<PAGE>

                                                                 EXHIBIT 10.1.15

                        EIGHTH AMENDMENT AND FIFTH WAIVER

               EIGHTH AMENDMENT AND FIFTH WAIVER, dated as of December 31, 2002
(this "Amendment"), to and under the Amended and Restated Credit and Guarantee
Agreement, dated as of July 27, 2000 (as heretofore amended, supplemented or
otherwise modified, the "Credit Agreement"), among SMTC Corporation
("Holdings"), HTM Holdings, Inc. (the "U.S. Borrower"), SMTC Manufacturing
Corporation of Canada (the "Canadian Borrower"; together with the U.S. Borrower,
the "Borrowers"), the several banks and other financial institutions or entities
from time to time parties thereto (the "Lenders"), Lehman Brothers Inc., as
advisor, lead arranger and book manager, The Bank of Nova Scotia, as syndication
agent, Lehman Commercial Paper Inc., as general administrative agent (in such
capacity, the "General Administrative Agent"), The Bank of Nova Scotia, as
Canadian administrative agent, Lehman Commercial Paper Inc., as collateral
monitoring agent, and General Electric Capital Corporation, as documentation
agent.

                              W I T N E S S E T H:

               WHEREAS, Holdings and the Borrowers requested that the Lenders
amend, and agree to waive, certain of the provisions of the Credit Agreement;
and

               WHEREAS, the Lenders have consented to the requested amendments
and waivers in the manner set forth below;

               NOW, THEREFORE, in consideration of the premises and the material
covenants herein contained, the parties hereto hereby agree as follows:

               1.   Defined Terms. Terms used herein and defined in the Credit
Agreement are used herein as therein defined.

               2.   Waivers of Events of Default. The Lenders hereby waive the
Defaults and Events of Default arising by reason of (a) the failure of Holdings
and the Borrowers to comply with the provisions of Section 7.5(g)(ii) of the
Credit Agreement for any period prior to the Amendment Effective Date (as
defined below), (b) any representation and warranty made by any Borrower, in
connection with any extension of credit under the Credit Agreement between June
30, 2002 and the Amendment Effective Date, to the effect that no Default or
Event of Default had occurred by reason of the failure of Holdings and the
Borrowers to comply with the provisions of Section 7.5(g)(ii) of the Credit
Agreement or (c) any failure of Holdings or any Borrower to give notice under
the Credit Agreement of the failure of Holdings and the Borrowers to comply with
the provisions of Section 7.5(g)(ii) of the Credit Agreement.

               3.   Amendment to Section 1.1 of the Credit Agreement (Defined
Terms). Section 1.1 of the Credit Agreement is hereby amended as follows:

               (a)  the definition of "Canadian Revolving Credit Commitment" is
          hereby amended by adding at the end thereof the following: "The
          aggregate amount of the

<PAGE>


                                                                               2

          Canadian Revolving Credit Commitments on the Eighth Amendment
          Effective Date is U.S.$7,593,750.";

               (b)  the definition of "Consolidated EBITDA" is hereby amended by
          (i) deleting "and" immediately prior to clause (n) thereof and
          substituting in lieu thereof a comma and (ii) adding immediately after
          clause (n) thereof the following:

               "and (o) incremental costs incurred by Holdings and its
               Subsidiaries during such period pursuant to the Eighth Amendment
               (including the fees and expenses of FTI Consulting, Simpson
               Thacher & Bartlett and any other advisors to the Lenders) and all
               fees and expenses of a strategic advisor engaged by Holdings and
               approved by the Lenders (such approval not to be unreasonably
               withheld),";

               (c)  the definition of "Eligible Accounts" is hereby amended by
          adding at the end thereof the following:

               "It being understood that Eligible Accounts (i) shall not include
               (x) any unissued credits, (y) Accounts which are owed by account
               debtors located outside the United States and Canada unless,
               subject to clause (z) below, a security interest (or the
               substantial equivalent thereof under appropriate local law as
               acceptable to the Required Lenders), is perfected under local law
               to the satisfaction of the General Administrative Agent and (z)
               Accounts payable to a Subsidiary of Holdings formed under the
               laws of Mexico or owed by account debtors located in Mexico and
               (ii) shall include Accounts payable by International Business
               Machines Corporation ("IBM") net of accounts payable by any Loan
               Party to IBM that are overdue more than 30 days and may be set
               off in accordance with the supply contract between IBM and
               Holdings as in effect on the Eighth Amendment Effective Date.";

               (d)  the definition of "Eligible Inventory" is hereby amended by
          adding at the end thereof the following

               "It being understood that Eligible Inventory shall not include
               (x) parts Inventory, (y) Inventory located at hubs outside the
               United States, Ireland and Canada and in transit other than up to
               the $500,000 of Inventory in transit permitted under clause (d)
               above and (z) Inventory located in Mexico or owned by a
               Subsidiary of Holdings formed under the laws of Mexico.";

               (e)  the definition of "Swing Line Lender" is hereby amended by
          deleting the proviso therein in its entirety and substituting in lieu
          thereof the following:

