fmea template

PROCESS FMEA

Ranking Guidelines: [attached as copy]

Erkki Rajala Retu Niemi 1 = Minor/No effect 10 = Very high/Hazardous

FMEA Responsible: Erkki Rajala Minna Keränen Matti Huoponen 1 = Remote/Unlikely 10 = Very high/Almost inevitable Date (Orig.): 23.9.1998

Other Areas Involved/Effected: Anssi Saari Jarmo U. Heinonen 1 = Very high/Almost certainly 10 = Very low/Unlikely Date (Rev.): 15.6.1999

Ari Pullinen Severity * Occurrence * Detection Page of

Process Description and Potential Potential Severity Potential Occurrence Current Process Detection RPN Recommended Responsible Completion Status Action Results

Process Purpose Failure Mode Effect(s) of Failure of effect Cause(s) of Failure of cause Control(s) of cause (S*O*D) Action(s) Person Date Action Taken [S] [O] [D]

Panel handling Humidity indicator missing Voids in solder joints 7 8 Visual inspection 5 280 JH

Complete

Panels have to be dried 3 7 Visual inspection 5 105 JH

Complete

Panel packages are broken Voids in solder joints 7 7 Humidity indicator 3 147 JH

Complete

Panels have to be dried 3 7 Humidity indicator 3 63

Poor solder joints 7 Handled with bare fingers 3 Work instructionn 4 84

Humidity in Aramid layers Voids in solder joints 7 7 5 245

de-lamination 7 inner layer separation 2 5 70

Wk36/00

6 Grippers are dirty 2 Maintenace 2 24

6 Production stoppages 4 Work instruction 3 72

3 2 None 10 60

Solder paste printing may fail 4 Grippers are dirty 2 Maintenace 2 16

4 Production stoppages 4 Work instruction 3 48

3 2 None 10 60

5 1 2 10

Panels are bended 6 Supplier process 2 2 24

6 Wrong way of storing 3 Work instructions 3 54

6 Inadequate material quality 2 2 24

Stencil bottom gets dirty 6 Supplier process 2 Supplier process control 2 24



Panel has to be rejected 4 Supplier process 2 Supplier process control 2 16


Process Name: Allu Board Assembly FMEA Team: FMEA Worksheet Document No:

Process Responsible: Riitta Hellman Severity of failure effect: File Location:

Occurrence of failure cause:

Detection of failure cause:

Risk Priority Number (RPN) =

Handling failure (supplier, transport or NMP)

Work instruction updating, supplier information. Moisture absorbtion study complete






Dirt (grease, finger prints, dust etc.) on PCB

brittle solder joints, poor reliability

Humidity indicator, PCB handling instructions

Humidity indicator, PCB handling instructions

Pasi to check with ASPOCOMP for root cause and corrective action

Panel picking from stacker

Panel gets dirty due to conaminated nozzles

Panel may be scrapped (at the end of process)

Extra dust generated from packing cell at the end of the line (near to paste printing)

Extra dust generated from packing cell at the end of the line (near to paste printing)

Two panels are picked in same time

Solder paste printing and SMD placements fail

Panels are wet (stacked while still damp)

Panels are dried out and hermetically packed. There is silicagel and humidity indicator in packages

Solder paste printing (side 1)

Panels move during paste printing

Supplier is measuring the straighness



PROCESS FMEA














Printing result inaccurate 6 Supplier process 2 3D-Laser Inspection 3 36

6 Wrong way of storing 3 3D-Laser Inspection 3 54

6 Inadequate material quality 2 3D-Laser Inspection 3 36

Wrong handling of panels Open solderings 6 Fingerprints on PCB 3 Work instructions 4 72

6 Panel is set to dirty surface 2 4 48

6 Dirt stucked on panel 3 CR-inspection 3 54

Solder paste viscosity wrong 8 5 2 80

Paste spreads (short circuits) 8 3 Supervising, PDM-system 2 48

8 4 7 224

JH wk32/99

Humidity-% of paste is wrong Voids in solder joints 8 Over-aged paste 3 Work instructions 3 72


