DETAILED ACTION
This office action addresses Applicant’s response filed on 2 January 2026. Claims 1-19 are pending.
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
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.
Claim(s) 1 is/are rejected under 35 U.S.C. 103 as being unpatentable over Teig (US 7,310,793) in view of Apte (US 2023/0214571).
Regarding claim 1, Teig discloses a method of routing an integrated circuit design, the method comprising performing a first detailed routing for a first plurality of nets to define a first plurality of detailed routes traversing a first set of N layers of the design (col. 5, lines 31-35; col. 7, lines 3-9); performing global routing to define global routes for a second plurality of nets and after the global routing, performing a second detailed routing for the second plurality of nets to define a second plurality of detailed routes traversing a second set of M layers of the IC design (col. 1, lines 33-38; col. 2, lines 20-26).
Teig does not appear to explicitly disclose that the first detailed routing is performed without first performing global routing for the first plurality of nets; Apte discloses these limitations (¶18). It would have been obvious to persons having ordinary skill in the art before the effective filing date of the application to combine the teachings of Teig and Apte, because doing so would have involved merely the routine use of a known technique to improve similar devices in the same way to achieve the predictable results of flexible detailed routing without the need for global routing. KSR Int’l Co. v. Teleflex Inc., 82 U.S.P.Q.2d 1385, 1396. Teig discloses preferred direction and non-preferred-direction detailed routing. Apte teaches non-preferred-direction detailed routing that provides additional flexibility and does not require global routing. The teachings of Apte are directly applicable to Teig in the same way, so that Teig would similarly perform non-preferred-direction detailed routing with more flexibility and without needing global routing beforehand.
Claim(s) 2-13, and 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Teig in view of Apte and Ruic (US 2023/0297756).
Regarding claim 2, Teig does not appear to explicitly disclose that the first set of N layers is below the second set of M layers. However, Teig discloses the first and second set of layers being arbitrary (col. 4, lines 26-30), and Ruic discloses that the first set of N layers is below the second set of M layers (Figs. 5A-B and 6A-C; persons having ordinary skill in the art would recognize the drawings as showing transistors and the lower wiring layers closer to the transistors).
It would have been obvious to persons having ordinary skill in the art before the effective filing date of the application to combine the teachings of Teig, Apte, and Ruic, because doing so would have involved merely the routine use of a known technique to improve similar devices in the same way to achieve the predictable results of allowing flexible routing of lower wiring layers. KSR Int’l Co. v. Teleflex Inc., 82 U.S.P.Q.2d 1385, 1396. Teig discloses preferred direction and non-preferred-direction detailed routing. Apte teaches freeform non-preferred-direction detailed routing, which Ruic teaches is performed in the lower wiring layers. The teachings of Apte and Ruic are directly applicable to Teig in the same way, so that Teig would similarly perform non-preferred-direction detailed routing of lower wiring layers with more flexibility.
Regarding claim 3, Teig discloses a method of routing an integrated circuit design that includes a first set of N routing layers and a second set of M routing layers, wherein each of the second set of M layers has one or more preferred wiring direction (col. 6, lines 26-35), the method comprising:
performing a non-preferred direction (NPD) first detailed routing for a first plurality of nets to define a first plurality of detailed routes traversing the first set of routing N layers of the design (col. 5, lines 31-35; col. 7, lines 3-9);
performing global routing to define global routes for a second plurality of nets and after the global routing, performing a preferred direction (PD) second detailed routing for the second plurality of nets to define a second plurality of detailed routes traversing the second set of M layers of the IC design (col. 1, lines 33-38; col. 2, lines 20-26), wherein the second plurality of detailed routes comprises a plurality of PD rectilinear routes defined by reference to preferred routing directions of the second set of M routing layers (col. 6, lines 26-35).
Teig does not appear to explicitly disclose that the first detailed routing is performed without first performing global routing for the first plurality of nets, and that the first plurality of detailed routes comprises a plurality of NPD curvilinear routes; Apte discloses these limitations (¶18). Motivation to combine remains consistent with claim 1.
