Reballing Process Controls and Cleanliness

Size: px

Start display at page:

Download "Reballing Process Controls and Cleanliness"

Caren Norris
6 years ago
Views:

1 Reballing Prcess Cntrls and Cleanliness DfR Webinar December 18, Virginia Manr Rd Ste 290, Beltsville MD

2 Intrductin: Reballing Techniques Reballing is bth ball remval and ball attach remval melts ff the pre-existing slder balls and prepares the slder pads fr new slder balls attachment is the placement f new slder spheres n the pads and reflwing them t frm an intermetallic bnd All reballers studied use cmparable methds fr ball attach 9000 Virginia Manr Rd Ste 290, Beltsville MD

3 Reballing Prcess Cntrls Five reballers emplying distinct techniques were audited during reballing f ball grid arrays Reballers identified as A, B, C, D, & E This presentatin cmpares bserved differences in Reballing techniques Cntrl f inic expsure Cleaning prcedures Resulting differences in cleanliness f reballed cmpnents 9000 Virginia Manr Rd Ste 290, Beltsville MD

Arnld et al, Impact f Reprcessing Technique n First Level Intercnnects f Pb-Free t SnPb Reballed Area Array Flip Chip

4 Test Vehicle Selectin Tw devices which each presented a unique challenge t reballers Fine pitch, lw mass Large plastic package Third cmpnent t study the impact f reballing stresses n 1 st level intercnnects 1 Flip chip 1 J. Arnld et al, Impact f Reprcessing Technique n First Level Intercnnects f Pb-Free t SnPb Reballed Area Array Flip Chip Devices, imaps Device Packaging Cnference, Virginia Manr Rd Ste 290, Beltsville MD

5 Test Vehicle: Dummy CSP Fine pitch, lw mass CSP 97 I/O, 0.4mm pitch 5mm square package, 3.2mm die Demands precise tling Requires care in handling 9000 Virginia Manr Rd Ste 290, Beltsville MD

6 Test Vehicle: Dummy BGA Large plastic BGA 1156 I/O, 1.0mm pitch 35mm square package, 15.2mm die Susceptible t warpage 9000 Virginia Manr Rd Ste 290, Beltsville MD

7 Test Vehicle: Active Flip Chip Vitesse VSC3312 crsspint switch 196 I/O, 1.0mm pitch 15mm square package, 3mm die 9000 Virginia Manr Rd Ste 290, Beltsville MD

8 Test Vehicle: Active Flip Chip Eight (8) input pair circuits Tw 50Ω pull-up resistrs between true and cmplement Manufacturer specifies 85Ω t 125Ω as acceptable range 9000 Virginia Manr Rd Ste 290, Beltsville MD

9 Results: Electrical Characterizatin All measurements fr all cmpnents within 85Ω and 125Ω range in specificatin Five (5) cmpnents prbed per ppulatin Eight (8) prbe pairs per cmpnent 9000 Virginia Manr Rd Ste 290, Beltsville MD

Remval Techniques: Melting and Wicking Manual prcedure s melted with an irn Liquid slder absrbed with fluxed wick 1 r 2 passes with the irn Used by

10 Remval Techniques: Melting and Wicking Manual prcedure s melted with an irn Liquid slder absrbed with fluxed wick 1 r 2 passes with the irn Used by Reballers B & D Device needs reballing remval placement attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

Used by Reballers C & E Device needs reballing remval placement attach Reballing

11 Remval Techniques: Disslutin in Mlten Slder Autmated prcedure SAC305 balls melted ff package by cntact with SnPb funtain Cmpnent cntacts mlten slder at least twice Used by Reballers C & E Device needs reballing remval placement attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

leveling Device needs reballing remval placement attach Reballing cmplete

12 Remval Techniques: Disslutin in Mlten Slder Reballer A Autmated prcedure SAC305 balls melted ff package by cntact with SnPb wave Ht air knife leveling Device needs reballing remval placement attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

Slder pads frm which balls have been remved - blue dtted circles. Dressed pads n flip chip; slder visible as radipacity.

