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 § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-15 and claims 31-37 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites, in part, “the first magnetic field sensing element configured to sense a first magnetic field associated with a first current through a first conductor and a second magnetic field associated with a second current through a second conductor”, “wherein the first magnetic field sensing element is disposed a first distance from the first conductor and a second distance from the second conductor” and “wherein the second magnetic field sensing element is disposed a third distance substantially equal to the first distance from the second conductor and a fourth distance substantially equal to the second distance from the first conductor”. The examiner notes that the claim does not affirmatively recite the first conductor and the second conductor as affirmative elements of the claimed current sensing system. It is therefore unclear whether the first conductor and the second conductor are to be regarded as required elements of the claimed current sensing system, or merely structures that functionally relate to the claimed current sensing system and the manner in which it is used. For purposes of the present examination the first conductor and the second conductor are not regarded as required elements of the claimed current sensing system, but rather structures that functionally relate to the claimed current sensing system and a manner of its use. The analogous issue is present in claim 31, with the same interpretation being applied for purposes of the present examination. Clarification is required so that the scope of the claims is clear. Claims 2-15 and claims 32-37 are rejected under 35 U.S.C. 112(b) by virtue of their dependence from claims 1 and 31, respectively.
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 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.
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.
Claims 1-9, 13-24 and 28-30 are rejected under 35 U.S.C. 103 as being unpatentable over US 2022/0137103 to Briano et al. (Briano) in view of US 2020/0105125 to Haas et al. (Haas).
Regarding claim 1, Briano discloses a current sensing system comprising:
a first semiconductor die supporting a first magnetic field sensing element, the first magnetic field sensing element configured to sense a first magnetic field associated with a first current through a first conductor and a second magnetic field associated with a second current through a second conductor, the first magnetic field sensing element further configured to generate a first output signal indicative of the first current and second current, wherein the first magnetic field sensing element is disposed a first distance from the first conductor and a second distance from the second conductor (Briano, e.g., Fig. 2A (duplicated below) and paragraphs 12 and 27-31, Fig. 2A is a sideview of a current sensor integrated circuit package mounted on a printed circuit board; note integrated circuit die 282 supporting first magnetic field sensing element, e.g., Hall plate 285; it is implicit in Briano’s arrangement that the magnetic field sensed by Hall plate 285 will be the combined magnetic field produced by current flows through respective current traces 266, 268; note also that other types of magnetic field sensing elements may be used, e.g., a vertical Hall element, or a magnetoresistance element, such as a giant magnetoresistance element (GMR), a tunneling magnetoresistance element (TMR) or a magnetic tunnel junction (MTJ), see, e.g., paragraphs 5, 28);
supporting a second magnetic field sensing element, the second magnetic field sensing element configured to sense the first magnetic field and the second magnetic field, the second magnetic field sensing element further configured to generate a second output signal indicative of the first current and second current, wherein the second magnetic field sensing element is disposed a third distance substantially equal to the first distance from the second conductor and a fourth distance substantially equal to the second distance from the first conductor (Briano, e.g., Fig. 2A (duplicated below) and paragraphs 12 and 27-31, Fig. 2A is a sideview of a current sensor integrated circuit package mounted on a printed circuit board; note integrated circuit die 282 supporting second magnetic field sensing element, e.g., Hall plate 287; it is implicit in Briano’s arrangement that the magnetic field sensed by Hall plate 287 will be the combined magnetic field produced by current flows through respective current traces 266, 268; note also that other types of magnetic field sensing elements may be used, e.g., a vertical Hall element, or a magnetoresistance element, such as a giant magnetoresistance element (GMR), a tunneling magnetoresistance element (TMR) or a magnetic tunnel junction (MTJ), see, e.g., paragraphs 5, 28); and
a circuit responsive to the first output signal from the first magnetic field sensing element and the second output signal from the second magnetic field sensing element, the circuit configured to generate a current sensor output signal based on a difference between the first output signal and the second output signal (Briano, e.g., Fig. 3 (duplicated below) and paragraphs 13, 26 and 32-36, Fig. 3 is a schematic overview of a circuit for use in the current sensor integrated circuit; the electrical current flowing through the current traces 266, 268 produces magnetic fields which are in opposite directions in FIG. 2 in the area of the current sensor IC 280; if the two currents are of the same magnitude but in opposite directions the net sum of magnetic field sensed by the Hall plates 285, 287 is near zero; in Fig. 3, magnetic field sensing elements 385, 387, are connected to first and second amplifiers 310, 312 respectively; the output of the amplifiers 310, 312 may be summed in a summing element 320; the sum of the two magnetic field sensing elements 385, 387 is input to a current calculation circuit 330, which may include a comparator to compare a difference (or sum) of the measured magnetic fields detected by magnetic field sensing elements 385, 387; also see paragraph 35; also see paragraph 6, last sentence; also see claims 7-8).
