<PAGE>   1


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  FORM 10-Q/A

                               Amendment No. 1 to

                                   (Mark One)
          (X)     QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15 (d) of
                  THE SECURITIES EXCHANGE ACT OF 1934

                   For the quarterly period ended MAY 2, 1998

                                       OR

          ( )     TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                  THE SECURITIES EXCHANGE ACT OF 1934 (NO FEE REQUIRED)

                FOR THE TRANSITION PERIOD FROM _______ TO _______


                         COMMISSION FILE NUMBER 0-12102


                                HADCO CORPORATION
             ------------------------------------------------------
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

MASSACHUSETTS                                                        04-2393279
-------------                                                        ----------
(State or other jurisdiction                                   (I.R.S. Employer
of incorporation or organization)                           Identification No.)


12A MANOR PARKWAY, SALEM, NEW HAMPSHIRE                                   03079
---------------------------------------                                   -----
(Address of principal executive offices)                             (Zip Code)


REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE:   (603) 898-8000

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. Yes  X   No
                                       ---     ---

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date.

Registrant had 13,242,127 shares of Common Stock, $0.05 Par Value, outstanding
at June 8, 1998.

<PAGE>   2
EXPLANATORY NOTE

This Quarterly Report on Form 10-Q/A of Hadco Corporation (Amendment No. 1 to
Quarterly Report on Form 10-Q for the quarter ended May 2, 1998) amends and
restates Item 1 of the Registrant's Quarterly Report on Form 10-Q for the
quarter ended May 2, 1998 (File No. 0-12102), by adding Note 11 to the Notes to
Consolidated Condensed Financial Statements.




 PART I - FINANCIAL INFORMATION

      ITEM 1. FINANCIAL STATEMENTS

<TABLE>
<CAPTION>
                           HADCO CORPORATION AND SUBSIDIARIES
                          CONSOLIDATED CONDENSED BALANCE SHEETS
                                       (unaudited)
                                     (In thousands)

 ASSETS                                                         May 2,       October 25,
                                                                  1998            1997
                                                                --------       -----------
<S>                                                             <C>             <C>     
 Current Assets:

    Cash and cash equivalents .............................     $  4,997        $ 12,171
    Short-term investments ................................            -           1,562
    Accounts receivable, net of allowance for
     doubtful accounts of $2,589 in 1998 and
     $1,700 in 1997, respectively .........................      114,352          92,222
    Inventories ...........................................       75,095          46,000
    Deferred tax asset ....................................       20,106          10,483
    Prepaid and other current expenses ....................        8,058           4,245
                                                                --------        --------
         Total Current Assets .............................      222,608         166,683
    Property, Plant and Equipment, net ....................      318,335         231,490
    Acquired Intangible Assets, net .......................      195,026         101,131
    Other Assets ..........................................        3,472           3,213
                                                                --------        --------
                                                                $739,441        $502,517
                                                                ========        ========
LIABILITIES AND STOCKHOLDERS' INVESTMENT

Current Liabilities:

    Short-term debt and current portion of long-term debt..     $  4,837        $  5,064
    Accounts payable ......................................       74,169          68,594
    Accrued Payroll and other employee benefits ...........       29,246          28,279
    Accrued Taxes .........................................          494           1,775
    Other accrued expenses ................................       15,229           9,278
                                                                --------        --------
         Total Current Liabilities ........................      123,975         112,990
                                                                --------        --------
Long Term Debt, net of current portion ....................      359,037         109,716
                                                                --------        --------
Deferred Tax Liability ....................................       51,668          30,685
                                                                --------        --------
Other Long-Term Liabilities ...............................        9,192           9,214
                                                                --------        --------
Commitments and Contingencies
Stockholders' investment:
    Common stock, $.05 par value -
    Authorized 50,000 shares in 1998 and 25,000 in 1997
    Issued and outstanding 13,212 in
    1998 and 13,086 in 1997 ...............................          662             655
Paid-in capital ...........................................      171,466         168,246
Deferred compensation .....................................          (75)           (117)
Retained earnings .........................................       23,516          71,128
                                                                --------        --------
         Total Stockholders' Investment ...................      195,569         239,912
                                                                --------        --------
                                                                $739,441        $502,517
                                                                ========        ========
</TABLE>


              The accompanying notes are an integral part of these
                  consolidated condensed financial statements.


                                       2

<PAGE>   3

<TABLE>
<CAPTION>

                                         HADCO CORPORATION AND SUBSIDIARIES
                                   CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS
                                                    (unaudited )
                                          (In thousands, except share data)

                                                                    Three Months Ended                      Six Months Ended
                                                                    ------------------                      ----------------
                                                                  May 2,          April 26,            May 2,          April 26,
                                                                   1998             1997               1998               1997
                                                               -----------       -----------        -----------        -----------
<S>                                                            <C>               <C>                <C>                <C>        
Net Sales ..................................................   $   209,587       $   180,662        $   407,863        $   292,198

Cost of Sales ..............................................       172,857           142,199            332,065            227,358
                                                               -----------       -----------        -----------        -----------
     Gross Profit ..........................................        36,730            38,463             75,798             64,840

Operating Expenses .........................................        21,526            17,999             39,310             28,819

Restructuring and other non-recurring charges (Note 7) .....         5,947                 -              5,947                  -

Write-off of acquired in-process                               
  research and development .................................        63,050                 -             63,050             78,000
                                                               -----------       -----------        -----------        -----------

Income (Loss) From Operations ..............................       (53,793)           20,464            (32,509)           (41,979)

Interest and Other Income (Expense), net ...................           844               (70)             1,377                806

