US20110061849A1 - Device for cooling semi-conductors - Google Patents
Device for cooling semi-conductors Download PDFInfo
- Publication number
- US20110061849A1 US20110061849A1 US12/883,640 US88364010A US2011061849A1 US 20110061849 A1 US20110061849 A1 US 20110061849A1 US 88364010 A US88364010 A US 88364010A US 2011061849 A1 US2011061849 A1 US 2011061849A1
- Authority
- US
- United States
- Prior art keywords
- connecting element
- metal
- seal
- cooling body
- base plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
- H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
- H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
- H01L23/3736—Metallic materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
Definitions
- the invention relates to a device for cooling electronic structural components which includes a cooling body and a metal base plate constructed as a part of a support of the structural element, wherein the cooling body is arranged adjacent the base plate and wherein a connecting element is arranged at least over certain areas between the base plate and the cooling body.
- Connecting elements of this type are typically constructed as so-called heat conducting pastes.
- heat conducting pastes contain silicon and/or graphite.
- connecting elements coated metal foils or non-metal heat conducting elements serve for an improvement of the heat transfer between the electronic structural component, typically a power semi-conductor element, and the cooling body.
- heat conducting foils From the field of constructing computers, it is also already known to use heat conducting foils. Such heat conducting foils have a melting point in the range of above 58° C., typically in the range of 60° C., and they are therefore not suitable for use in the field of power electronics because in that field frequently cooling body temperatures above 100° C. are encountered. Such cooling body temperatures may lead to the discharge of molten heat conducting foils and, consequently, there is the danger of short circuits.
- this object is met by constructing the connecting element at least over areas thereof of a metal which has a melting temperature of at least 60° C., and the connecting element is provided with a frame-like seal.
- the frame-like seal surrounds the metal connecting element and rests against a support side, on the one hand, and a cooling body, on the other hand.
- the seal is constructed of a metal having a melting temperature above 200° C.
- the connecting element so as to be foil-like.
- the connecting element extends at least over areas thereof at a distance from the seal.
- At least one recess facing the connecting element is arranged in the area of the seal.
- the seal has in a direction extending transversely of the cooling body a greater height than a thickness of the metal foil.
- FIG. 1 is a partial representation of a cross-section through a support for an electronic structural element which is in contact to a cooling body through a metal connecting element;
- FIG. 2 is a top view of a metal connecting element which is surrounded by a frame-like seal
- FIG. 3 is an embodiment modified in comparison to FIG. 2 , with expansion spaces;
- FIG. 4 is a further modified embodiment with a differently constructed expansion space.
- an electronic structural element 1 is positioned in the area of a support 2 , typically a module.
- the support 2 has a metal base plate 3 which is coupled through a connecting element 4 to a cooling body 5 .
- the cooling body 5 has for supporting its heat transfer to the ambient air cooling ribs 6 which extend preferably in a direction which is modified as compared to the structural element 1 .
- the connecting element 4 is composed of a metal foil 7 which is surrounded by a frame-like seal 8 .
- the seal 8 is clamped between the base plate 3 and the cooling body 5 in order to ensure a necessary tightness.
- one or more recesses 9 are arranged in the area of the metal foil 7 .
- the recesses 9 ensure a sufficient tightness of the frame 8 even when the metal foil 7 melts as a result of temperature influence and, as a result, a volume increase of the material of the metal foil 7 is caused.
- the recesses 9 constitute expansion spaces in the event of a corresponding volume increase.
- the metal foil 7 has a smaller thickness than a height of the seal 8 .
- the height of the seal 8 corresponds to a distance between the base plate 3 and the cooling body 5 .
- the appropriate dimensioning of the seal 8 ensures that above the metal foil 7 an expansion space 10 is arranged which can compensate for the corresponding volume increases of the material of the metal foil 7 in the case of liquefication.
- the metal foil 7 can in a liquefied state compensate even for different distances between the base plate 3 and the cooling body 5 which are caused by the fact that the base plate 3 assigned to the module typically has an arched shape.
- a preferred use of the metal connecting element 4 according to the invention takes place in connection with electronic structural elements 1 which are constructed as power semi-conductors. They are used in stationary as well as in mobile fields. Such mobile uses refer in particular to power electric devices or components.
