<?xml version="1.0" encoding="US-ASCII" standalone="no"?>
<!--Generated by ThunderDome XBRL - 05:41PM UTC 2026-08-14--><xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:apac="http://www.stonebridgespac.com/20260630" xmlns:country="http://xbrl.sec.gov/country/2026" xmlns:currency="http://xbrl.sec.gov/currency/2026" xmlns:dei="http://xbrl.sec.gov/dei/2026" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2020-01-21" xmlns:ecd="http://xbrl.sec.gov/ecd/2026" xmlns:enum2="http://xbrl.org/2020/extensible-enumerations-2.0" xmlns:exch="http://xbrl.sec.gov/exch/2026" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:naics="http://xbrl.sec.gov/naics/2026" xmlns:sic="http://xbrl.sec.gov/sic/2026" xmlns:srt="http://fasb.org/srt/2026" xmlns:srt-types="http://fasb.org/srt-types/2026" xmlns:stpr="http://xbrl.sec.gov/stpr/2026" xmlns:us-gaap="http://fasb.org/us-gaap/2026" xmlns:us-types="http://fasb.org/us-types/2026" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xlink="http://www.w3.org/1999/xlink" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.stonebridgespac.com/20260630">
  <xsd:import namespace="http://fasb.org/srt/2026" schemaLocation="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd"/>
  <xsd:import namespace="http://xbrl.sec.gov/ecd/2026" schemaLocation="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd"/>
  <xsd:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xsd:import namespace="http://xbrl.sec.gov/dei/2026" schemaLocation="https://xbrl.sec.gov/dei/2026/dei-2026.xsd"/>
  <xsd:import namespace="http://xbrl.sec.gov/exch/2026" schemaLocation="https://xbrl.sec.gov/exch/2026/exch-2026.xsd"/>
  <xsd:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
  <xsd:import namespace="http://xbrl.sec.gov/currency/2026" schemaLocation="https://xbrl.sec.gov/currency/2026/currency-2026.xsd"/>
  <xsd:import namespace="http://xbrl.sec.gov/country/2026" schemaLocation="https://xbrl.sec.gov/country/2026/country-2026.xsd"/>
  <xsd:import namespace="http://xbrl.sec.gov/naics/2026" schemaLocation="https://xbrl.sec.gov/naics/2026/naics-2026.xsd"/>
  <xsd:import namespace="http://www.xbrl.org/dtr/type/2020-01-21" schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/types.xsd"/>
  <xsd:import namespace="http://xbrl.org/2020/extensible-enumerations-2.0" schemaLocation="https://www.xbrl.org/2020/extensible-enumerations-2.0.xsd"/>
  <xsd:import namespace="http://xbrl.sec.gov/stpr/2026" schemaLocation="https://xbrl.sec.gov/stpr/2026/stpr-2026.xsd"/>
  <xsd:import namespace="http://xbrl.sec.gov/sic/2026" schemaLocation="https://xbrl.sec.gov/sic/2026/sic-2026.xsd"/>
  <xsd:import namespace="http://fasb.org/us-types/2026" schemaLocation="https://xbrl.fasb.org/us-gaap/2026/elts/us-types-2026.xsd"/>
  <xsd:import namespace="http://www.xbrl.org/2009/role/negated" schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd"/>
  <xsd:import namespace="http://fasb.org/srt-types/2026" schemaLocation="https://xbrl.fasb.org/srt/2026/elts/srt-types-2026.xsd"/>
  <xsd:import namespace="http://fasb.org/us-gaap/2026" schemaLocation="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd"/>
  <xsd:annotation>
    <xsd:appinfo>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="apac-20260630_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="apac-20260630_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="apac-20260630_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="apac-20260630_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="statement-document-and-entity-information" roleURI="http://www.stonebridgespac.com/20260630/role/statement-document-and-entity-information">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">000 - Document - Document And Entity Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-condensed-balance-sheets-unaudited" roleURI="http://www.stonebridgespac.com/20260630/role/statement-condensed-balance-sheets-unaudited">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">001 - Statement - Condensed Balance Sheets (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-condensed-balance-sheets-unaudited-parentheticals" roleURI="http://www.stonebridgespac.com/20260630/role/statement-condensed-balance-sheets-unaudited-parentheticals">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">002 - Statement - Condensed Balance Sheets (Unaudited) (Parentheticals)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-condensed-statements-of-operations-unaudited" roleURI="http://www.stonebridgespac.com/20260630/role/statement-condensed-statements-of-operations-unaudited">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">003 - Statement - Condensed Statements of Operations (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-condensed-statements-of-operations-unaudited-parentheticals" roleURI="http://www.stonebridgespac.com/20260630/role/statement-condensed-statements-of-operations-unaudited-parentheticals">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">004 - Statement - Condensed Statements of Operations (Unaudited) (Parentheticals)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-condensed-statements-of-changes-in-shareholders-equity-unaudited" roleURI="http://www.stonebridgespac.com/20260630/role/statement-condensed-statements-of-changes-in-shareholders-equity-unaudited">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">005 - Statement - Condensed Statements of Changes in Shareholders' Equity (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-condensed-statements-of-changes-in-shareholders-equity-unaudited-parentheticals" roleURI="http://www.stonebridgespac.com/20260630/role/statement-condensed-statements-of-changes-in-shareholders-equity-unaudited-parentheticals">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">006 - Statement - Condensed Statements of Changes in Shareholders' Equity (Unaudited) (Parentheticals)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-condensed-statements-of-cash-flows-unaudited" roleURI="http://www.stonebridgespac.com/20260630/role/statement-condensed-statements-of-cash-flows-unaudited">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">007 - Statement - Condensed Statements of Cash Flows (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-1-organization-and-plan-of-business-operations" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-1-organization-and-plan-of-business-operations">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">008 - Disclosure - Note 1 - Organization and Plan of Business Operations</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-2-summary-of-significant-accounting-policies" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-2-summary-of-significant-accounting-policies">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">009 - Disclosure - Note 2 - Summary of Significant Accounting Policies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-3-public-offering" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-3-public-offering">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">010 - Disclosure - Note 3 - Public Offering</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-4-private-placement" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-4-private-placement">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">011 - Disclosure - Note 4 - Private Placement</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-5-related-party-transactions-" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-5-related-party-transactions-">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">012 - Disclosure - Note 5 - Related Party Transactions</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-6-commitments" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-6-commitments">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">013 - Disclosure - Note 6 - Commitments</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-7-shareholders-equity" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-7-shareholders-equity">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">014 - Disclosure - Note 7 - Shareholder's Equity</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-8-segment-information" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-8-segment-information">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">015 - Disclosure - Note 8 - Segment Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-9-fair-value-measurements" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-9-fair-value-measurements">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">016 - Disclosure - Note 9 - Fair Value Measurements</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-10-subsequent-events" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-10-subsequent-events">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">017 - Disclosure - Note 10 - Subsequent Events</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-significant-accounting-policies-policies" roleURI="http://www.stonebridgespac.com/20260630/role/statement-significant-accounting-policies-policies">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995445 - Disclosure - Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-2-summary-of-significant-accounting-policies-tables" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-2-summary-of-significant-accounting-policies-tables">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995446 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-8-segment-information-tables" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-8-segment-information-tables">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995447 - Disclosure - Note 8 - Segment Information (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-9-fair-value-measurements-tables" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-9-fair-value-measurements-tables">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995448 - Disclosure - Note 9 - Fair Value Measurements (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-1-organization-and-plan-of-business-operations-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-1-organization-and-plan-of-business-operations-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995449 - Disclosure - Note 1 - Organization and Plan of Business Operations (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-2-summary-of-significant-accounting-policies-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-2-summary-of-significant-accounting-policies-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995450 