KE-750_MAINTE.pdf - 第136页

- 133 - 4. Problems caused by mount head Symptom Cause Remedy There is an offset in θ axis. (Mainly square chips at high sweep speed) The rotating torque of the rotary block is too high, and rotation during laser measure…

- 132 -

3. Problems caused by cramp state of the board on the board carriage

Symptom Cause Remedy

There is an

offset in XY and

θ axes.

(Specific area of

the board or

entire board)

The side cramp of the board is insufficient,

and there is a play in vertical direction.

The board moves in XYZ directions during

production.

Load the board by manual control,

and check that there is no play

upwards and downwards of the

board when it is cramped. If there

is play, readjust the mount position

of the rail guide shaft. (See QA

table: Carriage No.4.)

There is an

offset in XY and

θ axes.

(Around the

center of the

board)

There is a large space between the

backup pin and the bottom surface of the

board when the board is cramped, and the

board vibrates up and down when

mounting. This is likely to occur with a

large thin board.

Check the space between the

backup pin and the bottom surface

of the board. If it is too large,

readjust the height of the backup

pin. (See QA table: Carriage

No.8.)

There is an

offset in XY and

θ axes.

(Specific area of

the board)

The top surface of the board is not flat,

and this can occur when the part does not

gently touch the board but it is roughly

brought onto the board when mounting.

Check that the height of the top

surface of the CAL block and of the

top surface of the board is set within

the specified value. (See QA table:

Carriage No.10.) This can also be

checked with the HMS.

There is an

offset in XY and

θ axes. (Entire

board)

The clearance between the fiducial pin

and the positioning hole of the board is too

large, and the vibration during production

moves the board.

Change the positioning of the board

from pin fiducial to pattern fiducial.

There is an

offset in XY and

θ axes. (Entire

board)

There is too much play of the fiducial pin. Check that the play of the fiducial

pin is within the specified value.

(See QA table: Carriage No.5.)

There is an

offset in XY and

θ axes. (Entire

board)

When carrying in the board, deceleration

immediately before touching the stopper is

not effective, and the part is displaced by

the shock.

Check that there is no displacement

before and after board carriage. If

there an offset, change the position

of the STOP sensor, and adjust so

that the deceleration is carried out

correctly. (See QA table: Carriage

No.1.)

There is an

offset in XY and

θ axes. (Entire

board)

The shock caused by the upward and

downward movement of the backup table,

and by cramping and decramping, the

already mounted parts or normally

mounted part is displaced.

Readjust the speed control of

upward and downward movement of

the backup table. Readjust also

the orifice of the shock absorber.

(See QA table: Carriage No.4.)

There is an

offset in XY and

θ axes. (Entire

board)

When pattern fiducial is used, the shock of

the X cramp and Y cramp displace the part

previously mounted.

Check the depressure valve of the X

and Y cramps and the adjustment

value of the speed controller. (See

QA table: Carriage No.13 and

No.14.)

There is an

offset in Y axes.

(Entire board)

When patter fiducial is used, the

protruding amount of the Y pusher is

insufficient, and the part does not touch

the board. Or, carriage width is set too

large.

Perform readjustment if the

protruding amount of the Y pusher

is less than the specified value.

(See QA table: Carriage No.14.)

- 133 -

4. Problems caused by mount head

Symptom Cause Remedy

There is an

offset in θ axis.

(Mainly square

chips at high

sweep speed)

The rotating torque of the rotary block is

too high, and rotation during laser

measurement is not even, resulting in a

difference of measured values of Δθ.

This also affect the damping of the θ axis.

The silicon grease at the oil sealing part in

the rotary block is insufficient.

Check the rotating torque of the

rotary block. If it is out of

specification, apply grease. (See

QA table: Head No.1.)

There is an

offset in XY and

θ axes. (Entire

board)

There is play of the Z slider shaft in Z axis

direction, and the height changes during

laser measurement. Accordingly, there

are errors in the measured result resulting

in a mounting offset. In some cases, this

is found as an laser error.

Check the play in the Z axis

direction. If there is, reassemble

the set collar to remove the play.

(See QA table: Head No.3.)

There is an

offset in XY

axes. (Entire

board)

There is play of the Z slider shaft in XY

axes direction, and the shaft moves during

laser measurement. Accordingly, there

are errors in the measured result ΔX and

ΔY resulting in a mounting offset.

