Title of Invention	AN INNOVATIVE SIMPLE TECHNIQUE FOR THE DEPOSITION OF ANTI REFLECTION (AR) COATING ON PRINTED SILICON SOLAR CELLS
Abstract	TITLE: "AN INNOVATIVE SIMPLE TECHNIQUE FOR THE DEPOSITION OF ANTI- REFLECTION COATING ON PRINTED SILICON SOLAR CELS" The invention relates to a method for deposition of anti-reflection coating of silicon nitride on printed silicon solar cells in a plasma enhanced chemical vapour deposition (PECVD) process by keeping the solderability of the bus bars protected, comprising providing a device (1) having at least one masking strip (2) with a plurality of cavities (3), providing a plurality of stainless steel (ss) masking strips (2) in said cavities (3), placing at least one silicon wafer (4) on the device in an upside side down position, heating the device (1) including the at least one silicon wafer (4) into a preheated PECVD vacuum chamber to about 350-400°C for deposition of anti-reflection (AR) coating. The size of the cavities (3) is selected based on the co-efficient of thermal expansion of the steel so as to accommodate the masking strips (2) at 400°C, the solar cells (4) and the strips (2) are so disposed on the device that the bus bars (5) of the printed solar cells (4) are fully shadowed by the strips (2) and the bus bars (5) remain free from anti reflection coating.

Title of Invention

AN INNOVATIVE SIMPLE TECHNIQUE FOR THE DEPOSITION OF ANTI REFLECTION (AR) COATING ON PRINTED SILICON SOLAR CELLS

Abstract

TITLE: "AN INNOVATIVE SIMPLE TECHNIQUE FOR THE DEPOSITION OF ANTI- REFLECTION COATING ON PRINTED SILICON SOLAR CELS" The invention relates to a method for deposition of anti-reflection coating of silicon nitride on printed silicon solar cells in a plasma enhanced chemical vapour deposition (PECVD) process by keeping the solderability of the bus bars protected, comprising providing a device (1) having at least one masking strip (2) with a plurality of cavities (3), providing a plurality of stainless steel (ss) masking strips (2) in said cavities (3), placing at least one silicon wafer (4) on the device in an upside side down position, heating the device (1) including the at least one silicon wafer (4) into a preheated PECVD vacuum chamber to about 350-400°C for deposition of anti-reflection (AR) coating. The size of the cavities (3) is selected based on the co-efficient of thermal expansion of the steel so as to accommodate the masking strips (2) at 400°C, the solar cells (4) and the strips (2) are so disposed on the device that the bus bars (5) of the printed solar cells (4) are fully shadowed by the strips (2) and the bus bars (5) remain free from anti reflection coating.