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In Fig. 2A, Briano discloses that Hall plates 285, 287 are commonly supported by integrated circuit die 282. Fig. 2A of Briano is therefore not relied upon as explicitly disclosing a second semiconductor die supporting the second magnetic field sensing element. Implementing a sensor IC package such as Briano’s current sensor IC 280 of Fig. 2A using a single die, or a multi-die, is known. For example, in closely related art, Haas discloses in connection with Fig. 1 that dotted line boxes 50, 50a, 50b, 50c, and 50d, and 60 represent possible individual semiconductor die within the sensor IC package, and that many variations are possible in terms of partitioning of the described circuitry on one or more die and which variation is adopted generally will be based on safety requirements and space and cost considerations (Haas, e.g., Fig. 1 and paragraph 48; the examiner notes that in Fig. 1 of Haas that dotted line boxes 50a, 50c correspond to magnetic sensing elements 12, 14, respectively). It 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 to modify Briano such that magnetic field sensing elements, 285, 287 are supported by respective semiconductor dies within Briano’s sensor IC package 280 based on safety requirements and space/cost considerations as disclosed by Haas.
Regarding claim 2, Briano in view of Haas discloses wherein the current sensor output signal is indicative of a difference between the first current and the second current (see Briano in view of Haas as applied to claim 1, Briano, e.g., Fig. 3 (duplicated above) and paragraphs 13, 26 and 32-36, Fig. 3 is a schematic overview of a circuit for use in the current sensor integrated circuit; the electrical current flowing through the current traces 266, 268 produces magnetic fields which are in opposite directions in FIG. 2 in the area of the current sensor IC 280; if the two currents are of the same magnitude but in opposite directions the net sum of magnetic field sensed by the Hall plates 285, 287 is near zero; in Fig. 3, magnetic field sensing elements 385, 387, are connected to first and second amplifiers 310, 312 respectively; the output of the amplifiers 310, 312 may be summed in a summing element 320; the sum of the two magnetic field sensing elements 385, 387 is input to a current calculation circuit 330, which may include a comparator to compare a difference (or sum) of the measured magnetic fields detected by magnetic field sensing elements 385, 387; also see paragraph 3, last sentence; also see paragraph 6, last sentence; also see paragraph 35; also see paragraph 6, last sentence; also see claims 7-8).
Claim 3 recites wherein the first conductor and the second conductor comprise busbars. The examiner notes that the first conductor and the second conductor are not affirmatively recited as required elements of the current sensing system, but rather structures that functionally relate to the claimed current sensing system and the manner in which it is used (see 35 U.S.C. 112(b) rejection of claim 1 above). Under this interpretation, the first conductor and the second conductor do not carry patentable weight. Nevertheless, the examiner takes Official notice of the fact that use of conductive traces (as disclosed by Briano) and busbars on circuit boards for supplying current to devices/loads was well-known and conventional before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. It 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 to modify Briano in view of Haas such that the first conductor and the second conductor comprise busbars at least in view of the well-known and conventional use of busbars on circuit boards for supplying current to devices/loads. Additionally, or in the alternative, the prior art included each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the elements as claimed by known methods, and that in combination, each element merely performs the same function as it does separately. Moreover, one of ordinary skill in the art would have recognized that the results of the combination were predictable. For these reasons, the recitation that the first conductor and the second conductor comprise busbars does not patentably define over Briano in view of Haas when considered in light of the knowledge of a person of ordinary skill in the art.
Regarding claim 4, Briano in view of Haas discloses a substrate adjacent to the first magnetic field sensing element and the second magnetic field sensing element (see Briano in view of Haas as applied to claim 1, in Briano as modified (i.e., Hall plates 285, 287 of Fig. 2 supported by respective semiconductor dies), Briano’s internal lead frame connections of sensor IC package 280 (Briano, e.g., paragraph 27) necessarily provides a substrate adjacent to Hall plates 285, 287; in the alternative, in Fig. 2A of modified Briano circuit board 270 provides a substrate adjacent to Hall plates 285, 287).
