<PAGE>
 
                                                          FEDERAL IDENTIFICATION
                                                                 NO.  04-2777507
                                                                      ----------



                       THE COMMONWEALTH OF MASSACHUSETTS
                             WILLIAM FRANCIS GALVIN
                         Secretary of the Commonwealth
             One Ashburton Place, Boston, Massachusetts  02108-1512

                             ARTICLES OF AMENDMENT
                    (GENERAL LAWS, CHAPTER 156B, SECTION 72)
 
We,    John A. Pino                                        , * President
   --------------------------------------------------------
and    Douglass C. Greenlaw                                    , * Clerk
   ------------------------------------------------------------ 
of    ACT Manufacturing, Inc.                                           ,
  ----------------------------------------------------------------------
                          (Exact name of corporation)

located at:     108 Forest Avenue, Hudson,  MA 01749
           -------------------------------------------------------------------,
               (Street address of corporation in Massachusetts)

 certify that these Articles of Amendment affecting articles numbered:

         3
------------------------------------------------------------------------------
         (Number those articles 1, 2, 3, 4, 5, and/or 6 being amended)

of the Articles of Organization were duly adopted at a meeting held on 
May 20, 1997, by vote of:
--- --    --         

    7,685,399    shares of  Common Stock, $.01 par value  of  8,818,000
    ---------               ----------------------------      ---------
                            (type, class & series, if any) 
shares outstanding, 

                 shares of                                of         
    ---------               ----------------------------      ---------
                            (type, class & series, if any) 
shares outstanding, and     

                 shares of                                of         
    ---------               ----------------------------      ---------
                            (type, class & series, if any) 
shares outstanding,  

   /1/**being at least a majority of each type, class or series outstanding and
   entitled to vote thereon



 *Delete the inapplicable words. ** Delete the inapplicable clause.
 /1/For amendments adopted pursuant to Chapter 156B, Section 70.
 /2/For amendments adopted pursuant to Chapter 156B, Section 71.

 NOTE: IF THE SPACE PROVIDED UNDER ANY ARTICLE OR ITEM ON THIS FORM IS
 INSUFFICIENT, ADDITIONS SHALL BE SET FORTH ON ONE SIDE ONLY OF SEPARATE 8 1/2 X
 11 SHEETS OF PAPER WITH A LEFT MARGIN OF AT LEAST 1 INCH.  ADDITIONS TO MORE
 THAN ONE ARTICLE MAY BE MADE ON A SINGLE SHEET SO LONG AS EACH ARTICLE
 REQUIRING EACH ADDITION IS CLEARLY INDICATED.
<PAGE>
 
To change the number of shares and the par value (if any) of any type, class or
series of stock which the corporation is authorized to issue, fill in the
following:


The total presently authorized is:
 
WITHOUT PAR VALUE STOCKS                           WITH PAR VALUE STOCKS
-------------------------------------------------------------------------------
TYPE                 NUMBER OF SHARES     TYPE     NUMBER OF SHARES  PAR VALUE 
-------------------------------------------------------------------------------
Common:              0                   Common:     20,000,000       $.01     
-------------------------------------------------------------------------------
                                                                               
-------------------------------------------------------------------------------
Preferred:           0                   Preferred:   5,000,000       $.01     
-------------------------------------------------------------------------------
                                                                               
-------------------------------------------------------------------------------
 

Change the total authorized to:
 
WITHOUT PAR VALUE STOCKS                           WITH PAR VALUE STOCKS
-------------------------------------------------------------------------------
TYPE                 NUMBER OF SHARES     TYPE     NUMBER OF SHARES  PAR VALUE 
-------------------------------------------------------------------------------
Common:              0                   Common:     30,000,000       $.01     
-------------------------------------------------------------------------------
                                                                               
-------------------------------------------------------------------------------
Preferred:           0                   Preferred:   5,000,000       $.01     
-------------------------------------------------------------------------------
                                                                               
-------------------------------------------------------------------------------
 
 
<PAGE>
 
 The foregoing amendment(s) will become effective when these Articles of
 Amendment are filed in accordance with General Laws, Chapter 156B, Section 6
 unless these articles specify, in accordance with the vote adopting the
 amendment, a later effective date not more than thirty days after such filing,
 in which event the amendment will become effective on such later date.

 Later effective date:
                      ----------------

 SIGNED UNDER THE PENALTIES OF PERJURY, this   20   day of      May    , 1997  .
                                             ------        ------------    ---- 

 /s/ John A. Pino
 ---------------------------------------------------------------, *President

 /s/ Douglass C. Greenlaw
 ---------------------------------------------------------------, *Clerk

 *Delete the inapplicable words.
<PAGE>
 
                       THE COMMONWEALTH OF MASSACHUSETTS

                             ARTICLES OF AMENDMENT

                    (GENERAL LAWS, CHAPTER 156B, SECTION 72)


          =====================================================================
          I hereby approve the within Articles of Amendment, and the filing fee
          in the amount of $10,000 having been paid, said article is deemed to
                           -------                                            
          have been filed with me this  12th  day of         June          ,
                                       ------        ---------------------- 
          1997.
          ---- 


          Effective date:             6/12/97
                           ---------------------------------------------------



                          /s/ William Francis Galvin

                            WILLIAM FRANCIS GALVIN

                         Secretary of the Commonwealth



                         TO BE FILLED IN BY CORPORATION

                      PHOTOCOPY OF DOCUMENT TO BE SENT TO:


                         Joshua N. Sun, Esq.
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                         Testa, Hurwitz & Thibeault, LLP
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                         High Street Tower
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                         125 High Street
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                         Boston, MA  02110
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