               "provided, however, that at any time after the Eighth Amendment
               Effective Date, the term "Swing Line Lender" shall mean Lehman
               Commercial Paper Inc., in its capacity as the lender of Swing
               Line Loans";

<PAGE>

                                                                               3

               (f)  the definition of "U.S. Revolving Credit Commitment" is
          hereby amended by adding at the end thereof the following: "The
          aggregate amount of the U.S Revolving Credit Commitments on the Eighth
          Amendment Effective Date is U.S.$82,406,250.";

               (g)  deleting in their entirety the definitions of "Advance Rate"
          and "Borrowing Base"; and

               (h)  inserting the following new defined terms in their correct
          alphabetical order:

                    ""Advance Rate": (i) with respect to Eligible Accounts, 85%,
               and (ii) with respect to Eligible Inventory, valued on a
               first-in, first-out basis (at the lower of cost or market), 65%.

                    "Availability Adjustment": at any time, the sum of (a) the
               aggregate amount of scheduled amortization payments on the Term
               Loans made by the U.S. Borrower at such time on and after
               December 31, 2002, and (b) 65% of Inventory of the Borrowers and
               their Subsidiaries and located in Mexico at such time which
               satisfies all of the requirements of the definition of Eligible
               Inventory in this Section 1.1; provided, however, that for the
               period from the Eighth Amendment Effective Date through and
               ending 90 days thereafter, such Inventory shall not be required
               to satisfy the requirements set forth in subsections (b) and (h)
               of such definition (and thereafter shall be required to satisfy
               such requirements in the manner provided in Section 10.13)."

                    "Borrowing Base": with respect to the Borrowers, on any date
               of determination, the sum (without duplication) of (i) the
               product of (A) the aggregate outstanding Eligible Accounts of the
               Borrowers and their Subsidiaries on such date and (B) the
               applicable Advance Rate, plus (ii) the product of (x) the
               aggregate Eligible Inventory of the Borrowers and their
               Subsidiaries on such date, and (y) the applicable Advance Rate;
               provided, that not more than 50% of the Borrowing Base of the
               Borrowers may be attributable to Eligible Inventory. The
               Borrowing Base shall be as set forth in the most recent Borrowing
               Base Certificate delivered by the Borrowers absent manifest
               error; such Borrowing Base so determined shall remain in effect
               until the next determination thereof pursuant to this sentence.

                    "Borrowing Formula": at any time, the amount equal to (a)
               the Borrowing Base at such time, plus (b) the Availability
               Adjustment at such time, plus (c) on any day of any month set
               forth on Schedule 1.1A , the amount set forth opposite such month
               on such Schedule, plus (d) cash on deposit in the bank accounts
               of the Borrower and its Subsidiaries at such time, less (e) the
               amount equal to the checks written and automated clearinghouse
               debits requested that have not been paid or debited at such time
               against the bank accounts of the Borrowers (it being understood
               that on the last day of each calendar month, the Borrowers shall
               also be in compliance with the covenant contained in Section
               11.1(g)), plus (f) the amount by which the expenses associated
               with the Eighth Amendment (as

<PAGE>

                                                                               4

               described by the Borrower in reasonable detail to the Lenders)
               exceeds the amount for such expenses included in the Borrower's
               Business Plan.

                    "Cash Restructuring Costs": consists of the following to the
               extent paid in cash: (a) severance costs associated with
               operations of Holdings and its Subsidiaries which have been
               discontinued ("Discontinued Operations"); (b) costs associated
               with the physical relocation of equipment in connection with
               Discontinued Operations, and (c) staff site visits in connection
               with Discontinued Operations.

                    "Eighth Amendment": the Eighth Amendment and Fifth Waiver,
               dated as of December 31, 2002, to and under this Agreement.

                    "Eighth Amendment Effective Date": the Amendment Effective
               Date under and as defined in the Eighth Amendment.

                    "Quarterly Budget": as defined in Section 10.2(j).

                    "Registration Rights Agreement": the Amended and Restated
               Registration Rights Agreement, substantially in the form of
               Exhibit C to the Eighth Amendment, to be entered into pursuant to
               the Eighth Amendment.

                    "Total Revolving Extensions of Credit": as defined in
               Section 11.1(f)(i).

                    "Warrant Agreement": the Warrant Agreement, substantially in
               the form of Exhibit B to the Eighth Amendment, to be entered into
               pursuant to the Eighth Amendment.".

               4.   Amendment to Section 2.4 of the Credit Agreement (U.S.
Revolving Commitments). Section 2.4(a) of the Credit Agreement is hereby amended
by deleting clause (B) in the first sentence thereof and substituting in lieu
thereof the following:

          "(B) the Aggregate U.S. Revolving Extensions of Credit, when added to
          the Aggregate Canadian Revolving Extensions of Credit, would not
          exceed the Borrowing Formula.".