- the improved cooling effect can be utilized for achieving different advantages. For example, it is possible to increase the power density as a result of the improved cooling effect. Also, it is possible to facilitate an operation with increased cooling agent temperatures and/or at increased ambient temperatures. Generally, it is also possible to increase the service life of the structural elements 1 by reducing the operating temperatures.
- the structural elements are constructed as power semi-conductors, especially considered are realizations as IGBT or MOSFET. These may be present in discrete construction or in modular construction.
- the metal connecting elements 4 according to the invention reduce the DIE temperature by about 4 to 6° K. Also, compared to a use of heat conducting pastes, a markedly reduced assembly work is required. The reproducibility of the achieved cooling effect is improved and, as a result, quality requirements of the production process can be safely adhered to.
- used as material for the metal foil 7 are typically suitable alloys.
- the melting point can be influenced through the composition of the alloy.
- a typical alloy consists of indium, tin and bismuth. As necessary, indium can be replaced fully or partially by gallium.
- Used as the material for the seal 8 can be tin, aluminum or copper or an alloy which contains one or more of the aforementioned elements.
- a typical thickness of the metal foil 7 is about 30 micrometers. However, also usable are metal foils 7 with a thickness in the range of 20 micrometers up to 40 micrometers. A typical thickness of the seal 8 is about 60 micrometers. Basically, also usable are material thicknesses in the range of 40 micrometers up to 80 micrometers.
- the metal foil 7 used has during assembly a solid state of aggregation.
- the metal foil 7 has a liquid state of aggregation and a discharge of the molten metal is prevented by the seal 8 .
- the metal foil 7 returns into the solid state of aggregation. The changes from the liquid state into the solid state as well as from the solid state into the liquid state take place completely reversibly.
- FIG. 5 once again illustrates the arched configuration of the base plate 3 as already described above and the limitation of the expansion space 10 resulting therefrom. After a liquefication of the metal foil 7 , the latter fills out the expansion space 10 and leads to a large area contact between the base plate 3 and the cooling body 5 which is not illustrated.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
Abstract
The device serves for cooling electronic structural elements and has a cooling body and a metal base plate constructed as a part of the support of the structural element. The cooling body is arranged adjacent the base plate. A connecting element is arranged at least over areas between the base plate and the cooling body. The connecting element is at least partially constructed of a metal which has a melting temperature of at least 60° C. The connecting element is provided with a frame-like seal.
Description
- The invention relates to a device for cooling electronic structural components which includes a cooling body and a metal base plate constructed as a part of a support of the structural element, wherein the cooling body is arranged adjacent the base plate and wherein a connecting element is arranged at least over certain areas between the base plate and the cooling body.
- Connecting elements of this type according to the prior art are typically constructed as so-called heat conducting pastes. As a rule, such heat conducting pastes contain silicon and/or graphite. It is also already known to use as connecting elements coated metal foils or non-metal heat conducting elements. Generally, such connecting elements serve for an improvement of the heat transfer between the electronic structural component, typically a power semi-conductor element, and the cooling body.
- From the field of constructing computers, it is also already known to use heat conducting foils. Such heat conducting foils have a melting point in the range of above 58° C., typically in the range of 60° C., and they are therefore not suitable for use in the field of power electronics because in that field frequently cooling body temperatures above 100° C. are encountered. Such cooling body temperatures may lead to the discharge of molten heat conducting foils and, consequently, there is the danger of short circuits.
- It is the object of the present invention to construct a device of the above-described type in such a way that an effective cooling of electronic structural elements is made possible even at higher cooling body temperatures.
- In accordance with the invention, this object is met by constructing the connecting element at least over areas thereof of a metal which has a melting temperature of at least 60° C., and the connecting element is provided with a frame-like seal.
- Because of the selection of the above-mentioned melting temperature for the metal and the use of a frame-like seal, it is possible even at higher cooling temperatures to utilize the very good heat transfer between the structural element to be cooled, the metal connecting element and the cooling body, and to still prevent the discharge of liquefied metal when the melting point of the metal connecting element is exceeded. The frame-like seal surrounds the metal connecting element and rests against a support side, on the one hand, and a cooling body, on the other hand. In this connection, it is possible to provide either a direct contact between the connecting element and the electronic structural element; in accordance with other embodiments, it is also possible to position the electronic structural element on a metal support. It is essential for effective cooling that, starting from the ambient temperature and prior to reaching a maximum operating temperature, the metal changes its state of aggregation.
