WQB2000 QFP AND BGA REPAIR AND ASSEMBLY SYSTEM
INTRODUCTION
Congratulations! Youve just purchased the most accurate and economical solder re-flow; solder paste printing and component placement machine
on the market! Weller, a company well known for its hand soldering and desoldering tools has developed the WQB2000 to meet a growing need
for accurate removal, solder printing and placement of fine pitch SMDs including BGA components, on prototype and low volume production
PCBs.
With the WQB2000, you will be able to remove fine pitch and ultra-fine pitch surface-mount devices and then screen-print and place these same
devices onto your PC boards with very high yields. The patented templates and solder printing stencils provide a simple, effective, accurate and
repeatable method of solder paste printing and placing of surface-mount devices.
WQB2000 - FEATURES
Placement and removal of fine pitch components including BGAs
Soldering and desoldering of fine pitch components including BGAs
Temperature controlled hot air and radiant bottom heat
Timer with 20 user programmable cycles to control component/
board heat-up profile
Solder paste stenciling of individual components
Placement accuracy of 0.001"
Repeatability of 0.002" allowing for board to board variation
Patented, reusable templates and stencils
Test/Training Kit includes: 1 QFP and 1 BGA component, 2 clear test
boards, 2 copper test boards, templates, stencils, and hot air nozzle
for test components, plastic kit box
WARNING: This product, when used for soldering and similar applications, produces chemicals known to the State of
California to cause cancer and birth defects or other reproductive harm.
Requires shop air only 60 psi at 0.70 scfm
Quiet operation - less than 35 db(A) @ 1 meter
Air pressure on-off switch, regulator and gauge
Easy and flexible set-ups, will place components on boards up to
8" x 15"
Portable Vacuum pencil to aid in component pick-up and location
Compliant component vacuum pick-up nozzle
Stencil vacuum pick-up nozzle
Compact design - 12" x 18" footprint
One year limited warranty
The unique features of this machine are its placement accuracy and repeatability. Its accuracy is achieved with precision ball slides and precision
vacuum nozzles, combined with the unique component templates and solder paste stencils. These components keep the placement accuracy
within 0.001".
DESCRIPTION OF MACHINE COMPONENTS
WQB-A HOT AIR UNIT
This unit provides electronic temperature controlled hot air or if desired hot inert gas (such as nitrogen).
The temperature is variable from 250°F to 1000°F. Oil and water free compressed air (30 - 100 psi) must be provided. To meet this requirement a
filter has been provided that will filter oil and water down to 2 PPM. However, as your filter removes oil and water contaminants from the air, the
filter may start to clog and you may notice a pressure drop on the machines air gauge. This may also indicate an air compressor failure. In the
event that the filter clogs call your distributor for a new one.
The hot air will be free of static charge. A static ground is provided at the front of the unit for this purpose.
The unit also provides vacuum source required for component removal during desoldering as well as a hot air flow control adjustment.
WQB-P HOT PLATE UNIT FOR CIRCUIT BOARD BOTTOM HEAT
This unit provides electronic temperature control of the low voltage radiant hot plate heater.
The analog temperature control is variable between 125°F to 825°F. Temperatures can be pre-set and then viewed in real time on a digital display
by switching from pre-set to actual on the selection slide switch provided.
The unit is provided with an external sensor connector for alternatively controlling the bottom temperature of the PC board directly. This sensor is
not included with the WQB2000.
A static ground connector is provided at the rear of the unit.
WQB-C TIMER FOR CYCLE CONTROL
Microprocessor control guarantees reproducible soldering or desoldering time cycles. Optimum results are achieved due to a three stage ramp-up
heating cycle followed by a cool down interval. The microprocessor can store process parameters for up to 10 user programmable cycles, which
can be called up for use or edited and re-stored. There are also 10 preprogrammed cycles in memory. As the Timer is controlling the soldering
process, the time to complete each stage is displayed on a digital count down timer.