Solder balls 8 Over-aged paste 3 Work instructions 3 72


Wrong handling of paste Paste dries out 3 Use of partly dried out paste 3 3 27

3 3 Work instruction 3 27


Printer settings wrong Printing can't be done 3 Wrong program is selected 2 2 12

Positioning varies 5 2 3 30

Printing results vary 5 Locking of stencil is not working 1 Maintenance 1 5

5 1 Maintenance 1 5

5 Squeegee is not properly working 3 3 45


Work instruction, training about panel handling

Insufficient amount of solder on small pads

Wrong handling/storaging of paste

Work instruction, control of the dates

Production stoppages (paste dries out)

Viscosity varies in different batches

Supplier process control; Operator Visual Inspection, Monthly Audits

Metering of viscosity has been started in Merikaari. Updating work instruction about paste handling.

Work instructions, marks in paste containers'

Paste collecting from stencil not done

Stencil washing not properly done

Program names are identical with stencil and PCB

Setting values in program are not correct

SMD Process Specification defines parameters

Stencil tower is not adjusted compared to printing base

Maintenance, work instructions

PROCESS FMEA













Printer in defective condition 3 2 Maintenance 2 12

3 Sencors are dirty 2 Maintenance 2 12

3 Conveyor is not rotating 1 Maintenance 2 6

5 3 Maintenance 2 30







5 2 2 20

Location failures of panels Paste location varies 6 3 Maintenance 4 72

6 2 2 24


6 Camera out of its place 2 Maintenance 2 24

6 1 Test panel, line verification 2 12

6 1 Test panel, line verification 2 12

6 3 Work instructions 3 54

Stencil in defective condition Amount of paste varies 6 2 Visual inspection 2 24

Place of paste varies 6 2 2 24

Printing result unclear 6 2 Visual inspection 2 24

6 Frame is not straight 2 Visual inspection 2 24

PCB's are not traveling well in the conveyor

Conveyor belts are in defective condition (worn out, dirty)

Paste printing can't be done or printing result is not satisfactory

Squeegee system is not working properly (worn out, dirty, wrongly adjusted, imbalanced)

Stencil mounting rail is not clean, fastening is broken-down, adjustments are wrong

Height sensor in wrong place (moved) or is not clean or wrongly adjusted

Support table worn out, dirty, wrongly installed or dimensioned

Coplanarity of stencil and support table

Cleaning system functioning not properly (too much/little fluid, blade wrongly adjusted, paper feeding not functioning or mounting failure)

Focusing system not working properly (camera and locating rails dirty, adjustments wrong)

Printing program not working properly (wrong parameters, software bugs)

Maintenance, SMD Process Specification defines parameters

Fiducial marks are "wrong colour", unclear, dirty or damaged

Stencil or stencil version number is wrong


Camera dirty or lamp too weak (=too old)

Holes for components in support table are not deep enough or wrongly located

Support table is not properly installed (locking, straighness

Support table is not clean (tin, components etc.)

Stencil worn-out, damaged or scratched

Stencil or stencil version number is wrong


Stencil screen not tight enough

PROCESS FMEA













Stencil dimensions are wrong Wrong amount of paste 6 Stencil openings wrong size 2 Supplier process control 2 24

6 Stencil thickness wrong 2 Supplier process control 2 24

6 Dents on support table 3 Visual inspection 2 36

6 Support table is not clean 3 Work instruction 3 54

8 Variation in solder joint volume 4 3 96 AOI machine installed into line

8 absence of solder paste. 4 3 96

Data matrix marking EMC automatic board cleaner

Wrong laser power setting Internal failures in PCB

Incorrect Reading Inaccurate data collection 7 Panel Warping 4 3 84

7 Optical Failure 4 3 84

7 4 3 84

7 Wrong Software Program 4 3 84

Board Loading Failure Machine stops 5 Panel not positioned properly 3 1 15

5 Fiducial Not found 3 1 15

5 Optical Failure 3 1 15

5 Conveyor adjustment 3 1 15

SMD-placement CSP-components misaligned Component moves on PCB 6 3 Self Test at FLALI 3 54