               5.   Amendment to Section 2.6 of the Credit Agreement (Swing Line
Commitment). Section 2.6(a) of the Credit Agreement is hereby amended by:

               (a)  deleting clause (iii)(B) in the proviso in the first
          sentence thereof and substituting in lieu thereof the following:

               "(B) the Aggregate U.S. Revolving Extensions of Credit, when
               added to the Aggregate Canadian Revolving Extensions of Credit,
               would not exceed the Borrowing Formula"; and

               (b)  deleting the second sentence thereof and substituting in
          lieu thereof the following:

<PAGE>

                                                                               5

               "Notwithstanding anything to the contrary contained in the
               preceding sentence, at any time after the Eighth Amendment
               Effective Date, Lehman Commercial Paper Inc. shall be the only
               Swing Line Lender.".

               6.   Amendment to Section 2.7(a) of the Credit Agreement
(Procedure for Swing Line Borrowing; Refunding of Swing Line Loans). Section
2.7(a) of the Credit Agreement is hereby amended by (a) deleting the phrase
"1:30 P.M., New York City time (or, during the Fourth Amendment Waiver Period,
3:00 P.M., New York City time)" in the first sentence thereof and substituting
in lieu thereof "3:00 P.M., New York City time" and (b) deleting the phrase
"3:00 P.M., New York City time (or, during the Fourth Amendment Waiver Period,
4:30 P.M., New York City time)" in the third sentence thereof and substituting
in lieu thereof "4:30 P.M., New York City time".

               7.   Amendment to Section 5.1 of the Credit Agreement (Canadian
Revolving Commitments). Section 5.1(a) of the Credit Agreement is hereby amended
by deleting clause (B) in the first sentence thereof and substituting in lieu
thereof the following:

          "(B) the Aggregate Canadian Revolving Extensions of Credit, when added
          to the Aggregate U.S. Revolving Extensions of Credit, would not exceed
          the Borrowing Formula.".

               8.   Amendment to Section 5.6 of the Credit Agreement (Acceptance
Commitments). Section 5.6(a) of the Credit Agreement is hereby amended by
deleting clause (ii) therein and substituting in lieu thereof the following:

          "(ii) the Aggregate Canadian Revolving Extensions of Credit, when
          added to the Aggregate U.S. Revolving Extensions of Credit, would not
          exceed the Borrowing Formula.".

               9.   Amendment to Section 5.14 of the Credit Agreement (Canadian
Swing Line Commitment). Section 5.14(a) of the Credit Agreement is hereby
amended by deleting clause (ii)(B) in the proviso in the first sentence thereof
and substituting in lieu thereof the following:

          "(B) the Aggregate Canadian Revolving Extensions of Credit, when added
          to the Aggregate U.S. Revolving Extensions of Credit, would not exceed
          the Borrowing Formula.".

               10.  Amendment to Section 6.1 of the Credit Agreement (L/C
Commitments). Section 6.1 of the Credit Agreement is hereby amended as follows:

               (a)  Section 6.1(a) of the Credit Agreement is hereby amended by:

                    (i)    deleting clause (iii) in the first proviso in the
          first sentence thereof and substituting in lieu thereof the following:

<PAGE>

                                                                               6

                    "(iii) the Aggregate U.S. Revolving Extensions of Credit,
               when added to the Aggregate Canadian Revolving Extensions of
               Credit, would exceed the Borrowing Formula"; and

                    (ii)   deleting the following proviso at the end of the
          second sentence thereof:

               ", provided, further, that, notwithstanding anything to the
               contrary contained in this Section 6.1(a), with respect to any
               U.S. Letter of Credit issued or extended at any time on or after
               the Fourth Amendment Effective Date, such U.S. Letter of Credit
               shall expire no later than December 31, 2002"; and

               (b)  Section 6.1(b) of the Credit Agreement is hereby amended by:

                    (i)    deleting clause (iii) in the first proviso in the
          first sentence thereof and substituting in lieu thereof the following:

               "(iii) the Aggregate Canadian Revolving Extensions of Credit,
               when added to the Aggregate U.S. Revolving Extensions of Credit,
               would exceed the Borrowing Formula"; and

                    (ii)   deleting the following proviso at the end of the
          second sentence thereof:

               ", provided, further, that, notwithstanding anything to the
               contrary contained in this Section 6.1(b), with respect to any
               Canadian Letter of Credit issued or extended at any time on or
               after the Fourth Amendment Effective Date, such Canadian Letter
               of Credit shall expire no later than December 31, 2002".