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-2-summary-of-significant-accounting-policies-shares-subject-to-possible-redemption-details" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-2-summary-of-significant-accounting-policies-shares-subject-to-possible-redemption-details">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995451 - Disclosure - Note 2 - Summary of Significant Accounting Policies - Shares Subject to Possible Redemption (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-2-summary-of-significant-accounting-policies-net-income-per-ordinary-share-details" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-2-summary-of-significant-accounting-policies-net-income-per-ordinary-share-details">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995452 - Disclosure - Note 2 - Summary of Significant Accounting Policies - Net Income Per Ordinary Share (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-3-public-offering-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-3-public-offering-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995453 - Disclosure - Note 3 - Public Offering (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-4-private-placement-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-4-private-placement-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995454 - Disclosure - Note 4 - Private Placement (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-5-related-party-transactions-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-5-related-party-transactions-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995455 - Disclosure - Note 5 - Related Party Transactions (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-6-commitments-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-6-commitments-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995456 - Disclosure - Note 6 - Commitments (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-7-shareholders-equity-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-7-shareholders-equity-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995457 - Disclosure - Note 7 - Shareholder's Equity (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-8-segment-information-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-8-segment-information-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995458 - Disclosure - Note 8 - Segment Information (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-8-segment-information-schedule-of-segment-information-by-segment-details" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-8-segment-information-schedule-of-segment-information-by-segment-details">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995459 - Disclosure - Note 8 - Segment Information - Schedule of Segment Information By Segment (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-9-fair-value-measurements-details-textual" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-9-fair-value-measurements-details-textual">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995460 - Disclosure - Note 9 - Fair Value Measurements (Details Textual)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-9-fair-value-measurements-schedule-of-fair-value-hierarchy-details" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-9-fair-value-measurements-schedule-of-fair-value-hierarchy-details">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995461 - Disclosure - Note 9 - Fair Value Measurements - Schedule of Fair Value Hierarchy (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
      <link:roleType id="statement-note-9-fair-value-measurements-schedule-of-market-assumptions-details" roleURI="http://www.stonebridgespac.com/20260630/role/statement-note-9-fair-value-measurements-schedule-of-market-assumptions-details">
        <link:definition xmlns="http://www.xbrl.org/2003/linkbase">995462 - Disclosure - Note 9 - Fair Value Measurements - Schedule of Market Assumptions (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
      </link:roleType>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:element id="apac_AdjustmentsToAdditionalPaidInCapitalRemeasurementSharesToRedemptionValue" name="AdjustmentsToAdditionalPaidInCapitalRemeasurementSharesToRedemptionValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration"/>
  <xsd:element id="apac_BusinessCombinationCompletionPeriod" name="BusinessCombinationCompletionPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="instant"/>
  <xsd:element abstract="true" id="apac_CertainInvestorsMember" name="CertainInvestorsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_ClassAOrdinarySharesMember" name="ClassAOrdinarySharesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_DebtInstrumentMaximumAmount" name="DebtInstrumentMaximumAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant"/>
  <xsd:element id="apac_DeferredOfferingCostsAccruedThoughAccountsPayable" name="DeferredOfferingCostsAccruedThoughAccountsPayable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_DirectorsMember" name="DirectorsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_DocumentAndEntityInformation" name="DocumentAndEntityInformation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_EachDirectorsMember" name="EachDirectorsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_EmergingGrowthCompanyPolicyTextBlock" name="EmergingGrowthCompanyPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_EquityOfferingCashUnderwritingFeePerUnit" name="EquityOfferingCashUnderwritingFeePerUnit" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_EquityOfferingOptionMaximumSharesToBeIssued" name="EquityOfferingOptionMaximumSharesToBeIssued" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_EquityOfferingOptionPeriod" name="EquityOfferingOptionPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_EquityOfferingUnitsIssued" name="EquityOfferingUnitsIssued" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_ExpensesAndAccountsPayablePaid" name="ExpensesAndAccountsPayablePaid" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration"/>