Teig does not appear to explicitly disclose the second set of M routing layers being above the first set of N routing layers. However, Teig discloses the first and second set of layers being arbitrary (col. 4, lines 26-30), and Ruic discloses that the first set of N layers is below the second set of M layers (Figs. 5A-B and 6A-C; persons having ordinary skill in the art would recognize the drawings as showing transistors and the lower wiring layers closer to the transistors). Motivation to combine remains consistent with claim 2.
Regarding claim 4, Teig discloses that the global routes are defined by reference to the preferred routing directions of the second set of M layers (col. 7, lines 21-23).
Regarding claim 5, Teig does not appear to explicitly disclose that the detailed routing for the first N layers is curvilinear detailed routing; Apte discloses these limitations (¶18). Motivation to combine remains consistent with claim 1.
Regarding claim 6, Teig does not appear to explicitly disclose that curvilinear detailed routing has more than eight preferred directions of routing; Apte discloses these limitations (¶18). Motivation to combine remains consistent with claim 1.
Regarding claim 7, Teig does not appear to explicitly disclose that the curvilinear detailed routing defines a set of routes each of which has at least one curvilinear edge; Apte discloses these limitations (¶18). Motivation to combine remains consistent with claim 1.
Regarding claim 8, Teig discloses that the global and detailed routing for the set of M layers uses Manhattan preferred directions (col. 6, lines 30-31).
Regarding claim 9, Teig discloses that the global and detailed routing for the set of M layers uses up to eight preferred directions of routing (Fig. 1).
Regarding claim 10, Teig does not appear to explicitly disclose that the first set of N layers comprises the first two wiring layers of the IC design, and the second set of M layers comprises wiring layer three and higher wiring layers of the IC design; Ruic discloses these limitations (Figs. 5A-B and 6A-C). As discussed above, Ruic illustrates freeform routing on lower wiring layers, and Teig discloses that a design can have preferred direction routing on other layers (col. 4, lines 26-30). Motivation to combine remains consistent with claim 2.
Regarding claim 11, Teig does not appear to explicitly disclose that the first set of N layers comprises the third and fourth wiring layers of the IC design, and the second set of M layers comprises wiring layers higher than the fourth wiring layer. However, as discussed above, Teig discloses the first and second set of layers being arbitrary (col. 4, lines 26-30), and thus encompasses embodiments where the first set and second set comprise any layers, and Ruic also discloses the first set of layers being lower wiring layers (Figs. 5A-B and 6A-C). Persons having ordinary skill in the art would recognize that the first and second set of layers would be chosen by designers as needed/preferred for a given design. Motivation to combine remains consistent with claim 2.
Regarding claim 12, Teig does not appear to explicitly disclose that the first set of N layers comprises the first, second, third and fourth wiring layers of the IC design, and the second set of M layers comprises wiring layers higher than the fourth wiring layer. However, as discussed above, Teig discloses the first and second set of layers being arbitrary (col. 4, lines 26-30), and thus encompasses embodiments where the first set and second set comprise any layers, and Ruic also discloses the first set of layers being lower wiring layers (Figs. 5A-B and 6A-C). Persons having ordinary skill in the art would recognize that the first and second set of layers would be chosen by designers as needed/preferred for a given design. Motivation to combine remains consistent with claim 2.
Regarding claim 13, Teig discloses that the first detailed routing is a non-preferred direction (NPD) detailed routing operation, and wherein the second detailed routing is a preferred direction (PD) detailed routing operation, and the second plurality of detailed routes comprises a plurality of rectilinear routes traversing along preferred wiring directions of the second set of wiring layers (col. 6, lines 26-35).
Teig does not appear to explicitly disclose that the first plurality of detailed routes comprises a plurality of NPD curvilinear routes; Apte discloses these limitations (¶18). Motivation to combine remains consistent with claim 1.
Regarding claim 15, Teig discloses that the set of first N layers include more than the first two wiring layers of the IC design (col. 6, lines 26-35). Furthermore, as discussed above, Ruic teaches the first set of layers as include at least the first two wiring layers of the IC design (Figs. 5A-B and 6A-C), and Teig discloses the first and second set of layers being arbitrary (col. 4, lines 26-30), and thus encompasses embodiments where the first set and second set comprise any layers. Persons having ordinary skill in the art would recognize that the first and second set of layers would be chosen by designers as needed/preferred for a given design.