               11.  Amendment to Section 7.5 of the Credit Agreement (Mandatory
Prepayments; Application of Prepayments). Section 7.5(g) of the Credit Agreement
is hereby amended by:

               (a)  Amending paragraph (g)(i) by:

                    (i)    deleting the clause "the lesser of (A) the Borrowing
          Base of the U.S. Borrower and (B)" therein; and

                    (ii)   deleting the phrase "Borrowing Base of the U.S.
          Borrower" in the second proviso therein and substituting in lieu
          thereof "the U.S. Revolving Credit Commitments then in effect";

               (b)  Amending paragraph (g)(ii) by:

                    (i)    deleting the clause "the lesser of (A) the Borrowing
          Base of the Canadian Borrower and (B)" therein; and

<PAGE>

                                                                               7

                    (ii)   deleting the phrase "Borrowing Base of the Canadian
          Borrower" in the second proviso therein and substituting in lieu
          thereof "the Canadian Revolving Credit Commitments then in effect";
          and

               (c)  adding at the end of such Section the following new
          paragraph (iii):

                    (iii) If, at any time during the U.S. Revolving Credit
               Commitment Period or the Canadian Revolving Credit Commitment
               Period for a period of three consecutive Business Days, the
               amount of the Aggregate U.S. Revolving Extensions of Credit, when
               added to the Aggregate Canadian Extensions of Credit, exceeds the
               Borrowing Formula, the Borrowers shall immediately, without
               notice or demand, prepay the Canadian Revolving Credit Loans, the
               U.S. Revolving Credit Loans and the Swing Line Loans in an
               aggregate principal amount equal to such excess, together with
               interest on the principal amount being repaid accrued to the date
               of such payment or prepayment; provided that if the aggregate
               principal amount of the Canadian Revolving Credit Loans, the U.S.
               Revolving Credit Loans and the Swing Line Loans then outstanding
               is less than the amount of such excess (because U.S. L/C
               Obligations and/or Canadian L/C Obligations constitute a portion
               thereof), the Borrowers shall, to the extent of the balance of
               such excess, replace outstanding U.S. Letters of Credit and/or
               Canadian Letter of Credit and/or cash collateralize such U.S.
               Letters of Credit and/or Canadian Letter of Credit in the manner
               described in Section 13; provided further that if the sum of the
               Aggregate U.S. Revolving Extensions of Credit and the Aggregate
               Canadian Revolving Extensions of Credit, plus any cash collateral
               delivered to the General Administrative Agent pursuant to the
               immediately preceding proviso exceeds the Borrowing Formula for
               three consecutive Business Days the General Administrative Agent,
               at the request of either Borrower, shall promptly return such
               cash collateral in an aggregate amount equal to such excess. All
               payments made under this Section 7.5(g)(iii) shall be made
               ratably between the U.S. Revolving Extensions of Credit and the
               Canadian Revolving Extensions of Credit.".

               12.  Amendment to Section 7.14 of the Credit Agreement (Use of
Proceeds). Section 7.14 of the Credit Agreement is hereby amended to add at the
end thereof immediately prior to the period therein the following:

          ", and on and after the Eighth Amendment Effective Date, the proceeds
          of the Loans shall also be applied to checks written or automated
          clearinghouse debits requested in the ordinary course of business of
          Holdings and its Subsidiaries or for Cash Restructuring Costs
          permitted under this Agreement. ".

               13.  Amendment to Section 10.2 of the Credit Agreement
(Certificate; Other Information). Section 10.2 of the Credit Agreement is hereby
amended by (a) deleting the reference to "clause (j)" in the introductory clause
thereof and substituting in lieu thereof a reference to "clause (l)", (b)
relettering clause (j) as clause (l), (c) deleting "and" at the end of clause
(i) thereof and (d) adding immediately after clause (i) thereof the following:

<PAGE>

                                                                               8

               "(j) as soon as available, but in any event no later than fifteen
          Business Days prior to the end of each fiscal quarter of Holdings,
          projected weekly levels of cash receipts and cash disbursements for
          the immediately succeeding fiscal quarter (the "Quarterly Budget")
          which reconciles with the business plan of Holdings delivered to the
          General Administrative Agent on November 15, 2002, in a manner and in
          detail set forth on Schedule 10.2(j);

               (k)  as soon as available, but in any event not later than
          Wednesday of each calendar week, (i) flash reports of actual revenues
          and expenditures for the calendar week most recently ended and (ii) a
          comparison setting forth actual cash receipts and cash disbursements
          made, checks written and automated clearinghouse debits requested
          against the Quarterly Budget and a discussion of any variance with
          respect thereto, all of the foregoing in detail set forth on Schedule
          10.2(k); and".

               14.  Amendment to Section 10.3 of the Credit Agreement
(Collateral Reports). Section 10.3(a) of the Credit Agreement is hereby amended
by adding at the end thereof immediately before the semicolon therein the
following: "and a calculation of the Borrowing Formula".

               15.  Amendment to Section 10.13 of the Credit Agreement
(Additional Delivery of Collateral). Section 10.13 of the Credit Agreement is
hereby amended by deleting such Section in its entirety and substituting in lieu
thereof the following:

               "10.13 Additional Delivery of Collateral. On and after the Eighth
          Amendment Effective Date, use their reasonable best efforts to provide
          the General Administrative Agent with a perfected first priority Lien
          (or substantial equivalent thereof under applicable local law) on all
          Inventory and real property owned by the Borrowers and, unless the
          Borrowers shall have determined in good faith that it would result in
          adverse tax consequences to the Borrowers or any Subsidiary thereof,
          their Subsidiaries and located in Ireland. Within 90 days after the
          Eighth Amendment Effective Date, provide the General Administrative
          Agent with a perfected first priority Lien (or the substantial
          equivalent thereof under applicable local law as shall be acceptable
          to the Required Lenders) on substantially all property owned by the
          Borrowers or their Subsidiaries and located in Mexico (it being
          understood that the General Administrative Agent shall cooperate with
          the Borrowers to minimize the fees related to obtaining such Liens).".

