ansyscode.txt

Ansys code for the life prediction of melt

FINI
/clear
/title,FEA 2
/filname,Thermal,1
/PREP7

!******* mm units *******

!********************* Parameters **************************************

   pi=3.141592654
   a=pi/180
   inch=25.4 ! 25.4 mm

! Motherboard Dimensions

  PCBT = 0.04*inch		!board thickness

! BGA parameters

  JTHT = 0.02*inch   		!Solder ball height

! Components 

  PCKGT= 0.04*inch		!Total package thickness above solder balls

! SolderBall 

  CUTHSUB  = 0.001*inch	        ! CU PAD AT SUBSTRATE SIDE 
  CUPADTHB = 0.001*inch         ! Cu PAD ON PWB SIDE 
  BALLDIA  = 0.032*inch		! SOLDER BALL DIA 
  PITCH=0.04*inch		! PITCH = (1.016 mm)
  UNITSZ=0.04*inch

! DIESZ & DASZ

  PADSZT   = 0.024*inch		! SOLDER BALL PAD (0.4 mm)
  PADSZB   = 0.024*inch		! Cu PAD ON PWB (SAME)
  CUNIPADT = 0.033*inch		! Cu PAD ON TOP OF SOLDER

!******************* Material Propeties ********************************

!*** PCB ***  
mp,ex,1,31.75e6  
mp,nuxy,1,0.28                   Minor Poisson's ratios 
mp,dens,1,3.7e-6  
mp,alpx,1,17e-6                !Secant coefficients of thermal expansion 

!*** SOLDER *** 
mp,dens,2,8.42e-6 
mptemp,1,273,338,378,398
mpdata,ex,2,1,45e6,43e6,41e6,40e6 
mpdata,nuxy,2,1,0.35,0.35,0.35,0.35
mpdata,ctex,2,1,24e-6,24e-6,24e-6,24e-6 !Instantaneous coefficients of thermal expansion 

tb,anand,2		! ANAND'S constants for 62/36/2 solder
tbdata,1,12.41e3,9400,4.0e6,1.5,0.303,1379e3
tbdata,,13.79e3,0.07,1.3

!*** Overmold ***
mp,ex,3,20e6
mp,nuxy,3,0.3   
mp,dens,3,2e-6 
mp,alpx,3,3e-6

!*** Chip ***
mp,ex,4,131e6   
mp,nuxy,4,0.278   
mp,dens,4,2.33e-6  
mp,alpx,4,4.5e-6

!*** Substrate(BT) ***  
MP,DENS,5,2e-6  
MP,EX,5,16.8e6		
MP,EY,5,16.8e6
MP,EZ,5,7.34e6
MP,GXZ,5,3.48e7              !Shear modulious 
MP,GYZ,5,3.48e7
MP,GXY,5,7.94e6
MP,NUXZ,5,0.3
MP,NUYZ,5,0.3
MP,NUXY,5,0.11
MP,ALPX,5,18e-6
MP,ALPY,5,18e-6
MP,ALPZ,5,44e-6 

!*** Cu ***  
mp,ex,6,129e6 
mp,nuxy,6,0.344  
mp,dens,6,2e-6  
mp,ALPX,6,16.6e-6

!******************* Element Definition *********************************   

et,1,45                   !solid 45
et,2,visco107

!***** Define coordinate systems *********  

local,13,0,PITCH,0  
local,14,0,0,0  

!**************************** MODELING **********************************  

!****** PCB (Model quarter symmetry of single component first)

wpcsys,,14  
CSYS,4
!WPROTA,,-90

!****** CREATING KEYPOINTS

CSYS,4

K,1,,JTHT,0
K,2,,JTHT,-(PADSZB/2)
K,3,,(3*JTHT/4),-0.38
K,4,,JTHT/2,-(BALLDIA/2)
K,5,,(1*JTHT/4),-0.38
K,6,,0,-(PADSZT/2)
K,7,,(JTHT+CUTHSUB),0
K,8,,-CUPADTHB,-(PADSZT/2)
K,9,,-CUPADTHB,0
K,10,,(JTHT+CUTHSUB),-(PADSZB/2)
K,11,,0,0
K,12,,JTHT/2,0
K,13,,-CUPADTHB-PCBT,-(PADSZT/2)            !PCB side
K,14,,-CUPADTHB-PCBT,0
K,15,,(JTHT+CUTHSUB+pckgt),0                !Package side
K,16,,(JTHT+CUTHSUB+pckgt),-(PADSZB/2)

