Logitech WSB300 BONDER - Logitech Ltd

LOGITECH LTD
WSB300 Wafer Substrate Bonding
System
(300mm Version)
Operation and Maintenance
Equipment Manual
BE-01-01WBS300 Page 1

1. Contents
1. Contents .................................................................................................................................................... 2
2. Safety Precaution Sheet ............................................................................................................................ 3
3. Machine Overview ..................................................................................................................................... 4
4.1 Scope ....................................................................................................................................................... 5
4.2 Operation ................................................................................................................................................. 5
4.3 Operator Console .................................................................................................................................... 6
4.4 Installation and Test ................................................................................................................................ 8
4.5 Bonding Process and Recommended Waxes .......................................................................................... 9
DISPLAY SCREENS ........................................................................................................................................ 12
Start up ........................................................................................................................................................ 12
Recipe Edit ................................................................................................................................................... 13
PROCESS VIEW ............................................................................................................................................. 16
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2. Safety Precaution Sheet
The machine is designed for use with
consumables supplied by Logitech. If
subjected to misuse, improper
alteration, neglect, accident or
improper repair, Logitech will take no
responsibility for damage(s) to the
user or the equipment.
Logitech WSB300 BONDER
1. The operator should be fully aware of the use of the machine
According to the Operations Manual
2. The machine must be placed in an adequate working position, providing
level, stable support and adequate ventilation. All functions on the machine
and any connected equipment must be in working order.
3. Be sure that the supply voltage corresponds to the voltage stated
on the machine. The machine must be earthed.
4. Establish that rear air outlets are completely unobstructed.
5. Before loading samples, ensure that the installation test procedure has
been completed.
6. Ensure that the correct operation of the head locking screws is fully
understood.
7. Observe the current safety regulations for handling, emptying and
disposal of the waste materials and fluids.
8. Before opening the machine or working on any terminal connections,
always turn off the power, remove the plug or cable, and ensure that the
bonding heads are closed and at or near ambient temperature.
9. When working with the machine, always remember that the heating
system parts require extra care due to the system operating temperature.
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3. Machine Overview
1. VACUUM PUMP
2. WAX COATING ADVANCE
MODULE BUTTON
3. VACUUM BLEED VALVE
4. PRESSURE/ VACUUM GAUGE
5. MAIN BODY
6. CLAMP CYLINDER
7. PROCESS HEAD CLAMPS
8. SAFETY GAURD SPACERS
Features of ASF1‐1
9. UPPER DIAPHRAGM CHAMBER
10. VACUUM INLET PIPE
11. SAFETY GAURD
12. PROCESS/INFORMATION SCREEN
13. EMERGENCY STOP
14. JOYSTICK CONTROL
15. BONDER FRAME
16. ADJUSTABLE LOCKING WHEELS
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4. Introduction
4.1 Scope
This manual provides Instructions for installation, operation and maintenance of the Logitech WSB300
Wafer Substrate Bonding System.
4.2 Operation
The operation of the Logitech WSB300 Wafer Substrate Bonding System is illustrated. A wax coated glass
disc, to which the wafer or sample is to be bonded, is placed in the sample chamber. The sample is placed
on top of this glass disc and covered by a circle of filter paper or aluminium foil.
The chamber cover is then closed and secured using a pneumatic clamp mechanism. When the cover is
closed, the sample chamber can be evacuated to beyond 2 x 10‐1 mbar, the vacuum sealing on a large O‐
ring where the head cover locates. The cover of the sample chamber, or upper diaphragm chamber,
contains a diaphragm which can have atmospheric or positive pressure admitted to the space above it. The
diaphragm applies pressure to the sample during the bonding cycle to create a uniform wax bond between
the sample and the glass disc.