               16.  Amendment to Section 11.1 of the Credit Agreement (Financial
Condition Covenants). Section 11.1 of the Credit Agreement is hereby amended by:

               (a)  deleting Section 11.1(a) in its entirety and substituting in
          lieu thereof the following:

                    "(a)   Consolidated Leverage Ratio. Permit the Consolidated
               Leverage Ratio as at the last day of any period of four
               consecutive fiscal quarters of Holdings ending with any fiscal
               quarter set forth on Schedule 11.1(a) to exceed the ratio set
               forth on Schedule 11.1(a) opposite such fiscal quarter.";

<PAGE>

                                                                               9

               (b)  deleting Section 11.1(b) in its entirety and substituting in
          lieu thereof the following:

                    "(b) [Reserved].";

               (c)  deleting Section 11.1(c) in its entirety and substituting in
          lieu thereof the following:

                    "(c) Consolidated Interest Coverage Ratio. Permit the
               Consolidated Interest Coverage Ratio for any period of four
               consecutive fiscal quarters of Holdings ending with any fiscal
               quarter set forth on Schedule 11.1(c) to be less than the ratio
               set forth on Schedule 11.1(c) opposite such fiscal quarter.";

               (d)  deleting Section 11.1(d) in its entirety and substituting in
          lieu thereof the following:

                    "(d) [Reserved]."; and

               (e)  deleting Sections 11.1(e), (f) and (g) and substituting in
          lieu thereof the following:

                    "(e)   Minimum Cumulative Consolidated EBITDA. Permit the
               cumulative Consolidated EBITDA of Holdings and its Subsidiaries
               for the portion of any fiscal quarter ending on any date set
               forth on Schedule 11.1(e) to be less than the amount set forth
               opposite such date on Schedule 11.1(e); provided that, for
               purposes of determining compliance with the foregoing covenant,
               if the cumulative Consolidated EBITDA for any full fiscal quarter
               exceeds the amount set forth on Schedule 11.1(e) for such fiscal
               quarter, 50% of such excess may be carried over and added to the
               cumulative Consolidated EBITDA for the immediately following full
               fiscal quarter, to the extent that the cumulative Consolidated
               EBITDA for such following fiscal quarter would be less than the
               required amount set forth above for such fiscal quarter.

                    (f)    Maximum Outstanding Extensions of Credit. (i) Permit
               the sum of the Aggregate U.S. Revolving Extensions of Credit and
               the Aggregate Canadian Revolving Extensions of Credit (such sum,
               the "Total Revolving Extensions of Credit") on any date set forth
               on Schedule 11.1(f)(i) to be greater than the amount set forth
               opposite such date on Schedule 11.1(f)(i).

                    (ii)   On any day (other than the last day) of any month set
               forth on Schedule 11.1(f)(ii), permit the Total Revolving
               Extensions of Credit to exceed the lesser of (A) the Borrowing
               Formula in effect on such day and (B) the amount set forth
               opposite such month on Schedule 11.1(f)(ii).

                    (g)    Minimum Availability Test. As at the last day of
               each month on and after the Eighth Amendment Effective Date,
               permit the amount equal to (i) the Borrowing Base on such date,
               plus (ii) the Availability Adjustment, minus (iii) the

<PAGE>

                                                                              10

               Total Revolving Extension of Credit on such date, minus (iv) if
               on such date the aggregate amount of accounts payable of Holdings
               and its Subsidiaries that are more than 60 days past due (the
               "Past Due Accounts") exceeds 10% of the aggregate accounts
               payable of Holdings and its Subsidiaries on such date, the amount
               of such excess over 10%, plus (v) cash on deposit in the bank
               accounts of the Borrowers and its Subsidiaries, minus (vi) checks
               written and automated clearinghouse debits requested which have
               not yet cleared, to be less (or, in the case of a negative
               number, a larger negative number) than the amount set forth on
               Schedule 11.1(g) opposite such month on Schedule 11.1(g).".

               17.  Amendment to Section 11.7 of the Credit Agreement (Capital
Expenditures). Section 11.7 of the Credit Agreement is hereby amended by
deleting the second paragraph therein and substituting in lieu thereof the
following:

               "From and after the Eighth Amendment Effective Date, the
          foregoing covenant for the 2003 and 2004 fiscal years of Holdings
          shall not be applicable. Notwithstanding anything to the contrary
          contained in this Section 11.7, during the period from and after the
          Eighth Amendment Effective Date, Holdings shall not, and shall not
          permit any of its Subsidiaries to, directly or indirectly, make or
          commit to make any Capital Expenditure, except Capital Expenditures of
          Holdings and its Subsidiaries in the ordinary course of business not
          exceeding $1,250,000 during any fiscal quarter of Holdings.".