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MACHINE PLATFORM
The machine platform is comprised of the following items:
Slide Assembly
The accuracy of the slide assembly is the result of precision ball slides and the use of vacuum to pick-up components during operation. Three (3)
ball slides are used (see Figure 1). One for the hot air nozzle, one for the component pick-up and one for the solder paste stencil pick-up. Left to
right positioning of the vacuum pick-ups and nozzle during operation is accomplished with a spring-loaded plunger and V notched slide bar.
Pneumatic Enclosure
The pneumatics are housed in the rear enclosure. Incoming air pressure is turned on and off with a lever on the top of the enclosure (see Figure
1). The system air pressure can be adjusted with the front panel pressure regulator. Inside the enclosure there are two (2) vacuum transducers,
one for each vacuum pick-up, and two (2) air valves used to provide cooling air and the extension of the component vacuum lift inside the nozzle.
A quick connect air fitting is provided in the rear of the enclosure to provide an air supply to the WQB-A hot air unit. A connector for the timer is
located on the rear of the enclosure. The vacuum pick-up transducers are always on when the unit is in operation, therefore in-line air filters are
provided to prevent dirt particles from reaching the transducers and causing a malfunction.
Caution: Do not run system without these filters in place.
Heater in Table
The radiant heater (see Figure 1) built into the machine platform base provides bottom heat to the circuit board during the soldering operation, this
allows a slow uniform ramp up of the circuit board temperature to above the solder melt temperature.
ACCESSORIES
BGA HOT AIR NOZZLE
The closed nozzle housing permits optimum heating of the BGA component being soldered by guiding the hot air uniformly around the component
body and exiting the nozzle via exhaust ports in the top of the nozzle. During BGA soldering the nozzle is positioned against the PC board to effect
the proper air circulation and prevent adjacent components from being heated. Hot air temperature is controlled by a sensor fixed in the nozzle
manifold.
During component removal a vacuum lift (see Figure 1) is automatically activated to remove the BGA from the circuit board at the end of the
heating cycle.
The BGA nozzle can also be used for QFP components. Typically when used for QFPs the nozzle is not placed against the circuit board but
positioned slightly above the QFP. Select a size to match the outer edges of the QFP leads.
BGA and QFP Templates and Stencils
The positioning accuracy of this system is the result of the unique design of the templates. The templates serve three (3) functions: 1) Alignment
of the component to the circuit board pads, 2) alignment of the solder paste stencil to the circuit board pads, and 3) alignment of the nozzle to the
circuit board pads (see Figure 5).
In use the template is visually aligned with the corner pads on the circuit board using the sighting holes provided in the template. Very fine pitch
QFPs will require magnification during alignment. After proper alignment the template is temporarily secured to the circuit board with Kapton ® tape.
Training Kit for BGA and QFP Components
This kit includes two (2) copper test boards with six (6) patterns for BGA and QFP components. Two (2) clear practice boards for placement
training. One each of a BGA and QFP component for practice or test. Boards and components match the templates, stencils, and nozzle provided
with the WQB2000
COMPONENTS AND ITEMS INCLUDED
The WQB2000 comes with the following items:
Instruction Manual
Machine platform - See Figure 1 for machine nomenclature
Coalescent air filter and air hose
Portable Vacuum pencil with (2) tips and extra suction cups
3 Sets (6) registration pins (2 each in sizes ø.093, ø.125, ø.156)
3 Sets (6) of 1/2" registration pin spacers (2 each in sizes ø.093, ø.125, ø.156)
2 spacer blocks, 1/2" square x 3"
Compliant vacuum nozzle: with extra O-Rings (.500 dia.)
- Small vacuum nozzle adapter (.375" dia.)
- Mini vacuum nozzle adapter (.200" dia.)
Standard vacuum nozzle (.500" dia.)
