Weller WQB2000 User Manual
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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