Regarding claim 5, Briano in view of Haas discloses wherein the substrate is a printed circuit board (PCB) (see Briano in view of Haas as applied to claim 5 (alternative interpretation), Briano, e.g., Fig. 2A and paragraph 27, circuit board 270 includes current traces 266, 268 and therefore constitutes a PCB; also see Briano, paragraph 24, current traces 266, 268 may be patterned on the circuit board).
Claim 6 recites wherein the first conductor and the second conductor comprise conductive traces. The examiner notes that the first conductor and the second conductor are not affirmatively recited as required elements of the current sensing system, but rather structures that functionally relate to the claimed current sensing system and the manner in which it is used (see 35 U.S.C. 112(b) rejection of claim 1 above). Under this interpretation, the first conductor and the second conductor do not carry patentable weight. Nevertheless, the examiner notes that Briano discloses this feature (see Briano in view of Haas as applied to claim 5 (alternative interpretation), Briano, e.g., Fig. 2A and paragraph 27, circuit board 270 includes current traces 266, 268 and therefore constitutes a PCB; also see paragraph 24, current traces 266, 268 may be patterned on the circuit board).
Regarding claim 7, Briano in view of Haas discloses wherein the substrate is a lead frame (see Briano in view of Haas as applied to claim 4 (first interpretation), Briano’s internal lead frame connections of sensor IC package 280 (Briano, e.g., paragraph 27) necessarily provides a substrate adjacent to Hall plates 285, 287).
Regarding claim 8, Briano in view of Haas discloses wherein the first current flows in an opposite direction from the second current (see Briano in view of Haas as applied to claim 1, e.g., Briano, Fig. 2A, indicated current directions in current traces 266, 268 are opposite each other).
Regarding claim 9, Briano in view of Haas discloses current calculation circuit 330 compares a difference (or sum) of the measured magnetic fields detected by magnetic field sensing elements 385, 387 to a threshold (see, e.g., Briano, paragraphs 3, 32) and can be implemented using analog blocks or digital blocks (Briano, e.g., paragraph 19). Although Briano is not relied upon as explicitly disclosing that current calculation circuit 330 includes a differential operational amplifier, the examiner takes Official notice of the fact that use of an analog differential operational amplifier for obtaining a difference between two input signals was well-known and conventional before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. It 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 to modify Briano in view of Haas such that that current calculation circuit 330 includes an analog differential operational amplifier for obtaining a difference of the measured magnetic fields detected by magnetic field sensing elements at least in view of the well-known and conventional use of differential operational amplifier for this purpose.
Regarding claim 13, Briano in view of Haas discloses wherein the first and second magnetic field sensing elements comprise one or more magnetoresistive elements or Hall effect elements (see Briano in view of Haas as applied to claim 1, Briano, e.g., Fig. 2A, Hall plates 285, 287; also see Briano, e.g., paragraph 5, current sensor may contain one or more magnetic field sensing elements, which may comprise a planar Hall element, a vertical Hall element, or a magnetoresistance element, such as a giant magnetoresistance element (GMR), a tunneling magnetoresistance element (TMR) or a magnetic tunnel junction (MTJ), or a combination of magnetic field sensing elements).
Claim 14 recites wherein the first conductor is disposed vertically to the second conductor and symmetrically to first magnetic field sensing element and the second magnetic field sensing element. The examiner notes that the first conductor and the second conductor are not affirmatively recited as required elements of the current sensing system, but rather structures that functionally relate to the claimed current sensing system and the manner in which it is used (see 35 U.S.C. 112(b) rejection of claim 1 above). Under this interpretation, the first conductor and the second conductor do not carry patentable weight. Nevertheless, the examiner notes that Briano discloses this feature (see Briano in view of Haas as applied to claim 1, Briano, e.g., Fig. 2A, first conductor in the form of current trace 268 is disposed vertically relative to second conductor in the form of current trace 265; additionally, first conductor in the form of current trace 268 is disposed symmetrically relative to Hall plates 285, 287).