BGA (QFP) hot air nozzle
Plastic case for pins and nozzles
Training Kit with Plastic case, 2 Dummy components (1 BGA and 1 QFP), 2 copper PC Boards and 2 clear PC boards for machine set-up,
testing and training
2 standard alignment templates and printing stencils (Other JEDEC QFP and BGA templates are available, consult with your distributor or
the Weller factory)
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One (1) roll of Kapton
®
tape
Tooling Square for slide alignment
Knife (Spatula) Handle
Spatula Blades (3)
MACHINE SETUP
1. Remove boxes from top of shipping carton and unpack components.
2. Remove machine from carton packing and place on solid table. We recommend setting the machine up at its permanent workstation,
preferably a static-safe (ESD) workstation. Unlock slides by loosening slide tension spring adjustment screw for each slide (two
screws on hot air nozzle slide).
3. Position WQB-A hot air power supply and WQB-P hot plate power supply to left side of machine; they can be stacked if desired. Position
timer to right side of machine. The location of the WQB-A must be to the left side of the machine platform; the other components can be
placed to suit the workbench layout.
4. Plug WQB-C TIMER connectors into sockets as indicated on connector bodies.
Connect 6-pin connector marked WQB-P to WQB-P 6-pin power supply connector in rear of unit.
Connect 7-pin connector marked WQB-A to WQB-A 7-pin power supply connector in rear of unit.
Connect 7-pin connector marked WQB-T to 7-pin connector in rear of machine table cabinet.
5. Plug rectangular radiant heater plate connector into WQB-P socket in front of unit.
6. Plug nozzle air temperature control nozzle sensor into REAR of WQB-A power supply.
CAUTION: DO NOT PLUG NOZZLE SENSOR INTO FRONT OF WQB-P, if connected, the hot air nozzle temperature will
7. Attach filter/air hose to the air input port, filter next to unit, a swivel fitting is provided so that the filter can be turned to
position the liquid bleed valve pointing downward.
NOTE: Check the air filter and empty daily.
8. Connect the short air supply tube from the quick-connect fitting on the rear of the machine platform enclosure to the quickconnect fitting on the rear of the WQB-A hot air power supply.
9. Screw the hot air heater into the nozzle manifold (see Figure 1). Plug the hot air connector into the WQB-A socket and screw locking
shell to connector. Attach clear air tubing for hot air heater to air port and black vacuum tubing to vacuum port. Plug static grounding plug
into socket provided. Attach black vacuum tube to component vacuum pick-up stem, route and secure tube so that it will not interfere
with nozzle slide travel. Adjust slide tension screws to prevent nozzle from slipping down under its own weight when released.
10. Remove nozzle by turning locking knob to left (see Figure 1). Check and seat red vacuum cup to the vacuum stem in the nozzle
manifold and then re-attach the hot air nozzle to the quick mount connector by sliding the nozzle up over the vacuum cup, aligning the
nozzle mount and the connector keys and locking the nozzle mount into the connector by turning the locking handle to the right.
11. Attach retractable air hose to shop air.
12. Connect WQB-P and WQB-A to 120VAC power supply.
Your machine is now ready for operation!
exceed the temperature control setting and component and/or board damage may occur.
MACHINE OPERATION AND TEST
1. Turn on air supply with toggle switch at the top center of housing (see Figure 1). If no air pressure is evident, check air supply for
closed valves.
2. Adjust air regulator (see Figure 1) by pulling out the locking ring and turning the knob (clockwise to increase) until the gauge reads 60
psi. Push the locking ring back to lock the regulator.
3. Test both vacuum pick-ups for vacuum by placing your finger over the pick-up opening, vacuum should be evident. The vacuum levels
are fixed for each pick-up and can only be changed by adjusting the system air pressure. Adjust slide tension screws to prevent
nozzles from slipping down under their own weight when released.
CAUTION: Do not exceed 85 psi.
