DETAILED ACTION
Applicant’s Response
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant’s submission filed on March 3, 2026, has been entered.
Claims 1 and 7 are amended.
The applicant contends that the cited prior art fails to disclose the new material presently recited by claim 1 – namely, the feature of a “four-quadrant bidirectional switch” which both conducts positive and negative current and blocks positive and negative voltage.
In response, the examiner accepts this characterization and has withdrawn the outstanding rejections. Subsequent further search, however, new rejections have been applied below.
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 of this title, 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.
According to a First Grounds of Rejection:
Claims 1, 5, 7, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Nguyen et al., US 2021/0013006, in view of Cairoli et al., US 2021/0091767, and Rueda et al., “Series Resonant Inverter Efficiency Improvement,” as disclosed in the July 15, 2025 IDS.
Claim 1: Nguyen discloses a bias supply to apply a periodic voltage, comprising:
An output node (Vo) (Fig. 22);
A return node (ground);
A switch (220) configured to enable current control between a first node and a second node;
A power section (230, 250) coupled to the output node, the return node, and the first and second nodes of the switch [0044];
A controller (260) configured to control a direction of current through the switch over a full current cycle [0044].
As shown by Figure 4, Nguyen’s controller is configured to control a direction of current through the switch over a full current cycle [0047]. The cycle includes a first half current cycle inducing positive current flow, starting from zero at time t0, that increases to a positive peak value and then decreases back to zero at time t1. The cycle also includes a second half current cycle inducing negative current flow, starting from zero current at time t2, that increases to a negative peak value and then decreases back to zero current at time t3. This constitutes an application of periodic voltage between the output and return nodes, whereby the examiner understands the phenomenon to read upon the claimed term, “bidirectional.”
It is not clear that Nguyen’s switch is “four-quadrant” in its configuration. This design, however, is known in the art. Cairoli, for example, avails a four-quadrant bidirectional switch within the context of a bias power supply, whereby the switch conducts bidirectional current in an ON state and blocks bidirectional voltage in an OFF state [0003, 0010ff]. Advantages of this switch design include superior power density and reduced complexity by substituting a monolithic design, in the case of Cairoli, for a collection of discrete switches (claim 6). It would have been obvious to configure Nguyen’s bidirectional switch as a four-quadrant design since applying a known technique to a similar device in the same way is within the scope of ordinary skill.
Lastly, Nguyen does not appear to impose a deadtime between each half current cycle. In supplementation, Rueda elaborates a method of operating a bidirectional switch within the context of semiconductor processing, where a first half current cycle comprising positive current flow (idbd) is separated by a deadtime, “Interval C,” before initiating a second half negative current flow (Fig. 4). By regulating current, voltage and gas breakdown can be controlled in turn (p. 2). It would have been obvious to integrate a deadtime within Nguyen’s scheme of current control, as applying a known technique to a known device ready for improvement to yield predictable results is within the scope of ordinary skill.
Claim 5: The examiner interprets this claim language to establish the controller’s capacity to institute “deadtime” rather than formally requiring the application of said deadtime during processing. It is the Office’s position that Nguyen’s controller is capable of applying a deadtime, since a recitation concerning the manner in which a claimed apparatus is to be employed does not differentiate the apparatus from prior art satisfying the claimed structural limitations (Ex parte Masham 2, USPQ2D 1647).
Claim 7: As shown by Figure 2 of Nguyen, a voltage source (230) is oriented in series with an inductor (250) across the bidirectional switch (208) [0044].
Claim 19: The power section of Nguyen includes a first node of a first inductor (240) coupled to the bidirectional switch and a second node of the first inductor coupled to the output node. Further, a first node of a second inductor (250) is coupled to the first node of the first inductor, and a voltage source (230) is coupled to a second node of the second inductor (250) and the return node.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Nguyen in view of Cairoli and Rueda, and in further view of Brouk et al., US 2014/0061156.
As shown by Figure 4, Nguyen discloses only a single switch and keeps it closed through the duration of the current cycle. In supplementation, Brouk teaches a bias supply comprising two switches (T1, T2) which regulate drive signals V2 and V4 (Fig. 2). These signals can be modulated to lengthen a pulse or establish a delay [0080]. For instance, Figure 8 depicts a full cycle waveform moving from peak to peak in opposing directions, along with an added delay or deadtime controlled by the opening and closing of the two switches. It would have been obvious to integrate a second switch within Nguyen’s system to promote the application of a periodic voltage, since using a known technique to improve similar devices in the same way is within the scope of ordinary skill.
