DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1 and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 112133769; see English machine translation) in view of Yang et al. (CN 113629155; see English machine translation) in view of Emeraud et al. (WO 2014/128113) in view of Zhao (CN 106876492; see English machine translation).
Regarding claim 1, Li discloses a preparation method for a solar cell ([0028]-[0035]), which method comprises:
step 101: sequentially forming a tunnel silicon oxide layer (50), an N-type doped polysilicon layer (20), and a back passivated anti-reflection film (66) on a back surface of an N-type silicon substrate (10) (it is disclosed the silicon substrate and the doped polycrystalline silicon layer can be n-type; [0069]; see Figure 7);
step 102: performing grooving (67; [0079]) on the back passivated anti-reflection film, forming a nickel metal layer (30; [0056]) in a grooved region (see Figure 7), and annealing the nickel metal layer for 10 s to 300 s to form a nickel-silicon alloy layer between the nickel metal layer and the N-type doped polysilicon layer ([0058]);
wherein the temperature of the annealing process is in a range of 200-400°C (it is disclosed the first metal layer that is nickel is annealed at 370 oC for 3 min; [0097]); and
step 103: printing a back fine gate electrode on the nickel metal layer (second metal layer 40; [0068]).
Li does not expressly disclose the thickness of the N-type doped polysilicon layer is from 80 nm to 150 nm.
Yang discloses a similar method of forming electrodes through forming a metal silicide interface layer, wherein the thickness of the doped polysilicon layer is desired to be less than 1 micron ([0012]), where in one example, the doped polysilicon layer is 150 nm thick ([0080]).
As Li is not limited to any specific examples of the thickness of the n-type doped polysilicon layer and as a thickness of less than 1 micron such as 150 nm was well known in the art before the effective filing date of the claimed invention, as evidenced by Yang above, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have selected any suitable thickness for the n-type doped polysilicon layer, including a thickness of less than 1 micron such as 150 nm in the method of Li. Said combination would amount to nothing more than the use of a known process for its intended use in a known environment to accomplish an entirely expected result.
While modified Li discloses the thickness of the first metal layer of nickel can be less than 2 microns to maintain good ohmic contact ([0063]), the reference does not expressly disclose the thickness of the nickel-silicon layer is from 10 nm to 30 nm.
Emeraud discloses on page 6 that a metal layer is provided in which better thickness control of the resulting metal silicide is desired, where the thickness of the metal layer can be between 1 nm and 2000 nm and more preferably between 20 nm and 50 nm. Emeraud further discloses on page 10 that the thickness of the nickel layer is preferably in the range between 20 nm and 200 nm and thinner nickel layers can be used, where at least part of the nickel layer is converted into a nickel silicide layer. Emeraud also discloses on page 3 that the improved metal silicide thickness uniformity improves the contact resistance uniformity within the cell and/or from cell to cell.
Therefore, as the contact resistance of the back electrode within the cell and from cell to cell and the overall cell efficiency are variables that can be modified, among others, by adjusting said thickness of the metal silicide that is formed, with said contact resistance and overall cell efficiency both increasing as the nickel silicon layer thickness is increased, the precise thickness of the nickel silicon layer would have been considered a result effective variable by one having ordinary skill in the art before the effective filing date of the claimed invention. As such, without showing unexpected results, the claimed nickel silicon layer thickness cannot be considered critical. Accordingly, one of ordinary skill in the art before the effective filing date of the claimed invention would have optimized, by routine experimentation, the thickness of the nickel silicon layer in the apparatus of modified Li to obtain the desired balance between the contact resistance of the back electrode and the overall cell efficiency (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223). It is also noted that only part of the nickel layer is formed into the nickel silicide contact layer, such that the nickel silicide layer is a smaller thickness than the nickel layer.
Modified Li does not expressly disclose printing a back main gate electrode on the back passivated anti-reflection film, wherein the back fine gate electrode is electrically connected to the back main gate electrode.
Zhao discloses printing a back fine gate electrode (7) and a back main gate electrode (9) on the back passivation film (see Figures 1 and 2), wherein the back fine gate electrode is electrically connected to the back main gate electrode (see Figure 2), wherein the back fine gate electrode can be made out of aluminum, silver, copper or nickel (page 2) and the back main gate electrode can be made out of silver (page 5).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have incorporated printing a back main gate electrode on the back passivated anti-reflection film wherein the back fine gate electrode is electrically connected to the back main gate electrode in the method of modified Li, as taught by Zhao, as collection of fine grid electrode with a main grid line is well known in the art (page 1).