BSPLIN,2,3,4
BSPLIN,4,5,6

L,11,12
L,12,1
L,12,4
L,6,11
L,1,2

AL,3,5,2,6
AL,4,7,1,5

A,1,2,10,7
A,9,8,6,11

A,15,16,10,7
A,9,8,13,14

lsel,all              
lsel,s,line,,5,14    !r direction
lsel,u,line,,12,13
lsel,u,line,,8
lsel,u,line,,10      !r direction
lsel,a,line,,18
lesize,all,,,4,1
lsel,all

lsel,all
lsel,s,line,,1,4
lesize,all,,,10,1     ! solderball layers!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

lsel,all
lsel,s,line,,8,10,2
lsel,a,line,,12,13
lesize,all,,,2,1     !Cu Pad layers

lsel,all
lesize,all,,,3,1           !mesh unselect lines
lsel,all

ASEL,ALL
VROTA,ALL,,,,,,1,9,90,2

!****** The ptxy of chip and extrud chip *******

WPROTA,,-90
CSYS,4
WPOFF,,,-CUTHSUB

PTXY,0,0,0,UNITSZ/2,UNITSZ/2,UNITSZ/2

PRISM,0,-pckgt
PTXY,DELE

PTXY,0,0,UNITSZ/2,0,UNITSZ/2,UNITSZ/2
PRISM,0,-pckgt
PTXY,DELE

CSYS,4
VSEL,ALL
VSEL,S,LOC,Z,-pckgt/2
VSEL,R,LOC,Y,0,PADSZB/2
VSEL,A,VOLU,,13
VSBV,13,ALL,,,KEEP
VSEL,ALL

CSYS,4
VSEL,ALL
VSEL,S,LOC,Z,-pckgt/2
VSEL,R,LOC,Y,0,PADSZB/2
VSEL,A,VOLU,,14
VSBV,14,ALL,,,KEEP
VSEL,ALL

!***** linesizing the Chip layer *****

LSEL,S,LOC,Z,-pckgt/2
LESIZE,ALL,,,3,1
LSEL,ALL

!***** linesizing the perimeter *****

WPROTA,22.5
LSEL,S,LOC,Y,0
LSEL,R,LOC,X,0,CUNIPADT/2
LSEL,U,LOC,X,0
LESIZE,ALL,,,4,1
LSEL,ALL

WPROTA,45
LSEL,S,LOC,Y,0
LSEL,R,LOC,X,0,CUNIPADT/2
LSEL,U,LOC,X,0
LESIZE,ALL,,,4,1
LSEL,ALL

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL

WPROTA,-67.5
LSEL,ALL
LSEL,S,LINE,,68,69
LSEL,A,LINE,,60,65,5   ! side of square
LESIZE,ALL,,,4,1
LSEL,ALL

LSEL,ALL
LESIZE,ALL,,,1,1
LSEL,ALL

!*** EXTRUDING THE PCB ***

WPOFF,,,JTHT+CUTHSUB+CUPADTHB
CSYS,4

PTXY,0,0,0,UNITSZ/2,UNITSZ/2,UNITSZ/2
PRISM,0,PCBT
PTXY,DELE

PTXY,0,0,UNITSZ/2,0,UNITSZ/2,UNITSZ/2
PRISM,0,PCBT
PTXY,DELE

CSYS,4
VSEL,ALL
VSEL,S,LOC,Z,PCBT/2
VSEL,R,LOC,Y,0,PADSZB/2
VSEL,A,VOLU,,15
VSBV,15,ALL,,,KEEP
VSEL,ALL

CSYS,4
VSEL,ALL
VSEL,S,LOC,Z,PCBT/2
VSEL,R,LOC,Y,0,PADSZB/2
VSEL,A,VOLU,,16
VSBV,16,ALL,,,KEEP
VSEL,ALL

!****** linesizing the PCB layer *****

LSEL,S,LOC,Z,PCBT/2
LESIZE,ALL,,,3,1
LSEL,ALL

!****** linesizing the perimeter *****

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL

WPROTA,-67.5
LSEL,ALL
LSEL,S,LINE,,81,82
LSEL,A,LINE,,73,78,5   ! side of square
LESIZE,ALL,,,4,1
LSEL,ALL