Interest Expense ...........................................        (4,195)           (4,318)            (6,294)            (5,251)
                                                               -----------       -----------        -----------        -----------
Income (Loss) Before                                           
Provision for Income Taxes .................................       (57,144)           16,076            (37,426)           (46,424)
                                                               
Provision for Income Taxes .................................         2,595             6,123             10,186             12,788
                                                               
Net Income (Loss) ..........................................   $   (59,739)      $     9,953        $   (47,612)       $   (59,212)
                                                               -----------       -----------        -----------        -----------
Income (loss) per common and common equivalent Shares (Note 1) 
  Basic Net Income (Loss) Per Share..........................       $(4.54)             $.95             $(3.63)            $(5.67)
                                                                    ======              ====             ======             ====== 
  Diluted Net Income (Loss) Per Share........................       $(4.54)             $.91             $(3.63)            $(5.67)
                                                                    ======              ====             ======             ====== 

Weighted average common and common equivalent Shares           
outstandingc (Note 1)                                          
  Basic ....................................................    13,161,078        10,458,213         13,130,418         10,434,555
                                                               ===========       ===========        ===========        =========== 
  Diluted ..................................................    13,161,078        10,956,458         13,130,418         10,434,555
                                                               ===========       ===========        ===========        =========== 
</TABLE>

              The accompanying notes are an integral part of these
                  consolidated condensed financial statements.


                                       3
<PAGE>   4

<TABLE>
<CAPTION>

                                   HADCO CORPORATION AND SUBSIDIARIES
                             CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS
                                               (unaudited)
                                              (In thousands)

                                                                                                     Six Months Ended
                                                                                                     ----------------
                                                                                                  May 2,        April 26,
                                                                                                   1998           1997
                                                                                                  -----         ---------
<S>                                                                                              <C>            <C>      
Total Cash Provided From Operating Activities ....................................               $  12,595      $  13,990
                                                                                                 ---------      ---------
Cash Flows From Investing Activities:
     Purchases of short-term investments .........................................                  (2,020)             -
     Maturities of short-term investments ........................................                   3,582          9,401
     Purchases of property, plant and equipment ..................................                 (48,186)       (29,611)
     Acquisitions of Continental in 1998 and Zycon in 1997 .......................                (190,032)      (209,661)
                                                                                                 ---------      ---------
Net Cash Used In Investing Activities ............................................                (236,656)      (229,871)
Cash Flows From Financing Activities:
     Principal payments of long-term debt ........................................                 (43,218)       (36,621)
     Proceeds from issuance of long-term debt ....................................                 256,878        225,000
     Proceeds from exercise of stock options .....................................                     477            435
     Tax benefit from exercise of stock options ..................................                   1,270          1,387
     Proceeds from the sale of Common Stock ......................................                   1,480              -
                                                                                                 ---------      ---------
Net Cash Provided by Financing Activities ........................................                 216,887        190,201
                                                                                                 ---------      ---------
Net decrease in Cash and Cash Equivalents ........................................                  (7,174)       (25,680)
Cash and Cash Equivalents Beginning of Period ....................................                  12,171         32,786
                                                                                                 ---------      ---------
Cash and Cash Equivalents End of Period ..........................................               $   4,997      $   7,106
                                                                                                 =========      =========
Supplemental disclosure of cash flow information:

Cash paid during period for:

      Interest ...................................................................               $   4,689      $   4,282
                                                                                                 =========      =========
      Income taxes  (net of refunds) .............................................               $  10,906      $   9,070
                                                                                                 =========      =========

Acquisitions of Continental in 1998 and Zycon in 1997:

     Fair value of assets acquired ...............................................               $ 140,123      $ 212,509
     Liabilities assumed .........................................................                 (47,905)      (114,993)
     Cash paid ...................................................................                (186,083)      (204,885)
     Acquisition costs incurred ..................................................                  (3,949)        (7,600)
     Write-off of acquired in-process
      research and development ...................................................                  63,050         78,000
                                                                                                 ---------      ---------
     Goodwill ....................................................................               $ (34,764)     $ (36,969)
                                                                                                 =========      =========
</TABLE>


              The accompanying notes are an integral part of these
                  consolidated condensed financial statements.

                                       4

<PAGE>   5

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                   (unaudited)


1.    SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

      Hadco Corporation's (the "Company" or "Hadco") principal products are
      multilayer rigid printed circuits and backplane assemblies. The
      consolidated condensed financial statements reflect the application of
      certain accounting policies. For information as to the significant
      accounting policies followed by the Company and other financial and
      operating information, see this note and elsewhere in the accompanying
      notes to consolidated condensed financial statements, as well as the
      Company's Annual Report on Form 10-K for the fiscal year ended October 25,
      1997, Quarterly Report on Form 10-Q for the fiscal quarter ended January
      31, 1998, Current Reports on From 8-K dated February 18, 1998. February
      20, 1998, and May 1, 1998 and current report on From 8-K dated March 26,
      1998 as amended by Current Report on Form 8-K/A dated May 1, 1998. These
      financial statements should be read in conjunction with the financial
      statements included in those above-referenced SEC filings.

      FOREIGN CURRENCY TRANSLATION

      The functional currency of the Company's Malaysian subsidiary is the
      United States dollar. Accordingly, all remeasurement gains and losses
      resulting from transactions denominated in currencies other than United
      States dollars are included in the consolidated condensed statements of
      operations. To date, the resulting gains and losses have not been
      material.

      RECLASSIFICATION

      The Company has reclassified certain prior year information to conform
      with the current year's presentation.