At the start of the bonding cycle, air is evacuated from space above the diaphragm, in the upper chamber,
causing it to lift away from the sample, and then from the sample chamber. As the sample chamber is
evacuated its temperature is raised to a preset point determined by the operator. This temperature should
be just below the wax melting point: at this temperature the wax will soften but not liquefy. The correct
temperature and vacuum are held constant for 10 minutes to allow temperatures throughout the head and
sample to stabilise and the wax time to outgas. After this soak time, atmospheric or positive pressure is
admitted to the space above the diaphragm, in the upper chamber, at a controlled rate, allowing the
diaphragm to drop and press the sample into the softened wax. This pressure is maintained for the preset
bond time. Once the bond time is complete, oil is circulated through the head and a heat exchanger to cool
the chamber and sample to ambient temperature, whilst maintaining the pressure on the specimen. When
the specimen chamber temperature has reduced to the end point temperature selected, the vacuum is
released at a controlled rate.
Head Cross Section, A. Diaphragm up, B. Diaphragm down
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4.3 Operator Console
4
3
2
2. Process skip button
3. Vacuum bleed valve
4. Vacuum gauge
The operator console comprises a 1/4 VGA display screen and joystick, one manual control for air flow and
one gauge.
The sequence of control screens is described in section 3.
The manual controls are as follows:‐
(3) CHAMBER AIR/+VE PRESSURE INLET ‐ A needle valve controls the rate at which the diaphragm drops,
as pressure is applied to the sample during the bonding phase. The default is set during factory set up and
should allow the diaphragm to fall to zero in less than one minute.
Ensure the user is aware of the following machine controls;
(2)‐ ’PROCEED’ button – moving the process to the next stage in Wax, Coat and Bond.
(4)‐ PRESSURE\ VACUUM GAUGE ‐ This gauge always shows the current pressure applied by the diaphragm
to the sample.
(14)‐ JOYSTICK to control the software interface.
12. Process / information screen
13. Emergency stop button
14. Joystick
(13)‐ The EMERGENCY STOP BUTTON. This will shut off the power to the unit, but care should be taken as
the bonding head may still be extremely hot.
(12)‐ Control screen, used at each stage to display relevant options or settings.
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12
13
14

11
9
15
16
6
6. CLAMP CYLINDER
9. UPPER DIAPHRAGM CHAMBER
11. SAFETY GAURD
15. HEATING AND SPACER PLATE
16. O‐RING
17. POSITIVE PRESSURE DIAPHRAGM
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4.4 Installation and Test
18
18. Electronics display power switch
19. Communication ports
20. Main power switch
21. Hanson type Air supply connection
22. Water inlet
23. Water outlet
24. Oil vapour drain
The WSB300 must be connected to a suitable AC mains supply. This must be 220‐240V according to the
rating plate at the rear of the machine. The supply lead colours are as follows:
LIVE‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐BROWN
NEUTRAL‐‐‐‐‐‐‐‐‐‐‐‐‐‐BLUE
EARTH‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐GREEN/YELLOW
The vacuum pump is situated under the machine and is already connected. The vacuum quality can be
checked using the test screen.
Connect cooling water inlet and outlet hoses to the large barbed tails at the back of the unit. The hose
connections require a 12mm I.D. Tubing (heating the tube in hot water for a few minutes will help to
expand it over the connections). N.B. The heat exchanger system cools the bonding head(s) from 188
degrees Celsius to 40 degrees Celsius in less than 9 minutes. In order to replicate this cooling time the
following cooling water conditions should be applied:
� Flow rate of 2 litres per minute
� Water Inlet temperature of 11 degrees Celsius.
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19
20
21
22
23
24

These conditions will produce a cool down time of less than 9 minutes from a head temperature of 188
degrees Celsius to 40 degrees Celsius. The outlet water temperature will rise to a maximum of 26 degrees
Celsius during cooling, i.e. immediately after the start of the cooling phase.
� Connect a service duct extract to the oil vapour outlet on the 6mm diameter barbed tail adjacent to
the cooling water connections.
� Connect an air line at a minimum pressure of 2 bar to the compressed air inlet "Hansen" connector
(Fig. 1 & 15) on the back of the unit.
