KE-750_MAINTE.pdf - 第137页

- 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 …

- 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.

- 135 -

6. Problems caused by XY axes

Symptom Cause Remedy

There is an

offset in XY

axes. (Entire

board)

This is caused by damping when the XY

axes stop. In this case, there is no

tendency in the mounting offset. It is at

random.

Check that the XY gain for the servo

driver has been correctly entered.

Then, perform production by

entering 100 ms for all 0 to 9 pages

of [0] to [5] of wPlcdmpg at 1. High

speed of 7. XY. If recovered, the

problem is related to damping, and

check the tension of the timing belt.

(See QA table: XY No.1.) (See

QA table: Electrical No.2.)

7. MS parameters entered

Most of MS parameters of the head and the VCS affect the mount accuracy.

Therefore, if there is an offset, it is necessary to check how it occurs with which

head.

Symptom Cause Remedy

There is an

offset in XY axes

in laser

recognition

mounting.

(Entire board)

This is caused by an offset of the laser

center of the laser 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°.

Re-enter the laser center offset of

the laser offset, and re-obtain the

head offset.

There is an

offset in XY axes

in laser

recognition

mounting.

(Entire board)

This is caused by the head offset. In this

case, disregarding the placement angle

and position, offset occurs always in the

same direction.

Re-obtain the head offset. Check

the entered value of the overall

placement offset after execution. If

a larger value has been entered,

record the value and set it to 0.

There is an

offset in XY and

θ axes in laser

recognition

mounting.

(Entire board)

This is caused by incorrect input of the

overall placement offset. If maintenance

of the head part which affect the accuracy

(head replacement, or Z slider shaft

replacement) was performed in the past,

the input value of the overall placement

offset changes. Accordingly, if a larger

value still remains, it affects.

Check the entered value of the

overall placement offset. If a larger

value has been entered, record the

value and set it back to 0. Or,

measure the offset with the camera,

and enter the correct value.

There is an

offset in XY and

θ axes in laser

recognition

mounting.

(Entire board)

This is caused by incorrect input of the

board height of the laser offset. If the

entered value is higher than the board

surface, the part falls down when

placement, and the offset of the placement

is at random.

Re-enter the board height of the

laser offset.