      INTERIM FINANCIAL STATEMENTS

      The accompanying consolidated condensed balance sheet as of May 2, 1998,
      and the consolidated statements of operations and cash flows for the six
      month periods ended May 2, 1998 and April 26, 1997 are unaudited but, in
      the opinion of management, include all adjustments (consisting only of
      normal, recurring adjustments) necessary for a fair presentation of
      results for these interim periods. Results of operations for the interim
      period are not necessarily indicative of results to be expected for the
      entire year or any future period.

      NET INCOME (LOSS) PER SHARE

      The Company adopted SFAS No. 128, "Earnings per share", effective for the
      quarter ended January 31, 1998 which replaces the calculation of primary
      and fully diluted earnings per share with basic and diluted earnings per
      share. Prior period amounts have been restated to conform to the current
      period presentation. Under SFAS No. 128, basic net income (loss) per
      common share is computed based on income (loss) available to common
      stockholders and the weighted average number of common shares outstanding
      during the period. The dilutive net income (loss) per share is computed
      based on including the number of additional common shares that would have
      been outstanding if the dilutive potential of common shares had been
      issued.


                                       5

<PAGE>   6

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                   (unaudited)


      Basic and diluted shares outstanding, are as follows:

<TABLE>
<CAPTION>

                                                       Three Months Ended   Six Months Ended  
                                                       ------------------   ----------------  
                                                       (in thousands, except per share data)

                                                       May 2,     April 26,  May 2,     April 26,
                                                        1998        1997      1998        1997
                                                        ----        ----      ----        ----
<S>                                                    <C>         <C>       <C>         <C>   
      Basic weighted average shares outstanding        13,161      10,458    13,130      10,435
      Weighted average common equivalent shares          -            498      -           -
                                                       ------      ------    ------      ------
      Diluted weighted average shares outstanding      13,161      10,956    13,130      10,435
                                                       ======      ======    ======      ======
</TABLE>

      Diluted weighted average shares outstanding for the three month periods
      ended May 2, 1998 and April 26, 1997, do not include 383,997 and 575,366
      common equivalent shares, respectively, as their effect would be
      anti-dilutive. Diluted weighted averages shares outstanding for the six
      month periods ended May 2, 1998 and April 26, 1997, respectively, do not
      include 401,798 and 571,815 common equivalent shares as their effect would
      be anti- dilutive.

2.    AQUISITIONS

      On January 10, 1997, the Company acquired (the "Zycon Acquisition") all of
      the outstanding common stock of Zycon Corporation ("Zycon"), and on March
      20, 1998, the Company acquired (the "Continental Acquisition", and
      together with the Zycon Acquistion, the "Acquisitions") all of the
      outstanding common stock of Continental Circuits Corp. ("Continental").
      These acquisitions were financed by the $400 million unsecured senior
      revolving credit facility with a group of banks, which amended and
      restated an existing credit facility (the "Amended Credit Facility"),
      under which the Company borrowed approximately $215,000,000 upon
      consummation of the Zycon Acquisition and approximately $220,000,000 upon
      consummation of the Continental Acquisition. These acquisitions were
      accounted for as purchases in accordance with Accounting Principles Board
      Opinion No. 16, and accordingly, Zycon's and Continental's operating
      results since the respective dates of acquisition are included in the
      accompanying consolidated condensed financial statements. In accordance
      with ABP Opinion No. 16, the Company allocated the purchase price of the
      Acquisitions based on the fair value of assets acquired and liabilities
      assumed. Significant portions of the purchase price of both Acquisitions
      were identified in independent appraisals as intangible assets using
      proven valuation procedures and techniques. These intangible assets
      include approximately $78,000,000 and $63,050,000 for Zycon and
      Continental, respectively, for acquired in-process research and
      development ("in-process R&D") for projects that did not have a future
      alternative use. Acquired intangibles include developed technology,
      customer relationships, assembled workforce, trade names and trademarks.
      These intangibles are being amortized over their estimated useful lives of
      12 to 30 years.

      Unaudited pro forma operating results for the Company, assuming the
      acquisitions of Zycon and Continental occurred on October 27, 1996, are as
      follows:

                                       6
<PAGE>   7


                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                   (unaudited)

      ACQUISITIONS (CONTINUED)

<TABLE>
<CAPTION>
                                       Three Months Ended     Six Months Ended
                                       ------------------     ----------------
                                        (in thousands, except per share data)

                                         May 2,   April 26,    May 2,  April 26,
                                         1998       1997       1998      1997
                                         ----       ----       ----      ----
<S>                                    <C>        <C>        <C>       <C>     
Net Sales ............................ $226,196   $212,524   $459,814  $414,633

Net Income ........................... $   (473)  $  9,010   $  8,880  $ 16,275

Basic Net Income (Loss) Per Share ....    $(.04)      $.86       $.68     $1.56

Diluted Net Income (Loss) Per Share ..    $(.04)      $.82       $.66     $1.49
</TABLE>


      For purposes of these pro forma operating results, the acquired in-process
      R&D was assumed to have been written off prior to October 27, 1996, so
      that the operating results presented include only recurring costs.

3.    INVENTORIES

      Inventories are stated at the lower of cost, first-in, first-out (FIFO),
      or market and consist of the following (in thousands):

<TABLE>
<CAPTION>

                                                  May 2,   October 25,
                                                   1998       1997
                                                   ----       ----
      <S>                                        <C>        <C>    
      Raw Materials.......................       $33,656    $14,167
      Work-in-process.....................        41,439     31,833
                                                 -------    -------
                                                 $75,095    $46,000
                                                 =======    =======
</TABLE>

4.    INTANGIBLE ASSETS

      The Company has assessed the realizability of its acquired intangible
      assets in accordance with SFAS No.121, "Accounting for the Impairment of
      Long-Lived Assets and for Long-Lived Assets to be Disposed of. " Under
      SFAS No. 121, the Company is required to assess the valuation of its
      long-lived assets, including intangible assets, based on the estimated
      cash flows to be generated by such assets. See Note 7.