� On connection to the mains supply the cooling fan on the WSB300 will be running. Switch on the
main switch at the rear of the machine (Fig. 1). The top level operating screen will be displayed
� Situated on the rear of the machine are 2 Communications connections and a machine counter I.D.
which identifies the machine module number.
Please note: The diaphragm material will release an oily film when heated for the first few timesit is run, as
the vacuum system will remove this fluid from the rubber material. This is normal and each time after
fitting a new diaphragm, cycle the system at temperature and vacuum pressure with a glass blank in the
chamber to outgas the diaphragm.
4.5 Bonding Process and Recommended Waxes
Samples may be bonded to 210mm (8.26”) or 310mm (12.2”) diameter BK7 glass mounting discs. The
chamber is manufactured to suit a wafer thickness of 1mm or below, used with an 8‐10mm BK7 thick glass
disc. These discs should be pre‐coated with an even layer of wax between 5 and 10 microns thick (when the
Logitech WCS10 wax evaporation system is used).
Where a manual application of wax is used, this is hand‐applied by the operator. The hot plate has a
315mm (12.4”) outside diameter.
WARNING ‐ DO NOT USE THE UNIT WITH THE CHAMBER EMPTY. Equally importantly, the unit should not
be operated using smaller diameter discs without having spacer rings in place, as there is a possibility of
damage to the diaphragm or displacement of the sample. A ring should be fitted with the grooved side face
down to provide a uniform surface for the diaphragm to press. An optional spacer disc can be provided if
thinner substrate materials are necessary, e.g. sapphire.
To bond a wafer to a glass substrate, both the wafer and glass must be prepared and cleaned before
placing them in the sample chamber.
First take appropriate wafer measurements, then clean and store the wafers ready for bonding. Clean and
measure the flatness and taper on the glass. This should be 2um or less to provide an effective substrate for
lapping and polishing the wafer.
By measuring the wafer and the glass before and after bonding, the wax layer uniformity and thickness can
be calculated. This will enable any process parameters to be adjusted to further improve the geometry of
the final component or device.
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The glass should then be placed in the sample chamber. A uniform layer of wax should be applied by hand
to the glass after placing it on the machine hotplate and heated to the wax melting point, manually coating
the surface with a thin, even layer.
Lay the wafers to be bonded on the waxed glasses; firmly press the wafer on to the glass to expel any
trapped air, and then cover each carefully with a disc of clean filter paper or aluminium foil. Before closing
the heads, ensure that the wafer has not floated off‐centre. Close the heads gently, seat them on the seals
and lightly tighten the clamp arm by hand and start the bonding cycle.
Two types of bonding wax are recommended:
QUARTZ WAX (0CON‐200) ‐ A brittle, opaque amber, chippable wax that is particularly suited to bonding
wafers. It is extremely fluid above its distinct melting point, hard and firm immediately below. It is soluble
in tri‐chloroethane. The recommended plate temperature for this wax is in the range 69oC ‐ 75°C.
HIGH MELTING POINT WAX (0CON‐196) ‐ A tan coloured, medium hard synthetic wax with a melting point
of 157‐162° C. It is soluble in hot trichloroethane. The recommended plate temperature for this wax is
180oC ‐ 183°C.
Both waxes have been chosen for two properties. Firstly, they are extremely pure and can be evaporated
on to the glass mounting discs using the Logitech WCS10 Wax Coating System. Secondly, finished wafers
can readily be removed from the glasses by heating in a hot Isopropanol vapour unit such as the Logitech
1ACCS‐5100 solvent vapour cleaner, or by using a non solvent cleaning fluid such as ECOCLEAR.
It will be noted that both recommended bonding temperatures are below the wax melting points. This is
fundamental to the process as it is intended that the sample be pressed into a softened layer of wax under
vacuum to achieve the bond, thus protecting any devices on the bonded face from contact with the glass
disc. For any particular combination of sample and wax the optimum temperature may vary by a few
degrees either side of the above recommended values.
