12
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`672
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 16 of 30 PageID #: 68
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 11 of 14
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 17 of 30 PageID #: 69
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 12 of 14
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 18 of 30 PageID #: 70
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`Dec. 26, 2006
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`Sheet 13 of 14
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`US 7,154,200 B2
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 19 of 30 PageID #: 71
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`U.S. Patent
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`Dec. 26, 2006
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`Sheet 14 of 14
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`US 7,154,200 B2
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`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 20 of 30 PageID #: 72
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`US 7,154,200 B2
`
`1
`MOTOR
`
`REFERENCE TO EARLIER FILED
`APPLICATIONS
`
`5
`
`The present application is a continuation of U.S. patent
`application Ser. No. 10/874,142, filed Jun. 21, 2004, issuing
`as U.S. Pat. No. 7,049,715, which is a continuation of U.S.
`patent application Ser. No. 09/470,428, filed Dec. 22, 1999,
`U.S. Pat. No. 6,753,628, which claims the benefit of the 10
`filing date under 35 U.S.C. § 119(e) of provisional U.S.
`patent application Ser. No. 60/146,446, filed Jul. 29, 1999,
`all of which are hereby incorporated by reference.
`
`FIELD OF THE INVENTION
`
`15
`
`The present invention relates generally to a high speed
`motor. It relates particularly to a spindle motor such as used
`in a hard disc drive, and to the construction and arrangement
`of the body of the spindle motor to align and retain the 20
`respective component parts of the motor, as well as stator
`assemblies used in the motors and hard disc drives using the
`motors, and methods of developing and manufacturing high
`speed motors.
`
`BACKGROUND OF THE INVENTION
`
`25
`
`30
`
`35
`
`40
`
`45
`
`Computers commonly use disc drives for memory storage
`purposes. Disc drives include a stack of one or more
`magnetic discs that rotate and are accessed using a head or
`read-write transducer. Typically, a high speed motor such as
`a spindle motor is used to rotate the discs.
`An example of a conventional spindle motor 1 is shown
`in FIG. 1. The motor 1 includes a base 2 which is usually
`made from die cast aluminum, a stator 4, a shaft 6, bearings
`7 and a disc support member 8, also referred to as a hub. A
`magnet 3 and flux return ring 5 are attached to the disc
`support member 8. The stator 4 is separated from the base 2
`using an insulator (not shown) and attached to the base 2
`using a glue. Distinct structures are formed in the base 2 and
`the disc support member 8 to accommodate the bearings 7.
`One end of the shaft 6 is inserted into the bearing 7
`positioned in the base 2 and the other end of the shaft 6 is
`placed in the bearing 7 located in the hub 8. A separate
`electrical connector 9 may also be inserted into the base 2.
`Each of these parts must be fixed at predefined tolerances
`with respect to one another. Accuracy in these tolerances can
`significantly enhance motor performance.
`In operation, the disc stack is placed upon the hub. The
`stator windings are selectively energized and interact with so
`the permanent magnet to cause a defined rotation of the hub.
`As hub 8 rotates, the head engages in reading or writing
`activities based upon instructions from the CPU in the
`computer.
`Manufacturers of disc drives are constantly seeking to 55
`improve the speed with which data can be accessed. To an
`extent, this speed depends upon the speed of the spindle
`motor, as existing magneto-resistive head technology is
`capable of accessing data at a rate greater than the speed
`offered by the highest speed spindle motor currently in 60
`production. The speed of the spindle motor is dependent
`upon the dimensional consistency or tolerances between the
`various components of the motor. Greater dimensional con-
`sistency between components leads to a smaller gap between
`the stator 4 and the magnet 3, producing more force, which 65
`provides more torque and enables faster acceleration and
`higher rotational speeds. One drawback of conventional
`
`2
`spindle motors is that a number of separate parts are required
`to fix motor components to one another. This can lead to
`stack up tolerances which reduce the overall dimensional
`consistency between the components. Stack up tolerances
`refers to the sum of the variation of all the tolerances of all
`the parts, as well as the overall tolerance that relates to the
`alignment of the parts relative to one another.