5.    LINES OF CREDIT

      The Company's $400 million Amended Credit Facility is pursuant to an
      Amended and Restated Revolving Credit Agreement, as amended (the
      "Agreement). The Agreement provides for direct borrowings or letters of
      credit for up to $400 million and expires January 8, 2002. Borrowings
      under the Agreement bear interest, at the Company's option, at either: (i)
      the Eurodollar Rate plus the Applicable Eurodollar Rate Margin (both as
      defined in the Agreement) ranging between .5% and 1.1375%, based on
      certain financial

                                       7
<PAGE>   8

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                   (unaudited)


      LINES OF CREDIT (CONTINUED)

      ratios of the Company, or (ii) the Base Rate (as defined in the
      Agreement). The Company is required to pay a quarterly commitment fee
      ranging from .2% to .375% per annum, based on certain financial ratios of
      the Company, of the unused commitment under the Agreement. If the Company
      obtains certain debt financing, as defined, the banks may require the
      Company to repay up to $150,000,000 of amounts outstanding under the
      Agreement. At May 2, 1998, borrowings of $345,000,000 were outstanding
      under the agreement at a weighted average interest rate of 6.56%.

      The Agreement places several restrictions on the Company, including
      limitations on mergers, acquisitions and sales of a substantial portion of
      its assets, as well as certain limitations on liens, guarantees,
      additional borrowings, changes in the Company's capitalization, as
      defined, and investments. The Agreement also requires the Company to
      maintain certain financial covenants, including, among other things,
      minimum levels of consolidated net worth, a maximum ratio of consolidated
      funded debt to EBITDA, maximum capital expenditures and minimum interest
      coverage, as defined, during the term of the Agreement. At May 2, 1998,
      the Company was in compliance with all loan covenants.

      The Company has a line of credit arrangement with a Malaysian bank
      denominated in Malaysian ringgits and U.S. dollars for aggregate
      borrowings of $3.4 million for the purpose of acquiring land, facilities
      and equipment for the Company's Malaysian subsidiary. The arrangement is
      renewable annually. At May 2, 1998, there were no amounts outstanding
      under this arrangement.

6.    LONG TERM DEBT

<TABLE>
<CAPTION>
                                                            May 2,   October 25,
                                                            1998        1997
                                                           -------   -----------
                                                              (In thousands)
      <S>                                                  <C>        <C>     
      Loan agreements in connection with the expansion 
      of a building. The loans bear interest at rates 
      from 1% to 7% through March, 2011 and are 
      collateralized by property and an irrevocable 
      letter of credit. Payments of principal and 
      interest are quarterly.............................  $    778   $    820
      Revolving credit agreement (Note 5)................   345,000    100,000
      Obligations under capital leases...................    18,096     13,960
                                                           --------   --------
                                                            363,874    114,780
      Less - Current portion.............................     4,837      5,064
                                                           --------   --------
                                                           $359,037   $109,716
                                                           ========   ========
</TABLE>


                                       8
<PAGE>   9

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                   (unaudited)


7.    RESTRUCTURING AND OTHER NON-RECURRING CHARGES

      On April 6, 1998, the Company announced the planned consolidation of its
      two East Coast quick-turn prototype facilities into the larger of the two
      facilities located at Haverhill, MA. The Company incurred and recorded in
      the fiscal quarter ended May 2, 1998 non-recurring charges in connection
      with the consolidation totaling $5.9 million. The component of this charge
      classified as restructuring-related met the criteria set forth in Emerging
      Issues and Task Force Issue ("EITF") 94-3, "Liability Recognition for
      Certain Employee Termination Benefits and Other Costs to Exit an Activity
      (including Certain Costs Incurred in a Restructuring)." The amount
      recorded as a liability, which totaled $1.5 million, relates to severance
      and other payroll-related costs, as well as lease termination costs.
      Non-recurring costs include costs associated with the abandonment of
      assets at one of the facilities. The components of the restructuring and
      other non-recurring costs during the three months ended May 2, 1998 are as
      follows:

<TABLE>
<CAPTION>
                                                                      Amount
                                                                  (in thousands)
      <S>                                                             <C>   
      Loss on abandonment of assets ................................  $1,965
      Severance benefits and associated legal costs ................     129
      Lease termination loss .......................................   1,336
                                                                      ------
      Total Restructuring Charges ..................................   3,430

      Other Non-recurring Charges ..................................   2,517
                                                                      ------

      Total Restructuring and Other Charges ........................  $5,947
                                                                      ======
</TABLE>

      Included in the restructuring and other charges is $2.5 million, which
      represents the write-down of existing assets to their net realizable
      value, in accordance with SFAS 121, "Accounting for the Impairment of
      Long-Lived Assets and Long-Lived Assets to be Disposed Of."