The maximum bonding temperature recommended with the WSBU is 188 degrees Celsius...
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5 OPERATION
NOTE. Since all of the cycle parameters for the WSBU are stored in non‐volatile memory they may be
recalled at any time. The last process is stored in the machine’s battery backed‐up memory.
To bond a wafer to a glass substrate both the wafer and glass must be placed in the bonding chamber. Lay
the wafers to be bonded on the waxed substrates. Cover each carefully with a disc of clean filter paper or
tissue. Once the vacuum evacuation and heating stage is reached, re‐tighten the locking screws using only
finger pressure.
The bonding temperature should be set according to the melting point of the wax in use. The end point
temperature is that at which the vacuum in the bonding chamber is released and the chamber lid may be
opened. The cycle time may be shortened by reducing the soak time or the bond time, or by raising the end
point temperature.
DO NOT HANDLE SAMPLES THAT ARE ABOVE 55oC WITHOUT GLOVES.
At the start of each cycle it is advisable to check that the vacuum reading on the main display is dropping
rapidly towards the ideal value of 2 x 10‐1 mbar. Slow pump down can either be caused by a leak at the
bonding head or by out gassing from the sample or bonding medium. Out gassing can cause significant
delays in the cycle depending on the materials used and in particular on residual solvents which may have
been used in cleaning operations. If, however, a vacuum leak is suspected, as a first step, stop the cycle,
open the head and clean the top face of the head seal O‐ring landing flat with a tissue moistened with a
smear of vacuum grease. Check also that the O‐rings are not damaged and that the grooves and rings are
clean.
During the bonding cycle the vacuum in the specimen chamber is constantly monitored. Should the vacuum
be lost then the process will be automatically aborted. A loss of vacuum is most likely to be caused by
allowing the air pressure in the upper chamber to go above 2 bar; reducing this pressure with the pressure
regulator should allow the vacuum to be re‐established.
When the machine is not in use the bonding chambers should be left closed.
NOTE: The machine must ALWAYS remain switched on while the water supply is connected to it. Should it
be switched off with the water supply still connected, there will be a pressure build up within the unit,
which may result in the supply pipe rupturing. This is due to the solenoid valve being positioned within the
unit itself, allowing water to enter the machine before being stopped at the valve. If the supply pipe were
to rupture within the machine itself this would have adverse effects on the unit. The supply pipe rupturing
outside the machine would be equally undesirable.
The operation of the Wafer Substrate Bonding System is controlled through a sequence of display screens
as described in section 3.
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6 USER INTERFACE
The user interface is designed to allow control of all processing parameters from the single display screen.
The user should be aware of the symbol at the bottom right of the screen. The symbol describes the
available actions the user can perform with the joystick.
The inputs are: UP, DOWN, LEFT, RIGHT ROTATE CLOCK WISE, ROTATE ANTI‐CLOCKWISE, BUTTON PUSH.
The symbol is process screen dependent and not all options will be available at all times. Arrows denote the
joystick movement available, whilst a white dot in the centre of the symbol denotes a button push is
available.
DISPLAY SCREENS
Start up
1) Switching on the machine displays the
start up logo. If this fails to display switch
the machine off and back on, after
checking the machine power leads are
securely inserted and energised.
Press the joystick button to continue.
2) The system checks the available resources
and displays the number of functioning
bonding heads available. A total of 8 heads
are able to be controlled using a single
interface.
Push the joystick button to continue.
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3) The user now has two options, either to edit a
stored recipe or move straight to the processing
stages.
Recipe Edit
1) After selecting recipe edit from the main
display screen the user can select 1 of 8 stored
recipes.
To edit a stored recipe move up or down with
the joystick until the recipe is highlighted and
then move right to select EDIT.
2) The recipe parameters and Recipe name can be
edited. To edit the recipe name move up the
screen until the name is highlighted and select.
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3) Using the joystick edit the recipe name. Move to
the EXIT option to return to the recipe edit
screen.