               18.  Amendment to Section 11 of the Credit Agreement (Negative
Covenants). Section 11 of the Credit Agreement is hereby amended by adding at
the end thereof a new Section 11.18 as follows:

               "11.18 Limitation on Cash Restructuring Costs. Permit Cash
          Restructuring Costs incurred by Holdings and its Subsidiaries on and
          after the Eighth Amendment Effective Date to exceed $5,600,000, in the
          aggregate.

               11.19. Limitation on Location of Business. Permit Holdings or any
          of its Subsidiaries, without the consent of the Required Lenders, to
          move the manufacturing operations, or any material portion of the
          business, of Holdings or such Subsidiary to any jurisdiction outside
          of the jurisdictions in which Holdings and its Subsidiaries operate on
          the Eighth Amendment Effective Date.".

               19.  Amendment to Section 13 of the Credit Agreement (Events of
Default). Section 13 of the Credit Agreement is hereby amended by deleting
Section 13(d) thereof in its entirety and substituting in lieu thereof the
following:

               "(d) (i) Any Loan Party shall default in the observance or
          performance of any agreement contained Section 10.1, 10.2(c), 10.2(f),
          10.2(g), 10.2(j), 10.2(k), 10.3(a) and 10.3(e) in this Agreement, and
          such default shall continue unremedied for a period of five Business
          Days after the date upon which such Loan party knows or should
          reasonably be expected to know the existence of such default or (ii)
          any Loan Party shall default in the observance or performance of any
          other agreement contained in this Agreement or any other Loan Document
          (other than as provided in paragraphs (a), (b), (c) or (d)(i) of this

<PAGE>

                                                                              11

          Section), and such default shall continue unremedied for a period of
          30 days after the date upon which such Loan party knows or should
          reasonably be expected to know the existence of such default; or".

               20.  Additional Schedules to the Credit Agreement. The Credit
Agreement is hereby amended by deleting Schedules 11.1(e) and (f) in their
entireties and substituting in lieu thereof and adding Schedules 1.1A, 10.2(j),
10.2(k), 11.1(a), 11.1(c), 11.1(e), 11.1(f)(i), 11.1(f)(ii) and 11.1(g) in the
forms attached hereto as Annexes A, B, C, D, E, F, G, H and I, respectively.

               21.  Effectiveness. The Amendment shall become effective on the
date of satisfaction of the following conditions precedent (the "Amendment
Effective Date"):

               (a)  The General Administrative Agent shall have received
          counterparts of this Amendment, duly executed and delivered by
          Holdings and each of the Borrowers.

               (b)  The General Administrative Agent shall have received
          executed Lender Consent Letters, substantially in the form of Exhibit
          A hereto ("Lender Consent Letters"), from Lenders constituting the
          Required Lenders.

               (c)  The General Administrative Agent shall have received an
          executed Acknowledgment and Consent, in the form set forth at the end
          of this Amendment, from each Subsidiary Guarantor.

               (d)  The General Administrative Agent shall have received an
          executed Acknowledgment and Consent, in the form and substance
          reasonably satisfactory to the General Administrative Agent, from each
          Canadian Subsidiary Guarantor.

               (e)  Each Loan Party shall have identified and, except as
          otherwise agreed by the General Administrative Agent, provided the
          General Administrative Agent (or other agent or trustee satisfactory
          to the General Administrative Agent), for the benefit of the Lenders,
          with a perfected first priority Lien in all material assets owned by
          any Loan Party not subject of such a security interest, including with
          respect to all real property of the Borrowers and their Subsidiaries
          located in the United States of America pursuant to Section 10.11(b)
          of the Credit Agreement.

               (f)  All corporate and other proceedings, and all documents,
          instruments and other legal matters in connection with the
          transactions contemplated by this Amendment shall be satisfactory in
          form and substance to the General Administrative Agent.

               (g)  Holdings and the General Administrative Agent shall have
          executed and delivered the Warrant Agreement and the Registration
          Rights Agreement and the Warrants required to be issued pursuant to
          the Warrant Agreement on the Amendment Effective Date shall have been
          issued.

<PAGE>

                                                                              12

               (h)  The Lenders and the General Administrative Agent shall have
          received a budget in form and substance satisfactory to them setting
          forth Holdings' projected weekly levels of revenue and expenses from
          October 31, 2002 through June 30, 2004.

               (i)  Holdings shall have provided a 13-week cash flow forecast
          for the period beginning with the first full calendar week following
          the Amendment Effective Date, in form, detail and substance reasonably
          satisfactory to the General Administrative Agent and which shall, in
          any event, include the total amount of checks outstanding, indicate
          the available amount permitted under the U.S. Revolving Credit
          Facility and the Canadian Revolving Credit Facility, and indicate
          whether there is a forecasted cash surplus or deficiency.