8.    ENVIRONMENTAL MATTERS

      The Company is required to comply with all federal, state, county and
      municipal regulations regarding protection of the environment. There can
      be no assurance that more stringent environmental laws will not be adopted
      in the future and, if adopted, the costs of compliance with more stringent
      environmental laws could be substantial. Waste treatment and disposal are
      major considerations for printed circuit manufacturers. The Company uses
      chemicals in the manufacture of its products that are classified by the
      Environmental Protection Agency (EPA) as hazardous substances. The Company
      is aware of certain chemicals that exist in the ground at certain of its
      facilities. The Company has notified various governmental agencies and
      continues to work with them to monitor and resolve these matters. During
      March 1995, the Company received a Record Of Decision (ROD) from the New
      York State Department of Environmental Conservation (NYSDEC),

                                      9
<PAGE>   10

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                 (unaudited)


      ENVIRONMENTAL MATTERS (CONTINUED)

      regarding soil and groundwater contamination at its Owego, New York
      facility. Based on a Remedial Investigation and Feasibility Study (RIFS)
      for apparent on-site contamination at that facility and a Focused
      Feasibility Study (FFS), each prepared by environmental consultants of the
      Company, the NYSDEC has approved a remediation program of groundwater
      withdrawal and treatment and iterative soil flushing. The Company has
      executed a Modification of the Order on Consent to implement the approved
      ROD. The cost, based upon the FFS, to implement this remediation is
      estimated to be $4.6 million, and is expected to be expended as follows:
      $260,000 for capital equipment and $4.3 million for operation and
      maintenance costs which will be incurred and expended over the estimated
      life of the program of 30 years. NYSDEC has notified the Company that it
      will take additional samples from a wetland area near the Company's Owego
      facility. Analytical reports of earlier sediment samples indicated the
      presence of certain inorganics. There can be no assurance that the Company
      and/or other third parties will not be required to conduct additional
      investigations and remediation at that location, the costs of which are
      currently indeterminable due to the numerous variables described in the
      fifth paragraph of this Environmental Matters note.

      From 1974 to 1980, the Company operated a printed circuit manufacturing
      facility in Florida as a lessee of property that is now the subject of a
      pending lawsuit (the "Florida Lawsuit") and investigation by the Florida
      Department of Environmental Protection (FDEP). Hadco and others are
      participating in alternative dispute resolution regarding the site with an
      independent mediator. In connection with mediation, in February 1992 the
      FDEP presented computer-generated estimates of remedial costs, for
      activities expected to be spread over a number of years, that ranged from
      approximately $3.3 million to $9.7 million. Mediation sessions were
      conducted in March 1992 but were then suspended during ongoing assessment
      and feasibility activities. On June 9, 1992, the Company entered into a
      Cooperating Parties Agreement in which it and Gould, Inc., another prior
      lessee of the site, agreed to fund certain assessment and feasibility
      study activities at the site. The cost of such activities is not expected
      to be material to the Company. Management believes it is likely that it
      will participate in implementing a continuing remedial program for the
      site, the costs of which are currently unknown. In June 1995, Hadco was
      named a third-party defendant in the Florida Lawsuit. See Note 9 below.

      The Company has commenced the operation of a groundwater extraction system
      at its Derry, New Hampshire facility to address certain groundwater
      contamination and groundwater migration control issues. Further
      investigation is underway to determine the areal extent of the groundwater
      contaminant plume. Because of the uncertainty regarding both the quantity
      of contaminants beneath the building at the site and the long-term
      effectiveness of the groundwater migration control system the Company has
      installed, it is not possible to make a reliable estimate of the length of
      time remedial activity will have to be performed. However, it is
      anticipated that the groundwater extraction system will be operated for at
      least 30 years. There can be no assurance that the Company will not be
      required to conduct additional investigations and remediation relating to
      the Derry facility. The total costs of such groundwater extraction system
      and of conducting any additional investigations and remediation relating
      to the Derry facility are not fully determinable due to the numerous
      variables described in the fifth paragraph of this Environmental Matters
      note.


                                       10
<PAGE>   11

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                 (unaudited)


      ENVIRONMENTAL MATTERS (CONTINUED)

      The City of Santa Clara adopted an ordinance that, as of April 1, 1997,
      reduced the amount of waste, including copper and nickel, that companies
      such as the Company may discharge into the city sanitary sewer. The
      ordinance provides for substantial penalties for intentional or negligent
      violations. These penalties include fines ranging from $10,000 to $50,000
      per day, revocation of required business permits, the issuance of a cease
      and desist order and, under certain circumstances, up to nine months'
      imprisonment. Under the ordinance, the Company is subject to stringent
      requirements on the amount of water it can discharge. The concentration
      limit for Hadco's copper discharge was reduced from 2.70 milligrams per
      liter to 1.02 milligrams per liter, and the concentration limit for
      Hadco's nickel discharge was reduced from 2.60 milligrams per liter to
      0.15 milligrams per liter. The Company believes it is currently in
      compliance with new discharge limits.

      The Company accrues estimated costs associated with known environmental
      matters, when such costs can be reasonably estimated. The cost estimates
      relating to future environmental clean-up are subject to numerous
      variables, the effects of which can be difficult to measure, including the
      stage of the environmental investigations, the nature of potential
      remedies, possible joint and several liability, the magnitude of possible
      contamination, the difficulty of determining future liability, the time
      over which remediation might occur, and the possible effects of changing
      laws and regulations.

      Management believes the ultimate disposition of above known environmental
      matters described in this "Environmental Matters" note will not have a
      material adverse effect upon the liquidity, capital resources, business or
      consolidated financial position of the Company. However, one or more of
      such environmental matters could have a significant negative impact on the
      Company's consolidated financial results for a particular reporting
      period.

9.    LEGAL PROCEEDINGS AND CLAIMS

      The Company is one of 33 entities which have been named as potentially
      responsible parties in a lawsuit pending in the federal district court of
      New Hampshire concerning environmental conditions at the Auburn Road,
      Londonderry, New Hampshire landfill site. Local, state and federal
      entities and certain other parties to the litigation seek contribution for
      past costs, totaling approximately $20 million, allegedly incurred to
      assess and remediate the Auburn Road site. In December 1996, following
      publication and comment period, the EPA amended the ROD to change the
      remedy at the Auburn Road site from active groundwater remediation to
      future monitoring. Other parties to the lawsuit also allege that future
      monitoring will be required. The Company is contesting liability, but is
      participating in mediation with 27 other parties in an effort to resolve
      the lawsuit.

