Wentworth
Laboratories
Pegasus Probe
Installation and Operation
Issue 2.0, December 2003
The Leader in ProbeAbility ™
Wentworth
Laboratories
Copyright notice
© Wentworth Laboratories Limited, 2002-2003.
ALL RIGHTS RESERVED
This document is copyrighted by Wentworth Laboratories Limited. No part of this
manual may be reproduced or transmitted in any form, by any means (electronic,
photocopying, recording, or otherwise) without the prior written permission of
Wentworth Laboratories Limited.
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not he property of Wentworth Laboratories Limited are acknowledged to be the property
of their respective holders.
Disclaimer
Wentworth Laboratories Limited makes no representations or warranties regarding the
contents of this document. We reserve the right to revise this document, or make
changes to the specifications of the products described within, at any time without
notice and without obligation to notify any person for such revision or change.
Contact Information
If you have any questions or comments about the Pegasus Probe or any other
Wentworth product, please direct your inquiry to your local sales representative or one
of the Wentworth offices:
Wentworth Laboratories, Inc
101 Commerce Drive
Brookfield, CT 06804
Tel: 203 775 9311
Fax: 203 775 4398
Wentworth Laboratories, Ltd
1 Gosforth Close
Sandy, Bedfordshire SG19 1RB
ENGLAND
Tel: +44 (0) 1767 681 221
Fax: +44 (0) 1767 691 951
Wentworth Laboratories, Inc.
1102 Walsh Avenue
Santa Clara, CA 95050
Tel: 408 919 1875
Fax: 408 919 6684
Wentworth Japan Co., Ltd
1-8-15 Nakagawa, Tsuzuki-ku
Yokohama 224
JAPAN
Tel: +81 (0) 45 912 8520
Fax: +81 (0) 45912 8524
Wentworth Laboratories, Inc.
3913 Todd Lane, Suite 505
Austin, TX 78744
Tel: 512 440 0792
Fax: 512 440 0530
Web site http://www.wentworthlabs.com
PEGASUS Operating and Service Manual
Wentworth
Laboratories
1 PEGASUS PROBE - DESCRIPTION
The Pegasus Probe was designed for use as a single probe with integrated edge sensor.
There are eight mounting positions that can be used for a combination of Pegasus Probes
and Inkers.
The first Pegasus Probe of any combination is the fixed probe. The position of this probe
will be set prior to shipment, such that the nominal position of the needle will be coincident
with the chuck centre when the prober is first initialised. Whilst it is possible to adjust the
position of this probe, it should not be necessary. Where a device has more than one pad, or
if multi-die probing, subsequent Pegasus Probes should be of the adjustable type. (See
photo below).
Fixed Pegasus Probe
Adjustable Pegasus Probe
Fig.1 Typical Probing Arrangement Using 1 fixed and 1 adjustable Pegasus Probes
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Laboratories
Radial, tangential and height adjustment of the Adjustable Pegasus Probe is easily
achieved using the thumbwheels.
To achieve optimum probe contact with the device, the amount of probe force required to
break the edge sense contact can be adjusted.
Replacement of the probe needle is quick and easily achieved without the requirement for
adhesives or any special tools.
The probe needle is isolated from the edge sense circuit and the probing equipment. The
Pegasus Probe can be provided with either a 45° or a 60° mounting position for the probe
needle. (This must be specified when ordering)
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2 SPECIFICATION
Fixed Pegasus Probe
Adjustment
Radial – 12mm coarse
Tangential - +/- 3mm
Height – 6mm
Probe Needle Size – 0.5mm diameter ( 0.020”)
Probe Force – from 3g upwards
Probe Management – Sprung loaded retention of the probe needle
Optional 45° or 60° probe to substrate orientation.
Adjustable Pegasus Probe
Adjustment
Radial – 12mm coarse
+/- 5mm fine
Tangential - +/- 5mm
Height – 10mm
Probe Needle Size – 0.5mm diameter ( 0.020”)
Probe Force – from 3g upwards
Probe Management – Sprung loaded retention of the probe needle
Optional 45° or 60° probe to substrate orientation.
Electrical Isolation
The Pegasus Probe is capable of withstanding 3kV when mounted in its normal operating
position of 4.5mm from the substrate.
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3 INSTALLATION
The Fixed Pegasus Probe can be installed in any of 4 locations. It is attached using the two
mounting screws shown in Figure 2. These screws also provide the means of achieving the
coarse radial adjustment. Vertical adjustment can be achieved by releasing the locking
screw and turning the vertical thumbwheel.
Note. The position of the fixed probe will have been set prior to shipment.