Claim 15 recites wherein the first conductor is disposed horizontally to the second conductor. The examiner notes that the first conductor and the second conductor are not affirmatively recited as required elements of the current sensing system, but rather structures that functionally relate to the claimed current sensing system and the manner in which it is used (see 35 U.S.C. 112(b) rejection of claim 1 above). Under this interpretation, the first conductor and the second conductor do not carry patentable weight. Nevertheless, the examiner notes that Briano discloses this feature (see Briano in view of Haas as applied to claim 1, e.g., Briano, paragraph 29, the position of the conductors, 266, 268 may also be changed to be next to each other rather than on top of each other as shown in FIG. 2A).
Claim 16 recites a method of sensing a current through one or more conductors, the method comprising:
providing a first semiconductor die supporting a first magnetic field sensing element, the first magnetic field sensing element configured to sense a first magnetic field associated with a first current through a first conductor and a second magnetic field associated with a second current through a second conductor, the first magnetic field sensing element further configured to generate a first output signal indicative of the first current and second current,
positioning the first magnetic field sensing element a first distance from the first conductor and a second distance from the second conductor;
providing a second semiconductor die supporting a second magnetic field sensing element, the second magnetic field sensing element configured to sense the first magnetic field and the second magnetic field, the second magnetic field sensing element further configured to generate a second output signal indicative of the first current and second current;
positioning the second magnetic field sensing element a third distance substantially equal to the first distance from the second conductor and a fourth distance substantially equal to the second distance from the first conductor; and
providing a circuit responsive to the first output signal from the first magnetic field sensing element and the second output signal from the second magnetic field sensing element, the circuit configured to generate a current sensor output signal based on a difference between the first output signal and the second output signal,
and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 1.
Claim 17 recites wherein the current sensor output signal is indicative of a difference between the first current and the second current and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 2.
Claim 18 recites wherein the first conductor and the second conductor comprise busbars and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 3.
Claim 19 recites providing a substrate adjacent to the first magnetic field sensing element and the second magnetic field sensing element and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 4.
Claim 20 recites wherein the substrate is a printed circuit board (PCB) and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 5.
Claim 21 recites wherein the first conductor and the second conductor comprise conductive traces and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 6.
Claim 22 recites wherein the substrate is a lead frame and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 7.
Claim 23 recites wherein the first current flows in an opposite direction from the second current and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 8.
Claim 24 recites wherein the circuit comprises a differential operational amplifier and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 9.
Claim 28 recites wherein the first and second magnetic field sensing elements comprise one or more magnetoresistive elements or Hall effect elements and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 13.
Claim 29 recites wherein the first conductor is disposed vertically to the second conductor and symmetrically to first magnetic sensing element and the second magnetic sensing element and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 14.
Claim 30 recites wherein the first conductor is disposed horizontally to the second conductor and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas for reasons analogous to those discussed above in connection with the rejection of claim 15.
Claims 10-12 and 25-27 are rejected under 35 U.S.C. 103 as being unpatentable over Briano in view of Haas, and further in view of US 2014/0266181 to Milano et al. (Milano).
Regarding claim 10, Briano in view of Haas as applied to claim 1 is not relied upon as explicitly disclosing a first compensation coil proximate to the first magnetic field sensing element and a second compensation coil proximate to the second magnetic field sensing element. In related art, Milano discloses an on-chip coil proximate a magnetic sensing element for generating a magnetic field for diagnostic/self test functionality, calibration, and/or back bias applications (Milano, e.g., paragraph 18) and/or for facilitating the manufacture of a closed loop sensor (Milano, e.g., paragraph 19; also see, e.g., Fig. 2A, sensing element 202, such as a Hall element, having a coil 204 wrapped around the sensing element 202). Milano discloses that in many instances the coil may be formed in the semiconductor die itself (Milano, e.g., paragraph 37, 71). Alternatively Milano discloses that the coil may be contained in the package, e.g., coil is located on an opposite side of the lead frame from the die and enclosed in an over molded package (Milano, e.g., paragraphs 3, 71). It 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 to modify Briano in view of Haas to include respective compensation coils proximate the magnetic field sensing elements, 285, 287. In this way, in the manner disclosed by Milano, functionalities such as diagnostic/self test functionality, calibration functionality, back bias applications and/or closed loop sensing can be implemented.
Regarding claim 11, Briano in view of Haas and Milano discloses wherein the first compensation coil is located in the first semiconductor die and the second compensation coil is located in the second semiconductor die (see Briano in view of Haas and Milano as applied to claim 10, Milano, e.g., paragraph 37, 71, in many instances the coil may be formed in the semiconductor die itself).