      In connection with the Florida Lawsuit pending in the Circuit Court for
      Broward County, Florida (described in Note 8 above), each of Hadco and
      Gould, Inc., another prior lessee of the site of the printed circuit
      manufacturing facility in Florida, was served with a third-party complaint
      in June 1995, as third-party defendants in such pending Florida Lawsuit by
      a party who had previously been named as a defendant when the Florida
      Lawsuit was commenced in 1993 by the FDEP. The Florida Lawsuit seeks
      damages relating to environmental pollution and FDEP costs and expenses,
      civil penalties, and declaratory and injunctive relief to require the
      parties to complete assessment and remediation of soil and groundwater
      contamination. The other parties include alleged owners of the property
      and Fleet Credit Corporation, a secured lender to a prior lessee of the
      property.


                                       11
<PAGE>   12

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                 (unaudited)


      LEGAL PROCEEDINGS AND CLAIMS (CONTINUED)

      In March 1993, the EPA notified Hadco Santa Clara (formerly Zycon) of its
      potential liability for maintenance and remediation costs in connection
      with a hazardous waste disposal facility operated by Casmalia Resources, a
      California Limited Partnership, in Santa Barbara County, California. The
      EPA identified Hadco Santa Clara as one of the 65 generators which had
      disposed the greatest amounts of materials at the site. Based on the total
      tonnage contributed by all generators, Hadco Santa Clara's share is
      estimated at approximately 0.2% of the total weight.

      The Casmalia site was regulated by the EPA during the period when the
      material was accepted. There is no allegation that Hadco Santa Clara
      violated any law in the disposal of material at the site, rather the EPA's
      actions stemmed from the fact that Casmalia Resources may not have the
      financial means to implement a closure plan for the site and because of
      Hadco Santa Clara's status as a generator of hazardous waste.

      In June 1997, the United States District Court in Los Angeles, California
      approved and entered a Consent Decree among the EPA and 49 entities
      (including Hadco Santa Clara) acting through the Casmalia Steering
      Committee (CSC). The Consent Decree sets forth the terms and conditions
      under which the CSC will carry out work aimed at final closure of the
      site. Certain closure activities will be performed by the CSC. Later work
      will be performed by the CSC, if funded by other parties. Under the
      Consent Decree, the settling parties will work with the EPA to pursue the
      non-settling parties to ensure they participate in contributing to the
      closure and long-term operation and maintenance of the facility.

      The EPA will continue as the lead regulatory agency during the final
      closure work. Because long-term maintenance plans for the site will not be
      determined for a number of years, it has not yet been decided which
      regulatory agency will oversee this phase of the work plan or how the
      long-term costs will be funded. However, the agreement provides a
      mechanism for ensuring that an appropriate federal, state or local agency
      will assume regulatory responsibility for long-term maintenance.

      The future costs in connection with the lawsuits described in the
      preceding paragraphs are currently indeterminable due to such factors as
      the unknown timing and extent of any future remedial actions which may be
      required, the extent of any liability of the Company and of other
      potentially responsible parties, and the financial resources of the other
      potentially responsible parties.

      On March 27, 1998, the Company received a written notice from legal
      counsel for the Lemelson Medical, Education & Research Foundation Limited
      Partnership (the "Lemelson Partnership"), alleging that the Company is
      infringing certain patents held by the Lemelson Partnership and offering
      to license such patents to the Company. The ultimate outcome of this
      matter is not currently determinable, and there can be no assurance that
      the outcome of this matter will not have a material adverse effect upon
      the Company's business, financial condition and results of operations.


                                       12
<PAGE>   13

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                 (unaudited)

      LEGAL PROCEEDINGS AND CLAIMS (CONTINUED)

      Litigation with respect to patents and other intellectual property matters
      can result in substantial damages, require the cessation of the
      manufacture, use and sale of infringing products and the use of certain
      processes, or require the infringing party to obtain a license to the
      relevant intellectual property.

      On January 12, 1998, Hadco Santa Clara (formerly Zycon) received notice of
      the filing of a lawsuit, before the Superior Court (County of Santa Clara,
      California), against it by Jackie Riley, Keith Riley and Richard Riley for
      damages (including punitive damages) for alleged injuries suffered,
      including Richard Riley's cancer, as a result of the alleged emission at a
      Zycon facility of effluent from allegedly toxic and hazardous chemical
      substances. Because this matter is at an early stage, the Company believes
      it cannot assess the potential range of damages that might be awarded
      should the plaintiffs prevail.

10.   SUBSEQUENT EVENT - DEBT OFFERING

      On May 18, 1998, the Company sold $200.0 million aggregate principal
      amount of its 9-1/2% Senior Subordinated Notes due 2008 (the "Notes") to
      certain purchasers. The purchasers subsequently resold the Notes to
      "qualified institutional buyers" in reliance upon Rule 144A under the
      Securities Act of 1933, as amended (the "Securities Act"), and offshore
      purchasers pursuant to Rule 904 of Regulation S under the Securities Act.
      The Notes were so resold at a price equal to 99.66% of their principal
      amount.

      Interest on the Notes is payable semiannually on each June 15 and December
      15, commencing December 15, 1998. The Notes are redeemable at the option
      of the Company, in whole or in part, at any time on or after June 15,
      2003, at 104.75% of their principal amount, plus accrued interest, with
      such percentages declining ratably to 100% of their principal amount, plus
      accrued interest. At any time on or prior to June 15, 2001 and subject to
      certain conditions, up to 35% of the aggregate principal amount of the
      Notes may be redeemed, at the option of the Company, with the proceeds of
      certain equity offerings of the Company at 109.50% of the principal amount
      thereof, plus accrued interest. In addition, at any time prior to June 15,
      2003, the Company may redeem the Notes, at its option, in whole or in
      part, at a price equal to the principal amount thereof, together with
      accrued interest, plus the Applicable Premium (as defined in the Indenture
      governing the Notes).

