ADDENDUM TO MASTER LEASE AGREEMENT




       THIS ADDENDUM TO MASTER LEASE  AGREEMENT  (this  "Addendum") is made this
12th day of May, 1995, and supplements that certain Master Lease Agreement dated
June 6, 1994 (the  "Master  Lease"),  by and between  First  Interstate  Bank of
Arizona,  N.A.  ("Lessor"),  and Cerprobe  Corporation,  an Arizona  corporation
("Lessee").

       Supplementing  the terms of the Master Lease,  Lessor and Lessee agree as
follows:

       l. Unless  otherwise  defined in this Addendum,  capitalized  terms shall
have the same meanings set forth in the Master Lease.

       2. To the extent that the  provisions of this Addendum can be interpreted
as  consistent  with the terms of the Master Lease and any  Equipment  Schedules
executed in connection therewith,  the terms of this Addendum, the Master Lease,
and such Equipment  Schedules shall be read together as a consistent  agreement.
To the  extent  of any  inconsistency  among the  Master  Lease,  the  Equipment
Schedules,  and this  Addendum,  the terms and provisions of this Addendum shall
control.

       3. All equipment lease pursuant to the Master Lease shall be evidenced by
an Equipment  Schedule,  which Equipment Schedule shall set forth specific terms
and conditions with regard to the Equipment  described  therein.  This Addendum,
the Master Lease, and the Equipment Schedules together shall establish the terms
and  conditions  governing the lease of Equipment  under the Master  Lease.  The
Master Lease, this Addendum, and the Equipment Schedules shall be referred to in
this Addendum as the "Agreement".

       4. Subject to  satisfaction of all conditions set forth in the Agreement,
Lessee may enter into Equipment  Schedules for Equipment having an aggregate Net
Cost of up to One Million Dollars  ($1,000,000.00) (the "Lease Line"). The Lease
Line shall be  non-revolving.  "Net Cost"  means one hundred  percent  (100%) of
Lessor's cost to purchase all  Equipment  plus the cost of  installation  of the
Equipment  at  Lessee's  place  of  business  as such  installation  cost may be
approved by Lessor in Lessor's sole discretion.

       5.  Lessee may enter into  Equipment  Schedules  under the Lease Line for
terms ranging between thirty-six (36) and sixty (60) months. The maximum term of
each  Equipment  Schedule  shall  be equal to the  useful  economic  life of the
applicable  Equipment  as Lessor may  determine  in  Lessor's  sole  discretion.
Notwithstanding  the  useful  economic  life of the  applicable  Equipment,  the
minimum term of an Equipment Schedule shall be thirty-six (36) months.

       6. Lessee's right to enter into Equipment  Schedules under the Lease Line
shall expire on April 27, 1996.  Lessee must accept  delivery of all  Equipment,
and the Equipment Schedule Acceptance Deadline shall be, no later than April 27,
1996.

       7. All Equipment  Schedules will be funded at a fixed rate  equivalent to
like tenor Treasury notes plus 2.0% at the time of funding. Treasury rates shall
be defined as those  issued  weekly in the Federal  Reserve  Boards  weekly H.15
report.

       8. Lessee Agrees that unless Lessor agrees  otherwise in writing,  Lessee
shall  comply with all terms and  covenants  (financial  or  otherwise)  of that
certain  Loan  Agreement  dated April 30,  1995  between  Lessee and Lessor,  as
subsequently  amended,  whether or not any amounts remain outstanding under such
Loan Agreement or such loan agreement has been terminated.

       9. Lessee  recognizes that Lessor has incurred and will continue to incur
certain  costs  and  expenses  in  connection  with  establishment  maintaining,
servicing,  and administering the credit facility. To ensure that Lessor is able
to recover such costs and expenses, Lessee agrees that, Lessor shall be entitled
to collect the  following  facility  charge,  which Lessee  hereby  promises and
agrees to pay: So long as Lessor shall have any obligation to extend or continue
credit to Lessee in any form, Lessee shall pay to lessor on the last day of each
and every calendar quarter a non-refundable  commitment fee in the amount of 1/4
of 1%  (percent)  of unused  balance  of the Lease  Line  during  the  preceding
calendar quarter.

Cerprobe Corporation                     First Interstate Bank of Arizona, N.A.

By: /s/ Zane Close                       By: /s/ Michael J. Hutchenson
   ---------------------------               --------------------------------

n:\Mike
Addendum.Doc:2