User-Manual-NeoDen-K1830-20200618.pdf - 第51页
⑥ Checking if PCB movin g o n rails smooth ly or not; Sen sor wo rkable or not. ⑦ Checking if the boa rd has been well fixed by magnetic ba r an d pins. 12.2. 2 Monthly Inspection Items Detailed Inspectio n X/Y axis Make…
●Operating strictly against equipment's instruction. Don’t use machine with problems. Stop the machine once malfunction
appears and contact with the after-sales service staff, restart to work after problem solved.
●Operator should be concentrated，
Observation-- to see whether there is abnormal situation, such as peel-box doesn’t work, plastic tape is broken etc.
Listening-- whether have strange sound, such as noise from placement head, sound of loss component, strange noise of
conveyor etc.
Handwork-- solve some small problems in time, such as install feeder, correction placement position etc. If the main
machine body or circuit problem, please consult after-sales staff. Formulate measures to reduce/ avoid big problem.
12.1.3 Formulate the measures to reduce/avoid big problem
The most easily appeared problem during work are placement wrong components and placement misaligned. Supply below
measures for ref.
①It needs to check whether the components package is matched with related feeder. If not, please correct them.
②As to tape reel feeder, when ran out of one reel, operator must check whether newly changed tape reel is correct or not.
③After import the SMD file or edit chip list manually, please recheck each components No., nozzle rotation angle and
placement position to make sure correct.
④Operator must check the first finished PCB of each file. If any problem, please find solutions such as revise program to
solve it.
⑤To check the placement position misaligned or not, component loss problem in regular work. Find reason in time and
solve it.
⑥Set pre-welding detection station (manual or AOI)
In sum, P&P machine's running speed and placement accuracy still has limit. Peoples work is important to run machine on
its proper role. So, it’s necessary to comply with effective measures to keep machine normal work, its placement quality and
efficiency.
12.2 Maintenance
Arrange regular inspection and maintenance system.
12.2.1 Daily Inspection
Items
Items check before
power on
①Temperature& Moisture: Temperature 20℃～26℃, humidity 45~70%
②Indoor environment: Air clean without aggregate air.
③No clutters within the placement area and keep rails clean.
④No spots on cameras and keep lens clean.
⑤No obstacles around the head nozzles
⑥ Checking if nozzles are dirty, distorted; If so, please clean or change the
nozzle.
⑦Checking if feeders are correctly installed in stacks and confirm no clutters
on stack.
⑧Checking the connection of air connector and air hose
⑨Checking air pressure.
Items check after
power on
①Checking if the monitor display normally after system start up.
②Checking if emergency button can work normally or not.
③Checking if placement head can move back to the origin.
④Checking if there’s abnormal noise while placement head move.
⑤Checking all nozzles vacuum pressure.
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⑥Checking if PCB moving on rails smoothly or not; Sensor workable or not.
⑦Checking if the board has been well fixed by magnetic bar and pins.
12.2.2
Monthly Inspection
Items Detailed Inspection
X/Y axis Make sure no abnormal noise while placement head moving.
X/Y motor Make sure X/Y motors no overheating.
Nozzle Checking if all nozzles are good without bend and nozzle surface is horizontal
Air hose
Checking the connection between air hose and machine, keep sure the hose in good
situation without wearing or air leaking.
Step motor
Checking if any dirty on step motor, synchronous belt, Synchronous wheel. Make sure the
Z-axis motor can up, down and rotate smoothly.
Z-axis motor
Checking if the placement head can go up and down smoothly. Use your finger to push the
nozzle to check if it moves smoothly. Let each nozzle head up and down beyond the normal
range.
Vacuum
pressure
Checking all nozzles’ vacuum pressure. If abnormal, please clean nozzles.
Positive
pressure
Checking if the positive pressure normal.
Optical axis Checking whether it is covered dusk. Please keep it clean and lubricated
Operation
button
Checking each button to make sure they are well-worked
Connector Checking if well-connected the air hose and air connector.
PCB clamp
block
check their wear pattern
12.3 Related issues during solder paste printing process
12.3.1 Stencil Printing Technology
Screen printing technology refer to using ready-made stencil, directly connect to the printer in a certain way, make the
solder paste evenly flow on the stencil and then leak into the mesh through the holes. When getting the stencil away, solder
paste had been covered to the printed circuit board solder graphics, then finish the solder paste printing on the PCB.
12.3.2 Inspecting of solder paste printing
Printing process is one of the key working procedures to ensure the quality of surface mounting. According to the statistics,
under the premise of guaranteed quality about components and PCB, correctly PCB design, 70% of the surface quality
problem caused during printing process. In order to ensure the quality of SMT assembly, it is necessary to strictly control
the quality of the solder paste printing.
The amount of solder paste printing requirements are as follows:
(1)The using amount of solder paste should be uniform, good consistency. Solder paste graphics should be clear, try to avoid
adhesion between adjacent graphics. Solder paste graphics and solder graphics should be consistent.
(2)In general, keep unit area amount of solder paste about 0.8 mg/mm². For fine pitch components, should be 0.5 mg/mm²
(using stencil thickness and hole size to control in the actual operation).
(3)Printed on the substrate of solder paste compared with required value, a certain deviation is permissible, the covering
area of the solder paste on each solder pad should be more than 75%.
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(4)Should be no seriously collapsing problem and edges neatly after solder paste had been printed, the dislocation shouldn’t
be larger than 0.2 mm, for solder pad of fine pitch components, dislocation shouldn’t be larger than 0.1MM, pollution by
solder paste is not permitted to the PCB.
Inspection by 2~5 times magnifier or 3~20 times microscope.
12.3.3
The defects of solder paste printing, reasons and solutions
Excellent printing graphics should be uniform in both vertical and horizontal direction, full, clean all round, solder paste fill
solder pad. Using above such printing graphics device, after reflow soldering, will get good welding effect then.
Problem Reason Issue Solution
Solder paste
graphics
dislocation
Holes on the stencil not good
match with solder pad; No
enough precision of the Printing
machine
easily cause bridge
connection
Adjust the stencil position;
Adjust the printing
machine
Solder paste
graphics have
icicles and dents
Scraper pressure is too large;
Rubber scraper hardness is not
enough; Holes are too big in the
stencil
Solder paste required
volume is not enough,
easy to appear faulty
soldering; solder joint
strength is not enough.
Adjust the printing
pressure; Use metal
scraper; Improved holes
designing in the stencil.
Too much solder
paste
Holes are too big in the stencil;
The gap is too big between
stencil and PCB
easily cause bridge
connection
Check the holes size in
stencil; Adjust the
parameters of printing,
especially the gap between
PCB and stencil
Graphic uneven
(have
breakpoints)
Holes’ wall are not smoothness
enough; not wipe residual solder
paste in using for many times;
Solder paste’s thixotropy is bad
Easy cause no enough
solder paste, lead to the
problem such as faulty
soldering.
Wipe the stencil
Contamination of
the graphics
Not wipe residual solder paste in
stencil after using for many
times; Poor quality of solder
paste; Shake problem when
getting the stencil way
easily cause bridge
connection
Wipe and clean stencil;
replace solder paste; adjust
the machine
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