4. Test the component vacuum nozzle for component pick-up by placing a clear test board on the tabletop. Place a BGA component onto
the test board centered to the nozzle. Manually lower the nozzle until it makes contact with the component, slightly compress the
compliant nozzle and then lift. If the part does not lift, check to see if the nozzle has its O-ring seated at the tip. If it does, then the nozzle
will need to be checked and adjusted for to be square to the tabletop. (See note below)
The slides were adjusted to be perpendicular to the tabletop at the factory, and should not need re-adjustment. If you are having trouble
picking up components or stencils you need to check the perpendicularly and adjust if necessary, use the square provided.
NOTE: Nozzle perpendicularly can be adjusted side-to-side by slightly loosening two screws on the vacuum pick-up bracket, square
nozzle by placing square provided on tabletop and aligning one side of nozzle to square then re-tighten screws. Front-to-back
squaring can be accomplished by loosening two mounting screws at rear of boom plate, then adjusting 4 leveling screws at
the top and bottom of the plate to square nozzle to table top. We recommend the front-to-back adjustment be made on the
stencil nozzle with the nozzle centered on the tabletop.
5. Test the vacuum break switch (see Figure 1) and component release by picking up the BGA part with the compliant nozzle. When the
slide is in its UP position (place your hand underneath the part to catch it as it falls), depress the vacuum break switch. The part should
fall off the moment you depress the switch. If it hangs or delays, reduce the vacuum by adjusting the air pressure regulator. Depending
on solder paste tackiness, a release delay should not affect the placement operation accuracy or acceptability.
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6. Turn on the WQB-P power supply. Check the WQB-C Timer to verify that the LEDs are lighted. If not, turn off WQB-P power supply and
check connectors for correct insertion into receptacles. See MACHINE SET-UP; section 4, 5 and 6. CAUTION: ALWAYS TURN WQB-P
POWER SUPPLY ON BEFORE TURNING ON THE WQB-A POWER SUPPLY. CONVERSELY, TURN OFF THE WQB-A POWER SUPPLY
BEFORE TURNING OFF THE WQB-P POWER SUPPLY. The hot air power is controlled by the WQB-P power supply. If the
WQB-A is ON and the WQB-P is OFF the hot air heater will be ON and could overheat and possibly burn out if left on
for an extended period.
Place the Read-Set slide switch to Set. Turn the temperature adjustment knob to the minimum setting, the temperature display should be
on and the set temperature value should change as you turn the knob. Place the Set-Read slide switch to the Read position, if the
display reads EEE the heater plug may not be connected correctly, check polarity and re-seat, if the display still reads EEE, the i
nternal heater sensor is open and the heater will need to be replaced.
7. Turn on the WQB-A power supply. The green heater on indictor LED may flash and then should stay off. Set the temperature control to
the minimum setting and set the air flow control to 5.
8. Press the PROGRAM button on the WQB-C timer once, the display will flash, then use the up or down arrow buttons to change the
program to P03. Allow the display to stop flashing. Press the PARAMETER SELECT button to cycle through the parameter settings
stored in memory for this program, note that the green LED lights will indicate which parameter is being viewed. Each press of the
PARAMETER SELECT button will advance the timer program to the next parameter. Select the parameter (1) WHP 300 (WQB-P)
TEMPERATURE, set the value with up or down button to 100°F. Set remaining parameters as follows:
(2) WQB-A TEMPERATURE to 100°F.
(3) WQB-A AIR FLOW to 5
(4) Time 1 PREHEAT 1 to 1 5
(5) Time 2 PREHEAT 2 to 1 0
(6) Time 3 REFLOW to 5
Press and hold down the PROGRAM button until the display stops flashing, this stores the parameters into memory. If the parameters are not
stored in memory the settings will be lost if another program is selected or the timer is powered off.
Press the DESOLDERING button once. The red LED above the DESOLDERING button should light and the component lift stem in the nozzle should
extend. Press the DESOLDERING button again and the stem should retract. Press the DESOLDERING button again to extend the component lift
stem and remove the nozzle. Press the VAC button once, the red LED above the VA C button should light and vacuum should be present at the
vacuum cup, test by placing finger over opening in cup. If no vacuum is present, check connections and be sure WQB-A is turned on.
