4OM-1603-007_w.pdf - 第366页

4OM-1603 5-3 2. T roubleshooting on Pickup Errors : Chap.5 2. T roubleshooting on Pickup Errors 2.1 Cause and Remedy of Pickup Errors (1) Component-Based Factors When the cause of a failure lies in specic components or …

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4OM-1603
5-2
1.ClassicationofFailureSymptomsandHelpfulHintsonCountermeasuresagainstFailure:Chap.5
Failures can further be classied as shown in the table below.
Classicationof
Failures
Contents of
Failures
Symptom of Failures
Failure before
Component
Placement
Component Pickup
Error
Components cannot be picked up.
Components are turned vertically.
A recognition error occurs.
Components fall down.
Others
Failure after
Component
Placement
Component
Placement Error
The positional and angular deviation of
component occurs.
Components are turned over and placed.
Some components are missing.
Some components are cracked or nicked.
Others
T4E1
1.2 Helpful Hints on Countermeasures against Failure
•
The rst helpful hint on countermeasures against failure is to catch precisely
what kind of symptom is produced and how frequently the symptom appears.
•
The second helpful hint is to grasp the tendency (environment and condition) of
a failure.
Shown below are the concrete items to be checked.
(1) Check if the failure occurs on specic components.
(2) Check if the failure occurs on a specic production lot.
(3) Check if the failure occurs on a specic machine.
(4) Check if the failure occurs at a limited stage.
•
The third helpful hint is to nd in which process the failure occurs.
In normal cases, a failure after component placement is found in the nal
inspection process. In such a case, it is required to track the failure by checking
all processes and specify the process in which the failure has occurred.
It is very important to grasp a failure symptom precisely on these helpful hints.
Precise capture of a failure symptom makes it possible to track the factor and
make a plan to take countermeasures against the failure.
In the case that the present status is not grasped correctly, the countermeasure
for the error takes time due to the execution of ineffective measures.
In particular, for the errors with low occurrence rate, it is required to collect the
data accurately, estimate the factors based on the data collection results, and
take the countermeasure.
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4OM-1603
5-3
2. Troubleshooting on Pickup Errors : Chap.5
2. Troubleshooting on Pickup Errors
2.1 Cause and Remedy of Pickup Errors
(1) Component-Based Factors
When the cause of a failure lies in specic components or lots, the
components must be examined rst of all.
Shown below are the cases of failures whose factors lie in components.
[Factors of Pickup Errors on Component Side]
(1-1) A component adheres to the bottom tape.
(1-2) The shape of a cavity is defective.
(1-3) The shape of a component is defective.
(1-4) A component turns sideways because the tape cavity is too large.
(1-5) The atness of the cavity bottom is defective.
(1-6) Oil or mold lubricant adheres to the bottom of a component.
The failures described in (1-1) through (1-4) have a tendency to occur easily
due to the components packaged in a paper tape and the failures described in
(1-4) through (1-6) due to the components packaged in an embossed tape.
Special caution should be paid to minute components such as 0603 and
1005 types because such components are directly affected by how they are
packaged in the tape.
To determine whether or not the taped components are packaged in good
condition, turn the tape upside down and check to see how the components
fall down from the cavities. If the components fall down freely, it means that
they were packaged in good condition.
The specications of taping are specied in "JIS-C0806". However, as the
detailed regulations are not provided as for the failures described in (1-1)
through (1-6), it is required to ask the component maker about the details
when the components are purchased.
ExemplicationofTroubledTapedComponentsF4E2
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4OM-1603
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2. Troubleshooting on Pickup Errors : Chap.5
(2) Machine-Based Factors
When a component has no problem, check the main body of the machine.
A failure can be tracked by checking if it occurs on a specic vacuum nozzle
or feeder slot No. (lane).
(2-1) Whenthevacuumnozzlehasbeenspecied:
Check the following items for the specied vacuum nozzle.
•
Check if the vacuum nozzle is abnormal.
•
Check if the vacuum line is abnormal.
•
Check if the vacuum ON/OFF valve is abnormal.
•
Check if the linear measure sensor is abnormal.
When a factory is dusty or a lot of components packaged in paper tapes are
used, the vacuum nozzles and their lters get dirty easily.
Therefore, it becomes important to clean the vacuum nozzles and lters
periodically.
Reference
Refer to "2.2 (1) Frequent Pickup Errors on Specic Vacuum Nozzle" in
"Chapter 5" for the troubleshooting.
(2-2) WhenthefeederslotNo.hasbeenspecied:
Check the following items for the specied feeder slot No. (tape feeder).
•
Check if the tape feeder is loaded correctly with components.
•
Check if the top cover tape is peeled off normally.
•
Check if the data related to the component picks is normal.
Reference
Refer to "2.2 (2) Frequent Pickup Errors on Specic Feeder Slot No." in
"Chapter 5" for the troubleshooting.
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