Full Text	FIELD OF INVENTION: The present invention relates to a method and device for deposition of anti reflection (AR) coating of silicon nitride on printed silicon solar cells by keeping the solderability of the bus bars protected. BACKGROUND OF THE INVENTION The typical manufacturing process of the mono crystalline silicon solar cells consists of the following major process steps: 1. Cleaning, degreasing and texturisation of the silicon wafers. 2. Diffusion of emitter. 3. Edge isolation. 4. Printing of metal contacts for the collection of photo generated carriers. 5. Firing of the printed metal contacts. Deposition of AR coating on silicon wafers reduces the reflection losses to a great extent and increases the efficiency of the solar cells by about 2 % absolute.1 This AR coating can be deposited either (a) after edge isolation step or (b) after the firing of the metal contacts. The industrial process equipment are commercially available to deposit ARC on full size silicon wafers (5-6" sq) using PECVD process. (a) If ARC is deposited after edge isolation step, the metal grids have to be printed on the ARC film and fired through. It has been reported in the literature that the exposure of the ARC to high firing temperature (750-800°C) affects the ARC properties of the film adversely and the reflectance of incident light increases. (b) In the other option if ARC is deposited after the firing step, the properties of layer remain same, as it is not exposed to high temperature of firing process. Usually this route is not followed as the deposition of ARC film on the printed metal lines make them non solderable and such cells cannot be interconnected by soldering tabs for making modules. In option (b) if a technique is available to deposit AR coating in PECVD system by masking the bus bars, ARC can be deposited after the firing step and solderability of the bus bars can still be maintained. Also, if one does not have an in-line ARC deposition facility, the cells can be completed till the printing: step and only good cells can be sent for the deposition of ARC elsewhere. This saves the cost of deposition of ARC on rejected cells as good and bad cells can be segregated only after printing and firing of contacts. In view of the above problem, a need exists to propose a solution by providing a method and device which enables masking the printed metal bus bar during the deposition of ARC in the PECVD system at substrate temperature of ~400 °C. OBJECTS OF THE INVENTION It is therefore an object of the invention to propose a method for deposition of anti reflection coating of silicon nitride adapting the Plasma Enhanced Chemical Vapour Deposition (PECVD) process on printed silicon solar cells without affecting the soiderability of the printed bus bars. Another object of the invention is to propose a device for deposition of anti- reflection coating of silicon nitride adapting the PECVD process on printed silicon solar cells without affecting the soiderability of the bus bars. SUMMARY OF THE INVENTION Accordingly there is provided a non-destructive method and device to deposit thin films of silicon nitride as AR coatings on printed silicon solar cells using PECVD process by masking the printed bus bars of the solar cells of large area (~ 5-6" sq.) without affecting the soiderability of the printed bus bars. According to the method, the finished printed solar cell wafers are loaded into a stainless steel carrier (device), which has metal strips at predefined locations and mask the printed bus bars. The metal strips are of ss material and kept loosely held in the cavities in the carrier. As the wafers and the carrier are heated inside the PECVD chamber to about 400 °C, the small gap left in the cavities allows free movement of the masking strips due to thermal expansion and these strips do not warp during deposition. The method allows the deposition of ARC of silicon nitride in a PECVD vacuum chamber on the full size solar cells of 5-inch square and masks the printed bus bars leaving their soiderability intact. The device of the invention is adaptable in photovoltaic solar cell manufacturing to deposit anti reflection coatings of silicon nitride using PECVD process on finished printed silicon solar cells without affecting the solderability of the printed bus bars. Solderability of bus bars is required for further use while interconnecting the cells in the module. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING Figure 1- shows a device for deposition of anti-reflection coating on printed silicon solar cells according to the invention. (1) Carrier, (2) masking ss strips shown without silicon wafer, (2a) masking ss strip shown with silicon wafer (3) cavities, (4) solar cell wafer, (5) printed bus bars to be masked, (6) 1mm collar, (7) 125mm pseudo square printed cell with back side up and (8) 125mm pseudo square printed cell with front side up. DETAILED DESCRIPTION OF THE INVENTION A photovoltaic solar cell generates electricity by absorbing solar radiations and its efficiency can be enhanced if the reflection losses are reduced. Anti reflection coatings of silicon nitride is used on silicon solar cells for reducing reflection losses. The AR coatings can be deposited on the silicon wafers by adapting the typical PECVD process either before the metal contacts are printed or after the metal contacts are printed and fired. Both the processes have their merits and demerits. a) If the AR coating is deposited before the printing and firing of metal grids and bus bars the AR coating has to be exposed to high temperature (~750°C) during the firing of the contacts. It has been reported in the literature that the properties of the AR coating change and reflection from the cell surface increases resulting in loss in efficiency. b) In the other option, if AR coating is deposited after the printing and firing processes are over, the printed bus bars are also coated with the AR coating and make them non-solderable. Such cells cannot be interconnected by soldering the tabs, which is a necessity for making solar modules. Therefore there was a necessity to develop a suitable technique to deposit AR coating of silicon nitride duly protecting their solderability for further use. Option (a) has the advantage that the solderability of the printed bus