  <xsd:element id="apac_FounderSharesLockupThresholdConsecutiveTradingDays" name="FounderSharesLockupThresholdConsecutiveTradingDays" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_FounderSharesLockupThresholdSharePrice" name="FounderSharesLockupThresholdSharePrice" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_FounderSharesLockupThresholdTradingDays" name="FounderSharesLockupThresholdTradingDays" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_FounderSharesMember" name="FounderSharesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_FounderSharesNotTransferrablePeriod" name="FounderSharesNotTransferrablePeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_IPOUnitWarrantsMember" name="IPOUnitWarrantsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_IndependentDirectorsMember" name="IndependentDirectorsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_JoelHuffmanMember" name="JoelHuffmanMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_MahboobSubuhaniMohamedMohideenMember" name="MahboobSubuhaniMohamedMohideenMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_MaximAndCertainThirdpartyInvestorsMember" name="MaximAndCertainThirdpartyInvestorsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_MaximumMonthlyReimbursement" name="MaximumMonthlyReimbursement" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant"/>
  <xsd:element abstract="true" id="apac_MeasurementInputProbabilityOfDeSPACAndInstrumentSpecificMarketAdjustmentMember" name="MeasurementInputProbabilityOfDeSPACAndInstrumentSpecificMarketAdjustmentMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_NoteToFinancialStatementDetailsTextual" name="NoteToFinancialStatementDetailsTextual" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_NotesToFinancialStatements" name="NotesToFinancialStatements" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_NotesToFinancialStatementsAbstract" name="NotesToFinancialStatementsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_NumberOfSharesAdjustedFromIssuance" name="NumberOfSharesAdjustedFromIssuance" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_NumberOfSharesPerUnitIssued" name="NumberOfSharesPerUnitIssued" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_NumberOfWarrantsPerUnit" name="NumberOfWarrantsPerUnit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant"/>
  <xsd:element abstract="true" id="apac_OfficeSpaceUtilitiesAndSecretarialAndAdministrativeSupportMember" name="OfficeSpaceUtilitiesAndSecretarialAndAdministrativeSupportMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_OwnershipPercentage" name="OwnershipPercentage" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:percentItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_PaymentsOfStockIssuanceCostsOther" name="PaymentsOfStockIssuanceCostsOther" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_PolicyTable" name="PolicyTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_PrivatePlacementTextBlock" name="PrivatePlacementTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_ProceedsFromIssuanceOfEquityDepositedInTrustAccount" name="ProceedsFromIssuanceOfEquityDepositedInTrustAccount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration"/>
  <xsd:element id="apac_ProceedsFromIssuanceOfEquityNotDepositedInTrustAccount" name="ProceedsFromIssuanceOfEquityNotDepositedInTrustAccount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_PromissoryNoteMember" name="PromissoryNoteMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_PublicRightsMember" name="PublicRightsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_RelatedPartiesPolicyTextBlock" name="RelatedPartiesPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_RepresentativeSharesMember" name="RepresentativeSharesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_RichardSaldanhaMember" name="RichardSaldanhaMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_RoshanBoodhooMember" name="RoshanBoodhooMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_ShareRightsPolicyTextBlock" name="ShareRightsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_SharesHeldByInvestors" name="SharesHeldByInvestors" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_SharesHeldInTrustAccountRedemptionPrice" name="SharesHeldInTrustAccountRedemptionPrice" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_SharesRedemptionPeriodTerm" name="SharesRedemptionPeriodTerm" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_SharesRedemptionPeriodTermExtension" name="SharesRedemptionPeriodTermExtension" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_SharesSubjectToForfeiture" name="SharesSubjectToForfeiture" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant"/>