- To prevent molten metal from being discharged, it is proposed that the seal is constructed of a metal having a melting temperature above 200° C.
- In particular, it is considered to construct the connecting element so as to be foil-like.
- For compensating for increased volumes due to melting of the metal, it is possible to arrange at least one recess in the area of the connecting element.
- Moreover, it is also being considered to arrange at least one material thickness reduction in the area of the connecting element.
- It is also possible that the connecting element extends at least over areas thereof at a distance from the seal.
- In accordance with another embodiment, it is provided that at least one recess facing the connecting element is arranged in the area of the seal.
- Moreover, it is also possible that the seal has in a direction extending transversely of the cooling body a greater height than a thickness of the metal foil.
- In the drawings, embodiments of the invention are schematically illustrated. In the drawing:
-
FIG. 1 is a partial representation of a cross-section through a support for an electronic structural element which is in contact to a cooling body through a metal connecting element; -
FIG. 2 is a top view of a metal connecting element which is surrounded by a frame-like seal; -
FIG. 3 is an embodiment modified in comparison toFIG. 2 , with expansion spaces; -
FIG. 4 is a further modified embodiment with a differently constructed expansion space. - In accordance with the embodiment of
FIG. 1 , an electronic structural element 1, typically a chip, is positioned in the area of asupport 2, typically a module. Thesupport 2 has ametal base plate 3 which is coupled through a connecting element 4 to acooling body 5. Thecooling body 5 has for supporting its heat transfer to the ambient air cooling ribs 6 which extend preferably in a direction which is modified as compared to the structural element 1. Alternatively or as a supplement to the use of cooling ribs 6, it is also possible to use liquid cooling. In particular, it is intended to conduct an appropriate cooling medium through assigned cooling ducts. - In accordance with the embodiment of
FIG. 2 , the connecting element 4 is composed of ametal foil 7 which is surrounded by a frame-like seal 8. In the mounted state illustrated inFIG. 1 , theseal 8 is clamped between thebase plate 3 and thecooling body 5 in order to ensure a necessary tightness. - In accordance with the embodiment of
FIG. 3 , one ormore recesses 9 are arranged in the area of themetal foil 7. Therecesses 9 ensure a sufficient tightness of theframe 8 even when themetal foil 7 melts as a result of temperature influence and, as a result, a volume increase of the material of themetal foil 7 is caused. Thus, therecesses 9 constitute expansion spaces in the event of a corresponding volume increase. - In accordance with the embodiment of
FIG. 4 , themetal foil 7 has a smaller thickness than a height of theseal 8. In this case, the height of theseal 8 corresponds to a distance between thebase plate 3 and thecooling body 5. The appropriate dimensioning of theseal 8 ensures that above themetal foil 7 anexpansion space 10 is arranged which can compensate for the corresponding volume increases of the material of themetal foil 7 in the case of liquefication. In particular, themetal foil 7 can in a liquefied state compensate even for different distances between thebase plate 3 and thecooling body 5 which are caused by the fact that thebase plate 3 assigned to the module typically has an arched shape. - A preferred use of the metal connecting element 4 according to the invention takes place in connection with electronic structural elements 1 which are constructed as power semi-conductors. They are used in stationary as well as in mobile fields. Such mobile uses refer in particular to power electric devices or components. The improved cooling effect can be utilized for achieving different advantages. For example, it is possible to increase the power density as a result of the improved cooling effect. Also, it is possible to facilitate an operation with increased cooling agent temperatures and/or at increased ambient temperatures. Generally, it is also possible to increase the service life of the structural elements 1 by reducing the operating temperatures.
- When the structural elements are constructed as power semi-conductors, especially considered are realizations as IGBT or MOSFET. These may be present in discrete construction or in modular construction.
- The metal connecting elements 4 according to the invention reduce the DIE temperature by about 4 to 6° K. Also, compared to a use of heat conducting pastes, a markedly reduced assembly work is required. The reproducibility of the achieved cooling effect is improved and, as a result, quality requirements of the production process can be safely adhered to.
