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 .
Election/Restrictions
Applicant’s election of Group I, Species B, and Species C in the reply filed on 28 July 2026 is acknowledged. Because applicant did not distinctly and specifically point out any supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
In the reply filed on 28 July 2026, the Applicant requests that claims 1-13. However, the Applicant elected Species B, which is directed to figures 4-5 and claim 6. As a result, the Applicant did not elect Species A, which is directed to figures 2-3 and claim 5. Therefore, claim 5 was not examined because Species B was elected. Moreover, the Applicant elected species C, which is directed to fig. 6 and claim 8. As a result, the Applicant did not elect Species D and Species E, which are directed to figs. 7-8 and claims 10-13. Therefore, because the Applicant elected Species B and C and did not elect Species A, D, and E, which are directed to claims 5 and 10-13, the claims that were examined in Group I are the remaining claims, i.e., claims 1-4 and 6-9.
Claim Rejections - 35 USC § 103
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.
Claims 1, 4, 6-7, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Kang et al. (US-20210273282) in view of Bohm et al. (US-20240165742-A1, effective filing date of 25 May 2021).
Regarding claim 1, Kang teaches a method for laser welding (“laser welding,” para 0053), the method comprising:
producing at least one continuously enclosing first weld seam (first region 210 of welding bead 200, fig. 3) with a first seam width (width between points 232 and 234, figs. 3-4), and
producing at least one second weld seam (second region 220 of welding bead 200, fig. 3) with a second seam width (width between points 227 and 228, fig. 3),
wherein the second seam width is at least 10% greater than the first seam width (“the first contact point 232 may be positioned between 40-60% with respect to one end 227 of the second boundary line 225, and the second contact point 234 may be positioned between 40-60% with respect to the other end 228 of the second boundary line 225,” para 0105; construed as a range of 1/0.4 to 1/0.6 or 1.67 to 2.5, i.e., the width between points 227 and 228 is between 67-150% greater than the width between points 232 and 234, fig. 3).
Kang, fig. 3
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Kang does not explicitly disclose a bipolar plate for a fuel cell comprising two metallic plate parts.
However, in the same field of endeavor of laser welding, Bohm teaches a bipolar plate for a fuel cell (“bipolar plates of a fuel cell,” para 0012) comprising two metallic plate parts (parts 1 and 3, fig. 1; “superimposed sheet metal parts,” par 0040).
Bohm, fig. 2
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Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date to modify the invention of Kang, in view of the teachings of Bohm, by using the laser welding method, as taught by Kang, to manufacture the bipolar plates of a fuel cell, as taught by Bohm, in order to use a two-laser-beam welding method that can be used in applications with thin material thickness, and because this amounts to simple substitution of one application (battery cell components) with another (bipolar plates of a fuel cell) with predictable results (Bohm teaches the welding method taught by Kang of using a narrow laser beam and a larger laser beam can be used for welding “in bipolar plates of a fuel cell, in battery cell components, in components of a battery module, an overall battery system,” para 0053).
Regarding claim 4, Kang teaches the invention as described above but does not explicitly disclose wherein a laser beam used for the production of the at least one first weld seam and the at least one second weld seam has a first beam diameter at a point of impact on the bipolar plate when producing the first weld seam and a second beam diameter when producing the second weld seam, wherein the second beam diameter is at least 10% greater than the first beam diameter.
However, in the same field of endeavor of laser welding, Bohm teaches wherein a laser beam (beam 10, fig. 2) used for the production of the at least one first weld seam (portion of the weld seam 4 caused by beam component 11, fig. 2) and the at least one second weld seam (portion of the weld seam 4 caused by beam component 13, fig. 2) has a first beam diameter at a point of impact on the bipolar plate (d1 at intersection between beam 11 and part 1, fig. 2) when producing the first weld seam and a second beam diameter when producing the second weld seam (d2 for beam 13, fig. 2), wherein the second beam diameter is at least 10% greater than the first beam diameter (“2.5≤d 2 /d 1≤4,” para 0026; construed as a range for d2 between 250-400% times d1, or 150%-300% greater than d1).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date to modify the invention of Kang, in view of the teachings of Bohm, by using a range for the ratio for the diameters of the beams 280 (d2) to 270 (d1) , as taught by Kang, such that 2.5≤ d2/d1 ≤4, as taught by Bohm, in order to use a diameter ratio that prevents the humping effect in the weld seam despite high processing speeds (Bohm, paras 0007 and 0060).