Replace nozzle, be sure that vacuum cup extends past nozzle air deflection plate. Press the VAC button once, vacuum should no longer be
present and the VAC LED should be off. Press the DESOLDERING button once, the stem should retract and the red LED above the DESOLDERING
button should be off. Check to see that the vacuum cup is up against the nozzle air deflection plate and not jammed in the plate hole.
Press the COOLING button once, cooling air should start to flow through the nozzle and the red LED above the COOLING button should be on.
Press the COOLING button again and the air flow should stop.
TESTING THE SYSTEM - SOLDERING
Press the start button once, the Time 1 green LED should light, the heater plate should start to warm, and the hot air flow should become warm.
The display will indicate the time remaining for this segment of the cycle and will count down to zero. An audible beep will be heard and air flow
will stop to indicate that the nozzle should be lowered to the circuit board (not necessary for this test).
After a slight delay to allow for nozzle lowering, the second preheat cycle will begin and air flow will resume but at a lower flow rate(not
adjustable), also indicated by the Time 2 green LED coming on. The timer will count down to zero; the Time 2 Green LED light will turn off.
The finial re-flow heating stage will start immediately indicated by the Time 3 green LED and a higher air flow rate. The display will indicate the time
remaining for this segment of the cycle and will count down to zero, at zero time the Time 3 green LED will turn off.
The cooling cycle will start at the end of the re-flow segment, the red cooling LED will light and the cooling air flow will start indicated by a higher
air flow rate. The cooling time is preprogrammed at 60 seconds; it can be changed but not stored in memory. It can be adjusted up or down by
holding the COOLING button down while pressing the up or down buttons. Any change in cooling time will revert to 60 seconds when the power
is removed from the WQB-P. We recommend a full 60-second cooling cycle. At the end of the cooling cycle another audible beep will be heard
indicating that the soldering cycle is complete, at this point the nozzle would be raised and the circuit board removed from the machine platform.
TESTING THE SYSTEM - DESOLDERING
Press the desoldering button once to start the desoldering cycle. The component vacuum lift stem will extend and the red LED above the
DESOLDERING button will turn on. The desoldering cycle will exactly follow the same cycle sequence as during soldering until the finish of the
reflow segment.
After the reflow segment is complete the WQB-C delays the cooling segment start until the component vacuum is activated, (indicated by the red
VAC light turning on) and then the removal of the component by the vacuum cup and lift stem (the red DESOLDERING LED light turns off). The
cooling segment starts, indicated by the red COOLING LED turning on. Cooling will continue until the timer reaches zero, the cooling air will stop
and an audible beep will be heard indicating that the desoldering cycle is complete, at this point the nozzle would be raised and the circuit board
removed from the machine platform.
The desoldered component will be held in the nozzle until the VA C button is pressed. To retrieve the component from the nozzle without damaging
fine leads on QFPs, place a paper tablet against the under side of the nozzle and then press the VAC button. This removes the vacuum from the
vacuum cup and the component will drop onto the paper tablet without damage.
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NOTE: The down stop may have to be adjusted so that the vacuum cup just comes in contact with the components top surface while
Once you have tested all features of the WQB2000 and are satisfied that the features are working properly, we recommend that you try alignment
and placement of components with the clear test boards and components provided in the Training Kit. After becoming familiar wit h the alignment
and placement procedures you be ready to practice the solder paste stenciling and reflow procedures on the copper test boards.
allowing the nozzle to be positioned correctly. For BGAs this position will be against the circuit board surface. For QFPs th e
correct nozzle position is approximately .04" (1 mm) above the components upper surface.
ALIGNMENT TOOLS AND METHODS
REGISTRATION PINS
The registration pins are designed to be secured on the machine table so that the PC boards can be placed and removed with a very high degree
of precision.
