EUKYX-199-4110_G5S2_Instruction_Vol4_E - 第350页
EUKYX 5-2 199-4100 1.2 Countermeasures against Failure Fa ilu res can furt her be cl a ss ified as shown i n the table belo w . Classification of Fail ure s Contents of Fail ure s Symptom of Failures Failure before Compo…
EUKYX
5-1199-4100
1. Classification of Failure and the Countermeasures
1. Classification of Failure and the Countermeasures
1.1 Classification of Failure
The machine processes can be classified into Processes A, B, C, D, and E as shown below.
Refer to “4. Surface Mounting Mechanism” in "Chapter 1 (Vol. 1: Guide)" for the outline of
actions.
Process A : The placement head moves to the feeder base and picks up a component.
Process B : The head moves to the area where the component recognition camera is installed
and a component recognition process is taken there.
Process C : The placement angle is corrected while the head is moving to the PCB
positioning section.
Process D : The component is placed on the PCB.
Process E : The component-placed PCB is discharged.
1
2
3
Feeder Base Section
Component Recognition Camera
PCB Positioning Section
Process A
Process B
Process C
Process D
Process E
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Based on these processes, failures can be divided roughly into the following two types.
Failure before Component Placement :
This type of failure occurs mainly in Processes A, B, and C.
Failure after Component Placement :
This type of failure occurs mainly at Processes D and E.
Reference
EUKYX
5-2199-4100
1.2 Countermeasures against Failure
Failures can further be classified as shown in the table below.
Classification 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
1.2 Countermeasures against Failure
•
The first 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 specific components.
(2) Check if the failure occurs on a specific production lot.
(3) Check if the failure occurs on a specific machine.
(4) Check if the failure occurs at a limited stage.
•
The third helpful hint is to find in which process the failure occurs.
In normal cases, a failure after component placement is found in the final 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.
EUKYX
5-3199-4100
2. Troubleshooting on Pickup Errors
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 specific components or lots, the components must be examined
first 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 flatness 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 specifications of taping are specified 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.
Component
adheres to
bottom tape.
(1-1)
Troubles caused by taping
(1-2) (1-3) (1-4) (1-4) (1-5) (1-6)
Component
is trapped by
burr of square
cavity.
Component
is trapped by
burr.
Component turns sideways
as tape hole is large.
Lead is trapped
at R section
of cavity bottom.
Oil, etc., adhere to
component bottom.
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