Regarding claim 6, Kang teaches the invention as described above but does not explicitly disclose wherein the laser beam is emitted from a laser light source that comprises a laser fibre with a core fibre and a ring fibre, and wherein the laser beam is emitted from the core fibre for producing the first weld seam, and is emitted from the ring fibre for producing the second weld seam.
However, in the same field of endeavor of laser welding, Bohm teaches wherein the laser beam is emitted from a laser light source that comprises a laser fibre (“optical fiber,” para 0015) with a core fibre and a ring fibre (“core/sheath guiding of the radiation,” para 0015), and wherein the laser beam is emitted from the core fibre for producing the first weld seam (“a radially inner core with a circular cross-sectional area forms the deep welding laser beam component 11,” para 0058; beam 11 produces part of the weld seam 4, fig. 2), and is emitted from the ring fibre for producing the second weld seam (“radially outer shell with a circular ring-shaped cross-section forms the melting laser beam component 13,” para 0058; beam 13 produces part of the weld seam 4, fig. 2).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date to modify the invention of Kang, in view of the teachings of Bohm, by using an optical fiber laser with a core/sheath, as taught by Bohm, to produce the core beam 270 and ring beam 280, as taught by Kang, in order to use a dual or multi-core fiber that allows for an independent power adjustment between the two beams, so that a sufficiently large melt pool channel results for the capillary flow (Bohm, paras 0017 and 0023).
Regarding claim 7, Kang teaches wherein the laser beam has a central intensity maximum in an interior of a cross section when producing the first weld seam (beam 270 has a central intensity maximum, which correlates with region 210, figs. 3 and 6), and has a ring-shaped intensity maximum outside a center when producing the second weld seam (beam 280 has a ring-shaped intensity maximum, which correlates with region 220, figs. 3 and 6).
Regarding claim 9, the combination of Kang in view of Bohm as set forth above regarding claim 4 teaches the invention of claim 9. Specifically, Bohm teaches wherein focal positions of the laser beam differ from each other (focal diameter d1 for beam 11 and focal diameter d2 for beam 13, fig. 2; “2.5≤d 2 /d 1≤4,” para 0026) when producing the first weld seam and the second weld seam (weld seam 4, fig. 2).
Claims 2-3 are rejected under 35 U.S.C. 103 as being unpatentable over Kang et al. (US-20210273282) in view of Bohm et al. (US-20240165742-A1, effective filing date of 25 May 2021) as applied to claim 1 above and further in view of Flamm et al. (WO-2021005061-A1, relying on US-20220126396-A1 for English translation).
Regarding claim 2, Kang teaches the invention as described above but does not explicitly disclose wherein the first seam width is at least 20 µm, and/or at most 200 µm.
However, in the same field of endeavor of laser welding, Flamm teaches wherein the first seam width is at least 20 µm, and/or at most 200 µm (the diameter “DK” is the diameter for the core zone in the “workpiece” for the “weld seam,” para 0055; “200 μm≤DK≤600 μm,” para 0055; construed as representing the width of the first region 210 for beam 270 that is taught by Kang).
Flamm, fig. 7
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Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date to modify the invention of Kang, in view of the teachings of Flamm, by using a core zone diameter DK for the weld seam in the workpiece such that 200 μm≤DK≤600 μm, as taught by Flamm, for the beam 270 that produces the first region 210 in the weld seam, as taught by Kang, in order to use size relationships for the core zone and ring zone that resulted in particularly good weld zone qualities (Flamm, para 0055) and since it has been held that in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Regarding claim 3, Kang teaches the invention as described above but does not explicitly disclose wherein the second seam width is at least 22 µm, and/or at most 600 µm.