Regarding claim 10, modified Li discloses all the claim limitations as set forth above, and further discloses a solar cell, prepared by the preparation method of claim 1 (as set forth above).
Claim(s) 2 and 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 112133769; see English machine translation) in view of Yang et al. (CN 113629155; see English machine translation) in view of Emeraud et al. (WO 2014/128113) in view of Zhao (CN 106876492; see English machine translation) in view of Murakami et al. (EP 2905812).
Regarding claim 2, modified Li discloses all the claim limitations as set forth above, and further discloses printing the back fine gate electrode and then sintering to form the second metal layer ([0068]).
Zhao further discloses the step 103 comprises:
step 3-1: printing the back fine gate electrode, and performing a first drying process (step 3 on page 5); and
step 3-2: printing the back main gate electrode, and performing a second drying process (step 2 on page 5), but Zhao does not expressly disclose the first drying process is in a range of 100-300°C and the temperature of the second drying process is in a range of 100-250°C.
Murakami discloses printing back electrode pattern and drying at a temperature between 150 to 250 oC.
As modified Li is not limited to any specific examples of drying temperatures for the first and second drying processes and as drying temperatures for an electrode paste between 150 to 250 oC were well known in the art before the effective filing date of the claimed invention, as evidenced by Murakami above, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use any suitable drying temperature for the two drying processes, including a temperature between 150 and 250 oC in the method of modified Li. Said combination would amount to nothing more than the use of a known process for its intended use in a known environment to accomplish an entirely expected result.
Regarding claim 3, modified Li discloses all the claim limitations as set forth above, and further discloses the back fine gate electrode can be copper, silver, cobalt, tungsten, tin or zinc ([0066]), but the reference does not expressly disclose the back fine gate electrode is made of an aluminum metal.
Zhao further discloses the back fine gate electrode is selected from aluminum, silver, copper, and nickel (page 2), where aluminum is often selected for its cost and the back main gate electrode is made of a silver metal (pages 5-6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have selected a back fine gate electrode made of aluminum and a back main gate electrode made of silver in the method of modified Li, as taught by Zhao, so that the overall cost of manufacture can be reduced by using cheaper materials such as aluminum as the back fine gate electrode that has a larger surface area while still maintaining good ohmic contact with the more expensive and preferred silver material as the main gate electrode.
Claim(s) 4 and 6-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 112133769; see English machine translation) in view of Yang et al. (CN 113629155; see English machine translation) in view of Emeraud et al. (WO 2014/128113) in view of Zhao (CN 106876492; see English machine translation) in view of Zhang (CN 113594296; see English machine translation).
Regarding claim 4, modified Li discloses all the claim limitations as set forth above, but the reference does not expressly disclose before the step 101, the method further comprises:
sequentially subjecting the back surface of the N-type silicon substrate to a texturing process and a polishing process.
Zhang discloses texturing the back surface of an N-type silicon substrate followed by a polishing process (pages 2 and 4).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have textured and polished the back surface of the N-type silicon substrate of modified Li prior to step 101 in the method, as taught by Zhang, so that the tunnel oxide layer can be formed with an improved density on the back surface, which leads to an enhanced back passivation with a good back contact, thus, improving the working performance of the solar cell (page 2).
Regarding claim 6, modified Li discloses all the claim limitations as set forth above, and further discloses
step 104: forming a P+ emitter (12) on a front surface of the N-type silicon substrate ([0089]);
step 105: forming a front passivated anti-reflection film (64) on the front surface of the N-type silicon substrate, the front passivated anti-reflection film covering the P+ emitter (see Figure 7); and
step 106: printing a front metal electrode (40) on the front passivated anti-reflection film ([0084]), but the reference does not expressly disclose forming the p+ emitter comprises subjecting a front surface of the N-type silicon substrate to a boron diffusion process to form a P+ emitter.
Zhang discloses step 1: subjecting a front surface of the N-type silicon substrate to a boron diffusion process to form a P+ emitter (2; pages 8 and 9).
As modified Li is not limited to any specific examples of forming a p+ emitter and as p+ emitters formed through the diffusion of born were well known in the art before the effective filing date of the claimed invention, as evidenced by Zhang above, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use any suitable method to form the p+ emitter, including a boron diffusion process in the method of modified Li. Said combination would amount to nothing more than the use of a known process for its intended use in a known environment to accomplish an entirely expected result.