13 X-Ray Images After Remval flip-chip x-ray image with examples f key features indicated. Slder bumps (first level intercnnects) - yellw circles. Plated thrugh hles in cmpnent substrate - red arrws. Slder pads frm which balls have been remved - blue dtted circles. Dressed pads n flip chip; slder visible as radipacity. Dark pads n left image indicate thicker cverage than faintly visible pads n right image Virginia Manr Rd Ste 290, Beltsville MD

Placement and Attachment placement techniques and tling are widely cnsidered trade secrets All reballers surveyed emplyed stencils t align new slder spheres with dressed pads

14 Placement and Attachment placement techniques and tling are widely cnsidered trade secrets All reballers surveyed emplyed stencils t align new slder spheres with dressed pads Generic stencil and fixture Device needs reballing remval placement attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

15 Fcus Des reballing the secnd level intercnnects (B) damage first level intercnnects (A)? 9000 Virginia Manr Rd Ste 290, Beltsville MD

16 Sample Preparatin Upn receipt, cmpnents reflwed t simulate assembly 9000 Virginia Manr Rd Ste 290, Beltsville MD

17 What are Cntur Plts A cntur plt is a graphic representatin f the relatinships amng three numeric variables in tw dimensins. Tw variables are fr X and Y axes, and a third variable Z is fr cntur levels. The cntur levels are pltted as curves; the area between curves can be clr cded t indicate interplated values. (1) Yu can interactively identify, label, clr, and mve cntur levels, and change the reslutins f rectangular grids t get better cnturing quality and perfrmance The plts n the next slide demnstrate that 95% f the time a resistance reading frm the reballed ppulatin will verlap with that f the nn-reballed ppulatin. Each plt indicates reballed and cntrl ppulatins f an I/O pair, and all the plts maintain the same behavir with 95% cnfidence. 1) SAS Institute Inc.,SAS/INSIGHT User s Guide, Versin 8, Cary, NC: SAS Institute Inc., pp 9000 Virginia Manr Rd Ste 290, Beltsville MD

18 S td S td S td S td S td S td S td S td Results: Electrical Characterizatin, cnt. Independence f A1-AN1 Resistance fr Reballed Flip Chip Ppulatins Independence f A3-AN3 Resistance fr Reballed Flip Chip Ppulatins Independence f A4-AN4 Resistance fr Reballed Flip Chip Ppulatins Independence f A7-AN7 Resistance fr Reballed Flip Chip Ppulatins Independence f A8-AN8 Resistance fr Reballed Flip Chip Ppulatins Mean Mean Mean Mean Mean Independence f A0-AN0 Resistance fr Reballed Flip Chip Ppulatins Independence f A10-AN10 Resistance fr Reballed Flip Chip Ppulatins Independence f A11-AN11 Resistance fr Reballed Flip Chip Ppulatins Mean Mean Cntur plts demnstrate verlap between mst ppulatins 95% cnfidence limit Reballer D may be distinguishable frm Reballers A and B Nt distinguishable frm Reballers C, E, r cntrl Mean 9000 Virginia Manr Rd Ste 290, Beltsville MD

19 Results: Scanning Acustic Micrscpy (SAM) Tmgraphic acustic micr-imaging (TAMI) perfrmed One flip chip per ppulatin Fcused n tw interfaces Where C4 bumps adhere t pads n the die Where C4 bumps adhere t substrate N bserved gaps, vids, r delaminatin n reballed r cntrl cmpnents 9000 Virginia Manr Rd Ste 290, Beltsville MD

20 Cntrl Results: TAMI-SAM, Die t Bump Interface A B C D E 9000 Virginia Manr Rd Ste 290, Beltsville MD

21 Results: X-ray Cmputed Tmgraphy (CT) Cmputed tmgraphy generates a 3-D mdel frm a series f x-ray slices One flip chip per ppulatin N cracks r defects bserved n reballed r cntrl cmpnents Sme viding bserved at bump t substrate interface 9000 Virginia Manr Rd Ste 290, Beltsville MD

22 Results: CT, Vid Measurement Slices thrugh C4 bumps near substrate prvide a snapsht f viding in the first level intercnnects Images were threshld crrected in ImageJ Enables estimatin f percent viding 9000 Virginia Manr Rd Ste 290, Beltsville MD

23 Results: CT, Measured Viding in C4 Bumps N industry standard fr viding in C4 bumps IPC-A-610E allws fr 25% viding in slder balls Viding was well belw 25% fr all reballers and cntrl 9000 Virginia Manr Rd Ste 290, Beltsville MD