Lastly, it should be noted that Nguyen also provides a dedicated diode for the existing switch, whereby it would have been obvious to incorporate a second dedicated diode given the existence of a second switch, as suggested by Brouk.
According to a Second Grounds of Rejection:
Claims 1, 4-5, 7, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Dorf et al., US 2022/0037121, in view of Brouk, Rueda, and Cairoli.
Claims 1, 4: Dorf discloses a bias supply to apply a periodic voltage, comprising:
An output node (104) (Fig. 3A);
A return node (ground);
A switch (SN1, SN2) configured to enable current control between a first node and a second node;
A power section (151) coupled to the output node, the return node, and the first and second nodes of the switch [0058];
A controller (126) configured to control a direction of current [0055].
Dorf, though, is silent regarding the application of a periodic voltage. Brouk, as discussed above, teaches a bias supply comprising two switches (T1, T2) containing diodes which regulate drive signals V2 and V4 (Fig. 2). As shown by Figure 8, Brouk applies a full current cycle comprising positive current flow for a specified interval and then negative current flow for a subsequent interval by regulating the status of each switch [0081, 0095]. During each interval, the current flow reaches a peak value before declining to a reference value, i.e., zero current. It would have been obvious incorporate this method of current application within Dorf’s system in order to induce a controlled bandwidth of ion energies so as to better regulate the etching process.
Lastly, Dorf does not appear to impose a deadtime between each half current cycle. In supplementation, Rueda elaborates a method of operating a bidirectional switch within the context of semiconductor processing, where a first half current cycle comprising positive current flow (idbd) is separated by a deadtime, “Interval C,” before initiating a second half negative current flow (Fig. 4). By regulating current, voltage and gas breakdown can be controlled in turn (p. 2). It would have been obvious to integrate a deadtime within Nguyen’s scheme of current control, as applying a known technique to a known device ready for improvement to yield predictable results is within the scope of ordinary skill.
It is not clear, though, if the cited art’s switch is “four-quadrant” in its configuration. This design, however, is known in the art. Cairoli, for example, avails a four-quadrant bidirectional switch within the context of a bias power supply, whereby the switch conducts bidirectional current in an ON state and blocks bidirectional voltage in an OFF state [0003, 0010ff]. Advantages of this switch design include superior power density and reduced complexity by substituting a monolithic design, in the case of Cairoli, for a collection of discrete switches (claim 6). It would have been obvious to configure Nguyen’s bidirectional switch as a four-quadrant design since applying a known technique to a similar device in the same way is within the scope of ordinary skill.
Claim 5: The examiner interprets this claim language to establish the controller’s capacity to institute “deadtime” rather than formally requiring the application of said deadtime during processing. It is the Office’s position that Dorf’s controller is capable of applying a deadtime, since a recitation concerning the manner in which a claimed apparatus is to be employed does not differentiate the apparatus from prior art satisfying the claimed structural limitations (Ex parte Masham 2, USPQ2D 1647).
Claim 7: As shown by Figure 2 of Nguyen, a voltage source (230) is oriented in series with an inductor (250) across the bidirectional switch (208) [0044].
Claim 19: Dorf’s power section (151) includes a first node of a first inductor (151B) coupled to the bidirectional switch and a second node of the first inductor coupled to the output node (104) (Fig. 3A). Further, a first node of a second inductor (151D) is coupled to the first node of the first inductor, and a voltage source (151F) is coupled to a second node of the second inductor (151D) and the return node.
Conclusion
The following prior art is made of record as being pertinent to Applicant’s disclosure, yet is not formally relied upon: Brouk et al., US 2012/0318456. Brouk discloses a bias power supply (206) comprising an output node (236), a return node (ground), a bidirectional switch (226) to regulate current, a power section (220) coupled to the output node, and a controller (212) (Fig. 2, [0069ff]).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NATHAN K FORD whose telephone number is (571)270-1880. The examiner can normally be reached on 11-7:30 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Parviz Hassanzadeh, can be reached at 571 272 1435. The fax phone number for the organization where this application or proceeding is assigned is 571 273 8300.
/N. K. F./
Examiner, Art Unit 1716
/KARLA A MOORE/ Primary Examiner, Art Unit 1716
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