               (j)  The Lenders and the General Administrative Agent shall have
          received all fees required to be paid, and all expenses required to be
          reimbursed for which invoices have been presented, on or before the
          Amendment Effective Date.

               (k)  All governmental and third party approvals necessary in
          connection with the Amendment shall have been obtained and be in full
          force and effect.

               (l)  The General Administrative Agent shall have received such
          legal opinions from counsel to Holdings and its Subsidiaries and such
          documents and other instruments as are customary for transactions of
          this type or as it may reasonably request.

               (m)  The General Administrative Agent shall have received from
          Holdings, for the account of each Lender, an amendment fee equal to
          0.50% of the sum of such Lender's Revolving Credit Commitments (as
          reduced pursuant to this Amendment) and Term Loans then outstanding.

               22.  Representations and Warranties. After giving effect to the
amendment and waivers contained herein, on the Amendment Effective Date, each of
Holdings and the Borrowers hereby confirms, reaffirms and restates the
representations and warranties set forth in Section 8 of the Credit Agreement,
except to the extent such representations and warranties specifically relate to
an earlier date, in which case such representations and warranties shall be true
and correct in all material respects as of such earlier date; provided that each
reference in such Section 8 to "this Agreement" shall be deemed to be a
reference both to this Amendment and to the Credit Agreement as amended by this
Amendment.

<PAGE>

                                                                              13

               23.  Release and Acknowledgements.

               (a)  In order to induce the Lenders to enter into this Amendment,
          each Loan Party hereby remises, releases and forever discharges, and
          by these presents does for its Subsidiaries (direct or indirect), and
          for itself and its predecessors, successors, affiliates and assigns
          (each, a "Releasor"), remise, release and forever discharge, each
          Agent, each Lender, and each predecessor, affiliate, subsidiary
          (direct or indirect), successor, assign, participant, officer,
          director, employee or agent of any Agent or any Lender (collectively,
          the "Released Parties"), of and from all manner of actions at law or
          equity, all causes of action for damages, costs, debts, sums of money,
          accounts, bills, rights of indemnity, breach of contract, provision of
          labor or materials, loss of use, loss of services, expenses,
          compensation, consequential or punitive damages, equitable
          subordination, avoidance of preferential or fraudulent transfers, or
          any other thing whatever, arising by virtue of actions taken, actions
          omitted to be taken or the occurrence of any other event on or prior
          to the Amendment Effective Date, relating in any way to (i) this
          Amendment, the Credit Agreement, any other Loan Document or the
          obligations of the Loan Parties under the Credit Agreement and the
          other Loan Documents (the "Obligations"), (ii) any claims (including,
          without limitation, for contribution or indemnification) which have or
          could have arisen out of any of the transactions contemplated by this
          Amendment or the Loan Documents or any other proceedings that have
          been brought or may be brought by any party hereto or to any Loan
          Document or any third party relating to the Loan Documents or the
          transactions contemplated thereby, (iii) any acts, transactions or
          events that are the subject matter of this Amendment or the Loan
          Documents or (iv) the prosecution of any claims or any settlement
          negotiations which such Releasor ever had, now or which it, its
          Subsidiaries (direct or indirect), or its successors or assigns
          hereafter can, shall or may have against the Released Parties by
          reason of (with respect to each of clauses (i)-(iv) above) any matter,
          cause or thing whatsoever on or prior to the Amendment Effective Date
          relating to this Amendment or the Loan Documents; provided, however,
          that nothing herein shall be construed or deemed to release any
          covenants or agreements contained herein or in any Loan Document so
          long as such Loan Document shall remain in full force and effect.

               (b)  Each Loan Party hereby acknowledges and agrees that the
          Obligations are secured by valid and enforceable first priority liens
          and security interests granted by the Loan Parties to an Agent, for
          the ratable benefit of the Lenders, upon all of the Collateral,
          subject only to Liens permitted under the Credit Agreement. The
          Obligations and the liens and security interests of the Agents, for
          the ratable benefit of the Lenders, in the Collateral are not subject
          to avoidance, defense, objection, action, counterclaim, setoff or
          subordination, except as may be limited by applicable bankruptcy,
          insolvency, reorganization, moratorium or other similar laws now or
          hereafter in effect relating to or affecting creditors' rights
          generally. The Obligations constitute legal, valid and binding
          obligations of each Loan Party, enforceable in accordance with the
          terms of the Loan Documents and pursuant to applicable law, except as
          limited by applicable bankruptcy, insolvency, reorganization,
          moratorium or other similar laws now or hereafter in effect relating
          to or affecting creditors' rights generally, and subject to the
          limitations imposed by general equitable principles (regardless
          whether such enforceability is considered in a

<PAGE>

                                                                              14

          proceeding at law or in equity). Furthermore, no Loan Party will use
          any of its cash or other assets to object to or contest in any manner,
          or raise any objections, counterclaims or defenses to, the validity,
          perfection, priority or enforceability of the claims or liens of the
          Agents and the Lenders relating to this Amendment, the Credit
          Agreement or any other Loan Document, or to investigate or assert any
          claims or causes of action arising on or prior to the Amendment
          Effective Date against the Agents or the Lenders relating to this
          Amendment, the Credit Agreement or any other Loan Document.