24 BUT WERE THEY CLEAN!! 9000 Virginia Manr Rd Ste 290, Beltsville MD

25 handling Surces f Cntaminatin Cntaminatin Flux frm ball remval Flux frm ball attach Handling Rinse water During cleaning fllwing ball remval and ball attach flux rinse flux Device needs reballing remval placement attach rinse Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

reballing remval placement attach Reballing cmplete 9000

26 Cntaminatin: Remval Flux Reballers use flux ver surface f BGA Manual prcesses brush n Rbtic prcesses dip flux Device needs reballing remval placement attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

27 Remval Flux IPC J-STD-004 Designatr Flux Cmpsitin Flux/Flux Residue Activity Levels Halides Reballer A ORH1 Organic High Yes Reballer B ORH0 Organic High N Reballer C ORH1 Organic High Yes Reballer D ORH1 Organic High Yes Reballer E ORM1 Organic Medium Yes 9000 Virginia Manr Rd Ste 290, Beltsville MD

surface f BGA flux Device needs reballing remval placement attach Reballing

28 Cntaminatin: Placement Flux Reballers use either tacky flux r slder paste fr ball attach Slder paste Squeegeed t pads thrugh stencil Tacky flux Applied ver whle surface f BGA flux Device needs reballing remval placement attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

29 Attach Flux IPC J-STD-004 Designatr Flux Cmpsitin Flux/Flux Residue Activity Levels Halides Stencil Reballer A ORH1 Organic High Yes Yes Reballer B ORH0 Organic High N N Reballer C RMA Rsin Mderate? N Reballer D RMA-RA Rsin-Resin Mderate-High? Yes Reballer E REL0 Resin Lw N Yes 9000 Virginia Manr Rd Ste 290, Beltsville MD

30 handling Cntaminatin: Handling Mst reballers take precautins t avid handling cntaminatin There are exceptins Device needs reballing remval placement attach Reballer C Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

Cntaminatin: Cleaning After Remval Cntaminatin can be intrduced withut prper prcess cntrls Deinizatin f rinse water Fresh slvent rinse Device

31 Cntaminatin: Cleaning After Remval Cntaminatin can be intrduced withut prper prcess cntrls Deinizatin f rinse water Fresh slvent rinse Device needs reballing remval placement attach Reballer D Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

Style Dishwasher, Reballer E rinse attach Reballing cmplete 9000

32 Cntaminatin: Cleaning After Attach Same surces as cleaning after ball remval Device needs reballing remval placement Fagr FI-120W Dr Style Dishwasher, Reballer E rinse attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

33 Cleaning Perfrmed Fllwing ball remval Fllwing ball attach wash Device needs reballing remval placement wash attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

34 Cleaning Techniques: Wipe Manually with isprpyl alchl Lintless wipe (i.e. Kimwipe) Brush Device needs reballing wash remval placement wash attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

wash Device needs reballing remval placement wash attach Reballing cmplete

35 Cleaning Techniques: Rinse Spray wash with warm deinized water Autmated technique Spray Swish May r may nt include a detergent Requires a bakeut wash Device needs reballing remval placement wash attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

36 Cleaning: Pst Remval Cleaning agent Manner Cleaning Mtin Temperature Reballer A IPA manual wipe rm Reballer B (time sensitive) Reballer B (time insensitive) Reballer C (large batch) Reballer C (small batch) Reballer D (all devices cleaned twice) Pst Slder Sphere Remval IPA manual wipe rm DI H 2 O manual wipe warm DI H 2 O autmated spray warm IPA manual brush rm IPA manual wipe rm DI H 2 O, detergent autmated rinse, spray warm Reballer E DI H 2 O autmated swish warm wash Device needs reballing remval placement attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

37 Cleaning: Pst Attach Cleaning agent Manner Cleaning Mtin Temperature Reballer A DI H 2 O autmated rinse, spray warm Reballer B (time sensitive) Reballer B (time insensitive) Pst Attach IPA manual wipe rm DI H 2 O manual wipe warm Reballer C IPA manual brush rm Reballer D DI H 2 O, detergent autmated rinse, spray warm Reballer E DI H 2 O, detergent autmated spray warm wash Device needs reballing remval placement attach Reballing cmplete 9000 Virginia Manr Rd Ste 290, Beltsville MD

Cleanliness: In Chrmatgraphy Metrhm Mdular In Chrmatgraphy System IPC-TM-650, 2.3.