bars remains intact and cells can be interconnected easily. It has the disadvantage that AR coating has to be exposed to high temperature (~750C) where the AR properties get affected adversely. Option (b) has the advantage that AR coating properties remain intact as in this case the AR coating is not exposed to high temperature. It has the disadvantage that while depositing AR coating, the printed bus bars are also coated with the AR film and tender it non-solderable. As shown in figure-1, in the PECVD deposition-up configuration the silicon solar cell wafers (4) are put upside down on the device (ss jigs/carrier) and transported into a preheated PECVD vacuum chamber. The masking strips (2) are used for masking the bus bars (5) of the printed solar cell (4). The silicon solar cell wafers (4) and the carrier (1) are heated to about 350-400°C for the deposition of AR coating. According to the invention, the masking strips (2) are kept loose in the cavities (3). The size of these cavities (3) is configured after considering the coefficient of thermal expansion of steel so as to accommodate the extra length of masking strips (2) after expansion at 400°C. If the device had a fixed metal strip for masking the printed bars, the masking metal strips would warp during the heating cycle and the masking becomes difficult. In the device configuration of figure-1, masking ss strips shown with silicon wafer (2a), the collars (6), pseudo square printed cell with backside up (7), and pseudo square printed cell with front-side up (8). According to the co-efficient of thermal expansion of steel, the maximum increase in the length of the 128 mm long ss strip will be 0.61 mm for AT as 400°C. A device (1) for loading of cells (4) according to the invention and placement of the masking strips (2) for masking the bus bars (5) of the solar cells (4) is shown in Fig.1. As the solar cells (4) are kept upside down with the printed bus bars (5) exactly seating on the masking strips (2) of the device (1) the front bus bars (5) are fully shadowed by these strips (2) and hence AR film deposition cannot take place on the bus bars (5). Hundreds of cells have been successfully coated using this technique and converted into modules. The silicon wafers (4) are allowed to seat on a collar (6) provided on the carrier (1). According to the invention ss metal masking strips (2) of 3mm X 1mm X 128 mm have been used to mask the printed bus bars (5) of the silicon solar cell (4) in a PECVD deposition set-up with the device (1) at about 400 °C substrate temperature. The length of the ss masking strip (2) has been kept slightly (3mm) more than the width of the cell (4) i.e 125 mm. The ss carrier (1) allow the silicon wafer (4) to seat on the 1mm collar (6) and the cavities (3) keep the masking strips (2) loose so as to allow expansion of the ss strip (2) to about 1mm. The use of the masking strips (2) is very simple and user friendly These masking strips (2) do not warp/bend during the heating cycle from room temperature to 400 °C due to the' configuration of the cavities (3), The solderability of the printed bus bars (5) remains intact after the deposition of AR coating of silicon nitride in a PECVD deposition set-up. We Claim: 1. A method for deposition of anti-reflection coating of silicon nitride on printed silicon solar cells in a plasma enhanced chemical vapour deposition (PECVD) process by keeping the solderability of the bus bars protected, comprising: - providing a device (1) having at least one masking strip (2) with a plurality of cavities (3); - providing a plurality of stainless steel (ss) masking strips (2) in said cavities (3); - placing at least one silicon wafer (4) on the device in an upside side down position; - heating the device (1) including the at least one silicon wafer (4) into a preheated PECVD vacuum chamber to about 350-400°C for deposition of anti-reflection (AR) coating, characterized in that: - the size of the cavities (3) is selected based on the co-efficient of thermal expansion of the steel so as to accommodate the masking strips (2) at 400°C, - the solar cells (4) and the strips (2) are so disposed on the device that the bus bars (5) of the printed solar cells (4) are fully shadowed by the strips (2) and the bus bars (5) remain free from anti reflection coating. 2. The method as claimed in claim 1, wherein the strips (2) are selected in a size of 3mm x 1mm x 128mm. 3. The method as claimed in claim 1, wherein the width of the solar cells (4) is 125 mm. 4. A device for deposition of anti-reflection coating of silicon nitride on printed silicon solar cells in a plasma enhanced chemical vapour depositon (PECVD) process by keeping the solderability of the bus bars protected, comprising: - a metal carrier (1) having at least one masking bar (2) which can accommodate at least one solar cell (4), the metal carrier (1) alongwith the solar cell (4) being heatable and shiftable, and - at least one cavity (3) configured on the carrier (1) to accommodate steel strips (2), the cavity (3) being configured corresponding to the co-efficient thermal expansion of the strips (2). TITLE: "AN INNOVATIVE SIMPLE TECHNIQUE FOR THE DEPOSITION OF ANTI- REFLECTION COATING ON PRINTED SILICON SOLAR CELS" The invention relates to a method for deposition of anti-reflection coating of silicon nitride on printed silicon solar cells in a plasma enhanced chemical vapour deposition (PECVD) process by keeping the solderability of the bus bars protected, comprising providing a device (1) having at least one masking strip (2) with a plurality of cavities (3), providing a plurality of stainless steel (ss) masking strips (2) in said cavities (3), placing at least one silicon wafer (4) on the device in an upside side down position, heating the device (1) including the at least one silicon wafer (4) into a preheated PECVD vacuum chamber to about 350-400°C for deposition of anti-reflection (AR) coating. The size of the cavities (3) is selected based on the co-efficient of thermal expansion of the steel so as to accommodate the masking strips (2) at 400°C, the solar cells (4) and the strips (2) are so disposed on the device that the bus bars (5) of the printed solar cells (4) are fully shadowed by the strips (2) and the bus bars (5) remain free from anti reflection coating.