6 Incorrect part data 2 3 36

6 2 3 36

6 3 Supplier process 3 54

6 Table moves too fast 2 Software controls table speed 4 48

Support table in defective condition

Solder bridges, tin balls, incomplete or missing solder joints

0.5 mm pitch CSP solder paste printing fails

open solder joint; poor reliability

3-D laser scanner inspection machine

component may move after placement

3-D laser scanner inspection machine

Line stops, PCB must be manually removed and scrapped

Data matrix laser marking fails

Line stops, panel must be manually removed

Can cause PCB failures on module area

Isolate data matrix on pcb, I.e., do not connect to any device.

3D Laser Inspection For Paste and Component

Soldermask thickness/colour varies

Component moves in nozzle during pick-up after camera inspection

Tape board, test panels, line verification

Camera inspection fails (Points in bottom of package are disturbing)

Tape board, test panels, line verification

Component placed in wrong position to tape

PROCESS FMEA













6 2 Software controls nozzle speed 4 48

6 Hitting existing components 5 2 60

Filter does not function electrically 7 5 5 175

Coil component misplaced chip coil placement fails 7 6 AOI ; test 5 210

Shield placement fails 7 3 Testing 4 84

7 3 Testing 4 84

Reflow soldering 7 6 4 168

7 3 Testing 2 42

7 Wrong reflow profile 2 3 42


Wrong soldering profile Open solder joints 8 2 Reflow profile measurements 3 48

Popcorning Component Damage 8 Moisture Absorbtion 3 Handling procedure 8 192

Buffer Panel has to be scrapped 7 Wrong track width in rack 2 None 2 28

7 Racks damaged 2 Visual inspection 2 28

7 2 None 2 28

7 Pusher defective 2 None 2 28

Panel falls down Panel has to be scrapped 7 Wrong track width in rack 2 None 2 28


7 2 None 2 28


Panel sticks Line stoppage 7 Wrong track width in rack 2 None 2 28


7 2 None 2 28

Component placement speed too high (in Z-direction)

Already Placed components will be moved

SAW-filters placed in wrong position

Polarity not properly marked to component

Tape board, test panels, line verification, AOI inspection

product fails in testing and must be reworked

AOI machine installed into line, Stencil thickness reduced to 100 um

Short circuits between components and metal can

Shield must be removed and module reworked or whole module scrapped

LEDs in short circuits with shield

Shield must be removed and module reworked or whole module scrapped

Metal shield bends during re-flow soldering

Shield coplanarity not within specs

shield perimeter not totally soldered, poor shield properties

Supplier process, Incoming Audit

Connection area between shield and PCB not big enough due to LEDs

Shield separates in drop tested

Shield is not soldering properly

Work instruction with standard profile, oven calibration

Fan is switched off by operator

Soldering temperature too low

Panel cracks while placing to buffer

Sensor adjustment wrong or sensor damaged



PROCESS FMEA














Panel sticks Line Stops 3 Conveyor speeds not balanced 2 Setup and Maintenance 3 18

3 3 Setup and Maintenance 3 27

3 Misaligned components 3 Setup and Maintenance 3 27

Panel falls down Damaged Board 5 Conveyor speeds not balanced 2 Setup and Maintenance 3 30

5 3 Setup and Maintenance 3 45

5 Misaligned components 3 Setup and Maintenance 3 45

NMP 7 Problem Solving Steps: 1 Identify Problem2 Analyse Problem3 Determine Cause(s)4 Develop Solution(s)/Model(s)5 Plan Actions6 Implement Solution7 Evaluate Outcome

Conveyors and gates etc.

Conveyor width/height adjusted wrongly

Conveyor width/height adjusted wrongly

fmea template

Documents

inadequate material quality

extra dust generated

wrong track width

aoi machine installed

sensor adjustment wrong

stencil version number

solder paste printing

supplier process control