38 Cleanliness: In Chrmatgraphy Metrhm Mdular In Chrmatgraphy System IPC-TM-650, Includes inic extractin in diluted isprpanl at 80 C fr 1 hur Vlume f extract limited by size f cmpnent Avids ver-dilutin f sample material CSPs yielded sufficient extract t measure anins BGAs yielded sufficient extract t measure anins and weak rganic acids 9000 Virginia Manr Rd Ste 290, Beltsville MD

39 Cmpnent Cleanliness: CSP 9000 Virginia Manr Rd Ste 290, Beltsville MD

40 Cmpnent Cleanliness: CSP (μg/in 2 ) Br - Cl - F - NO 3 - NO 2 - PO 4 3- SO 4 2- Reballer A Reballer B Reballer C Reballer D Reballer E Upper Cntrl Limit Virginia Manr Rd Ste 290, Beltsville MD

41 Cmpnent Cleanliness: BGA 9000 Virginia Manr Rd Ste 290, Beltsville MD

42 Cmpnent Cleanliness: BGA (μg/in 2 ) Br - Cl - F - NO 3 - NO 2 - PO 4 3- SO 4 2- WOA Reballer A Reballer B Reballer C Reballer D Reballer E Upper Cntrl Limit Virginia Manr Rd Ste 290, Beltsville MD

43 Surces f Cntaminants: Chlride (Cl - ) Incmpletely deinized rinse water Added t municipal water t cntrl bacterial grwth Unprtected handling Flux residue Nn halide-free fluxes nly 9000 Virginia Manr Rd Ste 290, Beltsville MD

44 Surces f Cntaminants: Nitrate (NO 3- ) Incmpletely deinized rinse water Ammnium nitrate and urea fertilizer run-ff Manufacturing residue Substrate etched with ammnium nitrate 9000 Virginia Manr Rd Ste 290, Beltsville MD

45 Surces f Cntaminants: Sulfate (SO 4 2- ) Incmpletely deinized rinse water Acid rain Manufacturing residue Substrate etched with sdium r ammnium persulfate Slder mask Cntact with paper, plastic, r rubber Sulfur a part f, r added t, many materials 9000 Virginia Manr Rd Ste 290, Beltsville MD

46 Cnclusins Undesirable cncentratins f halides were measured n final reballed cmpnents frm all studied suppliers Flux selectin crrelates best t inic cntaminatin Cnsistent with chlride as mst cmmn cntaminating species Cnsistent with use f halide cntaining fluxes 9000 Virginia Manr Rd Ste 290, Beltsville MD

47 CSP Cleanliness and Flux 9000 Virginia Manr Rd Ste 290, Beltsville MD

48 BGA Cleanliness and Flux 9000 Virginia Manr Rd Ste 290, Beltsville MD

49 Cnclusins, cnt. Reballers with pr handling cntrl d nt exhibit mst elevated cntaminatin Reballers with pr cntrl ver cleaning prcedures d nt exhibit mst elevated cntaminatin Cleaning technique appears t have little impact 9000 Virginia Manr Rd Ste 290, Beltsville MD

50 CSP Cleanliness and Cleaning 9000 Virginia Manr Rd Ste 290, Beltsville MD

51 BGA Cleanliness and Cleaning 9000 Virginia Manr Rd Ste 290, Beltsville MD

52 Impact Cntaminants present n reballed cmpnents will enter assembly prcedure Flux residues will have anther pprtunity t activate Cause f viding in assembled jints X-ray inspectin pst-assembly revealed n viding exceeding IPC-A-610E (25%) Can be present as inic cntaminatin in final prduct 9000 Virginia Manr Rd Ste 290, Beltsville MD

53 Impact, cnt. What s mst cncerning is that reballers think they are perfrming sufficient cleaning t remve inic residues ROSE measurement f rinse water des nt represent n-part cntaminatin Chse higher activity fluxes with false cnfidence 9000 Virginia Manr Rd Ste 290, Beltsville MD

54 Acknwledgements This wrk was supprted by a Small Business Innvatin Research grant frm the Office f the Secretary f Defense. The authr als wishes t thank the participating reballers fr their warm welcme and insight int the reballing prcess Virginia Manr Rd Ste 290, Beltsville MD

Impact of Reprocessing Technique on First Level Interconnects of Pb- Free to SnPb Reballed Area Array Flip Chip Devices

Impact of Reprocessing Technique on First Level Interconnects of Pb- Free to SnPb Reballed Area Array Flip Chip Devices Joelle Arnold, Steph Gulbrandsen, Dr. Nathan Blattau IMAPS Wait, what? o There s