Full Text

FIELD OF INVENTION:
The present invention relates to a method and device for deposition of anti
reflection (AR) coating of silicon nitride on printed silicon solar cells by keeping
the solderability of the bus bars protected.
BACKGROUND OF THE INVENTION
The typical manufacturing process of the mono crystalline silicon solar cells
consists of the following major process steps:
1. Cleaning, degreasing and texturisation of the silicon wafers.
2. Diffusion of emitter.
3. Edge isolation.
4. Printing of metal contacts for the collection of photo generated carriers.
5. Firing of the printed metal contacts.
Deposition of AR coating on silicon wafers reduces the reflection losses to a great
extent and increases the efficiency of the solar cells by about 2 % absolute.1 This
AR coating can be deposited either (a) after edge isolation step or (b) after the
firing of the metal contacts. The industrial process equipment are commercially
available to deposit ARC on full size silicon wafers (5-6" sq) using PECVD
process.

(a) If ARC is deposited after edge isolation step, the metal grids have
to be printed on the ARC film and fired through. It has been
reported in the literature that the exposure of the ARC to high
firing temperature (750-800°C) affects the ARC properties of the
film adversely and the reflectance of incident light increases.
(b) In the other option if ARC is deposited after the firing step, the
properties of layer remain same, as it is not exposed to high
temperature of firing process. Usually this route is not followed as
the deposition of ARC film on the printed metal lines make them
non solderable and such cells cannot be interconnected by
soldering tabs for making modules.
In option (b) if a technique is available to deposit AR coating in PECVD system by
masking the bus bars, ARC can be deposited after the firing step and
solderability of the bus bars can still be maintained. Also, if one does not have an
in-line ARC deposition facility, the cells can be completed till the printing: step
and only good cells can be sent for the deposition of ARC elsewhere. This saves
the cost of deposition of ARC on rejected cells as good and bad cells can be
segregated only after printing and firing of contacts.
In view of the above problem, a need exists to propose a solution by providing a
method and device which enables masking the printed metal bus bar during the
deposition of ARC in the PECVD system at substrate temperature of ~400 °C.

OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a method for deposition of
anti reflection coating of silicon nitride adapting the Plasma Enhanced Chemical
Vapour Deposition (PECVD) process on printed silicon solar cells without
affecting the soiderability of the printed bus bars.
Another object of the invention is to propose a device for deposition of anti-
reflection coating of silicon nitride adapting the PECVD process on printed silicon
solar cells without affecting the soiderability of the bus bars.
SUMMARY OF THE INVENTION
Accordingly there is provided a non-destructive method and device to deposit
thin films of silicon nitride as AR coatings on printed silicon solar cells using
PECVD process by masking the printed bus bars of the solar cells of large area (~
5-6" sq.) without affecting the soiderability of the printed bus bars.
According to the method, the finished printed solar cell wafers are loaded into a
stainless steel carrier (device), which has metal strips at predefined locations and
mask the printed bus bars. The metal strips are of ss material and kept loosely
held in the cavities in the carrier. As the wafers and the carrier are heated inside
the PECVD chamber to about 400 °C, the small gap left in the cavities allows free
movement of the masking strips due to thermal expansion and these strips do
not warp during deposition. The method allows the deposition of ARC of silicon
nitride in a PECVD vacuum chamber on the full size solar cells of 5-inch square
and masks the printed bus bars leaving their soiderability intact.