Claim(s) 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Teig in view of Apte, Ruic, and Hetzel (US 2005/0229134).
Regarding claim 14, Teig does not appear to explicitly disclose that the first and second wiring layers each has a plurality of regions with preferred direction rectilinear routes for pre-defined IP (intellectual property) circuit blocks, and the curvilinear routes on the first and second wiring layers are defined between the regions used for the PD rectilinear routes for the IP circuit blocks; Hetzel discloses these limitations (Fig. 4B; ¶39). Specifically, as discussed above with regard to claims 10-12, Teig in view of Apte and Ruic disclose curvilinear routing on first and second wiring layers, and Hetzel discloses specifying PD rectilinear routing regions for IP blocks on each layer, so the combination of Teig, Apte, Ruic, and Hetzel suggests first and second wiring layers with PD rectilinear regions for IP blocks (per Hetzel), and otherwise routing the layers with curvilinear routes (per Apte and Ruic).
It would have been obvious to persons having ordinary skill in the art before the effective filing date of the application to combine the teachings of Teig, Apte, Ruic, and Hetzel, because doing so would have involved merely the routine use of a known technique to improve similar devices in the same way to achieve the predictable results of setting IP block routing regions to improve routing around blockages. KSR Int’l Co. v. Teleflex Inc., 82 U.S.P.Q.2d 1385, 1396. Teig discloses routing on first and second layers, which Apte and Ruic teach is curvilinear routing. Hetzel teaches that the layers should have PD rectilinear routing regions for IP blocks. The teachings of Hetzel are directly applicable to Teig in the same way, so that Teig would similarly include PD rectilinear routing regions for IP blocks to allow routing around blockages.
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Teig in view of Apte and Sharp (US 6,480,990).
Regarding claim 16, Teig does not appear to explicitly disclose that the set of first N layers includes first and second subset of layers, wherein performing the detailed routing for the set of first N layers comprises: performing a first detailed routing operations for a first set of nets to define detailed routes that traverse the first subset of layers of the first N layers but not the second subset of layers; and after completing the first detailed routing operation, performing a second detailed routing operation for a second set of nets to define detailed routes that traverse the second subset of layers of the first N layers. Sharp discloses these limitations (col. 9, lines 5-18). It would have been obvious to persons having ordinary skill in the art before the effective filing date of the application to combine the teachings of Teig, Apte, and Sharp, because doing so would have involved merely the routine combination of known elements according to known techniques to produce merely the predictable results of routing multiple layers successively. KSR Int’l Co. v. Teleflex Inc., 82 U.S.P.Q.2d 1385, 1395. Teig discloses routing on multiple layers. Sharp teaches that the multiple layers are routed successively. The teachings of Sharp are directly applicable to Teig in the same way, so that Teig would similarly route the multiple layers successively.
Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Teig in view of Apte, Sharp, and Cobb (US 5,187,671).
Regarding claim 17, Teig does not appear to explicitly disclose that performing the first and second detailed routing operations comprise using a detailed router to perform the first detailed routing operation, and then recursively calling the detailed router to perform the second detailed routing operation. As discussed above with regard to claim 16, Sharp discloses performing the first detailed routing operation and then performing the second detailed routing operation (col. 9, lines 5-18); motivation to combine remains consistent with claim 16. Cobb further discloses recursively calling the detailed router to perform the second detailed routing operation (col. 9, lines 16-38). It would have been obvious to persons having ordinary skill in the art before the effective filing date of the application to combine the teachings of Teig, Apte, Sharp, and Cobb, because doing so would have involved merely the routine combination of known elements according to known techniques to produce merely the predictable results of correctly routing a design. KSR Int’l Co. v. Teleflex Inc., 82 U.S.P.Q.2d 1385, 1395. Teig discloses detailed routing of a design. Cobb teaches that detailed routing is performed by recursively calling a detailed router. The teachings of Cobb are directly applicable to Teig in the same way, so that Teig would similarly perform detailed routing by recursively calling a detailed router to correctly route a design.
Claim(s) 18 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Teig in view of Apte, Ruic, Liu (US 11,132,489), and Sharp.