Regarding claim 7, modified Li discloses all the claim limitations as set forth above.
Zhang further discloses after the step 104, the method further comprises:
subjecting the front surface of the N-type silicon substrate to winding plating cleaning (page 10; see Figure 6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have incorporated a winding plate cleaning step after step 104 in the method of modified Li, as taught by Zhang, so that leakage current between the upper and lower electrodes of the solar cell can be reduced (pages 8 and 9).
Regarding claim 8, modified Li discloses all the claim limitations as set forth above, and further discloses the back passivated anti-reflection film includes at least one of aluminum oxide, silicon oxide, gallium oxide, silicon nitride, aluminum nitride, and silicon oxynitride, and the front passivated anti-reflection film includes at least one of aluminum oxide, silicon oxide, gallium oxide, silicon nitride, aluminum nitride, and silicon oxynitride ([0086]).
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 112133769; see English machine translation) in view of Yang et al. (CN 113629155; see English machine translation) in view of Emeraud et al. (WO 2014/128113) in view of Zhao (CN 106876492; see English machine translation) in view of Adachi et al. (US 2016/0308079).
Regarding claim 11, modified Li discloses all the claim limitations as set forth above, and further discloses grooving on the back passivated anti-reflection film is performed by laser (as set forth above), but the reference does not expressly disclose the laser is an ultraviolet picosecond laser with a wavelength of 355 nm.
Adachi discloses using a YAG laser having a wavelength of 355 nm for forming a groove in the solar cell ([0175]).
As modified Li is not limited to any specific examples of lasers used for grooving and as the use of a YAG laser having a wavelength of 355 nm was well known in the art before the effective filing date of the claimed invention, as evidenced by Adachi above, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have selected any suitable laser to be used for the grooving of the solar cell, including a YAG laser having a wavelength of 355 nm in the method of modified Li. Said combination would amount to nothing more than the use of a known process for its intended use in a known environment to accomplish an entirely expected result.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 112133769; see English machine translation) in view of Yang et al. (CN 113629155; see English machine translation) in view of Emeraud et al. (WO 2014/128113) in view of Zhao (CN 106876492; see English machine translation) in view of Lin et al. (CN 107968127; see English machine translation)
Regarding claim 5, modified Li discloses all the claim limitations as set forth above, and further discloses the step 101 comprises:
step 1-1: forming the tunnel silicon oxide layer on the back surface of the N-type silicon substrate ([0091]);
step 1-3: forming the N-type doped polysilicon layer ([0092]); and
step 1-4: forming the back passivated anti-reflection film on the N-type doped polysilicon layer ([0024]),
but the reference does not expressly disclose
step 1-2: forming an intrinsic polysilicon layer on the tunnel silicon oxide layer; and
step 1-3: subjecting the intrinsic polysilicon layer to N-type doping to form the N-type doped polysilicon layer.
Lin further discloses the formation of a n+ doped polysilicon layer (16) by growing intrinsic polysilicon layer on the tunnel oxide layer (15) and annealing the substrate with phosphorus to form n+ doped polysilicon layer ([0023]).
As modified Li is not limited to any specific examples of forming the n + doped polysilicon layer and as a method of forming an n+ doped polysilicon layer in the manner as disclosed above was well known in the art before the effective filing date of the claimed invention, as evidenced by Lin above, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use any suitable method to form the n+ type doped polysilicon layer, including forming an intrinsic polysilicon layer on the tunnel silicon oxide layer and subjecting the intrinsic polysilicon layer to N-type doping in the method of modified Li. Said combination would amount to nothing more than the use of a known process for its intended use in a known environment to accomplish an entirely expected result.
Response to Arguments
Applicant’s arguments, see pages 5-6 of Remarks, filed 9/21/2026, with respect to the rejection(s) of claim(s) 1, 5, and 10 under Lu in view of Lin in view of Zhao in view of Emeraud have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Li et al. (CN 112133769; see English machine translation) in view of Yang et al. (CN 113629155; see English machine translation) in view of Emeraud et al. (WO 2014/128113) in view of Zhao (CN 106876492; see English machine translation).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTINA CHERN whose telephone number is (408)918-7559. The examiner can normally be reached Monday-Friday, 9:30 AM-5:30 PM PT.
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/CHRISTINA CHERN/ Primary Examiner, Art Unit 1722
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