LSEL,ALL
LESIZE,ALL,,,1,1
LSEL,ALL

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL

!******* Premeshing ********

!*** assigning attributes ***

! PCB

VSEL,S,LOC,Z,PCBT/2
VATT,1,,1
VSEL,ALL

! Solder Ball

VSEL,S,LOC,Z,-CUPADTHB,-JTHT
VATT,2,,2
VSEL,ALL

! Overmold

VSEL,S,LOC,Z,-(JTHT+CUPADTHB+CUTHSUB+pckgt/2)
VATT,3,,1
VSEL,ALL

! Cu Pad
vsel,all
vsel,s,loc,z,0,-CUPADTHB
vsel,a,loc,z,-(JTHT+CUPADTHB),-(JTHT+CUPADTHB+CUTHSUB)
vatt,6,,1

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL

!*** Using symmetry building the whole half piece

CSYS,4
WPROTA,67.5
VSEL,ALL
VSYMM,Y,ALL
ALLSEL,ALL

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL

!****** Creating the whole piece ******

allsel,all
wpcsys,,14  
CSYS,4
vsel,s,loc,x,0,UNITSZ/2
VSYMM,X,ALL

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL

!****** Creating the array ******

allsel,all
wpcsys,,14  
CSYS,4
vsel,s,loc,x,-UNITSZ/2,UNITSZ/2

vgen,2,all,,,unitsz

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL

/NUM,1
/PNUM,MAT,1

!**** Creating the PCB & Mold ************

allsel,all
wpcsys,,13  
CSYS,4
vsel,s,mat,,1
vsel,a,mat,,3
vsel,r,loc,x,-UNITSZ/2,UNITSZ/2
vgen,13,all,,,unitsz       ! 12 units (12*2*0.02)

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL

!************************** MESH *************************

!*** Meshing The Chip ***

ALLSEL,ALL
VMESH,ALL

/NUM,1
/PNUM,MAT,1

ALLSEL,ALL
NUMMRG,ALL
NUMCMP,ALL
ALLSEL,ALL






!************************** BOUNDARY CONDITIONS***************

csys,0  
alls,all
nsel,s,loc,x,13*UNITSZ+UNITSZ/2-0.01,13*UNITSZ+UNITSZ/2
dsym,symm,x     ! symmetry boundary conditions

nsel,s,node,,17263
nsel,a,node,,17296
d,all,UY,0,,,,UX,UZ

!************************** SOLVE ****************************

/solu                   ! enter soln processor
!eqslv,pcg,1.0e-08,3    ! set solver and tollerance
antype,static,new       ! set analysis type
nlgeom,on               ! set large def and strain
nropt,auto,,off         ! set newton-raphson soln
outres,all,last         ! write data to .rst file


!***** SET THERMAL CYCLE VARIABLES *****

hitmp=100+273           ! set hi cycle temp (K)
hirmp=10*60             ! set lo-hi ramp time (sec) slop
hidwl=5*60              ! set hi dwell time (sec)
lotmp=273               ! set lo cycle temp (K)
lormp=10*60             ! set hi-lo ramp time (sec)
lodwl=5*60              ! set lo dwell time (sec)
delta=hitmp -lotmp      ! calc delta temp
rmpstp=delta/10         ! calc ramp substeps
tref,hitmp              ! set zero strain temp

alls,all

!***** THERMAL CYCLE 1 *****

!***** RAMP LOW (LOAD STEP 1)

autots,off              ! turn off auto time step
nsubstp,rmpstp          ! set substeps
bf,all,temp,lotmp       ! apply temp to all nodes
kbc,0                   ! linearly ramp loads
time,lormp              ! set time
solve                   ! solve load step

!***** DWELL LOW (LOAD STEP 2)

autots,on               ! turn on auto time step
nsubst,10,100,1        ! set substeps
bf,all,temp,lotmp       ! apply temp to all nodes
kbc,1                   ! maintain loads
time,lormp+lodwl        ! set time
solve                   ! solve load step

!***** RAMP HIGH (LOAD STEP 3)

autots,off              ! turn off auto time step
nsubstp,rmpstp          ! set substeps
bf,all,temp,hitmp       ! apply temp to all nodes
kbc,0                   ! linearly ramp loads
time,lormp+lodwl+hirmp  ! set time
solve                   ! solve load step

!***** DWELL HIGH (LOAD STEP 4)

autots,on               ! turn on auto time step
nsubstp,10,100,1        ! set substeps
bf,all,temp,hitmp       ! apply temp to all nodes
kbc,1                   ! maintain loads
time,lormp+lodwl+hirmp+hidwl     ! set time
solve                   ! solve load step