Vertical Thumbwheel
Locking Screw Mounting Screws
Fig 2. Mounting the fixed Pegasus Probe
3.1 Fixed Probe Setting Procedure
Initialise the prober, then enter the Diagnose menu. Use the function key “Centre” to move
the stage to its centre position.
Mount the fixed probe in the desired location on the platform. Place a needle in the needle
holder. Looking down through a microscope, move the Pegasus Probe until the needle
point is over the central hole of the vacuum chuck. Lock the mounting screws.
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3.2 Fixed Pegasus Probe Height Adjustment
Ensure the Pegasus Probe connector is plugged in to number one edge sensor socket at the
rear of the prober, and a needle has been placed in the needle holder
Run the Probe Height facility on the prober to set the Gross and Fine heights.
Should it be required, the platform can be raised and lowered using the Platform adjusting
micrometer at the rear of the prober.
Platform Height Adjustment
Fig.3 Platform height adjustment
The best electrical isolation is achieved when the probe holder is 4.5mm from the
substrate.
Probe Holder
Chuck Plate
4.5mm
Figure 4. Optimum Working Distance Setting
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Laboratories
3.3 Setting the Adjustable Pegasus Probe
If a device has more than one pad, or if multi-die probing is required, the Adjustable
Pegasus Probe can be used in addition to the Fixed Pegasus Probe.
Mount the Adjustable Pegasus Probe/s in the desired remaining positions and insert the
needles.
Using the vertical thumbwheel ensure that the Adjustable Pegasus Probe/s are above the
Fixed Pegasus Probe. Insert the connectors into the edge sensor sockets at the rear of the
prober.
Run the probe height routine and raise the chuck until it comes into contact with the Fixed
Pegasus Probe. Using the vertical thumbwheel, lower each Adjustable Pegasus Probe until
an X appears on the screen indicating that the edge sensor has opened. Remove the
Adjustable Pegasus Probe connectors from the edge sensor sockets, leaving only the Fixed
Pegasus Probe connector in an edge sensor socket.
Only the X relating to the Fixed Pegasus Probe should now be displayed on the screen.
Accept this probe height.
Vertical Thumbwheel
Tangential Thumbwheel
Radial Thumbwheel
Fig 5.Adjustable Pegasus Probe
Using the Tangential and Radial Thumbwheels adjust the lateral position of the needle
until it is aligned with the required device or pad.
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Laboratories
3.4 Cable Managment
Cable management is important to the performance of the Pegasus Probe. The cable
from the tester should be attached directly to the connector provided on the side of the
Pegasus Probe body and anchored to the side of the body as shown. Connecting the
tester cable directly to the needle can influence the performance of the Pegasus Probe,
which may be detrimental to the quality of probe mark.
Ensure cable between connector an
d
p
robe holde
r
is loose
Tester cable anchored to body
Fig 6. Tester Cable Management
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Laboratories
Fig 7. Cable Management Clamps
Cable clamps are provided on the underside of both sides of the platform to guide the
tester and edge sense cables to the rear of the prober. (Fig.7/8)
Fig 8. Connectors
Edges Sensor Ports
Inker Ports
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Laboratories
4 ADJUSTMENT & OPERATION
Sprung Loaded Needle Clamp
Fig 9. Probe Needle Holder
The probe needle is inserted into the probe holder by pulling the sprung loaded clamp
back towards the Pegasus Probe body (Fig. 9) and inserting the needle through the
exposed hole from the underside. This operation can be performed with the Pegasus
Probe in-situ. The “Change Probe Card” function should be utilised on the S200 Prober,
this will move the chuck to a safe position and provide more access to change the
needle.
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PEGASUS Operating and Service Manual
Wentworth
Laboratories
4.1 Probe Contact Adjustment
Several parameters can be adjusted within the S200 and Pegasus Probe configuration to
obtain the desired probe mark/ throughput conditions. These are listed below:
• Probe Contact Force
• S200 Contact Enhancement Parameter
• S200 Damping Enhancement Parameter
Probe
mark size
Contact Force
Overtravel
S200 Contact Enhancement
S200 Damping Enhancement
Probe mark size
Through pu
t
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Wentworth
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4.1.1 Contact Force Adjustment
Contact Force Adjustment
Screw
Figure 10.
The contact force adjustment screw is on the left hand side of the probe holder housing.
By rotating this screw either clockwise or counter clockwise will increase or decrease the
contact force. The direction required can be obtained by stepping 1 or 2 devices after
adjustment and observing the size of the probe mark through the microscope.
The contact force will be set at the factory to 4.5g.
4.1.2 Contact and Damping Enhancement Parameters
These parameters can be set through the S200 Setup menu. (See S200 Manual)
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