`In an effort to enable increased motor speed, some hard
`disc manufacturers have turned to the use of hydrodynamic
`bearings. These hydrodynamic bearings, however, have dif-
`ferent aspect ratios from conventional bearings. An example
`of a different aspect ratio may be found in a cylindrical
`hydrodynamic bearing in which the length of the bearing is
`greater than it's diameter. This results in more susceptibility
`to problems induced by differing coefficients of thermal
`expansion than other metals used in existing spindle motors,
`making it difficult to maintain dimensional consistency over
`the operating temperature that the drive sees between the
`hydrodynamic bearings and other metal parts of the motor.
`Hydrodynamic bearings have less stiffness than conven-
`tional ball bearings so they are more susceptible to imprecise
`rotation when exposed to vibrations or shock.
`An important characteristic of a hard drive is the amount
`of information that can be stored on a disc. One method to
`store more information on a disc is to place data tracks more
`closely together. Presently this spacing between portions of
`information is limited due to vibrations occurring during the
`operation of the motor. These vibrations can be caused when
`the stator windings are energized, which results in vibrations
`of a particular frequency. These vibrations also occur from
`harmonic oscillations in the hub and discs during rotation,
`caused primarily by non-uniform size media discs.
`An important factor in motor design is the lowering of the
`operating temperature of the motor. Increased motor tem-
`perature affects the electrical efficiency of the motor and
`bearing life. As temperature increases, resistive loses in wire
`increase, thereby reducing total motor power. Furthermore,
`the Arhennius equation predicts that the failure rate of an
`electrical device is exponentially related to its operating
`temperature. The frictional heat generated by bearings
`increases with speed. Also, as bearings get hot they expand,
`and the bearing cages get stressed and may deflect, causing
`non-uniform rotation and the resultant further heat increase,
`non-uniform rotation requiring greater spacing in data
`tracks, and reduced bearing life. One drawback with existing
`motor designs is their limited effective dissipation of the
`heat, and difficulty in incorporating heat sinks to aid in heat
`dissipation. In addition, in current motors the operating
`temperatures generally increase as the size of the motor is
`decreased.
`Manufacturers have established strict requirements on the
`outgassing of materials that are used inside a hard disc drive.
`These requirements are intended to reduce the emission of
`materials onto the magnetic media or heads during the
`operation of the drive. Of primary concern are glues used to
`attach components together, varnish used to insulate wire,
`and epoxy used to protect steel laminations from oxidation.
`In addition to such outgassed materials, airborne particu-
`late in a drive may lead to head damage. Also, airborne
`particulates in the disc drive could interfere with signal
`transfer between the read/write head and the media. To
`reduce the effects of potential airborne particulate, hard
`drives are manufactured to exacting clean room standards
`and air filters are installed inside of the drive to reduce the
`contamination levels during operation.
`Heads used in disc drives are susceptible to damage from
`electrical shorts passing through a small air gap between the
`
`Copy provided by USPTO from the PIRS !mane Database on 10/24/2016
`
`

`

`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 21 of 30 PageID #: 73
`
`US 7,154,200 B2
`
`4
`BRIEF DESCRIPTION OF SEVERAL VIEWS OF
`THE DRAWINGS
`
`3
`media and the head surface. In order to prevent such shorts,
`some hard drives use a plastic or rubber ring to isolate the
`spindle motor from the hard drive case. A drawback to this
`design is the requirement of an extra component.
`Another example of a spindle motor is shown in U.S. Pat.