Regarding claim 12, Briano in view of Haas and Milano discloses wherein the first compensation coil and the second compensation coil are located on a substrate supporting the first semiconductor die and the second compensation coil (see Briano in view of Haas and Milano as applied to claim 10, Milano, e.g., paragraphs 3, 71, coil is located on an opposite side of the lead frame from the die and enclosed in an over molded package; the examiner notes that in Briano in view of Haas and Milano as applied to claim 1, a multi-die package is provided such that in the case of off-die coils disclosed by Milano, the coils will be commonly supported by the packaging).
Claim 25 recites providing a first compensation coil proximate to the first magnetic field sensing element and a second compensation coil proximate to the second magnetic field sensing element and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas and Milano for reasons analogous to those discussed above in connection with the rejection of claim 10.
Claim 26 recites wherein the first compensation coil is located in the first semiconductor die and the second compensation coil is located in the second semiconductor die and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas and Milano for reasons analogous to those discussed above in connection with the rejection of claim 11.
Claim 27 recites wherein the first compensation coil and the second compensation coil are located on a substrate supporting the first semiconductor die and the second compensation coil and is rejected under 35 U.S.C. 103 as unpatentable over Briano in view of Haas and Milano for reasons analogous to those discussed above in connection with the rejection of claim 12.
Claims 31 and 35-37 are rejected under 35 U.S.C. 103 as being unpatentable over US 2014/0097826 to Hebiguchi et al. (Hebiguchi) in view of Milano.
Regarding claim 31, Hebiguchi discloses a current sensing system comprising:
a first magnetic field sensing element, the first magnetic field sensing element configured to sense a first magnetic field associated with a current through a conductor and generate a first output signal indicative of the current, wherein the first magnetic field sensing element is disposed a first distance from the conductor (Hebiguchi, e.g., Fig. 1 and paragraphs 30-32; also see Fig. 3 and paragraphs 35-41, magnetoelectric conversion element 2a includes magnetoelectric conversion element 12a);
a first compensation coil proximate to the first magnetic field sensing element (Hebiguchi, e.g., Fig. 1 and paragraphs 30-32; also see Fig. 3 and paragraphs 35-41, magnetoelectric conversion element 2a includes compensation coil in the form of feedback coil 11a);
a second magnetic field sensing element, the second magnetic field sensing element configured to sense a second magnetic field associated with the current through the conductor and generate a second output signal indicative of the current, wherein the second magnetic field sensing element is disposed a second distance from the conductor equal to the first distance (Hebiguchi, e.g., Fig. 1 and paragraphs 30-32; also see Fig. 3 and paragraphs 35-41, magnetoelectric conversion element 2b includes magnetoelectric conversion element 12b; note in particular that Hebiguchi discloses in paragraph 30 that magnetoelectric conversion elements 2a and 2b are arranged at equivalent distances from the measurement-subject current path 5a);
a second compensation coil proximate to the second magnetic field sensing element (Hebiguchi, e.g., Fig. 1 and paragraphs 30-32; also see Fig. 3 and paragraphs 35-41, magnetoelectric conversion element 2b includes compensation coil in the form of feedback coil 11b); and
a circuit responsive to the first output signal from the first magnetic field sensing element and the second output signal from the second magnetic field sensing element, the circuit configured to generate a current sensor output signal based on a difference between the first output signal and the second output signal (Hebiguchi, e.g., Fig. 1 and paragraphs 30-32; also see Fig. 3 and paragraphs 35-41, circuit in the form of signal processing circuit 3; see in particular paragraphs 35 and 39, for example).
Hebiguchi is not relied upon as explicitly disclosing that the first and second magnetic field sensing elements are respectively supported by a first semiconductor die and a second semiconductor die. In related art, Milano discloses that a magnetic field sensor can be disposed on a semiconductor die (Milano, e.g., paragraph 4, a semiconductor die having a first surface in which a magnetic field sensing element is disposed). It 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 to modify Hebiguchi such that the first and second magnetic field sensing elements are respectively supported by a first semiconductor die and a second semiconductor die at least in view of the well-known advantages afforded by integrated circuits relative to circuits fabricated by discrete components, e.g., device miniaturization, improved performance, and reduced cost.