- Used as material for the
metal foil 7 are typically suitable alloys. The melting point can be influenced through the composition of the alloy. A typical alloy consists of indium, tin and bismuth. As necessary, indium can be replaced fully or partially by gallium. - Used as the material for the
seal 8 can be tin, aluminum or copper or an alloy which contains one or more of the aforementioned elements. - A typical thickness of the
metal foil 7 is about 30 micrometers. However, also usable aremetal foils 7 with a thickness in the range of 20 micrometers up to 40 micrometers. A typical thickness of theseal 8 is about 60 micrometers. Basically, also usable are material thicknesses in the range of 40 micrometers up to 80 micrometers. - The
metal foil 7 used has during assembly a solid state of aggregation. In a conventional operation, themetal foil 7 has a liquid state of aggregation and a discharge of the molten metal is prevented by theseal 8. During each longer interruption of operation, themetal foil 7 returns into the solid state of aggregation. The changes from the liquid state into the solid state as well as from the solid state into the liquid state take place completely reversibly. -
FIG. 5 once again illustrates the arched configuration of thebase plate 3 as already described above and the limitation of theexpansion space 10 resulting therefrom. After a liquefication of themetal foil 7, the latter fills out theexpansion space 10 and leads to a large area contact between thebase plate 3 and thecooling body 5 which is not illustrated.
Claims (9)
1-8. (canceled)
9. Device for cooling an electronic structural element, comprising; a cooling body; a metal base plate constructed as a part of a support of the structural element, the cooling body being arranged adjacent to the base plate; and a connecting element is arranged at least over areas between the base plate and the cooling body, wherein the connecting element is at least over areas thereof constructed of a metal which has a melting temperature of at least 60° C., and wherein the connecting element is provided with a frame-like seal.
10. The device according to claim 9 , wherein the seal is of a metal having a melting temperature above 200° C.
11. The device according to claim 9 , wherein the connecting element is constructed to be foil-like.
12. The device according to claim 9 , wherein at least one recess is arranged in the area of the connecting element.
13. The device according to claim 9 , wherein at least one material thickness reduction is arranged in the area of the connecting element.
14. The device according to claim 9 , wherein the connecting element extends at least over areas thereof at a distance from the seal.
15. The device according to claim 9 , wherein at least one recess is arranged in the area of the seal facing the connecting element.
16. The device according to claim 11 , wherein the seal has a greater height in a direction extending transversely of the cooling body than a thickness of the metal foil.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102009042519A DE102009042519A1 (en) | 2009-09-16 | 2009-09-16 | Device for cooling semiconductors |
DE102009042519.5 | 2009-09-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110061849A1 true US20110061849A1 (en) | 2011-03-17 |
Family
ID=43603503
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/883,640 Abandoned US20110061849A1 (en) | 2009-09-16 | 2010-09-16 | Device for cooling semi-conductors |
Country Status (2)
Country | Link |
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US (1) | US20110061849A1 (en) |
DE (1) | DE102009042519A1 (en) |
Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5043139A (en) * | 1990-10-09 | 1991-08-27 | Eastman Kodak Company | Amalgam preform, method of forming the preform and method of bonding therewith |
US5477409A (en) * | 1993-11-24 | 1995-12-19 | Vlsi Technology Inc. | Fusion heat sink for integrated circuit |
US5831831A (en) * | 1997-03-27 | 1998-11-03 | Ford Motor Company | Bonding material and phase change material system for heat burst dissipation |
US6054198A (en) * | 1996-04-29 | 2000-04-25 | Parker-Hannifin Corporation | Conformal thermal interface material for electronic components |
US20050155751A1 (en) * | 2002-08-09 | 2005-07-21 | Kenichi Azuma | Heat-dissipating member and joined structure |
US20060028799A1 (en) * | 2003-02-24 | 2006-02-09 | Fujitsu Limited | Electronic component and radiating member, and method of manufacturing semiconductor device using the component and member |