The WQB2000 comes with 3 sets of standoff registration pins (see Figure 2) and 3 sets of standard registration pins (used if only solder paste
stenciling and component placing for off-machine reflow). The standoff registration pins are needed to keep the circuit board from coming in
direct contact with the heater plate during the reflow cycle and to allow the machine to handle circuit boards with components on the bottom of
the board.
The sizes provided should fit most PC board tooling holes. In case you are working with a board that has different size tool holes, please call
Weller Customer Service Department at (843) 537-5167 to order the specific size(s) you need. Note: Special registration pins are made to order
and will require extra time. An alternate approach is to enlarge the PCB holes to one of the standard sizes provided by reaming to a +.0005"/.0000" tolerance.
ALIGNMENT TEMPLATES
Two alignment template and solder paste stencil sets are included with the WQB2000 for test and training.
The templates are designed to be secured to a bare PC board with the tape provided. You will notice that the templates have a pattern of holes
that match the component leads, some holes (see Figure 4) are actually through holes in certain pad locations. These through holes are used
to align the template to the board pads. The remaining holes are depressions that are used to align all component leads (or BGA balls) with the
PCB pads. The depressions provide a positive method of locating the component in the template and will prevent accidental movement of the
component prior to its being picked off the template. Additional templates are available, consult with your distributor or the Weller factory.
Additionally, the templates have bent up tabs on all sides; these tabs serve two functions:
1. The large tabs are used to engage with mating notches on the printing stencil and align the stencil (see Figures 3 and 4) with the PCB
pattern.
2. The smaller tabs, along with the large tabs, are used for nozzle alignment.
ALIGNMENT METHOD - NOZZLE TO CIRCUIT BOARD
1. Select the BGA template cut a piece of Kapton® tape long enough to span the template. Place tape across template perpendicularly to the
tape shelves (see Figure 3) press tape onto one side of template, pull tape taunt and press to opposite side of template. Press tape
down onto tape shelves and trim to edge of shelves with knife blade. The adhesive side of the tape should be above the lower surface
of the template. When the template is placed on the test board, it can be easily slid around without the tape adhering to the board.
NOTE: Kapton® tape leaves not adhesive on the tabletop or circuit board when removed and will withstand soldering temperatures.
2. Select the clear test board without adhesive or a green test board. Position template over a BGA pattern, align the through holes with the
pads (see Figures 4 and 5) until pads are visible and centered in all the through holes, the corner holes of the template are larger then
the rest to help with alignment. Position as accurately as possible, use magnification if necessary. When all pads are aligned, touch tape
lightly in middle of opening to fasten tape to board. Adjust alignment if necessary and then press tape to board to lock template to circuit
board.
HINT: Position the template so that the tape shelves are parallel to the sides of the WQB2000 tabletop. This will align the stencil in the
3. Place the .156 diameter standoff registration pins into two of the tooling holes of the test board. A set of spacer blocks and standoff
spacer pins are provided. Use these to support the board as necessary to keep it level with tabletop. Move the hot air nozzle to the
center of the table by moving the horizontal slide to right hand position. Place the board on the table top, adjusting its position so that the
nozzle is centered over the template.
Note: You will find that some boards will not use standard size tooling holes, or holes will be plated. In some cases, the holes will be
4. Lower the nozzle and position it using the six (6) location tabs, adjust board position for best fit. With the nozzle in the down position,
tape the registration pin plates in place with the Kapton® tape provided. Raise the nozzle and remove the board. Apply additional tape in
front of the registration pins as well as behind the pins (see Figure 5).
Acetone will remove any adhesive left by regular tape but we strongly recommend using Kapton® tape only.
best position for applying solder paste.
of the proper size but will be very tight. A drill of the proper size can be used to ream out the hole. Plated holes can have
solder in them and are therefore not uniform (some manufacturers plate them as grounding point). If you have difficulty in
achieving good pin registration, try a smaller pin and pull them tight to the sides. Use a minimum of four (4) pins pulled tight (but
not too tight) at 45 degree angle to achieve the best results. You may also be able to use three (3) or more pins and locate the
circuit board by edge referencing, although this is the least accurate method of registration.