Regarding claim 35, Hebiguchi in view of Milano as applied to claim 31 is not relied upon as explicitly disclosing wherein the first compensation coil is located in the first semiconductor die and the second compensation coil is located in the second semiconductor die. Milano discloses an on-chip coil proximate a magnetic sensing element for, among other things facilitating the manufacture of a closed loop sensor (Milano, e.g., paragraph 19; also see, e.g., Fig. 2A, sensing element 202, such as a Hall element, having a coil 204 wrapped around the sensing element 202). Milano discloses that in many instances the coil may be formed in the semiconductor die itself (Milano, e.g., paragraph 37, 71). Milano therefore discloses a compensation coil located in a semiconductor die. The prior art included each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the elements as claimed by known methods, and that in combination, each element merely performs the same function as it does separately. Moreover, one of ordinary skill in the art would have recognized that the results of the combination were predictable. For these reasons, the recitation that the first compensation coil is located in the first semiconductor die and the second compensation coil is located in the second semiconductor die does not patentably define over Hebiguchi in view of Milano when considered in light of the knowledge of one of ordinary skill in the art.
Regarding claim 36, Hebiguchi in view of Milano as applied to claim 31 is not relied upon as explicitly disclosing wherein the first compensation coil and the second compensation coil are located on a substrate supporting the first semiconductor die and the second compensation coil. Milano discloses an on-chip coil proximate a magnetic sensing element for, among other things facilitating the manufacture of a closed loop sensor (Milano, e.g., paragraph 19; also see, e.g., Fig. 2A, sensing element 202, such as a Hall element, having a coil 204 wrapped around the sensing element 202). Milano discloses that the coil may be contained in the package, e.g., coil is located on an opposite side of the lead frame from the die and enclosed in an over molded package (Milano, e.g., paragraphs 3, 71). Milano therefore discloses a compensation coil located on a substrate supporting a semiconductor die. The prior art included each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the elements as claimed by known methods, and that in combination, each element merely performs the same function as it does separately. Moreover, one of ordinary skill in the art would have recognized that the results of the combination were predictable. For these reasons, the recitation that the first compensation coil and the second compensation coil are located on a substrate supporting the first semiconductor die and the second compensation coil does not patentably define over Hebiguchi in view of Milano when considered in light of the knowledge of one of ordinary skill in the art.
Regarding claim 37, Hebiguchi in view of Milano discloses wherein the first and second magnetic field sensing elements comprise one or more magnetoresistive elements or Hall effect elements (see Hebiguchi in view of Milano as applied to claim 31, e.g., Hebiguchi, paragraph 32).
Claims 32-34 are rejected under 35 U.S.C. 103 as being unpatentable over Hebiguchi in view of Milano, or alternatively, over Hebiguchi in view of Milano in view of US 2012/0081110 to Racz (Racz).
Regarding claim 32, Hebiguchi in view of Milano discloses a substrate adjacent to the first magnetic field sensing element and the second magnetic field sensing element (see Hebiguchi in view of Milano as applied to claim 31, e.g., Hebiguchi, Fig. 1, PCB 4). In the alternative, a substrate in the form of a lead frame for supporting magnetic field sensing elements of the type disclosed by Hebiguchi in view of Milano is known (Racz, e.g., Fig. 1 and paragraph 18). It 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 to modify Hebiguchi in view of Milano to include a substrate adjacent to the first magnetic field sensing element and the second magnetic field sensing element in the form of a lead frame. In this way, in the manner disclosed by Racz, electrical connections with the magnetic field sensing elements can be established.
Regarding claim 33, Hebiguchi in view of Milano as applied to claim 32 discloses wherein the substrate is a printed circuit board (PCB) (see Hebiguchi in view of Milano as applied to claim 32, e.g., Hebiguchi, Fig. 1, PCB 4).
Regarding claim 34, Hebiguchi in view of Milano and Racz as applied to claim 32 wherein the substrate is a lead frame (see Hebiguchi in view of Milano and Racz as applied to claim 32).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 2013/0265041 to Friedrich et al. relates to high accuracy differential current sensors and to high accuracy differential current sensors disposed on a single integrated circuit.
US 2015/0177339 to Ausserlechner et al. relates to current difference sensors suitable, for example, for sensing small current differences.
Shede et al.," 2017 Third International Conference on Sensing, Signal Processing and Security (ICSSS), Chennai, India, 2017, pp. 181-185 relates to an overview of leakage current sensing techniques.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DANIEL R MILLER whose telephone number is (571) 270-1964. The examiner can normally be reached 10AM-6PM EST M-F.
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/DANIEL R MILLER/Primary Examiner, Art Unit 2863