!***** THERMAL CYCLE 2 *****

!***** RAMP LOW (LOAD STEP 1)

autots,off              ! turn off auto time step
nsubstp,rmpstp          ! set substeps
bf,all,temp,lotmp       ! apply temp to all nodes
kbc,0                   ! linearly ramp loads
time,2*lormp+lodwl+hirmp+hidwl         ! LS5
solve                   ! solve load step

!***** DWELL LOW (LOAD STEP 2)

autots,on               ! turn on auto time step
nsubstp,10,100,1        ! set substeps
bf,all,temp,lotmp       ! apply temp to all nodes
kbc,1                   ! maintain loads
time,2*lormp+2*lodwl+hirmp+hidwl       ! LS6
solve                   ! solve load step

!***** RAMP HIGH (LOAD STEP 3)

autots,off              ! turn off auto time step
nsubstp,rmpstp          ! set substeps
bf,all,temp,hitmp       ! apply temp to all nodes
kbc,0                   ! linearly ramp loads
time,2*lormp+2*lodwl+2*hirmp+hidwl     ! LS7
solve                   ! solve load step

!***** DWELL HIGH (LOAD STEP 4)

autots,on               ! turn on auto time step
nsubstp,10,100,1        ! set substeps
bf,all,temp,hitmp       ! apply temp to all nodes
kbc,1                   ! maintain loads
time,2*lormp+2*lodwl+2*hirmp+2*hidwl   ! LS8
solve                   ! solve load step

!***** THERMAL CYCLE 3 *****

!***** RAMP LOW (LOAD STEP 1)

autots,off              ! turn off auto time step
nsubstp,rmpstp          ! set substeps
bf,all,temp,lotmp       ! apply temp to all nodes
kbc,0                   ! linearly ramp loads
time,3*lormp+2*lodwl+2*hirmp+2*hidwl   ! LS5
solve                   ! solve load step

!***** DWELL LOW (LOAD STEP 2)

autots,on               ! turn on auto time step
nsubstp,10,100,1        ! set substeps
bf,all,temp,lotmp       ! apply temp to all nodes
kbc,1                   ! maintain loads
time,3*lormp+3*lodwl+2*hirmp+2*hidwl   ! LS6
solve                   ! solve load step

!***** RAMP HIGH (LOAD STEP 3)

autots,off              ! turn off auto time step
nsubstp,rmpstp          ! set substeps
bf,all,temp,hitmp       ! apply temp to all nodes
kbc,0                   ! linearly ramp loads
time,3*lormp+3*lodwl+3*hirmp+2*hidwl   ! LS7
solve                   ! solve load step

!***** DWELL HIGH (LOAD STEP 4)

autots,on               ! turn on auto time step
nsubstp,10,100,1        ! set substeps
bf,all,temp,hitmp       ! apply temp to all nodes
kbc,1                   ! maintain loads
time,3*lormp+3*lodwl+3*hirmp+3*hidwl   ! LS8
solve                   ! solve load step






























/post1
!----------------------------------------------------------------------------------------------
alls,all

nsel,s,loc,y,0,0.02*25.4*2/20

nsel,a,loc,y,0.02*inch*18/20,0.02*inch

esln,s
esel,r,mat,,2
!----------------------------------------------------------------------------------------------
!******** CALC AVG PLASTIC WORK FOR CYCLE 1 ********

set,4,last,1
etable,vtable,volu
etable,vsetable,nl,plwk
smult,pwtable,vtable,vsetable
ssum
*get,sumplwk,ssum,,item,pwtable
*get,sumvolu,ssum,,item,vtable
wavg1=sumplwk/sumvolu

!******** CALC AVG PLASTIC WORK FOR CYCLE 2 ********

set,8,last,1
etable,vtable,volu
etable,vsetable,nl,plwk
smult,pwtable,vtable,vsetable
ssum
*get,sumplwk,ssum,,item,pwtable
*get,sumvolu,ssum,,item,vtable
wavg2=sumplwk/sumvolu

!******** CALC AVG PLASTIC WORK FOR CYCLE 3 ********

set,12,last,1
etable,vtable,volu
etable,vsetable,nl,plwk
smult,pwtable,vtable,vsetable
ssum
*get,sumplwk,ssum,,item,pwtable
*get,sumvolu,ssum,,item,vtable
wavg3=sumplwk/sumvolu

!******** CALC DELTA AVG PLASTIC WORK ********
dwavg=0.5*(wavg2-wavg1+wavg3-wavg2)


!******** call the results ********
!*statues,wavg1
!*statues,wavg2
!*statues,wavg3
*statues,dwavg