QuickLinks -- Click here to rapidly navigate through this document

EXHIBIT 10.117

        [ COMPANY LETTERHEAD ]

May 9, 2002

Southwall Technologies Inc.
1029 Corporation Way
Palo Alto, CA 94303

ATTN: Thomas G. Hood
President and Chief Executive Officer

Dear Mr. Hood:

This letter is written with references to the Guarantee Agreement dated as of
May 6, 1997, between Southwall Technologies, Inc. ("STI") and Teijin Limited
("Teijin") as amended in August 1999 by Memorandum between STI and Teijin (such
Guarantee, as amended, the "Guarantee Agreement").

STI has advised Teijin that, as of December 31, 2001 and March 31, 2002, it was
not in compliance with the Minimum Quick Ratio, Tangible Net Worth Amount and
Maximum Debt/Tangible Net Worth of the financial covenants in Article 4-1(1) of
the Guarantee Agreement. STI has requested that Teijin waive STI's
non-compliance through September 30, 2003, including, without limitation, the
measurement periods ending on December 31, 2001 and March 31, 2002.

Subject to the conditions set forth below, this will confirm that Teijin hereby
waives any defaults under Article 5.1 of the Guarantee Agreement that may exist
through and including September 30, 2003, arising out of STI's failure to comply
with the financial covenants of the Minimum Quick Ratio, Tangible Net Worth
Amount and Maximum Debt Tangible Net Worth in Article 4-(1) of the Guarantee
Agreement.

This waiver does not apply to any period after September 30, 2003, after which
Teijin shall be entitled to enforce its rights under the Guarantee Agreement
with respect to STI's non-compliance with one or more of such covenants for the
any measurement period starting after September 30, 2003. This waiver is solely
and exclusively for the purpose of the Guarantee Agreement and without prejudice
to any other rights that Teijin has or may have against STI.

In addition, this waiver is conditioned on STI's agreement that, 1) in the event
that is issues new capital to third parties in a public offering of its equity
securities at any time prior to September 30, 2003, STI shall apply $2.5 million
of the proceeds of the offering to the prepayment of the 2004 installments of
the Sanwa loan and 2) in the event that it issues new capital to third parties
in one or more transactions other than a public offering of its equity
securities at any time prior to September 30, 2003, STI shall apply 10% of the
aggregate proceeds of such offerings to the prepayment of the 2004 installments
of the Sanwa loan. STI hereby confirms its obligation to make scheduled payments
in accordance with the terms of the Sanwa loan.

   
Very truly yours,

Teijin Limited

/s/ Y. Kobayashi

By Yakio Kobayashi
    Assistant to General Manager

--------------------------------------------------------------------------------

QuickLinks

EXHIBIT 10.117