               (c)  Except as expressly set forth in this Amendment, each of the
          Loan Parties acknowledges and agrees that the execution and delivery
          by the Agents of, or the consent by the Lenders to, this Amendment
          shall not be deemed (i) to create a course of dealing or otherwise
          obligate the Agents or the Lenders to forbear or execute similar
          agreements under the same or similar circumstances in the future, (ii)
          to modify, relinquish or impair any right of the Agents or the Lenders
          to receive any indemnity or similar payment from any Person or entity
          as a result of any matter arising from or relating to this Amendment,
          (iii) to waive any right of the Lenders to receive interest at an
          increased rate as a result of any Events of Default that may occur
          under the Credit Agreement as amended by this Amendment, (iv) to
          obligate the Lenders in any way to forbear from individually or
          collectively enforcing remedies under the Credit Agreement as amended
          by this Amendment in any manner or (v) a commitment from any of the
          Lenders to forbear or "stand still". Except as expressly set forth in
          this Amendment, no past or future forbearance on the part of any of
          the Lenders should be viewed as a limitation upon or waiver of the
          absolute right and privilege of the Lenders in exercising rights and
          remedies that currently exist or may exist after the Amendment
          Effective Date.

               24.  Continuing Effect; No Other Amendments. Except as expressly
amended or waived hereby, all of the terms and provisions of the Credit
Agreement and the other Loan Documents are and shall remain in full force and
effect. The amendments and waivers contained herein shall not constitute an
amendment or waiver of any other provision of the Credit Agreement or the other
Loan Documents or for any purpose except as expressly set forth herein.

               25.  No Default. No Default or Event of Default shall have
occurred and be continuing as of the Amendment Effective Date after giving
effect to this Amendment.

               26.  Counterparts. This Amendment may be executed in any number
of counterparts by the parties hereto, each of which shall be an original, and
all of which when taken together shall constitute one and the same instrument.
Delivery of an executed counterpart by facsimile transmission shall be effective
as delivery of a manually executed counterpart hereof.

               27.  GOVERNING LAW. THIS AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

<PAGE>

                                                                              15

               IN WITNESS WHEREOF, the parties hereto have caused this Amendment
to be duly executed and delivered by their respective proper and duly authorized
officers as of the day and year first above written.

                                          SMTC CORPORATION


                                          By: /s/ Paul Walker
                                              ----------------------------------
                                              Name:  Paul Walker
                                              Title: President


                                          HTM HOLDINGS, INC.


                                          By: /s/ Paul Walker
                                              ----------------------------------
                                              Name:  Paul Walker
                                              Title: President


                                          SMTC MANUFACTURING CORPORATION OF
                                          CANADA


                                          By: /s/ Paul Walker
                                              ----------------------------------
                                              Name:  Paul Walker
                                              Title: President

<PAGE>

                                                                              16

                                          LEHMAN COMMERCIAL PAPER INC., as
                                           General Administrative Agent


                                          By: /s/ G. Andrew Keith
                                              ----------------------------------
                                              Name:  G. Andrew Keith
                                              Title: Authorized Signatory

<PAGE>

                           ACKNOWLEDGMENT AND CONSENT

               Each of the undersigned parties to the Amended and Restated
Guarantee and Collateral Agreement, dated as of July 27, 2000, as amended,
supplemented or otherwise modified from time to time, made by the undersigned in
favor of Lehman Commercial Paper Inc., as General Administrative Agent, for the
benefit of the Lenders, hereby (a) consents to the transactions contemplated by
the Eighth Amendment to the Amended and Restated Credit and Guarantee Agreement
(the "Eighth Amendment"), (b) acknowledges and agrees that the guarantees and
grants of security interests contained in such Amended and Restated Guarantee
and Collateral Agreement and in the other Security Documents are, and shall
remain, in full force and effect after giving effect to the Eighth Amendment and
all prior modifications to the Amended and Restated Credit and Guarantee
Agreement and (c) agrees to and acknowledges the provisions of Section 23 of the
Eighth Amendment which are incorporated herein by reference.

                                          SMTC CORPORATION
                                          HTM HOLDINGS, INC.
                                          SMTC MANUFACTURING CORPORATION OF
                                           CALIFORNIA
                                          SMTC MANUFACTURING CORPORATION OF
                                           COLORADO
                                          SMTC MANUFACTURING CORPORATION OF
                                           MASSACHUSETTS
                                          SMTC MANUFACTURING CORPORATION OF
                                           NORTH CAROLINA
                                          SMTC MANUFACTURING CORPORATION OF
                                           TEXAS
                                          SMTC MANUFACTURING CORPORATION OF
                                           WISCONSIN
                                          SMTC MEX HOLDINGS, INC.
                                          QUALTRON, INC.


                                          By: /s/ Paul Walker
                                              ----------------------------------
                                              Name:
                                              Title: