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                                                                   EXHIBIT 10.20

                             AGREEMENT OF GUARANTY
                             ---------------------


       THIS AGREEMENT OF GUARANTY ("Guaranty") is made this 24th day of March,
1997, by INTEGRATED PACKAGING ASSEMBLY CORPORATION, a California corporation
(the "Guarantor"), to SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.), a Delaware
corporation ("Lender"), with reference to the following facts:

                                    RECITALS
                                    --------

       A.   Concurrently herewith, Lender is making a loan in the original
maximum principal amount of Six Million Seven Hundred Thousand and NO/100
Dollars ($6,700,000.00) (the "Loan") to IPAC PROPERTIES, a California
corporation ("Borrower").

       B.   The Loan is evidenced by that certain Promissory Note of even date
herewith in the original principal sum of $6,700,000.00 (the "Note") and is
secured by (i) that certain Deed of Trust, Financing Statement, Security
Agreement, and Fixture Filing (with Assignment of Rents and Leases) of even date
herewith and recorded in the Official Records of Santa Clara County, California
(the "Deed of Trust"), encumbering certain real property located in said County
and more particularly described in the Deed of Trust (the "Property"); (ii) that
certain UCC-1 Financing Statement of even date herewith to be filed in the
Office of the Secretary of State of the State of California; (iii) the
Environmental Agreement and Indemnity and (iv) various other security documents
and instruments executed by Borrower in favor of Lender.  All of the foregoing
documents and instruments are sometimes collectively referred to herein as the
"Loan Documents".

       C.   The person or entity named herein as Guarantor (or, if more than one
person or entity is named herein as Guarantor, each of the persons or entities
comprising Guarantor) wholly-owns all interest in Borrower, and will therefore
receive a direct and substantive benefit from the Loan.

       D.   Guarantor has reviewed, understood and approved all of the terms and
conditions of the Note, the Deed of Trust and all of the other Loan Documents
and all other documents executed in connection with the Loan, including, but not
limited to, this Guaranty; Guarantor has been afforded the full and fair
opportunity to consult with independent legal counsel of Guarantor own choice
with respect to each and all of such matters and documents and has done so to
the extent deemed appropriate by Guarantor.

       E. The execution and delivery of this Guaranty to Lender by Guarantor
is a condition precedent to Lender's making the Loan, is a material inducement
to Lender in making the Loan and Lender would be unwilling to make the Loan
without this further assurance of payment and performance.


                                   AGREEMENT
                                   ---------

       NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Guarantor hereby agrees as
follows:
<PAGE>

       1.  Each of the foregoing Recitals is true and correct and is
incorporated herein by this reference.

       2.  Subject to the provisions of the Note limiting liability after the
Lease Termination as defined in the Note and also as limited by the non-recourse
language before and after Lease Termination (as defined in the Note) on page 6
of the Note of even date herewith executed by Borrower, Guarantor hereby
unconditionally and irrevocably guaranties and promises, without demand by
Lender therefor, to pay all sums owing by Borrower to Lender under any of the
Loan Documents and to perform any and all of the terms, covenants, conditions
and agreements contained in any of the Loan Documents when and as required to be
paid and performed by Borrower thereunder, including, but not limited to, the
obligation to make payments of principal and interest due under the Note, the
obligation to repay the entire principal balance of the Note, whether at
maturity, through acceleration or otherwise, the obligation to pay all other
sums evidenced or secured by, or advanced to Borrower under, the Note, the Deed
of Trust, or any other of the Loan Documents and the obligation to perform all
of the covenants and agreements of Borrower to be performed under the Deed of
Trust or any of the other Loan Documents. The liability of Guarantor hereunder
shall be IN THE FULL AMOUNT AND FOR ALL OBLIGATIONS owed to Lender and any
trustee under any of the Loan Documents, including any interest, late charges,
default interest, costs and fees (including, without limitation, reasonable
attorneys' fees) that would have accrued under the Loan Documents and all other
obligations that would have been performable by Borrower under the Loan
Documents but for the commencement of a case under the Bankruptcy Code or any
other law governing insolvency, bankruptcy, reorganization, liquidation or like
proceeding, plus interest thereon as provided in the Note, plus the attorneys'
fees, costs and other expenses incurred by Lender in the enforcement of this
Guaranty.

       3.  If so provided in the Loan Documents, Guarantor agrees that
bankruptcy, insolvency and other actions by, against or on behalf of Guarantor,
or any Guarantor, as set forth therein may be declared by Lender to be events of
default under the Loan Documents.

       4.  The obligations of Guarantor hereunder are joint and several, and are
independent of the obligations of Borrower. Guarantor expressly and specifically
agrees that a separate action or actions may be brought and prosecuted against
Guarantor whether or not action is brought against Borrower and whether or not
Borrower is joined in any action against Guarantor.

       5.  Guarantor hereby authorizes Lender, without notice or demand and
without affecting Guarantor liability hereunder, from time to time to: (a)
change or extend the time, or manner, of payment of the Note; (b) make further
advances under the Note or increase or decrease the principal amount evidenced
thereby; (c) change any of the terms, covenants, conditions or provisions of the
Deed of Trust or any other of the Loan Documents; (d) transfer, assign or
negotiate the Note and transfer and assign the Deed of Trust and other Loan
Documents; (e) take and hold additional security for the payment of the Note or
the performance of the Deed of Trust, and exchange, enforce, waive and release
any such security; (f) release all or part of the Property from the Deed of
Trust whether in accordance with any partial release provision now contained in
the Deed of Trust or otherwise as Lender may determine in its discretion; (g)
apply the Property secured by the Deed of Trust to the payment of the Loan and
direct the order or manner of sale thereof as Lender may determine in its
discretion; (h) proceed against Borrower or Guarantor on the Note without first
foreclosing under the Deed of Trust; (i) accept a conveyance of all or part of
the Property secured by the Deed of Trust in partial satisfaction of the
indebtedness due under the Note and proceed against Borrower or Guarantor
<PAGE>

for the balance then due thereunder; (j) accept one or more substitute
properties to replace any portion of the Property released from the Deed of
Trust; (k) discharge or release any parties liable under the Loan Documents; (l)
accept or make compositions or other arrangements or file or refrain from filing
a claim in any bankruptcy proceeding of or affecting Borrower or any other
guarantor or pledgor or the property of any of them; or (m) credit payments in
such manner and order of priority to principal, interest or other obligations as
Lender may determine in its discretion.

       6.  In addition to all the other waivers agreed to and made by Guarantor
as set forth in this Guaranty, by executing this Guaranty Guarantor freely,
irrevocably and unconditionally waives all rights and defenses that the
Guarantor may have because the Borrower's debt is secured by real property. This
means, among other things:

      a.   Lender may collect from the Guarantor without first foreclosing on
           any real or personal property collateral pledged by the Borrower.

      b.   If Lender forecloses on any real property collateral pledged by the
           Borrower:

           (i) The amount of the debt may be reduced only by the price for which
           that collateral is sold at the foreclosure sale, even if the
           collateral is worth more than the sale price.

           (ii) The Lender may collect from the Guarantor even if the Lender, by
           foreclosing on the real property collateral, has destroyed any right
           the Guarantor may have to collect from the Borrower. This is an
           unconditional and irrevocable waiver of any rights and defenses the
           Guarantor may have because the Borrower's debt is secured by real
           property.  These rights and defenses include, but are not limited to,
           any rights or defenses based upon Section 580a, 580b, 580d, or 726 of
           the Code of Civil Procedure.

      c.   Guarantor waives all rights and defenses arising out of an election
           of remedies by Lender, even though that election of remedies, such as
           a nonjudicial foreclosure with respect to security for a guaranteed
           obligation, has destroyed the Guarantor's rights of subrogation and
           reimbursement against the principal by the operation of Section 580d
           of the Code of Civil Procedure or otherwise.

      d.   Guarantor waives the benefit of or right to assert any statute of
           limitations affecting the liability of Guarantor hereunder or the
           enforcement thereof to the extent permitted by law; any part payment
           by Borrower or other circumstance which operates to toll any statute
           of limitations as to Borrower shall also operate to toll the statute
           of limitations as to Guarantor;

      e.   Until the obligations guaranteed hereby have been fully paid and
           performed, Guarantor waives the Guarantor's or other surety's rights
           of subrogation, reimbursement, indemnification and contribution and
           other rights, benefits and defenses, if any, otherwise available to
           Guarantor pursuant to California law, including, without limitation,
           the rights, benefits or defenses set forth in California Civil Code
           Sections 2787 to 2855, inclusive, 2899 or 3433 and any rights,
           benefits or defenses resulting from alteration, impairment or
           suspension in any respect or by any means of any of Borrower's
           obligations under the Loan


<PAGE>

           Documents or any of Lender's rights or remedies under the Loan
           Documents without Guarantor's prior consent;

      f.   Guarantor acknowledges and agrees that Lender is relying on the above
           waivers in making the Loan, and that these waivers are a material
           part of the consideration which Lender is receiving for making the
           Loan;

      g.   Guarantor waives presentment, demand, protest, notice of protest,
           notice of dishonor and notice of non-payment and notice of acceptance
           of this Guaranty;

      h.   Guarantor waives the right, if any, to the benefit of, or to direct
           the application of, any security held by Lender, including, without
           limitation, the Property described in the Deed of Trust; and, until
           all the indebtedness and obligations, payment and performance of
           which are hereby guarantied, have been paid and performed in full,
           any right to enforce any remedy which Lender now has or hereafter may
           have against Borrower, and any right to participate in any security
           now or hereafter held by Lender; and

      i.   Guarantor waives the right to require Lender to proceed against
           Borrower, to proceed against the Property, or to proceed against any
           other security now or hereafter held by Lender or to pursue any other
           remedy in Lender's power.

If this Guaranty is secured by real property owned by Guarantor, Lender and
Guarantor agree that Guarantor's waivers pursuant to this Paragraph 6 are meant
to apply to the security and collateral provided by Borrower or any other
guarantor or pledgor and not to the real property of Guarantor securing this
Guaranty; provided, however, that this sentence shall not be applicable with
regard to the Property or any portion thereof or any interest therein now owned
or hereafter acquired by Guarantor whether with or without the consent of
Lender.

      7.   Any indebtedness of Borrower now or hereafter held by Guarantor is
hereby subordinated to the indebtedness of Borrower to Lender; and any such
indebtedness of Borrower to Guarantor, if Lender so requests, shall be
collected, enforced, received and held by Guarantor as trustee for Lender on
account of the indebtedness of Borrower to Lender and without affecting the
liability of Guarantor under this Guaranty.

      8.   It is not necessary for Lender to inquire into the powers of Borrower
or of the officers, partners, joint venturers or agents, if any, acting or
purporting to act on Borrower's behalf, and any indebtedness or other obligation
made or created in reliance upon the professed exercise of such powers shall be
guarantied hereunder.

      9.   Guarantor agrees to pay all reasonable attorneys' fees and other
costs and expenses which may be incurred by Lender in the enforcement of this
Guaranty, including, without limitation, those incurred in connection with any
case, action, proceeding, claim or otherwise under Chapters 7, 11 or 13 of the
Bankruptcy Code or any successor statute or statutes thereto whether the same be
commenced or filed by Borrower, Guarantor or any other person or entity.

      10.  This Guaranty shall bind the heirs, devisees, successors and assigns
of Guarantor and shall inure to the benefit of the successors and assigns of
Lender. As used herein, the term "Guarantor" shall also include any estate
created by the commencement of a case under Title 11
<PAGE>

of the United States Code or under any successor statute thereto ("Bankruptcy
Code") or under any other insolvency, bankruptcy reorganization or liquidation
proceeding, or whether acting by any trustee under the Bankruptcy Code,
liquidator, sequestrator or receiver of any person or entity comprising
Guarantor or of the property of any such person or entity or acting by similar
person or entity duly appointed pursuant to any law generally governing any
insolvency, bankruptcy, reorganization, liquidation, receivership or like
proceeding.

     11.  This Guaranty shall bind the heirs, devisees, successors and assigns
of Guarantor and shall inure to the benefit of the successors and assigns of
Lender.

     12.  This Guaranty shall follow the Note and the Deed of Trust and, in the
event that the Note and the Deed of Trust are sold, transferred, assigned or
conveyed by Lender, this Guaranty may be likewise sold, transferred, assigned or
conveyed by Lender to the successor holder of the Note and the Deed of Trust,
and, in such event, the successor holder of this Guaranty may enforce this
Guaranty just as if said holder had been originally named as Lender
hereunder.

     13.  If all or any portion of the obligations guarantied hereunder are paid
or performed, the obligations of Guarantor hereunder shall continue and shall
remain in full force and effect in the event that all or any part of such
payment or performance is avoided or recovered directly or indirectly from
Lender as a preference, fraudulent transfer or otherwise under the Bankruptcy
Code or any other Federal or state laws, irrespective of (a) any notice of
revocation given by Guarantor prior to such avoidance or recovery, and (b) full
payment and performance of all of the indebtedness and obligations evidenced and
secured by the Loan Documents.

     14.  No term or provision of this Guaranty may be changed, waived, revoked
or amended without Lender's prior written consent. Should any term or provision
of this Guaranty be determined by a court of competent jurisdiction to be
unenforceable, all other terms and provisions hereof shall remain effective.

     15.  This Guaranty shall apply to each of the individuals or entities
comprising Guarantor as if each had executed a separate guaranty, and the
liability of each Guarantor shall be joint and several. If for any reason this
Guaranty is held to be unenforceable against any of the individuals or entities
comprising Guarantor, such unenforceability shall not affect the obligations of
the remaining individuals or entities comprising Guarantor hereunder, and each
Guarantor agrees that suit may be brought against each Guarantor individually to
enforce the terms and conditions of this Guaranty.

     16.  Any notice, demand, consent, approval, directive, agreement or other
communication required or permitted hereunder or under the other Loan Documents
shall be in writing and shall be validly given and effectively served if mailed
by U.S. mail, first class or certified mail, return receipt requested, postage
prepaid, addressed as follows to the person entitled to receive the same:
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If to Lender:            Sun Life Assurance Company of Canada (U.S.)
                         One Sun Life Executive Park
                         Wellesley, Massachusetts  02181
                         Attn:  Legal Department

with a copy to:          Graham & James LLP
                         One Maritime Plaza, Suite 300
                         San Francisco, California 94111
                         Attn:  Bruce W. Hyman, Esq.

To Guarantor:            Integrated Packaging Assembly Corporation
                         2221 Old Oakland Road
                         San Jose, California 95131

with a copy to:          Wilson, Sonsini, Goodrich & Rosati
                         650 Page Mill Road
                         Palo Alto, California  94304
                         Attn: Debra Summers, Esq.

     17.  This Guaranty shall be governed by and construed in accordance with
the laws of the State of California. In the event any action is brought against
Guarantor hereunder, Guarantor agree to submit to the jurisdiction of the State
of California.

     18.  This Guaranty embodies the entire agreement of Guarantor and Lender
with respect to the matters set forth herein, and supersedes all prior and
contemporaneous agreements (whether oral or written) between Guarantor and
Lender with respect to the matters set forth herein. No course of prior dealing
between Guarantor and Lender, no usage of trade, and no parol or extrinsic
evidence of any nature shall be used to supplement, modify or vary any of the
terms hereof. There are no conditions to the full effectiveness of this
Guaranty.

     19.  This Agreement may be executed in any number of counterparts, each of
which shall be deemed to be an original and all of which together shall comprise
but a single instrument.

     20.  Notwithstanding anything to the contrary in this Guaranty, except with
respect to "recourse obligations" described in Section 5.9 of the Deed of Trust,
this Guaranty and all rights and privileges of Lender and all obligations and
liabilities of Guarantor hereunder shall automatically terminate upon the
occurrence of "Lease Termination" (as defined in Section 5.9 of the Deed of
Trust)."

     IN WITNESS WHEREOF, Guarantor has executed this Agreement of Guaranty as of
the date first above written.


                                         INTEGRATED PACKAGING ASSEMBLY
                                         CORPORATION, a California corporation
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                                         By:  /s/ Tony Lin
                                            _______________________

                                              Its: CFO
                                                  _________________