In this case, the offset is not not random

for all placement angle but there is a

tendency in specific placement angle.

The displacement in XY axes direction

differs between 0 to 180° and 90 to 270°.

Check the play in the XY axes

direction. If there is, reassemble

the set collar to remove the play.

Check also the push by the pusher

rubber. (See QA table: Head

No.4.)

There is an

offset in XY

axes. (Entire

board)

This is caused by eccentricity of the Z

slider shaft. This is related also to the

play of the Z slider shaft in ZXY direction.

Therefore, touch the shaft by hand to

check which is the cause of the trouble.

When caused by the eccentricity, the

offset is not not random for all placement

angle but there is a tendency in specific

placement angle. The displacement in

XY axes direction differs between 0 to

180° and 90 to 270°.

When this is caused only by

eccentricity, not caused by the play

in Z and XY axes direction, replace

the Z slider shaft. It is defective.

(See QA table: Head No.7.)

There is an

offset in XY

axes. (Entire

board)

This is caused by damping when the Z

axis stops. When the load of the Z axis

changes such as by sliding resistance of

the ball screw of the Z axis, the damping

of the Z axis during downward movement

for mount and the laser height after picking

are affected. Then, there is an

inaccuracy in the measurement and in the

vibrating surface when mounting.

When power is turned off, with the

head up spring removed, check that

the Z axis falls down by its own

weight, and that there is no

uneveness in the sliding resistance

in full stroke range. If there is a

problem, replace the head.

There is an

offset in XY and

θ axes. (Entire

board)

There is play of the nozzle slider in the XY

axes direction.

Replace the nozzle.

There is an

offset in θ axis.

(Entire board)

Tension of the timing belt θ is not

appropriate. At high tension, the load of

the θ axis increases, and this affect the

damping when stopping. The same thing

happens at low tension.

Readjust the tension. (See QA

table: Head No.21.)

5. Problems caused by vacuum or blow pressure when mount

- 134 -

Symptom Cause Remedy

There is an

offset in XY and

θ axes. (Entire

board)

The ejector is faulty, and this causes

insufficient vacuum value. When vacuum

value decreases, there is an weakness in

part pick. The part falls down or there is

a slip between the part and the nozzle in

the θ rotation during laser measurement,

resulting in in accurate mounting.

Connect the outlet of the ejector to

the pressure sensor. If the

vacuum pressure is less than -600

mmHg, replace the ejector.

There is an

offset in XY and

θ axes. (Entire

board)

This is caused by the faulty vacuum

solenoid. When vacuum destruction for

mounting, the vacuum solenoid may not

work, or there is a delay in its operation,

the vacuum is not destroyed, and the part

is picked by vacuum.

Check the function of the solenoid

valve by manually turning on and off

the vacuum. If there is a problem,

replace the vacuum solenoid.

There is an

offset in XY and

θ axes. (Entire

board)

This is caused by the blow solenoid. The

vacuum destruction by blow during

mounting is not correctly performed, and

the part is picked by the remaining

pressure of the vacuum pressure.

Check the function of the solenoid

valve by manually turning on and off

the blow solenoid. If there is a

problem, replace the blow solenoid.

Check at the same time that there is

no leakage in the positive pressure

when the blow solenoid is turned

off.

There is an

offset in XY and

θ axes. (Entire

board)

This is caused by clogging of the union

filter. The part is picked at vacuum by the

remaining pressure of vacuum pressure

when vacuum destruction for mounting.

With the vacuum set to on, check

the negative pressure at the

entrance and the exit of the union

filter. If there is a difference,

replace the union filter.

There is an

offset in XY and

θ axes. (Entire

board)

This is caused by low vacuum value

resulted from clogging of air tube.

Check that there is no clogging from

the ejector to the rotary block. In

particular, check that the holding

part of the tie-up band.

There is an

offset in XY and

θ axes. (Entire

board)

This is caused by leakage of the vacuum

resulted from deterioration in the oil

sealing in the rotary block of the head.

With the nozzle attached, stop the

tip with finger and check the

vacuum value. Then, compare this

vacuum value with that when the tip

of the air tube connected to the

rotary block is stopped. If there is

an air leakage, replace the rotary

block or the Z slider shaft.