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ALIGNMENT METHOD - COMPONENT TO CIRCUIT BOARD
1. Return the circuit board to the registration pins; seat board to pin shoulders, level board with spacer blocks and standoff pins. Place the
part on the template (see Figure 5) be sure to use the manual vacuum pen provided for QFP parts. Be sure to check two opposite
corners on leaded parts for correct engagement of leads in template depressions. BGA parts can be checked by looking for uniform
clearance between the component and the template edges on four sides. Both QFP and BGA components will nest in the templates and
will not slide out of the depressions when properly aligned.
2. Position component pick-up nozzle in the center of the table by moving the horizontal slide to middle position over component. Lower the
complaint nozzle and pick up the part. Raise the nozzle to maximum height. Avoid touching component during all of the following steps.
ALIGNMENT METHOD - STENCIL TO CIRCUIT BOARD
1. Position the stencil pick-up nozzle in the center of the table by moving the horizontal slide to left-hand position. Place the solder stencil
onto the template (see Figure 5) engaging the tabs and notches. Lower the stencil nozzle and pick up the stencil. Raise the nozzle to
maximum height.
2. Remove the circuit board with the template from the registration pins and replace with the board that will receive the solder paste and/or
component (Do not use clear test board with adhesive for solder stenciling practice or training).
CAUTION: Follow all of the manufacturers recommendations and heed all warnings when handling solder paste. The use of latex
NOTE: Due to limited shelf life, solder paste is not included with the WQB2000. We recommend using a SN63 or SN62 (2% Ag) alloy
3. Lower the stencil to the surface of the circuit board, apply positive downward pressure 2-3 lbs., and lock stencil slide in down position
with cam lock (see Figure 1). Spread solder paste over stencil openings with spatula blade then squeegee paste into openings with
the edge of spatula blade. Work the paste into openings moving the spatula blade in opposite directions to assure that openings are
completely filled. Remove excessive solder paste from stencil surface leveling the paste in the openings to the top of the stencil.
Release cam lock and raise stencil to upper position. Examine solder paste print for full and complete pattern. The circuit board can be
removed from registration pins for inspection and returned for component placement.
NOTE: If solder print is not complete or satisfactory, paste can be removed, the circuit board cleaned and then re-pasted. If the print is
4. Reposition the component over the solder pasted circuit board pattern, horizontal slide to right hand position. Lower component into
solder paste and slightly compress compliant nozzle to seat component leads or balls into paste. Release component by depressing
vacuum break button (see Figure 1) and then raise nozzle to upper position.
5. The green test circuit board is now ready for re-flow. If using clear test boards the component and solder paste can be viewed from
both sides of the board for placement accuracy.
CAUTION: Do not try to reflow clear test boards, they will not withstand soldering temperatures.
Additional test boards may be solder printed and assembled by repeating the above steps. The number of boards that can be assembled without
cleaning the stencil will depend on the print quality required, the solder paste used, the room humidity and room temperature. When print quality
falls below acceptable levels the stencil must be cleaned using typical cleaning methods. If you are unfamiliar with cleaning methods or do not
have cleaning equipment, we recommend using a shallow depth of alcohol in a small container, immersing the stencil in the alcohol and brushing
the stencil inside and out with a small paint brush to loosen the solder paste from the stencil. Additional clean up can be accomplished by manually
wiping the stencil with a LINT FREE WIPE.
It is a good idea to do several dry runs before you apply paste to a test board. To check the placement accuracy, use a magnification aid. The
clear test board with clear adhesive provides am excellent means for operator training and as test of placement accuracy. It is a very useful tool
for practice and can be reused over and over. If the clear test board with adhesive is being used the component can be removed from the test
board by slowly lifting the component from the adhesive with a pointed probe starting from one corner. These clear boards are especially useful
when training for BGA placement accuracy, in that after the BGA is placed on the clear adhesive board, the board can be turned over and the
alignment of BGA balls can be easily viewed through the back of the clear board.