`No. 5,694,268 (Dunfield et al.) (incorporated herein by
`reference). Referring to FIGS. 7 and 8 of this patent, a stator
`200 of the spindle motor is encapsulated with an overmold
`209. The overmolded stator contains openings through
`which mounting pins 242 may be inserted for attaching the
`stator 200 to a base. U.S. Pat. No. 5,672,972 (Viskochil)
`(incorporated herein by reference) also discloses a spindle
`motor having an overmolded stator. One drawback with the
`overmold used in these patents is that it has a different
`coefficient of linear thermal expansion ("CLTE") than the
`corresponding metal parts to which it is attached. Another
`drawback with the overmold is that it is not very effective at
`dissipating heat. Further, the overmolds shown in these
`patents are not effective in dampening some vibrations
`generated by energizing the stator windings.
`U.S. Pat. No. 5,806,169 (Trago) (incorporated herein by
`reference) discloses a method of fabricating an injection
`molded motor assembly. However, the motor disclosed in
`Trago is a step motor, not a high speed spindle motor, and
`would not be used in applications such as hard disc drives.
`Thus, a need exists for an improved high speed spindle
`motor, having properties that will be especially useful in a
`hard disc drive, overcoming the aforementioned problems.
`
`BRIEF SUMMARY OF THE INVENTION
`
`45
`
`50
`
`FIG. 1 is an exploded, partial cross-sectional and perspec-
`5 tive view of a prior art high speed motor.
`FIG. 2 is a perspective view of a stator used in a first
`embodiment of the present invention.
`FIG. 3 is an exploded, partial cross-sectional and perspec-
`tive view of a high speed motor in accordance with the first
`ro embodiment of the present invention.
`FIG. 3A is an exploded, partial cross sectional and per-
`spective view of an alternative embodiment of the motor
`shown in FIG. 3.
`FIG. 4 is a cross-sectional view of the high speed motor
`15 of FIG. 3.
`FIG. 5 is an exploded, partial cross-sectional and perspec-
`tive view of a high speed motor in accordance with a second
`embodiment of the present invention.
`FIG. 6 is a cross-sectional view of the high speed motor
`20 shown in FIG. 5.
`FIG. 7 is an exploded, partial cross-sectional and perspec-
`tive view of a high speed motor in accordance with a third
`embodiment of the present invention.
`FIG. 8 is an exploded, partial cross-sectional and perspec-
`25 tive view of a high speed motor in accordance with a fourth
`embodiment of the present invention.
`FIG. 9 is a cross-sectional view of a high speed motor in
`accordance with a fifth embodiment of the present invention.
`FIG. 10 is a cross-sectional view of a high speed motor in
`30 accordance with a sixth embodiment of the present inven-
`tion.
`FIG. 11 is a cross-sectional view of a high speed motor in
`accordance with a seventh embodiment of the present inven-
`tion.
`35 FIG. 12 is a perspective view of the inserts used in the
`high speed motor of FIG. 11.
`FIG. 13 is a cross-sectional view of a high speed motor in
`accordance with an eighth embodiment of the present inven-
`tion.
`40 FIG. 14 is an exploded, partial cross-sectional and per-
`spective view of a high speed motor in accordance with the
`ninth embodiment of the present invention.
`FIG. 15 is a drawing of a mold used to make the
`encapsulated stator of FIG. 3.
`FIG. 16 is a drawing of the mold of FIG. 15 in a closed
`position.
`FIG. 17 is an exploded and partial cross sectional view of
`components used in a pancake motor, a tenth embodiment of
`the invention.
`FIG. 18 is a cross-sectional view of a high speed motor in
`accordance with an eleventh embodiment of the invention.
`FIG. 19 is a perspective view of a stator and shaft used in
`a twelfth embodiment of the present invention.
`FIG. 20 is an exploded and partial cross sectional view of
`a hard disc drive of the present invention.
`
`A motor has been invented which overcomes many of the
`foregoing problems. In a first aspect, the invention is a motor
`having a stator substantially encapsulated within a body of
`thermoplastic material; and one or more solid parts used in
`the motor either within or near the body. The thermoplastic
`material has a coefficient of linear thermal expansion such
`that the thermoplastic material contracts and expands at
`approximately the same rate as the one or more solid parts.