The device of the invention is adaptable in photovoltaic solar cell manufacturing
to deposit anti reflection coatings of silicon nitride using PECVD process on
finished printed silicon solar cells without affecting the solderability of the printed
bus bars. Solderability of bus bars is required for further use while
interconnecting the cells in the module.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Figure 1- shows a device for deposition of anti-reflection coating on printed
silicon solar cells according to the invention. (1) Carrier, (2) masking ss strips
shown without silicon wafer, (2a) masking ss strip shown with silicon wafer (3)
cavities, (4) solar cell wafer, (5) printed bus bars to be masked, (6) 1mm collar,
(7) 125mm pseudo square printed cell with back side up and (8) 125mm pseudo
square printed cell with front side up.
DETAILED DESCRIPTION OF THE INVENTION
A photovoltaic solar cell generates electricity by absorbing solar radiations and its
efficiency can be enhanced if the reflection losses are reduced. Anti reflection
coatings of silicon nitride is used on silicon solar cells for reducing reflection
losses. The AR coatings can be deposited on the silicon wafers by adapting the
typical PECVD process either before the metal contacts are printed or after the
metal contacts are printed and fired. Both the processes have their merits and
demerits.

a) If the AR coating is deposited before the printing and firing of metal grids
and bus bars the AR coating has to be exposed to high temperature
(~750°C) during the firing of the contacts. It has been reported in the
literature that the properties of the AR coating change and reflection from
the cell surface increases resulting in loss in efficiency.
b) In the other option, if AR coating is deposited after the printing and firing
processes are over, the printed bus bars are also coated with the AR
coating and make them non-solderable. Such cells cannot be
interconnected by soldering the tabs, which is a necessity for making solar
modules. Therefore there was a necessity to develop a suitable technique
to deposit AR coating of silicon nitride duly protecting their solderability
for further use.
Option (a) has the advantage that the solderability of the printed bus bars
remains intact and cells can be interconnected easily. It has the disadvantage
that AR coating has to be exposed to high temperature (~750C) where the AR
properties get affected adversely.
Option (b) has the advantage that AR coating properties remain intact as in this
case the AR coating is not exposed to high temperature. It has the disadvantage
that while depositing AR coating, the printed bus bars are also coated with the
AR film and tender it non-solderable.

As shown in figure-1, in the PECVD deposition-up configuration the silicon solar
cell wafers (4) are put upside down on the device (ss jigs/carrier) and
transported into a preheated PECVD vacuum chamber. The masking strips (2)
are used for masking the bus bars (5) of the printed solar cell (4). The silicon
solar cell wafers (4) and the carrier (1) are heated to about 350-400°C for the
deposition of AR coating. According to the invention, the masking strips (2) are
kept loose in the cavities (3). The size of these cavities (3) is configured after
considering the coefficient of thermal expansion of steel so as to accommodate
the extra length of masking strips (2) after expansion at 400°C. If the device had
a fixed metal strip for masking the printed bars, the masking metal strips would
warp during the heating cycle and the masking becomes difficult.
In the device configuration of figure-1, masking ss strips shown with silicon
wafer (2a), the collars (6), pseudo square printed cell with backside up (7), and
pseudo square printed cell with front-side up (8).
According to the co-efficient of thermal expansion of steel, the maximum
increase in the length of the 128 mm long ss strip will be 0.61 mm for AT as
400°C. A device (1) for loading of cells (4) according to the invention and
placement of the masking strips (2) for masking the bus bars (5) of the solar
cells (4) is shown in Fig.1. As the solar cells (4) are kept upside down with the
printed bus bars (5) exactly seating on the masking strips (2) of the device (1)
the front bus bars (5) are fully shadowed by these strips (2) and hence AR film
deposition cannot take place on the bus bars (5). Hundreds of cells have been
successfully coated using this technique and converted into modules. The silicon
wafers (4) are allowed to seat on a collar (6) provided on the carrier (1).