When ready to place components on your production or repair circuit boards review the positioning and stenciling steps above. If you only have
one production or prototype circuit board, follow the above steps until the stencil is lifted from the template, then remove the template from the
board and proceed with the remaining steps. The tape holding the template to the board can be released without damage to the template by sliding
the edge of a registration pin plate between the tape and the board.
You will find that the set-ups are quite simple, and you can EASILY obtain acceptable low volume placement rates.
protective gloves is recommended.
with RMA flux for best results.
off registration, then the stencil needs to be removed and the board with template returned and the stencil repositioned and
picked up as previously. Be sure the stencil is completely seated into the template tabs, any slight out-of-level will cause a shift
in the printing.
MAINTENANCE
Check air filter weekly, drain if necessary.
Lubricate V bar felt wiper (see Figure 1) monthly.
Replace vacuum air filters yearly.
SUMMARY
We hope youll agree that the WQB2000 is everything we said it would be a truly remarkable product in terms of its accuracy and cost. As stated
before, it should give you years of satisfaction. If, however, you run into any problems, please dont hesitate to call the Weller factory for
technical support.
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HOT AIR NOZZLE
COMPONENT VACUUM NOZZLE
STENCIL VACUUM NOZZLE
TAPE
TEMPLATE
FIGURE 5
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COMPONENT
STANDOFF REGISTRATION PIN
Used if parts are present on bottom of PCB
STENCIL
ALIGNMENT NOTCH
STANDOFF BLOCK
Used to keep PCB level
FIGURE 1
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ADDITIONAL COMPANION PRODUCTS AVAILABLE
WPRB1000 Plastic BGA Re-balling Kit
WCRB1000 Ceramic BGA Re-balling Kit
WLSK1000 QFP Lead Straightening Kit
WQB103 uBGA Adapter Kit
ORDERING INFORMATION
The following items may be ordered through your distributor.
Alignment Template and stencil sets - including special orders
Hot air nozzles - including special orders
Registration pins - specify diameter and height (specify if standoff)
Vacuum Nozzles - compliant, standard
Small adapter and mini adapter, O-rings
Air Filters
Kapton® Tape, Vacuum Cups
Portable Vacuum Pen
Clear Test Board, specify with or without adhesive
Copper Test Board
Test Component - specify BGA or QFP
CUSTOMER SERVICES
Should your WQB2000 require repair or adjustment it may be sent to the following addresses:
USA
Cooper Tools - Weller
1000 Lufkin Road
Apex, NC 27539
ATTN: Repair Department
Phone: 1-800-476-3030
FAX: 919-387-2640
CANADA
Cooper Tools
164 Innisfil Street
Barrie, Ontario, Canada L4N 3E7
ATTN: Repairs
Phone: 705-728-5564 Ext. 2026
FAX: 1-800-403-8665
Kapton® is a registered Trade Name of DuPont.
S1049CH
8/97
Rev. 3/03
8
NOZZLE ALIGNMENT TAB
TAPE SHELF
WINDOW
STENCIL ALIGNMENT TAB
SIGHT HOLES
BALL
ALIGNMENT
DEPRESSIONS
TYPICAL BGA COMPONENT TEMPLATE TYPICAL QFP COMPONENT TEMPLATE
FIGURE 4
TAPE SHELF
WINDOW
STENCIL ALIGNMENT TAB
SIGHT HOLES,
CORNERS ONLY
LEAD ALIGNMENT
DEPRESSIONS
NOZZLE
ALIGNMENT
TAB
FIGURE 2
PC BOARD SUPPORT
REGISTRATION PIN
STANDOFF REGISTRATION PIN
STANDOFF BLOCK
STENCIL TAB
NOZZLE TAB
TAPE
TRIM FLUSH
FIGURE 3
9
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