`In another aspect, a motor for a hard disc drive comprises
`at least one conductor, at least one magnet, at least one
`bearing and a shaft; and a monolithic body of thermoplastic
`material substantially encapsulating the at least one conduc-
`tor. The bearing is either encapsulated in the thermoplastic
`material, housed in a hollow cylindrical insert encapsulated
`in the thermoplastic material, or secured in a bore formed in
`the body of thermoplastic material.
`In another aspect, the motor has improved shock resis-
`tance and comprises an assembly comprising windings and
`laminations; and shock absorbing thermoplastic material
`substantially encapsulating the assembly. The shock absorb-
`ing thermoplastic material has a vibration dampening such
`that the assembly has a reduction of harmonics in the range
`of 300-2000 Hz of at least 5 decibels compared to an
`assembly with the same windings and laminations not being
`encapsulated.
`The invention provides the foregoing and other features, 60
`and the advantages of the invention will become further
`apparent from the following detailed description of the
`presently preferred embodiments, read in conjunction with
`the accompanying drawings. The detailed description and
`drawings are merely illustrative of the invention and do not
`limit the scope of the invention, which is defined by the
`appended claims and equivalents thereof.
`
`55
`
`DETAILED DESCRIPTION OF THE DRAWINGS
`AND PREFERRED EMBODIMENTS OF THE
`INVENTION
`
`First Embodiment
`A first embodiment of a high speed motor of the present
`invention is shown in FIGS. 2-4. By "high speed" it is meant
`65 that the motor can operate at over 5,000 rpm. The spindle
`motor 10 is designed for rotating a disc or stack of discs in
`a computer hard disc drive. Motor 10 is formed using an
`
`Copy provided by USPTO from the PIRS !mane Database on 10/24/2016
`
`

`

`Case 1:17-cv-00300-UNA Document 1-3 Filed 03/20/17 Page 22 of 30 PageID #: 74
`
`US 7,154,200 B2
`
`5
`
`5
`encapsulation method which reduces the number of parts
`needed to manufacture the motor as compared with conven-
`tional motors used for disc drives, thereby reducing stack up
`tolerances and manufacturing costs and producing other
`advantages discussed below.
`Referring to FIG. 2, a stator 20 is first constructed, using
`conventional steel laminations 11 forming a magnetically
`inducible core 17 having a plurality of poles 21 thereon, and
`wire windings 15 which serve as conductors. The conductors
`induce or otherwise create a plurality of magnetic fields in 10
`the core when electrical current is conducted through the
`conductors. In this embodiment, a magnetic field is induced
`in each of the poles 21.
`The stator 20 is then used to construct the rest of the
`spindle motor 10 (FIG. 3). The spindle motor 10 includes a 15
`hub 12, which serves as a disc support member, the stator 20
`and a body 14. Together the stator 20 and body 14 make up
`a stator assembly 13. The body 14 is preferably a monolithic
`body 14. Monolithic is defined as being formed as a single
`piece. The body 14 substantially encapsulates the stator 20. zo
`Substantial encapsulation means that the body 14 either
`entirely surrounds the stator 20, or surrounds almost all of it
`except for minor areas of the stator that may be exposed.
`However, substantial encapsulation means that the body 14
`and stator 20 are rigidly fixed together, and behave as a 25
`single component with respect to harmonic oscillation vibra-
`tion.