US20060157223A1 (en) * | 2005-01-18 | 2006-07-20 | Gelorme Jeffrey D | Heterogeneous thermal interface for cooling |
US20070107872A1 (en) * | 2002-01-16 | 2007-05-17 | Fujitsu Limited | Heat sink with increased cooling capacity and semiconductor device comprising the hear sink |
US20070204972A1 (en) * | 2006-03-01 | 2007-09-06 | Sensis Corporation | Method and apparatus for dissipating heat |
US20070227704A1 (en) * | 2006-03-28 | 2007-10-04 | Sony Corporation | Plate-type heat transport device and electronic instrument |
US20070238219A1 (en) * | 2006-03-29 | 2007-10-11 | Glen Bennett | Low stress optics mount using thermally conductive liquid metal or gel |
US20090071635A1 (en) * | 2007-09-13 | 2009-03-19 | Shung-Wen Kang | Thermal spreader for simultaneously enhancing capillary effect and structural strength |
US20090122491A1 (en) * | 2007-11-08 | 2009-05-14 | Martin Yves C | Universal patterned metal thermal interface |
US20090139704A1 (en) * | 2005-04-06 | 2009-06-04 | Kabushiki Kaisha Toyota Jidoshokki | Heat sink device |
US20100302739A1 (en) * | 2009-06-02 | 2010-12-02 | Tsinghua University | Thermal interface material and method of using the same and electronic assembly having the same |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10250604A1 (en) * | 2002-10-30 | 2004-05-19 | Tyco Electronics Amp Gmbh | Integrated circuit system with latent heat storage module |
DE10347518A1 (en) * | 2003-10-13 | 2005-05-25 | Siemens Ag | Electronic component, circuit carrier assembly and electronic unit with heat accumulator |
-
2009
- 2009-09-16 DE DE102009042519A patent/DE102009042519A1/en not_active Ceased
-
2010
- 2010-09-16 US US12/883,640 patent/US20110061849A1/en not_active Abandoned
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5043139A (en) * | 1990-10-09 | 1991-08-27 | Eastman Kodak Company | Amalgam preform, method of forming the preform and method of bonding therewith |
US5477409A (en) * | 1993-11-24 | 1995-12-19 | Vlsi Technology Inc. | Fusion heat sink for integrated circuit |
US6054198A (en) * | 1996-04-29 | 2000-04-25 | Parker-Hannifin Corporation | Conformal thermal interface material for electronic components |
US5831831A (en) * | 1997-03-27 | 1998-11-03 | Ford Motor Company | Bonding material and phase change material system for heat burst dissipation |
US20070107872A1 (en) * | 2002-01-16 | 2007-05-17 | Fujitsu Limited | Heat sink with increased cooling capacity and semiconductor device comprising the hear sink |
US20050155751A1 (en) * | 2002-08-09 | 2005-07-21 | Kenichi Azuma | Heat-dissipating member and joined structure |
US20060028799A1 (en) * | 2003-02-24 | 2006-02-09 | Fujitsu Limited | Electronic component and radiating member, and method of manufacturing semiconductor device using the component and member |
US20060157223A1 (en) * | 2005-01-18 | 2006-07-20 | Gelorme Jeffrey D | Heterogeneous thermal interface for cooling |
US20090139704A1 (en) * | 2005-04-06 | 2009-06-04 | Kabushiki Kaisha Toyota Jidoshokki | Heat sink device |
US20070204972A1 (en) * | 2006-03-01 | 2007-09-06 | Sensis Corporation | Method and apparatus for dissipating heat |
US20070227704A1 (en) * | 2006-03-28 | 2007-10-04 | Sony Corporation | Plate-type heat transport device and electronic instrument |
US20070238219A1 (en) * | 2006-03-29 | 2007-10-11 | Glen Bennett | Low stress optics mount using thermally conductive liquid metal or gel |
US20090071635A1 (en) * | 2007-09-13 | 2009-03-19 | Shung-Wen Kang | Thermal spreader for simultaneously enhancing capillary effect and structural strength |
US20090122491A1 (en) * | 2007-11-08 | 2009-05-14 | Martin Yves C | Universal patterned metal thermal interface |
US20100302739A1 (en) * | 2009-06-02 | 2010-12-02 | Tsinghua University | Thermal interface material and method of using the same and electronic assembly having the same |
Also Published As
Publication number | Publication date |
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DE102009042519A1 (en) | 2011-03-24 |
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Owner name: ESW GMBH, GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:GRIMMIG, MARKUS;WENSKE, JAN;SIGNING DATES FROM 20100906 TO 20101004;REEL/FRAME:025233/0993 |
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STCB | Information on status: application discontinuation |
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