Quality Improvement Activity of Capacitor. QI team Chairman Adviser Leader Secretary Sub-Leader Member.

Quality Improvement Activity Quality Improvement Activity of Capacitorof Capacitor

QI team

Chairman

Adviser

Leader

Secretary

Sub-Leader

Member

Assembly process (soldering)

Issuing process

Coating process

Electrical testing process

Out going process

Processing

Steel Type

151K 151K 151K 151K 151K

DC Volt

TV Test (Measuring process )Customer

Appearance

Dimension

Electrical

Customer complaint

THEME SELECTION

Cause-and-effect analysis

Material

Connector(metal)

Coating (resin, polymer)

contactBody

(ceramic)

Crack, chipresistivity

Heat resistance

Environment

Heat

Applied voltage

complaint defect analysisusing

dispersion C&E diagram

Electrical damage(burn& short circuit)

Back side Back side

Chipping

Resin swelled

Small ceramics

L

Short circuit complaint defect analysis

Total12.94

10.5918.82

11.76

45.88

Top ( 1 )

Side top ( 2,8 )

Side ( 3,7 )

Side bottom ( 4,6 )

bottom ( 5 )

Analyze position of chip on TV defect

Position on unit

12

3456

78

Item

5

4

3

2

1 A B

A

A

B

B

Chip size

A B

A B< 1.3

> 1.3

< 1.0

< 0.7

< 0.5

1.0 <

0.7 <

0.5 <

> 0.7

< 0.5< 0.4

< 0.3

< 0.70.5 <

0.3 <0.4 <

0

12

34

56

7

0 1 2 3 4 5 6

classification of chip size

Vol

tage

(kV

)

Relationship between short-circuit voltage and chip size

large

small

Q: what is the meaning of this relationship?

Cause-and-effect analysis

Issuing

Assembly(soldering)

Electricaltesting

Coating

(chipping) defect analysisusing

process C&E diagram

Chipping

Chip unit sizeGroup 1 2 3 4 5

A > 1.3 1.0 < A < 1.3 0.7 < A < 1.0 0.5 < A < 0.7 A < 0.5

B > 0.7 0.5 < B < 0.7 0.4 < B < 0.5 0.3 < B < 0.4 B < 0.3Chip unit

A

B

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

Incoming Issuing DLS ttl TV(CCM)

Process

%

Group 5

Group 4

Group 3

Group 2

Group 1

Chip Unit

Q: which process you are going to solve first? Why?

Unit issue methodCause: Chip unit occurred when pouring unit to the box for confirm unit weight by this method make more chip unit.Action : Cancel pouring unit by pick up unit with vinyl sheet and take it in to prepared box for confirm unit weight after that send the unit with prepared box to DLS process.

Confirm unit weight on vinyl sheet.

Confirm unit weight by pouring unit to the box.

ISSUING (1)

Action:

1.Hopper :Use for supply unit to part feeder.

2. Change unit supply method by pick up all unit with vinyl sheet

3. Modify circuit to auto unit supply at hopper

Cause:Unit supply by use small plastic box pour unit direct to part feeder so it make unit broken and chip.

No HopperPart feeder

HopperPart feeder

ISSUING (2)

Unit feeding trackCause:Chip unit occurred when unit running attack to final track of part feederAction : Addition absorber rubber for protect unit attack with steel material directly.

Assembling (1)

Steel Type

UPE Type

Cause: Unit head pusher attach to unit edge that made from Steel material. Effect to edge of unit chip.Action: We change material type to UPE type for soft contact with unit edge

DLS process

Assembling (2)

Cause:Unit easy impact to guide of products container .That effect to edge of unit chip. Action:We took action by change and fix container type to be no slot type.And attach coating tape for prevent edge of unit attack with guide.

Container slot type Container no slot type

Assembling (3)

Cause: Unit impact take out rail guide at the corner position

Countermeasure: Changed takeout type to slope type

Chipping position Slop type

Assembling (4)

TV Defect ( Test Voltage )

151K 151K 151K 151K 151K

DC Volt

TV Defective Means defect that occur after test voltage that effect to product’s short circuit

Electrical testing

A > 1.3 mm

B > 0.7 mm

Judge NG

A > 1.3 mmA > 1.0 mm

B > 0.5 mm

Current Limit Sample

Judge NG

Old criteria New criteria

Chip unit ratio result

0.73

1.43

0.69

0.150.24

0.49 0.400.22

0.00

0.50

1.00

1.50

2.00

Incoming Issuing DLS TV(CCM)

Before action

After action

Data from experiment: 50 Kpcs

Cause-and-effect analysis

Issuing

Assembly(soldering)

Electricaltesting

Coating

Chipping

Weibull distribution

Raw materialMechanical properties

Electrical properties

resistivity

Chemical properties