<PAGE>   1


                                                                     EXHIBIT 4.6

THIS NOTE HAS NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR
THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM
REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES
ACT"), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN
EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN
AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION
REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE
SECURITIES LAWS.



                                 SHELDAHL, INC.

                                      NOTE

$ 15,000                                                       December 28, 2000


         FOR VALUE RECEIVED, Sheldahl, Inc., a Minnesota corporation (the
"Company"), hereby promises to pay to the order of Ampersand IV Companion Fund
Limited Partnership (the "Holder"), the principal sum of Fifteen Thousand
($15,000), together with interest (computed on the basis of a 360 day year, so
that 1/360th of the annualized interest will accrue for each day that principal
is outstanding) from the date hereof until the earlier of (i) the Maturity Date
(as defined in the Purchase Agreement referred to below), or (ii) the date this
Note and all amounts payable in connection herewith have been paid to the Holder
on the unpaid balance hereof at the rate of interest set forth in the Purchase
Agreement, payable quarterly in arrears, on the last day of each March, June,
September and December, commencing December 31, 2000, and on the Maturity Date
(each such date an "Interest Payment Date").

         Payments of principal of, and prepayment fees, if any, in connection
with this Note are to be made in lawful money of the United States of America
except as provided in the immediately following sentence. Payments of interest
on this Note until December 28, 2001 may be made by issuing additional notes in
aggregate principal amounts equal to the amount of interest then due. Payments
shall be made to the Holder at such place and by such means as provided in the
Purchase Agreement.


<PAGE>   2



         This Note is one of a series of notes issued pursuant to an Amended and
Restated Subordinated Notes and Warrant Purchase Agreement, dated as of December
28, 2000 (as from time to time amended, the "Purchase Agreement"), among the
Company, as issuer, and the Purchasers signatory thereto. This Note may be
subject to redemption prior to Maturity Date, as provided in the Purchase
Agreement.

Each of the notes shall include the following legend on the note:

THIS INSTRUMENT IS SUBJECT TO THE TERMS OF A SUBORDINATION AGREEMENT BY HOLDER
IN FAVOR OF CERTAIN SENIOR LENDERS DATED AS OF DECEMBER 28, 2000.

         In case an Event of Default (as defined in the Purchase Agreement)
shall occur and be continuing, the principal of and accrued interest on this
Note may be declared to be due and payable in the manner and with the effect
provided in the Purchase Agreement.

         The Company hereby waives presentment, demand, protest or notice of any
kind in connection with this Note.

         THIS NOTE SHALL BE CONSTRUED UNDER THE LAWS OF THE STATE OF NEW YORK.


                                           SHELDAHL, INC.



                                            By: /s/ Jill D. Burchill
                                               ---------------------------------
                                               Name: Jill D. Burchill
                                               Title: Vice President and Chief
                                                      Financial Officer