According to the invention ss metal masking strips (2) of 3mm X 1mm X 128 mm
have been used to mask the printed bus bars (5) of the silicon solar cell (4) in a
PECVD deposition set-up with the device (1) at about 400 °C substrate
temperature.
The length of the ss masking strip (2) has been kept slightly (3mm) more than
the width of the cell (4) i.e 125 mm. The ss carrier (1) allow the silicon wafer (4)
to seat on the 1mm collar (6) and the cavities (3) keep the masking strips (2)
loose so as to allow expansion of the ss strip (2) to about 1mm.
The use of the masking strips (2) is very simple and user friendly
These masking strips (2) do not warp/bend during the heating cycle from room
temperature to 400 °C due to the' configuration of the cavities (3),
The solderability of the printed bus bars (5) remains intact after the deposition of
AR coating of silicon nitride in a PECVD deposition set-up.

We Claim:
1. A method for deposition of anti-reflection coating of silicon nitride on
printed silicon solar cells in a plasma enhanced chemical vapour deposition
(PECVD) process by keeping the solderability of the bus bars protected,
comprising:
- providing a device (1) having at least one masking strip (2) with a
plurality of cavities (3);
- providing a plurality of stainless steel (ss) masking strips (2) in said
cavities (3);
- placing at least one silicon wafer (4) on the device in an upside side
down position;
- heating the device (1) including the at least one silicon wafer (4)
into a preheated PECVD vacuum chamber to about 350-400°C for
deposition of anti-reflection (AR) coating, characterized in that:
- the size of the cavities (3) is selected based on the co-efficient of
thermal expansion of the steel so as to accommodate the masking
strips (2) at 400°C,
- the solar cells (4) and the strips (2) are so disposed on the device
that the bus bars (5) of the printed solar cells (4) are fully
shadowed by the strips (2) and the bus bars (5) remain free from
anti reflection coating.

2. The method as claimed in claim 1, wherein the strips (2) are selected in a
size of 3mm x 1mm x 128mm.
3. The method as claimed in claim 1, wherein the width of the solar cells (4)
is 125 mm.
4. A device for deposition of anti-reflection coating of silicon nitride on
printed silicon solar cells in a plasma enhanced chemical vapour depositon
(PECVD) process by keeping the solderability of the bus bars protected,
comprising:
- a metal carrier (1) having at least one masking bar (2) which can
accommodate at least one solar cell (4), the metal carrier (1)
alongwith the solar cell (4) being heatable and shiftable, and
- at least one cavity (3) configured on the carrier (1) to
accommodate steel strips (2), the cavity (3) being configured
corresponding to the co-efficient thermal expansion of the strips
(2).

TITLE: "AN INNOVATIVE SIMPLE TECHNIQUE FOR THE DEPOSITION OF ANTI-
REFLECTION COATING ON PRINTED SILICON SOLAR CELS"
The invention relates to a method for deposition of anti-reflection coating of
silicon nitride on printed silicon solar cells in a plasma enhanced chemical vapour
deposition (PECVD) process by keeping the solderability of the bus bars
protected, comprising providing a device (1) having at least one masking strip
(2) with a plurality of cavities (3), providing a plurality of stainless steel (ss)
masking strips (2) in said cavities (3), placing at least one silicon wafer (4) on
the device in an upside side down position, heating the device (1) including the
at least one silicon wafer (4) into a preheated PECVD vacuum chamber to about
350-400°C for deposition of anti-reflection (AR) coating. The size of the cavities
(3) is selected based on the co-efficient of thermal expansion of the steel so as
to accommodate the masking strips (2) at 400°C, the solar cells (4) and the
strips (2) are so disposed on the device that the bus bars (5) of the printed solar
cells (4) are fully shadowed by the strips (2) and the bus bars (5) remain free
from anti reflection coating.