      The Notes are guaranteed, on a senior subordinated basis, by each of the
      Company's U.S. Restricted Subsidiaries (as defined in the Indenture) (the
      "Guarantors"). The net proceeds received by the Company from the issuance
      and sale of the Notes, approximately $193,820 million, was used to repay
      outstanding indebtedness under the Amended Credit Facility previously
      incurred to, among other things, finance the Acquisitions.

      The Indenture under that which the Notes were issued (the "Indenture")
      imposes certain limitations on the ability of the Company, its
      subsidiaries and, in certain circumstances, the Guarantors, to, among
      other things, incur indebtedness, pay dividends, prepay subordinated
      indebtedness, repurchase capital stock, make investments, create liens,
      engage in transactions with stockholders and affiliates, sell assets and
      engage in mergers and consolidations.







                                       13
<PAGE>   14

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                 (unaudited)

 
11. SUPPLEMENTAL GUARANTOR CONDENSED CONSOLIDATING FINANCIAL STATEMENTS 
    (UNAUDITED)
 
                     CONDENSED CONSOLIDATING BALANCE SHEET
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                                        AS OF MAY 2, 1998
                                             -----------------------------------------------------------------------
                                              GUARANTOR     NON-GUARANTOR     PARENT      ELIMINATION   CONSOLIDATED
                                             SUBSIDIARIES   SUBSIDIARIES    CORPORATION     ENTRIES        TOTAL
                                             ------------   -------------   -----------   -----------   ------------
                                                                         (IN THOUSANDS)
<S>                                          <C>            <C>             <C>           <C>           <C>
                                                       ASSETS
Current Assets:
  Cash and cash equivalents................    $    927        $ 1,534       $  2,536      $      --      $  4,997
  Accounts receivable, net.................      18,776            441         95,135             --       114,352
  Inventories..............................      28,696          6,815         40,095           (511)       75,095
  Deferred tax asset.......................       8,623             --         11,483             --        20,106
  Prepaid expenses and other current
     assets................................       2,015          4,173          1,870             --         8,058
                                               --------        -------       --------      ---------      --------
          Total current assets.............      59,037         12,963        151,119           (511)      222,608
Property, Plant and Equipment, net.........     139,696         43,481        135,158             --       318,335
Intercompany Receivable....................       5,218             87         54,694        (59,999)           --
Investments in subsidiaries................      24,106             --        274,044       (298,150)           --
Acquired Intangible Assets, net............     195,026             --             --             --       195,026
Other Assets...............................       2,036            330          1,106             --         3,472
                                               --------        -------       --------      ---------      --------
                                               $425,119        $56,861       $616,121      $(358,660)     $739,441
                                               ========        =======       ========      =========      ========
 
                                      LIABILITIES AND STOCKHOLDERS' INVESTMENT
Current Liabilities:
  Current portion of long-term debt........    $  3,899        $   107       $    831      $      --      $  4,837
  Accounts payable.........................      30,237          6,313         37,619             --        74,169
  Intercompany payable.....................      35,219         26,699             --        (61,918)           --
  Accrued payroll and other employee
     benefits..............................       3,755            167         25,324             --        29,246
  Accrued taxes............................      12,388            368        (12,262)            --           494
  Other accrued expenses...................       3,080             80         12,069             --        15,229
                                               --------        -------       --------      ---------      --------
          Total current liabilities........      88,578         33,734         63,581        (61,918)      123,975
Long-term Debt, net of current portion.....      12,326            327        346,384             --       359,037
Deferred Tax Liability.....................      50,785             --            883             --        51,668
Other Long-term Liabilities................          --             --          9,192             --         9,192
Stockholders' Investment:
  Common stock, $0.05 par value;
     Authorized -- 50,000 shares
     Issued and outstanding -- 13,212 in
       1998................................          11         29,654            662        (29,665)          662
  Paid-in Capital..........................     400,616             --        171,466       (400,616)      171,466
  Deferred Compensation....................          --             --            (75)            --           (75)
  Retained Earnings........................    (127,197)        (6,854)        24,028        133,539        23,516
                                               --------        -------       --------      ---------      --------
          Total stockholders' investment...     273,430         22,800        196,081       (296,742)      195,569
                                               --------        -------       --------      ---------      --------
                                               $425,119        $56,861       $616,121      $(358,660)     $739,441
                                               ========        =======       ========      =========      ========
</TABLE>
 

<PAGE>   15

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                 (unaudited)


                CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                                     FOR THE SIX MONTHS ENDING MAY 2, 1998
                                                    -----------------------------------------------------------------------
                                                     GUARANTOR     NON-GUARANTOR     PARENT      ELIMINATION   CONSOLIDATED
                                                    SUBSIDIARIES   SUBSIDIARIES    CORPORATION     ENTRIES        TOTAL
                                                    ------------   -------------   -----------   -----------   ------------
                                                                                (IN THOUSANDS)
<S>                                                 <C>            <C>             <C>           <C>           <C>
Net Sales.........................................    $152,103        $17,278       $240,078       $(1,596)      $407,863
Cost of Sales.....................................     129,926         16,112        187,112        (1,085)       332,065
                                                      --------        -------       --------       -------       --------
  Gross Profit....................................      22,177          1,166         52,966          (511)        75,798
Operating Expenses................................       7,444          1,836         30,030            --         39,310
Restructuring and Other Non-Recurring Charges.....          --             --          5,947            --          5,947
Write-off of Acquired In-Process Research and
  Development.....................................      63,050             --             --            --         63,050
                                                      --------        -------       --------       -------       --------
  Income (Loss) From Operations...................     (48,317)          (670)        16,989          (511)       (32,509)
Interest and Other Income.........................         822            612            (57)           --          1,377
Interest Expense..................................        (390)          (390)        (5,514)           --         (6,294)
                                                      --------        -------       --------       -------       --------
  Income (Loss) Before Provision for Income
    Taxes.........................................     (47,885)          (448)        11,418          (511)       (37,426)
Provision for Income Taxes........................       7,524             98          2,564            --         10,186
Equity in income (loss) of subsidiary.............      (1,249)            --        (55,955)       57,204             --
                                                      --------        -------       --------       -------       --------
  Net Income (Loss)...............................    $(56,658)       $  (546)      $(47,101)      $56,693       $(47,612)
                                                      ========        =======       ========       =======       ========
</TABLE>
 
                CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                                     FOR THE SIX MONTHS ENDING MAY 2, 1998
                                                    -----------------------------------------------------------------------
                                                     GUARANTOR     NON-GUARANTOR     PARENT      ELIMINATION   CONSOLIDATED
                                                    SUBSIDIARIES   SUBSIDIARIES    CORPORATION     ENTRIES        TOTAL
                                                    ------------   -------------   -----------   -----------   ------------
                                                                                (IN THOUSANDS)
<S>                                                 <C>            <C>             <C>           <C>           <C>
Net cash provided by (used in) operating
  activities......................................    $    206        $(2,017)      $ 14,917       $  (511)      $ 12,595
                                                      --------        -------       --------       -------       --------
Cash Flows from Investing Activities:
  Purchases of short-term investments.............          --             --         (2,020)           --         (2,020)
  Maturities of short-term investments............          --             --          3,582            --          3,582
  Foreign Sales Corp. dividend....................          --           (703)           703            --             --
  Purchases of property, plant and equipment......     (11,735)       (11,491)       (24,960)           --        (48,186)
  Investments in subsidiaries.....................       5,691             --         (6,202)          511             --
  Acquisition of Continental Circuits in 1998, net
    of cash acquired..............................          --             --       (190,032)           --       (190,032)
                                                      --------        -------       --------       -------       --------
    Net cash used in investing activities.........      (6,044)       (12,194)      (218,929)          511       (236,656)
                                                      --------        -------       --------       -------       --------
Cash Flows from Financing Activities:
  Principal payments of long-term debt............     (42,433)           (22)          (763)           --        (43,218)
  Proceeds from issuance of long-term debt........      10,730             --        246,148            --        256,878
  Proceeds from exercise of stock options.........          --             --            476            --            476
  Increase (Decrease) of intercompany payable.....      40,071         13,518        (53,589)           --             --
  Sale of common stock, net of issuance costs.....          --             --          1,480            --          1,480
  Tax benefit from exercise of stock options......          --             --          1,271            --          1,271
    Net cash provided by financing activities.....       8,368         13,496        195,023            --        216,887
                                                      --------        -------       --------       -------       --------
Net Increase (Decrease) in Cash and Cash
  Equivalents.....................................       2,530           (715)        (8,989)        3,085         (7,174)
Cash and Cash Equivalents, Beginning of Period....      (1,603)         2,249         11,525            --         12,171
                                                      --------        -------       --------       -------       --------
Cash and Cash Equivalents, End of Period..........    $    927        $ 1,534       $  2,536       $ 3,085       $  4,997
                                                      ========        =======       ========       =======       ========
</TABLE>
 

<PAGE>   16

                       HADCO CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                 (unaudited)

 
Basis of presentation.  In connection with the acquisition of Continental
Circuits Corp., which was financed with approximately $184 million of
borrowings from the Credit Facility, the Company on May 18, 1998 sold
$200,000,000 aggregate principal amount of 9 1/2% Senior Subordinated Notes due
in 2008 (the Notes). The Notes are fully and unconditionally guaranteed on a
senior subordinated basis, jointly and severally, by certain of the Company's
direct wholly-owned domestic subsidiaries (the Guarantors). The Guarantors are
Hadco Santa Clara, Inc., Hadco Phoenix, Inc., CCIR of Texas Corp., and CCIR of
California Corp. The condensed consolidating financial statements of the
Guarantors are presented above and should be read in connection with the
Consolidated Financial Statements of the Company. Separate financial statements
of the Guarantors are not presented because (i) the Guarantors are wholly-owned
and have fully and unconditionally guaranteed the Notes on a joint and several
basis and (ii) the Company's management has determined such separate financial
statements are not material to investors and believes the condensed
consolidating financial statements presented are more meaningful in
understanding the financial position of the Guarantors.
 
There are no significant restrictions on the ability of the Guarantors to make
distributions to the Company.
 
Condensed consolidating financial information has not been presented for 1996
and 1995 because the Guarantors were not subsidiaries of the Company in its
1996 and 1995 fiscal years.
 

<PAGE>   17

                                    SIGNATURE

      Pursuant to the requirements of the Securities Exchange Act of 1934, the
      registrant has duly caused this report to be signed on its behalf by the
      undersigned thereunto duly authorized.

                                    Hadco Corporation

     Date:  June 23, 1998           By: /s/ Timothy P. Losik
                                       -----------------------------------
                                       Timothy P. Losik
                                       Senior Vice President and Chief
                                       Financial Officer (principal financial
                                       officer and principal accounting officer)


                                       14