  <xsd:element abstract="true" id="apac_SingleReportableSegmentMember" name="SingleReportableSegmentMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_SponsorMember" name="SponsorMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_StockIssuableDuringPeriodShares" name="StockIssuableDuringPeriodShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_StockIssuedDuringPeriodSharesSharesForfeited" name="StockIssuedDuringPeriodSharesSharesForfeited" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_StockSurrenderedDuringPeriodShares" name="StockSurrenderedDuringPeriodShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_StocksIssuedAndTransferred" name="StocksIssuedAndTransferred" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_ThirdPartyInvestorsMember" name="ThirdPartyInvestorsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_TrustCovenantDepositThreeMonthExtension" name="TrustCovenantDepositThreeMonthExtension" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant"/>
  <xsd:element id="apac_TrustCovenantDepositThreeMonthExtensionPerShare" name="TrustCovenantDepositThreeMonthExtensionPerShare" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_TrustCovenantDepositThreeMonthExtensionPostDeadline" name="TrustCovenantDepositThreeMonthExtensionPostDeadline" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant"/>
  <xsd:element id="apac_TrustCovenantDepositThreeMonthExtensionPostDeadlinePerShare" name="TrustCovenantDepositThreeMonthExtensionPostDeadlinePerShare" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_TrustCovenantMaximumWithdrawableForDissolutionExpenses" name="TrustCovenantMaximumWithdrawableForDissolutionExpenses" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant"/>
  <xsd:element id="apac_TrustPricePerShare" name="TrustPricePerShare" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" xbrli:periodType="instant"/>
  <xsd:element abstract="true" id="apac_UnderwritersMember" name="UnderwritersMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_UnitsIssuedDuringPeriodShares" name="UnitsIssuedDuringPeriodShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_UnitsMember" name="UnitsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="apac_WarrantsAndRightsOutstandingFairValuePerShare" name="WarrantsAndRightsOutstandingFairValuePerShare" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" xbrli:periodType="instant"/>
  <xsd:element id="apac_WorkingCapitalDeficit" name="WorkingCapitalDeficit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant"/>
  <xsd:element abstract="true" id="apac_WorkingCapitalLoansMember" name="WorkingCapitalLoansMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-2-summary-of-significant-accounting-policies-net-income-per-ordinary-share-details" name="statement-statement-note-2-summary-of-significant-accounting-policies-net-income-per-ordinary-share-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-2-summary-of-significant-accounting-policies-net-income-per-ordinary-share-detailsA1999AE7-504C-4615-82D7-929B301A311C" name="statement-statement-note-2-summary-of-significant-accounting-policies-net-income-per-ordinary-share-detailsA1999AE7-504C-4615-82D7-929B301A311C" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-2-summary-of-significant-accounting-policies-shares-subject-to-possible-redemption-details" name="statement-statement-note-2-summary-of-significant-accounting-policies-shares-subject-to-possible-redemption-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-2-summary-of-significant-accounting-policies-tables" name="statement-statement-note-2-summary-of-significant-accounting-policies-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-8-segment-information-schedule-of-segment-information-by-segment-details" name="statement-statement-note-8-segment-information-schedule-of-segment-information-by-segment-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-8-segment-information-schedule-of-segment-information-by-segment-details2DD39D4A-D6DB-4A50-A987-0552A620A32A" name="statement-statement-note-8-segment-information-schedule-of-segment-information-by-segment-details2DD39D4A-D6DB-4A50-A987-0552A620A32A" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-8-segment-information-tables" name="statement-statement-note-8-segment-information-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-9-fair-value-measurements-schedule-of-fair-value-hierarchy-details" name="statement-statement-note-9-fair-value-measurements-schedule-of-fair-value-hierarchy-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-9-fair-value-measurements-schedule-of-fair-value-hierarchy-details16D06D58-9F6D-4E8A-958B-729EF1F43731" name="statement-statement-note-9-fair-value-measurements-schedule-of-fair-value-hierarchy-details16D06D58-9F6D-4E8A-958B-729EF1F43731" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-9-fair-value-measurements-schedule-of-market-assumptions-details" name="statement-statement-note-9-fair-value-measurements-schedule-of-market-assumptions-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-note-9-fair-value-measurements-tables" name="statement-statement-note-9-fair-value-measurements-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="apac_statement-statement-significant-accounting-policies-policies" name="statement-statement-significant-accounting-policies-policies" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
</xsd:schema>
