KE-750_MAINTE.pdf - 第133页
- 130 - Symptom Cause Remedy There is an offset among XY and θ when mounting using adhesive. (In particular, for medium-size parts such as aluminum electrolytic capacitors, tantalum capacitors, and trimmers) Medium-sized…
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7. TROUBLESHOOTING
7.1 Part Mount
Part mount offset can be classified in an offset of XY, θ, or XYθ. And, it can
also be classified by causes as follows:
1. Bond (adhesive) or cream solder
2. Mount program entered
3. Cramp state of the board on the board carriage
4. Mount head
5. Vacuum or blow pressure when mount
6. XY axes
7. MS parameters entered
1. Problems caused by dispenser or cream solder
The adhesive and cream solder are main causes of trouble. On a
double-sided tape, it is necessary to be mounted correctly.
Symptom Cause Remedy
There is an
offset in XY and
θ axes when
mounting using
adhesive. (In
particular, for
small-sized parts
such as
2125/3216
capacitors, Melf,
and SOT)
With adhesive, there is an offset mainly in
θ axis, and this is affected by the amount
and position of adhesive. In particular,
2125/3216 capacitors, Melf, and SOT are
affected by the amount of adhesive. For
capacitors, the body is raised with respect
to its edges, and if little adhesive is applied
the body does not touch the adhesive. In
addition to this, if adhesive displacement
occurs, it is fixed by 1 point, and the part is
largely affected. This applies also to
SOT. The body is raised with respect to
the leads. Melf is likely to roll because of
its shape, and it can be largely affected by
the amount of adhesive.
In general, the amount of adhesive
increases, a stable mount is performed.
Check that there is no adhesive
displacement on the board to which
the adhesive is applied, using
position tracking. For the amount
of adhesive, check on the board
which the parts are mounted so that
the adhesive adequately touches
the parts. If there is problem with
the placement and amount of
adhesive, make corrections on the
application conditions of the
dispenser for the specific part type,
or for all part types.
- 130 -
Symptom Cause Remedy
There is an
offset among XY
and θ when
mounting using
adhesive. (In
particular, for
medium-size
parts such as
aluminum
electrolytic
capacitors,
tantalum
capacitors, and
trimmers)
Medium-sized tall parts such as aluminum
electrolytic capacitors, tantalum
capacitors, and trimmers are likely to roll.
And, this is also affected by warp and size
of the board. Warp of the board when
mounting is a repulsion force of Z upward
movement, resulting in an offset. The
offset is mainly found in θ axis.
It is better to apply much adhesive.
On the mounter, install a backup pin
under the board around where the
parts are mounted to prevent board
warp. If this is not effective
enough, change the lift up speed to
medium or low after mounting.
There is an
offset in XY and
θ axis when
placement on
cream solder.
(When this
occurs with all
parts.)
For cream soldering, different from the
case of adhesive, there is little effect with
printing offset because of wide pat.
However, for soldering, leaving time and
viscosity after printing largely affect the
performance. The conditions of the
leaving time and the viscosity cannot be
the same because of the difference in type
of the solder, humidity of the leaving time,
and environmental conditions.
Check that the solder is dried out
before mounting.
There is an
offset in XY and
θ axis when
placement on
cream solder.
(In particular,
medium-sized
parts such as
aluminum
electrolytic
capacitors,
tantalum
capacitors, and
trimmers.)
This is also affected by dry soldering.
However, in this case, the same as the
adhesive, thickness and size of the board
affect the performance. Warp of the
board when mounting is a repulsion force
of Z upward movement, resulting in an
offset. In some case, it jumps.
Install a backup pin under the board
around where the parts are
mounted to prevent board warp. If
this is not effective enough, change
the lift up speed to medium or low
after mounting.
- 131 -
2. Problems caused by mount program entered
Symptom Cause Remedy
There is an
offset in XY and
θ axes. (In
particular,
small-sized parts
such as SOT
and square
chips).
This can occur for part data of SOT, etc., if
incorrect part size (width and depth) or
incorrect feeding direction is entered. In
this case, a laser error also occurs. (Error
code 98)
For part size, if the dimensions at a
feeding angle of 0 degree has been
entered, but it is set for 90 degrees, enter
the width and depth of setting of 0 degree.
If not, the mounter will measure first the
longer side of the part, and the minimum
width of the shadow cannot be measured.
Then, an error occurs. Even if it can be
measured and mounting is performed, an
offset will occur because of inaccurate
measurement data used.
Check the part data so that the
feeding angle is set correctly as part
dimensions.
There is an
offset in XY and
θ axes.
There is an offset caused by incorrect
measured value where the laser height for
the laser measurement is not set correctly.
In some cases, this can be indicated as a
laser error.
For the laser height of the laser
measurement, it is automatically computed
according to the part type and part height
in the part data. This will occur when
either of them is set incorrectly.
Check the part type and part height
of the part data, and also the laser
measurement height. For a
special shaped part which does not
indicate the part type, check the
appropriate value for the
measurement height by manual
control (laser control), and enter that
value for the part data.
There is an
offset in XY
axes.
There is a difference in the distance of
BOC marks between their centers from
the mark coordinate value of the board
data. Mount displacement results in an
offset of right angle or in longer/shorter XY
axes. The distance between the centers
of the mark may be large when the set
value is larger than the measured value on
the machine. It is smaller when opposite.
Measure the distance between the
centers of the mark by camera
teaching. (If possible, use a
2-dimensional measuring
instrument.) Then, compare the
measured value with the set value.
Check by loading the board before
mounting so that the mount pattern
matches by mount tracking.
There is an
offset in θ axis.
There is an offset in pick position. For
the part whose pick position is easy to slip
such as square chip resistors, network
resistors, etc., when the nozzle diameter is
small but the part size is large, an offset
will occur when rotating if the part is
displaced and picked.
Check first the pick position. If
some cases, consider the use of a
specially ordered nozzle.