4) The [PROCESS TYPE] is chosen by selecting
[process type] on the [edit recipe] screen. The
process type affects the processes the bonder will
perform during the bond.
5) The [Edit Recipe] screen allows Process, temperature and air parameters to be adjusted to best
suit the process. The available options are dependent on the process chosen, and each process will
be decribed later in the manual. The [WAX COAT AND BOND] process is used here to describe the
setup.
6) Selecting [PROCESS SETUP] from the main screen
allows the user to set the time for each stage of
the process, as well as the operation of the lid.To
edit move until the desired option is highlighted
and rotate the joystick to move the set point.
Move to EXIT to return to the menu screen.
The options available are;
� [Soak] – the time spent at the bonding
temperature before positive pressure is applied to
the sample, allowing the sample and wax to reach
the desired temperature.
� [Out Gas Limit]. – The time given for the wax to outgas after positive pressure is applied before
the process is aborted
� [PP Delay]. The time between [Soak] ending and positive pressure being applied to the sample.
� [Lid mode] – Choose between Auto where the lid position is automatically controlled or manual
where the user would manually open the lid after a process has completed.
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7) Selecting [TEMPERATURE SETUP] allows all
temperatures to be set for each stage of the
process. Edit the temprerature by rotating the
joystick over the selected option to increase or
decrease the value.
� [Coating] The temperature of the hot plate to
allow the wax to be applied to the warmed
substrate.
� [Loading] The temperature of the hotplate during
mounting of a sample on a substrate.
� [Hardening] The temperature of the hotplate at
the point of the bonding head closing on a
mounted sample.
� [Bonding] The temperature of the bonding head during the bonding cycle.
� [End point] The temperature the head is brought to after the bonding process is complete. In the
case of wax bonding the temperature the head is cooled to at the end of the process.
� [offset] If a noticeable temperature gradient is experienced through a substrate to the wax bond
layer a temperature offset can be introduced. The maximum offset allowed is 20 degrees celcius.
� [Units] The default units are Celsius.
8) Selecting [AIR SET UP] allows the user to set
the vacuum and positive pressure options.
� [Vac proceed level] If set pressure reached the
bonding process will begin.
� [Vac abort level] If set pressure reached
process will be aborted.
� [Positive Pressure] Sets the pressure to be
applied through the diaphragm to the bonding
site.
9) [Copy to] at the bottom of the main edit recipe
screen will save all settings to the particular
recipe chosen.
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PROCESS VIEW
The process view screen is selected from the Main
menu. The screen displays the number of module
heads, the chosen recipe, Elapsed time, current status,
the State information panel and the actual vacuum
reading at the bonding head.
When performing bonding operations the [Current
State] bar will cycle through the stages of the process
as they are initiated. The [State information] panel
will show relevant information regarding the current
process, whether it be time remaining, target
temperature etc.
At the bottom of the screen an [Options] tab allows
the user to cycle through the available steps at that
time.
[Cycle] Cycles through the process steps.
[Manual] allows access to the manual operation
screen.
[Start] Starts the process selected.
When a process has commenced the [Options] button
also presents the user with another two options;
[Abort] Aborts the current recipe.
[Advance] Advances the program to the next process step. The available steps for each process are shown
in the table below;
Process
Heat and Resin Cold
Wax coat and Bond out‐gas Bond Process
Heat for Coating y x x x
Cool to loading y x x x
Cool to harden y x x x
Closing Lid y y y y
Lifting Diaphragm y y y y
Outgas x x x y
Heat and Out‐gas y y y x
Soaking
Bonding ‐ No positive
y y y y
pressure y y y y
Bonding & Positive pressure y y y y
Cool y y y n
Open y y y y
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The [Manual] screen allows the user to activate the
functions of the machine independently of a recipe.
When the [Start] option is pressed the bonder will perform the stages as set in the edit recipe section.
A typical wax coat and bond process will cycle through the following screens;
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Depending on the process chosen the process screens will cycle through the relevent information. Please
refer to the table on page 16 for process specific assembly steps.
END
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