`The body 14 is preferably formed of a phase change
`material, meaning a material that can be used in a liquid
`phase to envelope the stator, but which later changes to a 30
`solid phase. There are two types of phase change materials
`that will be most useful in practicing the invention: tem-
`perature activated and chemically activated. A temperature
`activated phase change material will become molten at a
`higher temperature, and then solidify at a lower temperature. 35
`However, in order to be practical, the phase change material
`must be molten at a temperature that is low enough that it
`can be used to encapsulate a stator. Preferred temperature
`activated phase change materials will be changed from a
`liquid to a solid at a temperature in the range of about 200 40
`to 700° F. The most preferred temperature activated phase
`change materials are thermoplastics. The preferred thermo-
`plastic will become molten at a temperature at which it is
`injection-moldable, and then will be solid at normal oper-
`ating temperatures for the motor. An example of a phase 45
`change material that changes phases due to a chemical
`reaction, and which could be used to form the body 14, is an
`epoxy. Other suitable phase change materials may be clas-
`sified as thermosetting materials.
`As shown in FIG. 4, a shaft 16 is connected to the hub or so
`disc support member 12 and is surrounded by bearings 18,
`which are adjacent against the body 14. A rotor or magnet 28
`is fixed to the inside of the hub 12 on a flange so as to be in
`operable proximity to the stator. The magnet 28 is preferably
`a permanent magnet, as described below. The body 14 55
`includes a base 22. In addition, mounting features, such as
`apertures 25, and terminals comprising a connector 26 for
`connecting the conductors to an external power source are
`formed as a part of the stator assembly. The terminals 26 are
`partially encapsulated in the body 14.
`Referring to FIGS. 3-4, the base 22 of the body 14 is
`generally connected to the hard drive case (not shown).
`Connecting members (not shown), such as screws, may be
`used to fix the base 22 to the hard drive case, using holes 25
`as shown in FIG. 3. Alternatively, other types of mounting 65
`features such as connecting pins or legs may be formed as
`part of the base 22. The connector 26 is preferably a
`
`60
`
`6
`through-hole pin type of connector 26 and is coupled
`through the hard drive case to the control circuit board
`residing on the outer surface of the base (not shown).
`Alternatively the connector may be a flexible circuit with
`copper pads allowing spring contact interconnection.
`The stator 20 is positioned in the body 14 generally in a
`direction perpendicular to an interior portion 30. Referring
`to FIG. 2, the stator 20 is preferably annular in shape and
`contains an open central portion 32. The poles 21 extend
`radially outward from this central portion 32. Faces of the
`poles 21 are positioned outward relative to the central
`portion 32 of the stator 20. The body 14 is molded around
`the stator 20 in a manner such that the faces of the poles are
`exposed and are surrounded by and aligned concentrically
`with respect to the disc support member 12. Alternatively,
`the poles may be totally encapsulated in body 14 and not be
`exposed. FIG. 3A shows such an alternate embodiment of
`the motor depicted in FIG. 3. The poles 111 are totally
`encapsulated by the body in the stator assembly 113. As a
`result, no external surfaces of the stator are exposed.
`Referring to FIG. 4, the body 14 has an upper portion 40
`that extends upwardly from the stator 20. The upper portion
`40 is also preferably annular shaped. The body 14 includes
`the interior portion 30. The interior portion 30 is generally
`sized and shaped to accommodate the bearings 18. The
`interior portion 30 includes an upper support portion 42 and
`a lower support portion 44. In the embodiment illustrated in
`FIG. 4 the interior portion 30 is preferably cylindrically
`shaped.
`The phase change material used to make the body 14 is
`preferably a thermally conductive but non-electrically con-
`ductive plastic. In addition, the plastic preferably includes
`ceramic filler particles that enhance the thermal conductivity
`of the plastic. A preferred form of plastic is polyphenyl
`sulfide (PPS) sold under the tradename "Konduit" by LNP.
`Grade OTF-212 PPS is particularly preferred. Examples of
`other suitable thermoplastic resins include, but are not
`limited to, thermoplastic resins such as 6,6-polyamide,
`6-polyamide, 4 6-polyamide, 12,12-polyamide, 6,12-polya-
`mide, and polyamides containing aromatic monomers, poly-
`butylene terephthalate, polyethylene terephthala