Regarding claim 18, Teig discloses a method of routing an integrated circuit design that includes a first set of N routing layers and a second set of M routing layers (col. 6, lines 26-35), the method comprising: performing a first detailed routing for a first plurality of nets until a first plurality of detailed routes traversing a first set of N layers of the design are defined for a first plurality of nets (col. 5, lines 31-35; col. 7, lines 3-9); and
for a remaining second plurality of the nets in the order that do not have a detailed route defined through the first detailed routing operation: performing global routing to define global routes for the second plurality of nets and after the global routing, performing a second detailed routing operation for the second plurality of nets to define a second plurality of detailed routes traversing a second set of M layers of the IC design (col. 1, lines 33-38; col. 2, lines 20-26).
Teig does not appear to explicitly disclose that the first detailed routing is performed without first performing global routing for the first plurality of nets; Apte discloses these limitations (¶18). Motivation to combine remains consistent with claim 1.
Teig does not appear to explicitly disclose the second set of M routing layers being above the first set of N routing layers. However, Teig discloses the first and second set of layers being arbitrary (col. 4, lines 26-30), and Ruic discloses that the first set of N layers is below the second set of M layers (Figs. 5A-B and 6A-C; persons having ordinary skill in the art would recognize the drawings as showing transistors and the lower wiring layers closer to the transistors). Motivation to combine remains consistent with claim 2.
Teig does not appear to explicitly disclose sorting a set of nets in an ascending order of size of the nets; based on the order, iteratively selecting nets and performing routing operations for the selected nets. Liu discloses these limitations (col. 6, line 63 to col. 7, line 8). It would have been obvious to persons having ordinary skill in the art before the effective filing date of the application to combine the teachings of Teig, Apte, Ruic, and Liu, because doing so would have involved merely the routine use of a known technique to improve similar devices in the same way to achieve the predictable results of assigning nets to appropriate layers to improve timing and reduce errors. KSR Int’l Co. v. Teleflex Inc., 82 U.S.P.Q.2d 1385, 1396. Teig discloses routing nets on a plurality of layers. Liu teaches that the nets should be sorted and assigned to layers based on size to improve timing and reduce errors. The teachings of Liu are directly applicable to Teig in the same way, so that Teig would similarly assign nets to layers based on size to improve timing and reduce errors.
If Teig in view of Liu is found to be unclear regarding iteratively selecting and routing nets, Sharp discloses the same (col. 9, lines 5-18). It would have been obvious to persons having ordinary skill in the art before the effective filing date of the application to combine the teachings of Teig, Apte, Ruic, Liu, and Sharp, because doing so would have involved merely the routine combination of known elements according to known techniques to produce merely the predictable results of routing multiple layers successively. KSR Int’l Co. v. Teleflex Inc., 82 U.S.P.Q.2d 1385, 1395. Teig discloses routing on multiple layers. Sharp teaches that the multiple layers are routed successively. The teachings of Sharp are directly applicable to Teig in the same way, so that Teig would similarly route the multiple layers successively.
Regarding claim 19, Teig does not appear to explicitly disclose computing an estimate wire length for each net, said wire lengths used to quantify the size of each nets; Liu discloses these limitations (col. 6, lines 60-62).
Response to Arguments
Applicant's arguments filed 2 January 2026 have been fully considered but they are not persuasive.
Applicant asserts that the prior art fails to teach detailed routing without global routing for a first set of layers and using both global and detailed routing for a second set of layers. Remarks 8. The examiner disagrees. Teig discloses performing non-Manhattan detailed routing on a first set of layers, global routing, and preferred-direction detailed routing on a second set of layers. Apte discloses a non-Manhattan router that does not require global routing. Persons having ordinary skill in the art, reading Teig and Apte, would clearly recognize that Apte’s detailed router would be used for the non-Manhattan detailed routing of Teig, thus routing the first set of layers without performing global routing, as claimed.
Applicant asserts that the prior art fails to teach amended limitations of claims 3 and 18. Remarks 9. The amended claims are addressed above under new grounds of rejection.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ARIC LIN whose telephone number is (571)270-3090. The examiner can normally be reached M-F 07:30-17:00 ET.
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7 February 2026
/ARIC LIN/ Examiner, Art Unit 2851
/JACK CHIANG/ Supervisory Patent Examiner, Art Unit 2851