Documents:

00488-kol-2008-abstract.pdf

00488-kol-2008-claims.pdf

00488-kol-2008-correspondence others.pdf

00488-kol-2008-description complete.pdf

00488-kol-2008-drawings.pdf

00488-kol-2008-form 1.pdf

00488-kol-2008-form 2.pdf

00488-kol-2008-form 3.pdf

00488-kol-2008-gpa.pdf

488-KOL-2008-(10-07-2012)-CORRESPONDENCE.pdf

488-KOL-2008-ABSTRACT 1.2.pdf

488-KOL-2008-ABSTRACT-1.1.pdf

488-KOL-2008-CLAIMS 1.2.pdf

488-KOL-2008-CLAIMS-1.1.pdf

488-KOL-2008-CORRESPONDENCE.pdf

488-KOL-2008-DESCRIPTION (COMPLETE) 1.2.pdf

488-KOL-2008-DESCRIPTION (COMPLETE)-1.1.pdf

488-KOL-2008-DRAWINGS 1.2.pdf

488-KOL-2008-DRAWINGS-1.1.pdf

488-KOL-2008-EXAMINATION REPORT REPLY RECIEVED.pdf

488-KOL-2008-EXAMINATION REPORT.pdf

488-KOL-2008-FORM 1 1.2.pdf

488-KOL-2008-FORM 1-1.1.pdf

488-KOL-2008-FORM 18 1.1.pdf

488-kol-2008-form 18.pdf

488-KOL-2008-FORM 2 1.2.pdf

488-KOL-2008-FORM 2-1.1.pdf

488-KOL-2008-FORM 3.pdf

488-KOL-2008-GPA.pdf

488-KOL-2008-GRANTED-ABSTRACT.pdf

488-KOL-2008-GRANTED-CLAIMS.pdf

488-KOL-2008-GRANTED-DESCRIPTION (COMPLETE).pdf

488-KOL-2008-GRANTED-DRAWINGS.pdf

488-KOL-2008-GRANTED-FORM 1.pdf

488-KOL-2008-GRANTED-FORM 2.pdf

488-KOL-2008-GRANTED-SPECIFICATION.pdf

488-KOL-2008-REPLY TO EXAMINATION REPORT.pdf

488-KOL-2008-SPECIFICATION.pdf

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Patent Number

254729

Indian Patent Application Number

488/KOL/2008

PG Journal Number

50/2012

Publication Date

14-Dec-2012

Grant Date

12-Dec-2012

Date of Filing

10-Mar-2008

Name of Patentee

BHARAT HEAVY ELECTRICALS LIMITED

Applicant Address

REGIONAL OPERATIONS DIVISION (ROD), PLOT NO. : 9/1, DJ BLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI- 110049, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	ANIL KUMAR SAXENA	BHARAT HEAVY ELECTRICALS LIMITED, REGIONAL OPERATIONS DIVISION (ROD), PLOT NO. : 9/1, DJ BLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI- 110049, INDIA.
2	SUSHIL KUMAR SHARMA	BHARAT HEAVY ELECTRICALS LIMITED, REGIONAL OPERATIONS DIVISION (ROD), PLOT NO. : 9/1, DJ BLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI- 110049, INDIA.
3	RAMESH KUMAR BHOGRA	BHARAT HEAVY ELECTRICALS LIMITED, REGIONAL OPERATIONS DIVISION (ROD), PLOT NO. : 9/1, DJ BLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI- 110049, INDIA.
4	S. RAGHUNATH REDDY	BHARAT HEAVY ELECTRICALS LIMITED, REGIONAL OPERATIONS DIVISION (ROD), PLOT NO. : 9/1, DJ BLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI- 110049, INDIA.

PCT International Classification Number

C23C14/34 H01L21/288; H01L31/0216;

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA