
<PAGE>   1
                                                                    EXHIBIT 5.1


                          [FENNEMORE CRAIG LETTERHEAD]


                                  July 14, 1997


ADFlex Solutions, Inc.
2001 West Chandler Boulevard
Chandler, Arizona  85224

         RE:  ADFlex Solutions, Inc. Registration Statement on Form S-8

Gentlemen:

                  We have acted as special counsel to ADFlex Solutions, Inc., a
Delaware corporation (the "Company"), in connection with the Registration
Statement on Form S-8 (the "Registration Statement"), to be filed by the Company
with the Securities and Exchange Commission (the "Commission"). The Registration
Statement relates to the registration under the Securities Act of 1933, as
amended (the "Act"), of 300,000 shares (the "Shares") of the Company's Common
Stock, par value $.01 per share, to be issued under the Company's Employee Stock
Purchase Plan, as amended (the "Plan").

                  In connection with this opinion, we have examined originals or
copies, certified or otherwise identified to our satisfaction, of (i) the Plan,
(ii) the Restated Certificate of Incorporation and the Bylaws of the Company,
(iii) certain resolutions of the Board of Directors of the Company relating to
the Plan, (iv) the form of Registration Statement proposed to be filed with the
Commission, and such other documents as we have deemed necessary or appropriate
as a basis for the opinions set forth below. In such examination, we have
assumed the genuineness of all signatures, the legal capacity of natural
persons, the authenticity of all documents submitted to us as
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FENNEMORE CRAIG

ADFlex Solutions, Inc.
July 14, 1997
Page 2

originals, the conformity to original documents of all documents submitted to us
as certified or photostatic copies and the authenticity of the originals of such
latter documents. As to any facts material to this opinion which we did not
independently establish or verify, we have relied upon statements and
representations of officers and other representatives of the Company and others.

                  Based upon and subject to the foregoing and the limitations
set forth below, we are of the opinion that the Shares have been duly authorized
and, after the Registration Statement becomes effective and when the Shares are
issued and sold in accordance with the Plan and the Form S-8 prospectus to be
delivered to the Plan participant, for consideration having a value at least
equal to the par value thereof, the Shares will be duly issued, fully paid and
nonassessable.

                  We are opining herein as to the effect on the subject
transaction only of United States federal law and the Delaware General
Corporation Law, and we assume no responsibility as to the applicability
thereto, or the effect thereon, of the laws of any other jurisdiction.

                  This opinion is furnished to you solely for your benefit in
connection with the filing of the Registration Statement and is not to be used,
circulated, quoted or otherwise referred to for any other purpose without our
prior written consent. Notwithstanding the foregoing, we hereby consent to the
filing of this opinion with the Commission as Exhibit 5.1 to the Registration
Statement. In giving this consent, we do not thereby admit that we are included
in the category of persons whose consent is required under Section 7 of the Act
or the rules and regulations of the Commission.

                                                Very truly yours,


                                                /s/ FENNEMORE CRAIG
                                                FENNEMORE CRAIG,
                                                a Professional Corporation


KCM/wte