However, in the same field of endeavor of laser welding, Flamm teaches wherein the second seam width is at least 22 µm, and/or at most 600 µm (the diameter “DR” is the diameter for the ring zone in the “workpiece” for the “weld seam,” para 0055; “600 μm≤DR≤1800 μm,” para 0055; construed as representing the width of the second region 220 for beam 280 that is taught by Kang).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date to modify the invention of Kang, in view of the teachings of Flamm, by using a ring zone diameter DR for the weld seam in the workpiece such that 600 μm≤DR≤1800 μm, as taught by Flamm, for the beam 280 that produces the first region 220 in the weld seam, as taught by Kang, in order to use size relationships for the core zone and ring zone that resulted in particularly good weld zone qualities (Flamm, para 0055) and since it has been held that in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Kang et al. (US-20210273282) in view of Bohm et al. (US-20240165742-A1, effective filing date of 25 May 2021) as applied to claims 1 and 4 above and further in view of Bea et al. (US-20100206857-A1).
Regarding claim 8, Kang teaches the invention as described above but does not explicitly disclose wherein the laser beam is emitted from a laser light source that comprises a zoom optics, which allows an imaging ratio of between 1:1 and 5:1, and wherein a first zoom factor of the zoom optics is applied for producing the first weld seam, and a second zoom factor of the zoom optics is applied for producing the second weld seam, wherein the second zoom factor is at least 10% greater than the first zoom factor.
However, in the same field of endeavor of laser welding, Bohm teaches wherein the laser beam is emitted from a laser light source that comprises a zoom optics (“scanner optics,” para 0031), which allows an imaging ratio of between 1:1 and 5:1 (“The imaging is preferably performed via scanner optics, with an imaging ratio between 1 and 6, in particular between 2 and 4,” para 0027; construed as an imaging ratio between 2:1 and 4:1). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date to modify the invention of Kang, in view of the teachings of Bohm, by using the processing optics 5, as taught by Bohm, for the imaging of the beams 270 and 280, as taught by Kang, in order to using a processing optics that enables a concentric arrangement between beams 11 and 13, so that a sufficiently large melt pool channel results for the capillary flow (Bohm, paras 0023 and 0058).
Kang/Bohm teach the invention as described above but do not explicitly disclose wherein a first zoom factor of the zoom optics is applied for producing the first weld seam, and a second zoom factor of the zoom optics is applied for producing the second weld seam, wherein the second zoom factor is at least 10% greater than the first zoom factor.
However, in the same field of endeavor of laser welding, Bea teaches wherein a first zoom factor () of the zoom optics (vortex mirror 30, fig. 1A) is applied for producing the first weld seam (weld seam due to the “beam radius (SR),” paras 0033-0034), and a second zoom factor of the zoom optics is applied for producing the second weld seam (weld seam due to the “radial ring width (RB),” paras 0033-0034), wherein the second zoom factor is at least 10% greater than the first zoom factor (“The quotient (Q) (e.g., ratio) of the ring width (RB) and the beam radius (SR) is a numerical value without a unit which, in some cases, is smaller than 0.6,” para 0029; construed such that the diameter ratio between the beams is greater than 1/0.6 or diameter for RB that is 66.67% greater than the diameter for SR; the Specification discloses that the zoom factors in the zoom optics result in different diameters for the beams).
Bea, fig. 1A
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Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date to modify the invention of Kang, in view of the teachings of Bea, by using the vortex mirror, as taught by Bea, inside the processing optics, as taught by Bohm, in order to use vortex structure that transforms a laser beam into a ring structure, enabling a relatively compact beam with little divergence (Bea, para 0050).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Asami et al. (US-20150145241-A1) teach overlapping laser welds.
Brescoe et al. (US-11389894-B2) teach power adjustments between the annular core and center core.
Bocksrocker et al. (US-20230256540-A1) teach laser welding two thin workpieces.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ERWIN J WUNDERLICH whose telephone number is (571)272-6995. The examiner can normally be reached Mon-Fri 7:30-5:30.
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/ERWIN J WUNDERLICH/Examiner, Art Unit 3761 8/31/2026
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